Category Archive Fracture of Bone A-Z

Sacroiliac Joint Fracture/Sacroiliitis are common terms used to describe the pain of the sacroiliac joint. It is usually caused by abnormal motion (i.e. hyper- or hypo-mobile) or malalignment of the sacroiliac joint. The joint can be hyper or hypo-mobile which can cause pain. Pain is usually localized over the buttock. Patients usually describe the pain as sharp, dull, achy, stabbing, or shooting pain directly over the affected joint.

Sacroiliac joint (SIJ) pain refers to the pain arising from the SIJ joint structures. SIJ dysfunction generally refers to an aberrant position or movement of SIJ structures that may or may not result in pain. This paper aims to clarify the difference between these clinical concepts and present currently available evidence regarding the diagnosis and treatment of SIJ disorders.

Sacroiliitis is inflammation within the sacroiliac joint. It is a feature of spondyloarthropathies, such as axial spondyloarthritis (including ankylosing spondylitis), psoriatic arthritis, reactive arthritis or arthritis related to inflammatory bowel diseases, including ulcerative colitis or Crohn’s disease. It is also the most common presentation of arthritis from brucellosis.

Anatomy of Sacroiliac Joint Fracture

Six variants of the sacroiliac joints have been observed: accessory joints, iliosacral complex, bipartite iliac bony plate, crescent-like iliac bony plate, semicircular defects at the sacral or iliac side and ossification centers.

• Accessory sacroiliac joint – Accessory sacroiliac joint is found medial to the posterior superior iliac spine and lateral to the second sacral foramen amongst a rudimentary transverse tuberosity. On CT imaging, accessory joints have articular surfaces that resemble osseous projects from the ilium to the sacrum.  An accessory joint can be present at birth; however, they more commonly result from the stress of weight-bearing.  Accessory joints are more commonly present in the obese population and the older population, as well as a higher prevalence in women with 3 or more childbirths, compared to 2 or less.
• Iliosacral complex – Iliosacral complex forms from a projection from the ilium articulating with a complementary sacral recess. These complexes can be unilateral or bilateral, and like accessory joints, these complexes exist at the posterior sacroiliac joint from the level of first to the second sacral foramen. This variant has been seen more in older patients greater than 60 years, as well as obese women more so than normal-weight women.
• Bipartite iliac bony plate – Bipartite iliac bony plate is located at the posterior portion of the sacroiliac joint and appears as described, consisting of two parts and appears unilaterally.
• Semicircular defects on the iliac/sacral side – The fourth variant is semicircular defects on either the sacral or iliac aspects of the articular surface of the sacroiliac joint. These can be unilateral or bilateral and again are present at the posterior portion of the sacroiliac joint from the level of the first to the second sacral foramen. This defect has been observed more in women than men and in patients older than 60 years.
• Crescent-like iliac bony plate – The fifth variant is a crescent-like articular surface which may be present unilaterally or bilaterally. CT imaging demonstrates a crescent-like iliac plate with accompanying a bulged sacral surface. This defect is found usually at the posterior portion of the sacral iliac joint spanning the levels of the first and second sacral foramen. This defect was observed only in women and more commonly in patients greater than 60 years old.
• Ossification centers of the sacral wings – The sixth anatomical variant observed is ossification centers presenting as triangular osseous bodies located within the joint space at the anterior portion of the sacroiliac joint. This defect is found at the level of the first sacral foramen, typically unilaterally.[rx][rx]

Causes of Sacroiliac Joint Fracture

Diagnosis of Sacroiliac Joint Fracture

In most clinical evaluations, common laboratory findings in the aseptic setting include:

• WBC count – usually normal (elevated in infection/septic presentation)
• ESR – elevated
• CRP – elevated
• HLA-B27 – About 1-2% of patients with ankylosing spondylitis will be HLA-B27 positive
• Rheumatoid Factor (RF) – Negative in the setting of true ankylosing spondylitis

Spondylolisthesis and Pars Fractures/Lumbar degenerative spondylolisthesis/Pars Interarticularis Defect (otherwise referred to as spondylolysis) represents a common cause of axial back pain in adolescents, especially in the case of young athletes. The pars interarticularis (pars) lies between the superior and inferior articular process bilaterally at each vertebral level. Anatomically, one can describe the pars as the region between two, one superior and one inferior, zygapophyseal joints. The definition of pars interarticularis defect is a unilateral or bilateral overuse or fatigue stress fracture involving the pars interarticularis of the posterior vertebral arch. This injury occurs almost exclusively in the lower lumbar region, most often at L5 [rx].

Spondylolysis is a unilateral or bilateral defect in the region of the pars interarticularis, which may or may not be accompanied by vertebral displacement, and is most commonly the result of repetitive trauma to the growing immature skeleton of a genetically susceptible individual. [rx][rx][rx] The pars interarticularis is considered the isthmus or bone bridge between the inferior and superior articular surfaces of a single vertebra. [rx][rx][rx]

Types of Spondylolisthesis and Pars Fractures

Injury of the pars interarticularis is among the most common causes of low back pain, especially in adolescent athletes. Sometimes these lesions develop in an asymptomatic manner, and they are detected in adulthood when the injury becomes chronic and symptomatic.[rx]

The spectrum of pathologies in the pars interarticularis ranges from bone stress, pars fracture (spondylolysis) to isthmic spondylolisthesis, which represents an anterior vertebral slippage. Bone stress is considered the earliest sign of disease. Repetitive bone stress causes bone remodeling and may result in spondylolysis, a non-displaced fracture of the pars interarticularis.[rx] Also, radiographically visualized spondylolysis is associated with spondylolisthesis about 25% of cases.[rx][rx]

Spondylolisthesis, a related condition to spondylolysis, is defined by the forward displacement of the upper vertebra relative to the caudal vertebra. In 1976 Wiltse et al.[rx] classified spondylolisthesis into five types:

• Type I or dysplastic – is attributed to congenital dysplasia of the superior articular process of the sacrum.
• Type II or isthmic – is due to a lesion in the pars interarticularis; these subclassify as:
  • (a) Lytic, when a fatigue pars fracture is present
  • (b) Pars elongation due to multiple healed stress fractures
  • (c) Acute pars fracture
• Type III or degenerative – originates from facet instability without a pars fracture.
• Type IV or traumatic – the displacement is due to an acute posterior arch fracture other than pars.
• Type V or pathological – is due to posterior vertebral arch bone disease.[rx]
• Type VI or iatrogenic – it is a potential sequel to spinal surgery.

For this activity, the focus will be on type II or isthmic spondylolisthesis.

Spondylolisthesis was classified by Meyerding et al. [rx] in five subtypes according to the magnitude of slippage on plain lateral lumbar radiograph measured in accordance to the inferior vertebra.

• Grade I,  less than 25% of displacement,
• Grade II, between 25 and 50%,
• Grade III, between 50 and 75%,
• Grade IV, between 75 and 100% and
• Grade V or spondyloptosis, when there is no contact between the vertebrae endplates. The commonly used Grade V, representing more than a 100% slip or spondyloptosis, is not part of the original grading system.

The majority of pars lesions or spondylolysis occur at L5 (85 to 95%), with L4 being the second most commonly affected vertebra (5 to 15%). The other lumbar levels are less often affected.[rx][rx][rx][rx][rx] The defect is unilateral in 22% of the cases.

Causes of Pars Interarticularis Defect

These sports include gymnastics and dance as the highest prevalence with an increased incidence also seen in football (particularly linemen), rugby, wrestling, martial arts, soccer, basketball, cheerleading, pitching, golf, tennis, volleyball servers, weightlifting, and butterfly and breaststroke swimming.[rx][rx][rx][rx]

Pars defects (spondylolysis) subdivide into five categories according to the Wiltse-Newman Classification[rx]

• Dysplastic – congenital abnormalities/attenuated pars (approximately 20%)
• Isthmic – lesions in the pars resulting from a stress fracture or acute fractures (approximately 50%)
  • Type II-A: pars fatigue fracture
  • Type II-B: pars elongation due to a healed fracture
  • Type II-C: pars acute fracture
• Degenerative – degeneration of the intervertebral discs that results in segmental instability and alterations of the articular processes
• A traumatic – acute fracture that results in fractures to various regions of the neural arch
• Pathological – bone disease such as tumors and infections that result in lesions to the pars

There are many causes of spondylolisthesis including congenital, degenerative, traumatic, pathologic, iatrogenic, and isthmic. Isthmic spondylolisthesis, which will be the topic of this discussion, refers to a defect in the pars interarticularis that then results in anterior subluxation over time, most commonly at L5-S1 followed by L4-5.  The resulting anterior subluxation can produce back pain, central canal stenosis, and lateral recess or foraminal stenosis.

Symptoms of Lumbar Spondylolysis and Spondylolisthesis

• Numbness or tingling  – People who have a herniated disk often have radiating numbness or tingling in the body part served by the affected nerves.
• Weakness – Muscles served by the affected nerves tend to weaken. This can cause you to stumble, or affect your ability to lift or hold items.
• A general stiffening of the back and a tightening of the hamstrings, with a resulting change in both posture and gait.
• A leaning-forward or semi-kyphotic posture may be seen, due to compensatory changes.
• A “waddle” may be seen in more advanced causes, due to compensatory pelvic rotation due to decreased lumbar spine rotation.
• A result of the change in gait is often a noticeable atrophy in the gluteal muscles due to lack of use.
• Generalized lower-back pain may also be seen, with intermittent shooting pain from the buttocks to the posterior thigh, and/or lower leg via the sciatic nerve.
• Pain in the neck, back, low back, arms, or legs
• Inability to bend or rotate the neck or back
• Numbness or tingling in the neck, shoulders, arms, hands, hips, legs, or feet
• Weakness in the arms or legs
• Limping when walking
• Increased pain when coughing, sneezing, reaching, or sitting
• Inability to stand up straight; being “stuck” in a position, such as stooped forward or leaning to the side
• Difficulty getting up from a chair
• Inability to remain in 1 position for a long period of time, such as sitting or standing, due to pain
• Pain that is worse in the morning
• This is a sharp, often shooting pain that extends from the buttock down the back of one leg. It is caused by pressure on the spinal nerve.
• Numbness or a tingling sensation in the leg and/or foot
• Weakness in the leg and/or foot

Diagnosis of Pars Interarticularis Defect

Physical Exam

• The major components of the physical exam for spondylolisthesis consists of observation, palpation, and maneuvers. The most common finding is pain with lumbar extension. Neurological examination is often normal in patients with spondylolisthesis, but lumbosacral radiculopathy is commonly seen in patients with degenerate spondylolisthesis.^[rx]

Observation

• The patient should be observed walking and standing. Most patients present with a normal gait. An abnormal gait is often the sign of a high-grade case. A patient with high-grade spondylolisthesis may present with a posterior pelvic tilt causing a loss in the normal contour of the buttocks. An antalgic gait, rounded back and decreased hip extension, can result from severe pain. ^[rx][rx]

Palpation

• Detection of spondylolisthesis by palpation is most often done by palpating for the spinous process.^[rx] Each level of the lumbar spine should be palpated. Spinous process palpation by itself is not a definitive method for the detection of spondylolisthesis.^[rx]

Maneuvers

• Spinal range of motion testing – Range of motion limitations may be seen.
• Lumbar hyperextension – Extension often elicits pain. This can be assessed by having the patient hyperextend the lumbar spine, provide resistance against back extensions, or undergo repeated lumbar extensions.
• Sport-specific motion – Patients can be asked to repeat aggravating movements that they experience during their activity. During the movement, ask the patient to point to any places with focal pain.
• Straight leg raise – Maneuver used to assess for hamstring tightness. The straight leg raise has been found to be positive in only 10% of patients with spondylolisthesis.^[rx]
• Muscle strength exercises – Lower abdominal, gluteal, and lumbar extensors should be assessed for weakness. Weakness in these muscles can increase lordosis and contribute to sacroiliac instability.^[rx] Abdominal flexor strength can be assessed with the abdominal flexor endurance test. The test involves the patient lying supine while holding a 45 degree flexed trunk and 90 degree flexed knees for 30 seconds. Gluteal strength can be assessed with a single leg squat. Lastly, a lumbar extension can be assessed with a single leg bridge.

Imaging

• Scintigraphy – is an excellent screening tool for low back pain in children or adolescents. It has shown high sensitivity for the detection of acute injuries and bone stress reaction in the pars. However, some lesions may not display an increased contrast uptake.
• Computed tomography scan (CT) – may be helpful in some cases due to its higher specificity. The tomographic finding of an acute injury include the margin reabsorption in the pars; pars sclerosis may indicate chronic stress, and marginal sclerosis with widening may indicate a chronic condition.
• Magnetic resonance imaging (MRI) – offers advantages in terms of visualizing other types of pathology present in the lumbar spine and may potentially detect pars edema secondary to stress in their clinical course.[rx] The lack of ionizing radiation with MRI may also make it a particularly desirable modality for studying pars lesions, especially in the female adolescent population.[rx]
• Electrodiagnostic testing – (Electromyography and nerve conduction studies) can be an option in patients that demonstrate equivocal symptoms or imaging findings as well as to rule out the presence of a peripheral mononeuropathy. The sensitivity of detecting cervical radiculopathy with electrodiagnostic testing ranges from 50% to 71%.[rx]
• The straight leg raise test – With the patient lying supine, the examiner slowly elevates the patient’s led at an increasing angle, while keeping the leg straight at the knee joint. The test is positive if it reproduces the patient’s typical pain and paresthesia.[rx]
• The contralateral (crossed) straight leg raise test – As in the straight leg raise test, the patient is lying supine, and the examiner elevates the asymptomatic leg. The test is positive if the maneuver reproduces the patient’s typical pain and paresthesia. The test has a specificity greater than 90%.
• Myelography – An X-ray of the spinal canal following the injection of contrast material into the surrounding cerebrospinal fluid spaces will reveal the displacement of the contrast material. It can show the presence of structures that can cause pressure on the spinal cord or nerves, such as herniated discs, tumors, or bone spurs.

Treatment of Lumbar Spondylolysis and Spondylolisthesis

There is insufficient evidence to support the natural course or treated pars defect as the preferred management. Management generally reflects the following treatment algorithm. [rx][rx][rx]

• Symptomatic spondylolysis (type II)
• Symptomatic low-grade spondylolisthesis
• Physical therapy program for 6 months and include
  • Hamstring stretching
  • Pelvic tilts
  • Core strengthening

TLSO bracing for 6 to 12 weeks

• Acute pars stress reaction
• Spondylolysis (type II) that has failed to improve with physical therapy
• Low-grade spondylolisthesis that has failed to improve with physical therapy
• Brace immobilization is superior to activity restriction alone for acute stress reaction

Non-Pharmacological Treatment

Conservative Treatments – Acute cervical or lumbar radiculopathies secondary to pars interarticularis injury a  are typically managed with non-surgical treatments as the majority of patients (75 to 90%) will improve. Modalities that can be used include[rx][rx][rx]:

• Rest the area by avoiding any activity that causes worsening symptoms in the arms or legs.
• Stay active around the house, and go on short walks several times per day. The movement will decrease pain and stiffness and help you feel better.
• Apply ice packs to the affected area for 15 to 20 minutes every 2 hours.
• Sit in firm chairs. Soft couches and easy chairs may make your problems worse.
• Deep tissue massage may be helpful
• Acupuncture – In acupuncture, the therapist inserts fine needles into certain points on the body with the aim of relieving pain.
• Reiki – Reiki is a Japanese treatment that aims to relieve pain by using specific hand placements.
• Moxibustion – This method is used heat specific parts of the body (called “therapy points”) by using glowing sticks made of mugwort (“Moxa”) or heated needles that are put close to the therapy points.
• Massages – Various massage techniques are used to relax muscles and ease tension.
• Heating and cooling – This includes the use of hot packs and plasters, a hot bath, going to the sauna, or using an infrared lamp. Heat can also help relax tense muscles. Cold packs, like cold wraps or gel packs, are also used to help with irritated nerves.
• Ultrasound therapy – Here the lower back is treated with sound waves. The small vibrations that are produced generate heat to relax body tissue.
• Cervical Manipulation – There is limited evidence suggesting that cervical manipulation may provide short-term benefits for neck pain and pars interarticularis injury. Complications from manipulation are rare and can include worsening radiculopathy, myelopathy, spinal cord injury, and vertebral artery injury. These complications occur ranging from 5 to 10 per 10 million manipulations.
• Lumbar Corset or Collar for Immobilization – In patients with acute neck pain, a short course (approximately one week) of collar immobilization may be beneficial during the acute inflammatory period.
• Traction – May be beneficial in reducing the radicular symptoms associated with pars interarticularis injury. Theoretically, traction would widen the neuroforamen and relieve the stress placed on the affected nerve, which, in turn, would result in the improvement of symptoms. This therapy involves placing approximately 8 to 12 lbs of traction at an angle of approximately 24 degrees of neck flexion over a period of 15 to 20 minutes.

Physical Therapy

• Exercising in water – can be a great way to stay physically active when other forms of exercise are painful. Exercises that involve lots of twisting and bending may or may not benefit you. Your physical therapist will design an individualized exercise program to meet your specific needs.
• Weight-training exercises – though very important, need to be done with proper form to avoid stress to the back and neck.
• Reduce pain and other symptoms – Your physical therapist will help you understand how to avoid or modify the activities that caused the injury, so healing can begin. Your physical therapist may use different types of treatments and technologies to control and reduce your pain and symptoms.
• Improve posture –If your physical therapist finds that poor posture has contributed to your herniated disc, the therapist will teach you how to improve your posture so that pressure is reduced in the injured area, and healing can begin and progress as rapidly as possible.
• Improve motion – Your physical therapist will choose specific activities and treatments to help restore normal movement in any stiff joints. These might begin with “passive” motions that the physical therapist performs for you to move your spine, and progress to “active” exercises and stretches that you do yourself. You can perform these motions at home and in your workplace to help hasten healing and pain relief.
• Improve flexibility – Your physical therapist will determine if any of the involved muscles are tight, start helping you to stretch them, and teach you how to stretch them at home.
• Improve strength – If your physical therapist finds any weak or injured muscles, your physical therapist will choose, and teach you, the correct exercises to steadily restore your strength and agility. For neck and back disc herniations, “core strengthening” is commonly used to restore the strength and coordination of muscles around your back, hips, abdomen, and pelvis.
• Improve endurance – Restoring muscular endurance is important after an injury. Your physical therapist will develop a program of activities to help you regain the endurance you had before the injury, and improve it.
• Learn a home program – Your physical therapist will teach you strengthening, stretching, and pain-reduction exercises to perform at home. These exercises will be specific for your needs; if you do them as prescribed by your physical therapist, you can speed your recovery.

Eat Nutritiously During Your Recovery

• All bones and tissues in the body need certain nutrients in order to heal properly and in a timely manner. Eating a nutritious and balanced diet that includes lots of minerals and vitamins are proven to help heal broken bones of all types. Therefore focus on eating lots of fresh produce (fruits and veggies), whole grains, lean meats, and fish to give your body the building blocks needed to properly repair your. In addition, drink plenty of purified water, milk, and other dairy-based beverages to augment what you eat.
• Broken bones need ample minerals (calcium, phosphorus, magnesium, boron) and protein to become strong and healthy again.
• Excellent sources of minerals/protein include dairy products, tofu, beans, broccoli, nuts and seeds, sardines, and salmon.
• Important vitamins that are needed for bone healing include vitamin C (needed to make collagen), vitamin D (crucial for mineral absorption), and vitamin K (binds calcium to bones and triggers collagen formation).
• Conversely, don’t consume food or drink that is known to impair bone/tissue healing, such as alcoholic beverages, sodas, most fast food items, and foods made with lots of refined sugars and preservatives.

Medication

Pharmacotherapy – There is no evidence to demonstrate the efficacy of non-steroidal anti-inflammatories (NSAIDs) in the treatment of cervical radiculopathy. However, they are commonly used and can be beneficial for some patients. The use of COX-1 versus COX-2 inhibitors does not alter the analgesic effect, but there may be decreased gastrointestinal toxicity with the use of COX-2 inhibitors. Clinicians can consider steroidal anti-inflammatories (typically in the form of prednisone) in severe acute pain for a short period. A typical regimen is prednisone 60 to 80 mg/day for five days, which can then be slowly tapered off over the following 5 m to 14 days. Another regimen involves a prepackaged tapered dose of Methylprednisolone that tapers from 24 mg to 0 mg over 7 days.

• Non-steroidal anti-inflammatory drugs (NSAIDs) – These painkillers belong to the same group of drugs as acetylsalicylic acid (ASA, the drug in medicines like “Aspirin”). NSAIDs that may be an option for the treatment of sciatica include diclofenac, ibuprofen, and naproxen. Anti-inflammatory drugs are drugs that reduce inflammation. This includes substances produced by the body itself like cortisone. It also includes artificial substances like ASA – acetylsalicylic acid (or “aspirin”) or ibuprofen –, which relieve pain and reduce fever as well as reducing inflammation.
• Acetaminophen (paracetamol) – Acetaminophen (paracetamol) is also a painkiller, but it is not an NSAID. It is well tolerated and can be used as an alternative to NSAIDs – especially for people who do not tolerate NSAID painkillers because of things like stomach problems or asthma. But higher doses of acetaminophen can cause liver and kidney damage. The package insert advises adults not to take more than 4 grams (4000 mg) per day. This is the amount in, for example, 8 tablets containing 500 milligrams each. It is not only important to take the right dose, but also to wait long enough between doses.
• Opioids – Strong painkillers that may only be used under medical supervision. Opioids are available in many different strengths, and some are available in the form of a patch. Morphine, for example, is a very strong drug, while tramadol is a weaker opioid. These drugs may have a number of different side effects, some of which are serious.
• Skeletal Muscle relaxant – If muscle spasms are prominent, the addition of a muscle relaxant may merit consideration for a short period. For example, cyclobenzaprine is an option at a dose of 5 mg taken orally three times daily. Antidepressants (amitriptyline) and anticonvulsants (gabapentin and pregabalin) have been used to treat neuropathic pain, and they can provide a moderate analgesic effect.
• Steroids – Anti-inflammatory drugs that can be used to treat various diseases systemically. That means that they are taken as tablets or injected. The drug spreads throughout the entire body to soothe inflammation and relieve pain. Steroids may increase the risk of gastric ulcers, osteoporosis, infections, skin problems, glaucoma, and glucose metabolism disorders.
• Muscle relaxants – Sedatives which also relax the muscles. Like other psychotropic medications, they can cause fatigue and drowsiness, and affect your ability to drive. Muscle relaxants can also affect liver functions and cause gastro-intestinal complications. Drugs from the benzodiazepine group, such as tetrazepam, can lead to dependency if they are taken for longer than two weeks.
• Nerve Relaxant and Neuropathic Agents – Drugs(pregabalin & gabapentin) or Vitamin B1 B6, B12 and mecobalamin that address neuropathic—or nerve-related pain remover. This includes burning, numbness, and tingling.
• Anticonvulsants – These medications are typically used to treat epilepsy, but some are approved for treating nerve pain (neuralgia). Their side effects include drowsiness and fatigue. This can affect your ability to drive.
• Antidepressants – These drugs are usually used for treating depression. Some of them are also approved for the treatment of pain. Possible side effects include nausea, dry mouth, low blood pressure, irregular heartbeat, and fatigue.
• Topical Medications – These prescription-strength creams, gels, ointments, patches, and sprays help relieve pain and inflammation through the skin.
• Calcium & vitamin D3 – to improve bone health and healing fracture. As a general rule, men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day.
• Glucosamine & Diacerein, Chondroitin sulfate – can be used to tightening the loose tension, cartilage, ligament, and cartilage, ligament regenerate cartilage or inhabit the further degeneration of cartilage, ligament
• Injections near the spine – Injection therapy uses mostly local anesthetics and/or anti-inflammatory medications like corticosteroids (for example cortisone). These drugs are injected into the area immediately surrounding the affected nerve root. There are different ways of doing this:
  • In lumbar spinal nerve analgesia (LSPA) – the medication is injected directly at the point where the nerve root exits the spinal canal. This has a numbing effect on the nerve root.
  • In lumbar epidural analgesia – the medication is injected into what is known as the epidural space (“epidural injection”). The epidural space surrounds the spinal cord and the spinal fluid in the spinal canal. This is also where the nerve roots are located. During this treatment, the spine is monitored using computer tomography or X-rays to make sure that the injection is placed at exactly the right spot.
  • Interventional Treatments – Spinal steroid injections are a common alternative to surgery. Perineural injections (translaminar and transforaminal epidurals, selective nerve root blocks) are an option with pathological confirmation by MRI. These procedures should take place under radiologic guidance.[rx]

Surgical treatment

There are no clear radiological or medical guidelines or indications for surgical interventions in degenerative spondylolisthesis.^[rx] A minimum of three months of conservative management should be completed prior to considering surgical intervention.^[rx] Three indications for potential surgical treatment are as follows: persistent or recurrent back pain or neurologic pain with a persistent reduction of quality of life despite a reasonable trial of conservative (non-operative) management, new or worsening bladder or bowel symptoms, or a new or worsening neurological deficit.^[rx][rx]:

• Pars defect that has failed nonoperative management
• Multiple pars defects
• Low-grade spondylolisthesis (Myerding grade I & II) that fails conservative treatment, is progressive, has neurologic deficits, or likely to progress
• Posterolateral fusion
• Bucks fusion of facet joints
• High-grade spondylolisthesis (Myerding grade III, IV, V)
• Direct pars interarticularis repair

Additionally, on the discovery of the condition, vitamin D should be checked, and repleted levels are low.

References

What Is Spinal Cord Injury?/Spinal Cord Injury, The spinal cord is a tubular structure composed of nervous tissue that extends from the brainstem and continuing distally before tapering at the lower thoracic/upper lumbar region as the conus medullaris.  The spinal cord is anchored distally by the filum terminal, a fibrous extension of the pia mater anchoring the spinal cord to the coccyx.[rx] Protecting the spinal cord is the surrounding cerebrospinal fluid (CSF), supportive soft tissue membranes and meninges, and the osseous vertebral column.[rx]

Traumatic spinal cord injury (TSCI) is sudden forceful damage to the spinal nerves resulting in temporary or permanent paralysis, bladder and bowel dysfunction, and autonomic imbalance among other consequences [rx,rx]. A person with spinal cord injury is at immediate risk of respiratory and cardiac failure which may lead to death in the acute phase [rx]. Those who survive the acute phase faces a lifelong risk of secondary complications such as pressure ulcers, urinary tract infections, deep venous thrombosis, contractures, chronic pain, and spasms [rx,rx].

Trauma to the spinal cord may result from a road traffic accident (RTA), fall, assault and recreational or occupational accident [rx,rx]. The World Health Organization informs that up to 90% of all spinal cord lesions are due to trauma and that the leading cause globally is RTA [rx].

Anatomy of Spinal Cord

The major tracts and their most defining features are as follows

Ascending Tracts

• Dorsal column – contains the gracile fasciculus and cuneate fasciculus, which together are the dorsal funiculus. The dorsal column is responsible for pressure and vibration sensation as well as two-point discrimination, movement sense, and conscious proprioception. The dorsal column decussates at the superior portion of the medulla oblongata and forms medial lemniscus.
• Lateral spinothalamic – carries pain and temperature information. The lateral spinothalamic tract decussates at the anterior commissure two segments above the entry to the spinal cord.
• Anterior spinothalamic – carries crude touch and pressure information. It decussates similar to the lateral spinothalamic tract.[rx]
• Dorsal and ventral spinocerebellar – transmit unconscious proprioception sensory information to the cerebellum. The ventral spinocerebellar tract does not decussate, while the dorsal spinocerebellar tract decussates twice, making them both ipsilateral.[rx]

 Descending Tracts

• Lateral and anterior corticospinal – involved in conscious control of the skeletal muscle. The majority of lateral corticospinal tract fibers decussate at the inferior portion of the medulla oblongata while anterior corticospinal descends ipsilaterally in the spinal cord and decussates at the segmental level. Lateral corticospinal tract, also called pyramidal tract, innervates primarily contralateral muscles of the limbs, while anterior innervates proximal muscles of the trunk.
• Vestibulospinal – carries information from the inner ear to control head positioning and is involved in modifying muscle tone to maintain posture and balance. The vestibulospinal tract does not decussate.
• Rubrospinal – is involved in the movement of the flexor and extensor muscles. The rubrospinal tract originates from the red nuclei in the midbrain and decussates at the start of its pathway.
• Reticulospinal – originates from the reticular formation housed in the brainstem and it facilitates, influences, and supplements the corticospinal tract.[rx] The reticulospinal tract does not decussate.

There is a laminar distribution of neurons in the gray matter, characterized by density and topography

• Lamina I – is located at the tip of the dorsal horn and is composed of loosely packed neuropil along with neurons of low neuronal density. The most abundant neuron in lamina I is the Waldeyer cell: large, fusiform, and with a disk-shaped dendritic domain.[rx][rx]
• Lamina II – is composed mostly of islet cells with rostrocaudal axes, which contain GABA and are thought to be inhibitory, and stalked cells with dorsoventral dendritic trees.[rx]
• Lamina III – has cells of intermediate size, including antenna-like and radial neurons, many of which contain GABA or glycine and are also considered inhibitory.[rx][rx]
• Lamina IV – contains antenna-like cells and transverse cells, with dendrites that mostly go to Laminas II and III, and whose axons are mainly thought to enter the spinothalamic tract. Lateral from lamina IV is the lateral spinal nucleus, which sends signals to lamina IV from the midbrain and brainstem.[rx][rx]
• Lamina V and VI – are composed of medium-sized multipolar neurons, that can be fusiform or triangular. These neurons communicate with the reticular formation of the brainstem.
• Lamina VII – is composed of homogenous medium-sized multipolar neurons, and contains, in individual segments, well-defined nuclei, including the intermediolateral nucleus (T1-L1), which has autonomic functions, and the dorsal nucleus of Clarke (T1-L2), which make up the dorsal spinocerebellar tract.
• Lamina VIII – consists of neurons with dorsoventrally polarized dendritic trees.
• Lamina IX – has the cell bodies of motor neurons, with dendrites extending dorsally into laminas as far as VI. Lamina IX – also has Renshaw cells, inhibitory interneurons, placed at the medial border of motor nuclei.
• Lamina X –  is the substantia grisea centralis or the gray matter that surrounds the central canal. In the distal portion, lamina X consists of bipolar cells with fan-shaped dendritic trees, and in the ventral portion, lamina X consists of bipolar cells with poorly ramified longitudinal dendrites.[rx]

Symptoms of Spinal Cord Injury

A spinal cord injury is not the sort of thing you have to wonder about having. If you’ve suffered a spinal cord injury, your life is in danger, and you’ll know you’re injured. You can’t use symptoms to diagnose the sort of spinal cord injury you have, and every patient’s prognosis is different. Some make a miraculous recovery within months; others need years of physical therapy and still make little to no progress.

The outcome depends on the nature of the injury, the quality of medical care you receive, the degree to which you work at your own recovery by adopting a healthy lifestyle, your psychological health, luck, and innumerable other factors.

A partial list of common spinal cord injury symptoms includes:

• Varying degrees of paralysis, including tetraplegia/quadriplegia, and paraplegia
• Difficulty breathing; the need to be on a respirator
• Problems with bladder and bowel function
• Frequent infections; the likelihood of this increases if you are on a feeding or breathing tube
• Extreme pain or pressure in the neck, head or back
• Tingling or loss of sensation in the hand, fingers, feet or toes
• Partial or complete loss of control over any part of the body
• Urinary or bowel urgency, incontinence or retention
• Abnormal band-like sensations in the thorax (pain, pressure)
• Bedsores
• Chronic pain
• Headaches
• Muscle weakness
• Loss of voluntary muscle movement in the chest, arms, or legs
• Breathing problems
• Loss of feeling in the chest, arms, or legs
• Loss of bowel and bladder function
• Changes in mood or personality
• Loss of libido or sexual function
• Loss of fertility
• Nerve pain
• Chronic muscle pain
• Pneumonia (more than half of cervical spinal cord injury survivors struggle with bouts of pneumonia)
• Unusual lumps on the head or spine

Paraplegia

Knee arthroplasty is a reconstruction of the knee joint. It is more commonly referred to as a total knee replacement and is a very reliable procedure with predictable results. Total knee arthroplasty (TKA) is an excellent treatment option for individuals with symptomatic osteoarthritis in at least 2 of the 3 compartments of the knee and who have failed conservative treatment.[rx][rx] Additionally, partial knee arthroplasty (PKA) is an excellent treatment option for individuals with symptomatic osteoarthritis localized to 1 compartment of the knee and who have failed conservative treatment.[rx] The primary goal of either surgery is durable pain relief with the improvement of functional status.

References

Accidental Knee Dislocation/Knee Injury is a potentially devastating injury and is often a surgical emergency. This injury requires prompt identification, evaluation with appropriate imaging, and consultation with surgery for definitive treatment. Vascular injury and compartment syndrome are dreaded complications that the clinician should not miss in the workup of a knee dislocation. Note that this is in distinct contrast to patellar dislocations, which generally do not require immediate surgical or vascular intervention.[rx][rx]

A knee dislocation is a knee injury in which there is a complete disruption of the joint between the tibia and the femur. Symptoms include knee pain and instability of the knee. Complications may include injury to an artery around the knee, most commonly the artery behind the knee, or compartment syndrome.^[rx][rx][rx]

Types /Classification of Knee Dislocation

They may be divided into five types: anterior, posterior, lateral, medial, and rotatory. This classification is based on the movement of the tibia with respect to the femur. Anterior dislocations are the most common, followed by posterior dislocations. They may also be classified based on what ligaments are damaged.^[rx]

Kennedy classification based on the direction of displacement of the tibia

Anterior (30-50%)

• most common
• due to hyperextension injury
• usually involves tear of PCL
• an arterial injury is generally an intimal tear due to traction
• the highest rate of peroneal nerve injury

Posterior (30-40%)

• 2nd most common
• due to axial load to the flexed knee (dashboard injury)

The highest rate of vascular injury (25%) based on Kennedy classification

• has highest incidence of a complete tear of the popliteal artery

Lateral (13%)

• due to a varus or valgus force
• usually involves tears of both ACL and PCL

Medial (3%)

• varus or valgus force
• usually disrupted PLC and PCL

Rotational (4%)

• posterolateral is most common rotational dislocation
• usually irreducible
• buttonholing of femoral condyle through the capsule

Anatomic Classification System

The letters C and N can be added to denote arterial and neurologic injury, respectively.

Schenck Classification

• based on a pattern of multi ligamentous injury of knee dislocation (KD)

• Car accidents – If you bang your knee against a hard surface like your dashboard, the force of the blow may be strong enough to dislocate your knee.
• Sports injuries – This is less common than car accidents, but it’s possible to dislocate your knee if you collide with great force with another player or with the ground when your knee is bent, or if you over-extend your knee (bend it back farther than it’s supposed to go).
• Hard falls – It may happen to skiers or runners who lose control and fall on a bent or overextended knee. You may even dislocate your knee if you fall after stepping into a hole in the ground by mistake.
• Result of major trauma – and about half occur as a result of minor trauma.^[rx] Major trauma may include mechanisms like falls from a significant height, motor vehicle collisions, or a pedestrian being hit by a motor vehicle.
• Genetic Disorder – often have other injuries.^[rx] Minor trauma may include tripping while walking or while playing sports. Risk factors include obesity.^[rx] The condition may also occur in a number of genetic disorders such as Ellis–van Creveld syndrome, Larsen syndrome, and Ehlers–Danlos syndrome.^[rx]
• Sudden forceful  fall down
• Road traffic accident
• Falls – Falling onto an outstretched hand is one of the most common causes of the broken or dislocation knee.
• Sports injuries – Many cervical spine fractures occur during contact sports or sports in which you might fall onto an outstretched hand — such as in-line skating or snowboarding.
• Motor vehicle crashes – Motor vehicle crashes can cause the knee dislocation to break, sometimes into many pieces, and often require surgical repair.
• Have osteoporosis –  a disease that weakens your bones
• Eave low muscle mass or poor muscle strength – or lack agility and have poor balance (these conditions make you more likely to fall)
• Walk or do other activities in the snow or on the ice – or do activities that require a lot of forwarding momenta, such as in-line skating and skiing.
• Previous fractures record.
• Wave an inadequate intake of calcium or vitamin D.
• Football or soccer, especially on artificial turf
• Athletic injury with a sports injury.

The ligamentum patellae. Attached above to the lower border of the patella and below to the tuberosity of the tibia. A continuation of the central portion of the common tendon of the quadriceps femoris muscle. The oblique popliteal ligament. A tendinous expansion derived from the semimembranosus muscle. It strengthens the posterior aspect of the capsule.

Symptoms of Accidental Knee Dislocation

• Symptoms include knee pain. The joint may also be obviously out of place. A joint effusion is not always present.^[rx]
• Hearing a “popping” sound at the time of injury
• Severe pain in the area of the knee
• A visible deformity at the knee joint
• Instability of the knee joint, or feeling like your knee joint is “giving way”
• Limitations in the range of movement of your knee
• Inability to continue with activities, whether they involve day-to-day tasks or sports
• Feeling the kneecap shift or slide out of the groove
• Feeling the knee buckle or give way
• Hearing a popping sound when the patella dislocates
• Swelling
• A change in the knee’s appearance — the knee may appear misshapen or deformed
• Apprehension or fear when running or changing direction.

Diagnosis of Accidental Knee Dislocation

Vascular exam (especially popliteal artery distribution)

Perfusion Assessment

• Dorsalis pedis pulse
• Posterior tibial pulse
• Capillary Refill
• Ankle-Brachial Index (ABI) – Normal ABI (as well as pulses, Capillary Refill) may not exclude popliteal artery disruption

Hard signs of vascular injury

• Distal pulse loss or ischemia (e.g. pallor, coolness)
• Active bleeding
• Expanding hematoma
• Palpable thrill or bruit over the popliteal artery

Neurologic Exam (especially peroneal nerve)

• First web space and dorsal foot sensation
• Ankle dorsiflexion

Multidirectional instability

• Multidirectional instability may be only finding if knee spontaneously reduced prior to presentation
• Three of four ligaments are likely injured (ACL Tear, PCL Tear, LCL tear, MCL tear)

Skin changes

• Dimple Sign – Anteromedial skinfold at medial joint line. Seen in posterolateral dislocation (not reducible without surgery)
• Skin necrosis – Entrapped skin at femoral condyle
• Overlying Laceration – Suggests open Knee Dislocation (accompanies 20-30% of Knee Dislocations)

Others exam may include

• Checking the pulse in several places on your leg and knee – This is called checking posterior tibial and dorsal pedal pulses, which are located in the region of the knee and foot. Lower pulses in your injured leg could indicate an injury to a blood vessel in your leg.
• Checking the blood pressure in your leg – Called the ankle-brachial index (ABI), this test compares the blood pressure measured in your arm to the blood pressure measured in your ankle. A low ABI measurement can indicate poor blood flow to your lower extremities.
• Checking your sense of touch or sensation – Your doctor will assess the feeling in the injured leg versus the unaffected leg.
• Checking nerve conduction – Tests like electromyography (EMG) or nerve conduction velocity (NCV) will measure the function of the nerves in your leg and knee.
• Checking your skin color and temperature – If your leg is cold or changing colors, there may be blood vessel problems.
• X-rays – These tests create clear pictures of bone. Your doctor may order x-rays to look for skeletal abnormalities in the knee, such as a shallow groove in the femur.
• Magnetic resonance imaging (MRI) scans – These scans create better pictures of the soft structures surrounding the knee, like ligaments. An MRI is seldom necessary because the doctor can usually diagnose a dislocated patella through an examination and x-rays. However, if your doctor needs additional, more detailed images, he or she may order an MRI.

^{Treatment of Accidental Knee Dislocation}

Nonoperative

• Immobilization – Your doctor may recommend that your child wear a brace for 3 to 4 weeks. This stabilizes the knee while it heals.
• Weightbearing –  Because putting weight on the knee may cause pain and slow the healing process, your doctor may recommend using crutches for the first week or two after the injury.
• Physical therapy – Once the knee has started to heal, your child’s doctor will recommend physical therapy to help your child regain normal motion. Specific exercises will strengthen the thigh muscles holding the knee joint in place. Your child’s commitment to the exercise program is important for a successful recovery. Typically, children return to activity 3 to 6 weeks after the injury.
• Emergent closed reduction followed by vascular assessment/consult – indications to considered an orthopedic emergency, vascular consult indicated if pulses are absent or diminished following reduction if arterial injury confirmed by arterial duplex ultrasound or CT angiography
• Immobilization as definitive management – successful closed reduction without vascular compromise, most cases require some form of surgical stabilization following reduction, outcomes of worse outcomes are seen with nonoperative management/prolonged immobilization will lead to loss of ROM with persistent instability.
• Rest Your Leg – Once you’re discharged from the hospital in a legislating, your top priority is to rest your and not further inflame the injury. Of course, the arm sling not only provides support, but it also restricts movement, which is why you should keep it on even during sleep. Avoiding the temptation to move your will help the bone mend quicker and the pain fades away sooner.

Medication

• Antibiotic – Cefuroxime or Azithromycin, or  Flucloxacillin or any others cephalosporin/quinolone antibiotic must be used to prevent infection or clotted blood remove to prevent furthers swelling and edema
• NSAIDs – Prescription-strength drugs that reduce both pain and inflammation. Pain medicines and anti-inflammatory drugs help to relieve pain and stiffness, allowing for increased mobility and exercise. There are many common over-the-counter medicines called non-steroidal anti-inflammatory drugs (NSAIDs). They include and Ketorolac, Aceclofenac, Naproxen, Etoricoxib.
• Corticosteroids – Also known as oral steroids, these medications reduce inflammation.
• Muscle Relaxants –  These medications provide relief from associated muscle spasms.
• Neuropathic Agents – Drugs(pregabalin & gabapentin) that address neuropathic—or nerve-related—pain. This includes burning, numbness, and tingling.
• Opioids – Also known as narcotics, these medications are intense pain relievers that should only be used under a doctor’s careful supervision.
• Topical Medications – These prescription-strength creams, gels, ointments, patches, and sprays help relieve pain and inflammation through the skin.
• Calcium & vitamin D3 – to improve bone health and healing fracture. As a general rule, men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day.
• Glucosamine & Diacerein, Chondroitin sulfate – can be used to tightening the loose tension, cartilage, ligament, and cartilage, ligament regenerate cartilage or inhabit the further degeneration of cartilage, ligament
• Dietary supplement-to remove general weakness & improved health.
• Antidepressants – A drug that blocks pain messages from your brain and boosts the effects of endorphins (your body’s natural painkillers).

Surgical Treatment

Open reduction

• irreducible knee
• posterolateral dislocation
• open fracture-dislocation
• obesity (may be difficult to obtain closed)
• vascular injury

External fixation

• vascular repair (takes precedence)
• open fracture-dislocation
• compartment syndrome
• obese (if difficult to maintain reduction)
• polytrauma patient

Delayed ligamentous reconstruction/repair

• instability will require some kind of ligamentous repair or fixation
• patients can be placed in a knee immobilizer until treated operatively
• improved outcomes with early treatment (within 3 weeks)

Arthroscopy +/- open debridement

• Arthroscopic or open debridement with removal of any loose bodies may be necessary for displaced osteochondral fractures or loose bodies.

MPFL re-attachment or reconstruction (proximal realignment)

• Proximal realignment constitutes the reconstruction of the MPFL. In brief, to repair the ligament, a longitudinal incision is made at the border of the VMO, just anterior to the medial epicondyle. The ligament is usually re-attached to the femur using bone anchors. If the patient has had recurrent dislocations, then reconstruction may be necessary by harvesting gracilis or semitendinosus which are then attached to the patella and femur.
• Isolated repair/reconstruction of the MPFL is not a recommendation in those with bony abnormalities including TT-TG distance greater than 20mm, convex trochlear dysplasia, severe patella alta, advanced cartilage degeneration or severe femoral anteversion.[rx]

Lateral release (distal realignment)

• A lateral release cuts the retinaculum on the lateral aspect of the knee joint. The aim is to improve the alignment of the patella by reducing the lateral pull.

Osteotomy (distal realignment)

• Where there is abnormal anatomy contributing to poor patella tracking and a high TT-TG distance, the alignment correction can be through an osteotomy. The most common procedure of this type is known as the Fulkerson-type osteotomy and involves an osteotomy as well as removing the small portion of bone to which the tendon attaches and repositioning it in a more anteromedial position on the tibia.

Trochleoplasty

• Trochleoplasty is indicated in recurrent dislocators with a convex or flat trochlea. The trochlear groove is deepened to create a groove for the patella to glide through; this may take place alongside an MPFL reconstruction. Studies suggest it is not advisable in those with open growth plates or severely degenerative joints. This procedure is uncommon except in refractory cases.

Complications of Traumatic Knee Dislocation

Vascular compromise

• incidence of – 5-15% in all dislocations. 40-50% in anterior or posterior dislocations
• risk factors – KD IV injuries have the highest rate of vascular injuries
• treatment-emergent vascular repair and prophylactic fasciotomies

Stiffness (arthrofibrosis)

• incidence – most common complication (38%)
• risk factors – more common with delayed mobilization
• avoid stiffness with early reconstruction and motion
• arthroscopic lysis of adhesion
• manipulation under anesthesia

Laxity and instability 

• incidence – 37% of some instability, however, redislocation is uncommon
• treatment – arthroscopic lysis of adhesion, manipulation under anesthesia

Peroneal nerve injury 

• incidence- 25% occurrence of a peroneal nerve injury, 50% recover partially
• posterolateral dislocations

Treatment

• A to prevent equinus contracture
• neurolysis or exploration at the time of reconstruction
• nerve repair or reconstruction or tendon transfers if chronic nerve palsy persists
• a dynamic tendon transfer involves transferring the posterior tibial tendon (PTT) to the foot

References

Traumatic Knee Dislocation/Knee Injury is a potentially devastating injury and is often a surgical emergency. This injury requires prompt identification, evaluation with appropriate imaging, and consultation with surgery for definitive treatment. Vascular injury and compartment syndrome are dreaded complications that the clinician should not miss in the workup of a knee dislocation. Note that this is in distinct contrast to patellar dislocations, which generally do not require immediate surgical or vascular intervention.[rx][rx]

A knee dislocation is a knee injury in which there is a complete disruption of the joint between the tibia and the femur. Symptoms include knee pain and instability of the knee. Complications may include injury to an artery around the knee, most commonly the artery behind the knee, or compartment syndrome.^[rx][rx][rx]

Types /Classification of Knee Dislocation

They may be divided into five types: anterior, posterior, lateral, medial, and rotatory. This classification is based on the movement of the tibia with respect to the femur. Anterior dislocations are the most common, followed by posterior dislocations. They may also be classified based on what ligaments are damaged.^[rx]

Kennedy classification based on the direction of displacement of the tibia

Anterior (30-50%)

• most common
• due to hyperextension injury
• usually involves tear of PCL
• an arterial injury is generally an intimal tear due to traction
• the highest rate of peroneal nerve injury

Posterior (30-40%)

• 2nd most common
• due to axial load to the flexed knee (dashboard injury)

The highest rate of vascular injury (25%) based on Kennedy classification

• has highest incidence of a complete tear of the popliteal artery

Lateral (13%)

• due to a varus or valgus force
• usually involves tears of both ACL and PCL

Medial (3%)

• varus or valgus force
• usually disrupted PLC and PCL

Rotational (4%)

• posterolateral is most common rotational dislocation
• usually irreducible
• buttonholing of femoral condyle through the capsule

Anatomic Classification System

The letters C and N can be added to denote arterial and neurologic injury, respectively.

Schenck Classification

• based on a pattern of multi ligamentous injury of knee dislocation (KD)

• Car accidents – If you bang your knee against a hard surface like your dashboard, the force of the blow may be strong enough to dislocate your knee.
• Sports injuries – This is less common than car accidents, but it’s possible to dislocate your knee if you collide with great force with another player or with the ground when your knee is bent, or if you over-extend your knee (bend it back farther than it’s supposed to go).
• Hard falls – It may happen to skiers or runners who lose control and fall on a bent or overextended knee. You may even dislocate your knee if you fall after stepping into a hole in the ground by mistake.
• Result of major trauma – and about half occur as a result of minor trauma.^[rx] Major trauma may include mechanisms like falls from a significant height, motor vehicle collisions, or a pedestrian being hit by a motor vehicle.
• Genetic Disorder – often have other injuries.^[rx] Minor trauma may include tripping while walking or while playing sports. Risk factors include obesity.^[rx] The condition may also occur in a number of genetic disorders such as Ellis–van Creveld syndrome, Larsen syndrome, and Ehlers–Danlos syndrome.^[rx]
• Sudden forceful  fall down
• Road traffic accident
• Falls – Falling onto an outstretched hand is one of the most common causes of the broken or dislocation knee.
• Sports injuries – Many cervical spine fractures occur during contact sports or sports in which you might fall onto an outstretched hand — such as in-line skating or snowboarding.
• Motor vehicle crashes – Motor vehicle crashes can cause the knee dislocation to break, sometimes into many pieces, and often require surgical repair.
• Have osteoporosis –  a disease that weakens your bones
• Eave low muscle mass or poor muscle strength – or lack agility and have poor balance (these conditions make you more likely to fall)
• Walk or do other activities in the snow or on the ice – or do activities that require a lot of forwarding momenta, such as in-line skating and skiing.
• Previous fractures record.
• Wave an inadequate intake of calcium or vitamin D.
• Football or soccer, especially on artificial turf
• Athletic injury with a sports injury.

The ligamentum patellae. Attached above to the lower border of the patella and below to the tuberosity of the tibia. A continuation of the central portion of the common tendon of the quadriceps femoris muscle. The oblique popliteal ligament. A tendinous expansion derived from the semimembranosus muscle. It strengthens the posterior aspect of the capsule.

Symptoms of Child Knee Dislocation

• Symptoms include knee pain. The joint may also be obviously out of place. A joint effusion is not always present.^[rx]
• Hearing a “popping” sound at the time of injury
• Severe pain in the area of the knee
• A visible deformity at the knee joint
• Instability of the knee joint, or feeling like your knee joint is “giving way”
• Limitations in the range of movement of your knee
• Inability to continue with activities, whether they involve day-to-day tasks or sports
• Feeling the kneecap shift or slide out of the groove
• Feeling the knee buckle or give way
• Hearing a popping sound when the patella dislocates
• Swelling
• A change in the knee’s appearance — the knee may appear misshapen or deformed
• Apprehension or fear when running or changing direction.

Diagnosis of Traumatic Knee Dislocation

Vascular exam (especially popliteal artery distribution)

Perfusion Assessment

• Dorsalis pedis pulse
• Posterior tibial pulse
• Capillary Refill
• Ankle-Brachial Index (ABI) – Normal ABI (as well as pulses, Capillary Refill) may not exclude popliteal artery disruption

Hard signs of vascular injury

• Distal pulse loss or ischemia (e.g. pallor, coolness)
• Active bleeding
• Expanding hematoma
• Palpable thrill or bruit over the popliteal artery

Neurologic Exam (especially peroneal nerve)

• First web space and dorsal foot sensation
• Ankle dorsiflexion

Multidirectional instability

• Multidirectional instability may be only finding if knee spontaneously reduced prior to presentation
• Three of four ligaments are likely injured (ACL Tear, PCL Tear, LCL tear, MCL tear)

Skin changes

• Dimple Sign – Anteromedial skinfold at medial joint line. Seen in posterolateral dislocation (not reducible without surgery)
• Skin necrosis – Entrapped skin at femoral condyle
• Overlying Laceration – Suggests open Knee Dislocation (accompanies 20-30% of Knee Dislocations)

Others exam may include

• Checking the pulse in several places on your leg and knee – This is called checking posterior tibial and dorsal pedal pulses, which are located in the region of the knee and foot. Lower pulses in your injured leg could indicate an injury to a blood vessel in your leg.
• Checking the blood pressure in your leg – Called the ankle-brachial index (ABI), this test compares the blood pressure measured in your arm to the blood pressure measured in your ankle. A low ABI measurement can indicate poor blood flow to your lower extremities.
• Checking your sense of touch or sensation – Your doctor will assess the feeling in the injured leg versus the unaffected leg.
• Checking nerve conduction – Tests like electromyography (EMG) or nerve conduction velocity (NCV) will measure the function of the nerves in your leg and knee.
• Checking your skin color and temperature – If your leg is cold or changing colors, there may be blood vessel problems.
• X-rays – These tests create clear pictures of bone. Your doctor may order x-rays to look for skeletal abnormalities in the knee, such as a shallow groove in the femur.
• Magnetic resonance imaging (MRI) scans – These scans create better pictures of the soft structures surrounding the knee, like ligaments. An MRI is seldom necessary because the doctor can usually diagnose a dislocated patella through an examination and x-rays. However, if your doctor needs additional, more detailed images, he or she may order an MRI.

^{Treatment of Traumatic Knee Dislocation}

Nonoperative

• Immobilization – Your doctor may recommend that your child wear a brace for 3 to 4 weeks. This stabilizes the knee while it heals.
• Weightbearing –  Because putting weight on the knee may cause pain and slow the healing process, your doctor may recommend using crutches for the first week or two after the injury.
• Physical therapy – Once the knee has started to heal, your child’s doctor will recommend physical therapy to help your child regain normal motion. Specific exercises will strengthen the thigh muscles holding the knee joint in place. Your child’s commitment to the exercise program is important for a successful recovery. Typically, children return to activity 3 to 6 weeks after the injury.
• Emergent closed reduction followed by vascular assessment/consult – indications to considered an orthopedic emergency, vascular consult indicated if pulses are absent or diminished following reduction if arterial injury confirmed by arterial duplex ultrasound or CT angiography
• Immobilization as definitive management – successful closed reduction without vascular compromise, most cases require some form of surgical stabilization following reduction, outcomes of worse outcomes are seen with nonoperative management/prolonged immobilization will lead to loss of ROM with persistent instability.
• Rest Your Leg – Once you’re discharged from the hospital in a legislating, your top priority is to rest your and not further inflame the injury. Of course, the arm sling not only provides support, but it also restricts movement, which is why you should keep it on even during sleep. Avoiding the temptation to move your will help the bone mend quicker and the pain fades away sooner.

Medication

• Antibiotic – Cefuroxime or Azithromycin, or  Flucloxacillin or any others cephalosporin/quinolone antibiotic must be used to prevent infection or clotted blood remove to prevent furthers swelling and edema
• NSAIDs – Prescription-strength drugs that reduce both pain and inflammation. Pain medicines and anti-inflammatory drugs help to relieve pain and stiffness, allowing for increased mobility and exercise. There are many common over-the-counter medicines called non-steroidal anti-inflammatory drugs (NSAIDs). They include and Ketorolac, Aceclofenac, Naproxen, Etoricoxib.
• Corticosteroids – Also known as oral steroids, these medications reduce inflammation.
• Muscle Relaxants –  These medications provide relief from associated muscle spasms.
• Neuropathic Agents – Drugs(pregabalin & gabapentin) that address neuropathic—or nerve-related—pain. This includes burning, numbness, and tingling.
• Opioids – Also known as narcotics, these medications are intense pain relievers that should only be used under a doctor’s careful supervision.
• Topical Medications – These prescription-strength creams, gels, ointments, patches, and sprays help relieve pain and inflammation through the skin.
• Calcium & vitamin D3 – to improve bone health and healing fracture. As a general rule, men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day.
• Glucosamine & Diacerein, Chondroitin sulfate – can be used to tightening the loose tension, cartilage, ligament, and cartilage, ligament regenerate cartilage or inhabit the further degeneration of cartilage, ligament
• Dietary supplement-to remove general weakness & improved health.
• Antidepressants – A drug that blocks pain messages from your brain and boosts the effects of endorphins (your body’s natural painkillers).

Surgical Treatment

Open reduction

• irreducible knee
• posterolateral dislocation
• open fracture-dislocation
• obesity (may be difficult to obtain closed)
• vascular injury

External fixation

• vascular repair (takes precedence)
• open fracture-dislocation
• compartment syndrome
• obese (if difficult to maintain reduction)
• polytrauma patient

Delayed ligamentous reconstruction/repair

• instability will require some kind of ligamentous repair or fixation
• patients can be placed in a knee immobilizer until treated operatively
• improved outcomes with early treatment (within 3 weeks)

Arthroscopy +/- open debridement

• Arthroscopic or open debridement with removal of any loose bodies may be necessary for displaced osteochondral fractures or loose bodies.

MPFL re-attachment or reconstruction (proximal realignment)

• Proximal realignment constitutes the reconstruction of the MPFL. In brief, to repair the ligament, a longitudinal incision is made at the border of the VMO, just anterior to the medial epicondyle. The ligament is usually re-attached to the femur using bone anchors. If the patient has had recurrent dislocations, then reconstruction may be necessary by harvesting gracilis or semitendinosus which are then attached to the patella and femur.
• Isolated repair/reconstruction of the MPFL is not a recommendation in those with bony abnormalities including TT-TG distance greater than 20mm, convex trochlear dysplasia, severe patella alta, advanced cartilage degeneration or severe femoral anteversion.[rx]

Lateral release (distal realignment)

• A lateral release cuts the retinaculum on the lateral aspect of the knee joint. The aim is to improve the alignment of the patella by reducing the lateral pull.

Osteotomy (distal realignment)

• Where there is abnormal anatomy contributing to poor patella tracking and a high TT-TG distance, the alignment correction can be through an osteotomy. The most common procedure of this type is known as the Fulkerson-type osteotomy and involves an osteotomy as well as removing the small portion of bone to which the tendon attaches and repositioning it in a more anteromedial position on the tibia.

Trochleoplasty

• Trochleoplasty is indicated in recurrent dislocators with a convex or flat trochlea. The trochlear groove is deepened to create a groove for the patella to glide through; this may take place alongside an MPFL reconstruction. Studies suggest it is not advisable in those with open growth plates or severely degenerative joints. This procedure is uncommon except in refractory cases.

Complications of Traumatic Knee Dislocation

Vascular compromise

• incidence of – 5-15% in all dislocations. 40-50% in anterior or posterior dislocations
• risk factors – KD IV injuries have the highest rate of vascular injuries
• treatment-emergent vascular repair and prophylactic fasciotomies

Stiffness (arthrofibrosis)

• incidence – most common complication (38%)
• risk factors – more common with delayed mobilization
• avoid stiffness with early reconstruction and motion
• arthroscopic lysis of adhesion
• manipulation under anesthesia

Laxity and instability 

• incidence – 37% of some instability, however, redislocation is uncommon
• treatment – arthroscopic lysis of adhesion, manipulation under anesthesia

Peroneal nerve injury 

• incidence- 25% occurrence of a peroneal nerve injury, 50% recover partially
• posterolateral dislocations

Treatment

• A to prevent equinus contracture
• neurolysis or exploration at the time of reconstruction
• nerve repair or reconstruction or tendon transfers if chronic nerve palsy persists
• a dynamic tendon transfer involves transferring the posterior tibial tendon (PTT) to the foot

References

Knee Medial Dislocation/Knee Dislocation is a potentially devastating injury and is often a surgical emergency. This injury requires prompt identification, evaluation with appropriate imaging, and consultation with surgery for definitive treatment. Vascular injury and compartment syndrome are dreaded complications that the clinician should not miss in the workup of a knee dislocation. Note that this is in distinct contrast to patellar dislocations, which generally do not require immediate surgical or vascular intervention.[rx][rx]

A knee dislocation is a knee injury in which there is a complete disruption of the joint between the tibia and the femur. Symptoms include knee pain and instability of the knee. Complications may include injury to an artery around the knee, most commonly the artery behind the knee, or compartment syndrome.^[rx][rx][rx]

Types /Classification of Knee Dislocation

They may be divided into five types: anterior, posterior, lateral, medial, and rotatory. This classification is based on the movement of the tibia with respect to the femur. Anterior dislocations are the most common, followed by posterior dislocations. They may also be classified based on what ligaments are damaged.^[rx]

Kennedy classification based on the direction of displacement of the tibia

Anterior (30-50%)

• most common
• due to hyperextension injury
• usually involves tear of PCL
• an arterial injury is generally an intimal tear due to traction
• the highest rate of peroneal nerve injury

Posterior (30-40%)

• 2nd most common
• due to axial load to the flexed knee (dashboard injury)

The highest rate of vascular injury (25%) based on Kennedy classification

• has highest incidence of a complete tear of the popliteal artery

Lateral (13%)

• due to a varus or valgus force
• usually involves tears of both ACL and PCL

Medial (3%)

• varus or valgus force
• usually disrupted PLC and PCL

Rotational (4%)

• posterolateral is most common rotational dislocation
• usually irreducible
• buttonholing of femoral condyle through the capsule

Anatomic Classification System

The letters C and N can be added to denote arterial and neurologic injury, respectively.

Schenck Classification

• based on a pattern of multi ligamentous injury of knee dislocation (KD)

• Car accidents – If you bang your knee against a hard surface like your dashboard, the force of the blow may be strong enough to dislocate your knee.
• Sports injuries – This is less common than car accidents, but it’s possible to dislocate your knee if you collide with great force with another player or with the ground when your knee is bent, or if you over-extend your knee (bend it back farther than it’s supposed to go).
• Hard falls – It may happen to skiers or runners who lose control and fall on a bent or overextended knee. You may even dislocate your knee if you fall after stepping into a hole in the ground by mistake.
• Result of major trauma – and about half occur as a result of minor trauma.^[rx] Major trauma may include mechanisms like falls from a significant height, motor vehicle collisions, or a pedestrian being hit by a motor vehicle.
• Genetic Disorder – often have other injuries.^[rx] Minor trauma may include tripping while walking or while playing sports. Risk factors include obesity.^[rx] The condition may also occur in a number of genetic disorders such as Ellis–van Creveld syndrome, Larsen syndrome, and Ehlers–Danlos syndrome.^[rx]
• Sudden forceful  fall down
• Road traffic accident
• Falls – Falling onto an outstretched hand is one of the most common causes of the broken or dislocation knee.
• Sports injuries – Many cervical spine fractures occur during contact sports or sports in which you might fall onto an outstretched hand — such as in-line skating or snowboarding.
• Motor vehicle crashes – Motor vehicle crashes can cause the knee dislocation to break, sometimes into many pieces, and often require surgical repair.
• Have osteoporosis –  a disease that weakens your bones
• Eave low muscle mass or poor muscle strength – or lack agility and have poor balance (these conditions make you more likely to fall)
• Walk or do other activities in the snow or on the ice – or do activities that require a lot of forwarding momenta, such as in-line skating and skiing.
• Previous fractures record.
• Wave an inadequate intake of calcium or vitamin D.
• Football or soccer, especially on artificial turf
• Athletic injury with a sports injury.

The ligamentum patellae. Attached above to the lower border of the patella and below to the tuberosity of the tibia. A continuation of the central portion of the common tendon of the quadriceps femoris muscle. The oblique popliteal ligament. A tendinous expansion derived from the semimembranosus muscle. It strengthens the posterior aspect of the capsule.

Symptoms of Knee Medial Dislocation 

• Symptoms include knee pain. The joint may also be obviously out of place. A joint effusion is not always present.^[rx]
• Hearing a “popping” sound at the time of injury
• Severe pain in the area of the knee
• A visible deformity at the knee joint
• Instability of the knee joint, or feeling like your knee joint is “giving way”
• Limitations in the range of movement of your knee
• Inability to continue with activities, whether they involve day-to-day tasks or sports
• Feeling the kneecap shift or slide out of the groove
• Feeling the knee buckle or give way
• Hearing a popping sound when the patella dislocates
• Swelling
• A change in the knee’s appearance — the knee may appear misshapen or deformed
• Apprehension or fear when running or changing direction.

Diagnosis of Knee Medial Dislocation

Vascular exam (especially popliteal artery distribution)

Perfusion Assessment

• Dorsalis pedis pulse
• Posterior tibial pulse
• Capillary Refill
• Ankle-Brachial Index (ABI) – Normal ABI (as well as pulses, Capillary Refill) may not exclude popliteal artery disruption

Hard signs of vascular injury

• Distal pulse loss or ischemia (e.g. pallor, coolness)
• Active bleeding
• Expanding hematoma
• Palpable thrill or bruit over the popliteal artery

Neurologic Exam (especially peroneal nerve)

• First web space and dorsal foot sensation
• Ankle dorsiflexion

Multidirectional instability

• Multidirectional instability may be only finding if knee spontaneously reduced prior to presentation
• Three of four ligaments are likely injured (ACL Tear, PCL Tear, LCL tear, MCL tear)

Skin changes

• Dimple Sign – Anteromedial skinfold at medial joint line. Seen in posterolateral dislocation (not reducible without surgery)
• Skin necrosis – Entrapped skin at femoral condyle
• Overlying Laceration – Suggests open Knee Dislocation (accompanies 20-30% of Knee Dislocations)

Others exam may include

• Checking the pulse in several places on your leg and knee – This is called checking posterior tibial and dorsal pedal pulses, which are located in the region of the knee and foot. Lower pulses in your injured leg could indicate an injury to a blood vessel in your leg.
• Checking the blood pressure in your leg – Called the ankle-brachial index (ABI), this test compares the blood pressure measured in your arm to the blood pressure measured in your ankle. A low ABI measurement can indicate poor blood flow to your lower extremities.
• Checking your sense of touch or sensation – Your doctor will assess the feeling in the injured leg versus the unaffected leg.
• Checking nerve conduction – Tests like electromyography (EMG) or nerve conduction velocity (NCV) will measure the function of the nerves in your leg and knee.
• Checking your skin color and temperature – If your leg is cold or changing colors, there may be blood vessel problems.
• X-rays – These tests create clear pictures of bone. Your doctor may order x-rays to look for skeletal abnormalities in the knee, such as a shallow groove in the femur.
• Magnetic resonance imaging (MRI) scans – These scans create better pictures of the soft structures surrounding the knee, like ligaments. An MRI is seldom necessary because the doctor can usually diagnose a dislocated patella through an examination and x-rays. However, if your doctor needs additional, more detailed images, he or she may order an MRI.

^{Treatment of Knee Medial Dislocation} 

Nonoperative

• Immobilization – Your doctor may recommend that your child wear a brace for 3 to 4 weeks. This stabilizes the knee while it heals.
• Weightbearing –  Because putting weight on the knee may cause pain and slow the healing process, your doctor may recommend using crutches for the first week or two after the injury.
• Physical therapy – Once the knee has started to heal, your child’s doctor will recommend physical therapy to help your child regain normal motion. Specific exercises will strengthen the thigh muscles holding the knee joint in place. Your child’s commitment to the exercise program is important for a successful recovery. Typically, children return to activity 3 to 6 weeks after the injury.
• Emergent closed reduction followed by vascular assessment/consult – indications to considered an orthopedic emergency, vascular consult indicated if pulses are absent or diminished following reduction if arterial injury confirmed by arterial duplex ultrasound or CT angiography
• Immobilization as definitive management – successful closed reduction without vascular compromise, most cases require some form of surgical stabilization following reduction, outcomes of worse outcomes are seen with nonoperative management/prolonged immobilization will lead to loss of ROM with persistent instability.
• Rest Your Leg – Once you’re discharged from the hospital in a legislating, your top priority is to rest your and not further inflame the injury. Of course, the arm sling not only provides support, but it also restricts movement, which is why you should keep it on even during sleep. Avoiding the temptation to move your will help the bone mend quicker and the pain fades away sooner.

Medication

• Antibiotic – Cefuroxime or Azithromycin, or  Flucloxacillin or any others cephalosporin/quinolone antibiotic must be used to prevent infection or clotted blood remove to prevent furthers swelling and edema
• NSAIDs – Prescription-strength drugs that reduce both pain and inflammation. Pain medicines and anti-inflammatory drugs help to relieve pain and stiffness, allowing for increased mobility and exercise. There are many common over-the-counter medicines called non-steroidal anti-inflammatory drugs (NSAIDs). They include and Ketorolac, Aceclofenac, Naproxen, Etoricoxib.
• Corticosteroids – Also known as oral steroids, these medications reduce inflammation.
• Muscle Relaxants –  These medications provide relief from associated muscle spasms.
• Neuropathic Agents – Drugs(pregabalin & gabapentin) that address neuropathic—or nerve-related—pain. This includes burning, numbness, and tingling.
• Opioids – Also known as narcotics, these medications are intense pain relievers that should only be used under a doctor’s careful supervision.
• Topical Medications – These prescription-strength creams, gels, ointments, patches, and sprays help relieve pain and inflammation through the skin.
• Calcium & vitamin D3 – to improve bone health and healing fracture. As a general rule, men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day.
• Glucosamine & Diacerein, Chondroitin sulfate – can be used to tightening the loose tension, cartilage, ligament, and cartilage, ligament regenerate cartilage or inhabit the further degeneration of cartilage, ligament
• Dietary supplement-to remove general weakness & improved health.
• Antidepressants – A drug that blocks pain messages from your brain and boosts the effects of endorphins (your body’s natural painkillers).

Surgical Treatment

Open reduction

• irreducible knee
• posterolateral dislocation
• open fracture-dislocation
• obesity (may be difficult to obtain closed)
• vascular injury

External fixation

• vascular repair (takes precedence)
• open fracture-dislocation
• compartment syndrome
• obese (if difficult to maintain reduction)
• polytrauma patient

Delayed ligamentous reconstruction/repair

• instability will require some kind of ligamentous repair or fixation
• patients can be placed in a knee immobilizer until treated operatively
• improved outcomes with early treatment (within 3 weeks)

Arthroscopy +/- open debridement

• Arthroscopic or open debridement with removal of any loose bodies may be necessary for displaced osteochondral fractures or loose bodies.

MPFL re-attachment or reconstruction (proximal realignment)

• Proximal realignment constitutes the reconstruction of the MPFL. In brief, to repair the ligament, a longitudinal incision is made at the border of the VMO, just anterior to the medial epicondyle. The ligament is usually re-attached to the femur using bone anchors. If the patient has had recurrent dislocations, then reconstruction may be necessary by harvesting gracilis or semitendinosus which are then attached to the patella and femur.
• Isolated repair/reconstruction of the MPFL is not a recommendation in those with bony abnormalities including TT-TG distance greater than 20mm, convex trochlear dysplasia, severe patella alta, advanced cartilage degeneration or severe femoral anteversion.[rx]

Lateral release (distal realignment)

• A lateral release cuts the retinaculum on the lateral aspect of the knee joint. The aim is to improve the alignment of the patella by reducing the lateral pull.

Osteotomy (distal realignment)

• Where there is abnormal anatomy contributing to poor patella tracking and a high TT-TG distance, the alignment correction can be through an osteotomy. The most common procedure of this type is known as the Fulkerson-type osteotomy and involves an osteotomy as well as removing the small portion of bone to which the tendon attaches and repositioning it in a more anteromedial position on the tibia.

Trochleoplasty

• Trochleoplasty is indicated in recurrent dislocators with a convex or flat trochlea. The trochlear groove is deepened to create a groove for the patella to glide through; this may take place alongside an MPFL reconstruction. Studies suggest it is not advisable in those with open growth plates or severely degenerative joints. This procedure is uncommon except in refractory cases.

Complications of Knee Lateral Dislocation

Vascular compromise

• incidence of – 5-15% in all dislocations. 40-50% in anterior or posterior dislocations
• risk factors – KD IV injuries have the highest rate of vascular injuries
• treatment-emergent vascular repair and prophylactic fasciotomies

Stiffness (arthrofibrosis)

• incidence – most common complication (38%)
• risk factors – more common with delayed mobilization
• avoid stiffness with early reconstruction and motion
• arthroscopic lysis of adhesion
• manipulation under anesthesia

Laxity and instability 

• incidence – 37% of some instability, however, redislocation is uncommon
• treatment – arthroscopic lysis of adhesion, manipulation under anesthesia

Peroneal nerve injury 

• incidence- 25% occurrence of a peroneal nerve injury, 50% recover partially
• posterolateral dislocations

Treatment

• A to prevent equinus contracture
• neurolysis or exploration at the time of reconstruction
• nerve repair or reconstruction or tendon transfers if chronic nerve palsy persists
• a dynamic tendon transfer involves transferring the posterior tibial tendon (PTT) to the foot

References

Knee Posterior Dislocation/Knee Dislocation is a potentially devastating injury and is often a surgical emergency. This injury requires prompt identification, evaluation with appropriate imaging, and consultation with surgery for definitive treatment. Vascular injury and compartment syndrome are dreaded complications that the clinician should not miss in the workup of a knee dislocation. Note that this is in distinct contrast to patellar dislocations, which generally do not require immediate surgical or vascular intervention.[rx][rx]

A knee dislocation is a knee injury in which there is a complete disruption of the joint between the tibia and the femur. Symptoms include knee pain and instability of the knee. Complications may include injury to an artery around the knee, most commonly the artery behind the knee, or compartment syndrome.^[rx][rx][rx]

Types /Classification of Knee Dislocation

They may be divided into five types: anterior, posterior, lateral, medial, and rotatory. This classification is based on the movement of the tibia with respect to the femur. Anterior dislocations are the most common, followed by posterior dislocations. They may also be classified based on what ligaments are damaged.^[rx]

Kennedy classification based on the direction of displacement of the tibia

Anterior (30-50%)

• most common
• due to hyperextension injury
• usually involves tear of PCL
• an arterial injury is generally an intimal tear due to traction
• the highest rate of peroneal nerve injury

Posterior (30-40%)

• 2nd most common
• due to axial load to the flexed knee (dashboard injury)

The highest rate of vascular injury (25%) based on Kennedy classification

• has highest incidence of a complete tear of the popliteal artery

Lateral (13%)

• due to a varus or valgus force
• usually involves tears of both ACL and PCL

Medial (3%)

• varus or valgus force
• usually disrupted PLC and PCL

Rotational (4%)

• posterolateral is most common rotational dislocation
• usually irreducible
• buttonholing of femoral condyle through the capsule

Anatomic Classification System

The letters C and N can be added to denote arterial and neurologic injury, respectively.

Schenck Classification

• based on a pattern of multi ligamentous injury of knee dislocation (KD)

• Car accidents – If you bang your knee against a hard surface like your dashboard, the force of the blow may be strong enough to dislocate your knee.
• Sports injuries – This is less common than car accidents, but it’s possible to dislocate your knee if you collide with great force with another player or with the ground when your knee is bent, or if you over-extend your knee (bend it back farther than it’s supposed to go).
• Hard falls – It may happen to skiers or runners who lose control and fall on a bent or overextended knee. You may even dislocate your knee if you fall after stepping into a hole in the ground by mistake.
• Result of major trauma – and about half occur as a result of minor trauma.^[rx] Major trauma may include mechanisms like falls from a significant height, motor vehicle collisions, or a pedestrian being hit by a motor vehicle.
• Genetic Disorder – often have other injuries.^[rx] Minor trauma may include tripping while walking or while playing sports. Risk factors include obesity.^[rx] The condition may also occur in a number of genetic disorders such as Ellis–van Creveld syndrome, Larsen syndrome, and Ehlers–Danlos syndrome.^[rx]
• Sudden forceful  fall down
• Road traffic accident
• Falls – Falling onto an outstretched hand is one of the most common causes of the broken or dislocation knee.
• Sports injuries – Many cervical spine fractures occur during contact sports or sports in which you might fall onto an outstretched hand — such as in-line skating or snowboarding.
• Motor vehicle crashes – Motor vehicle crashes can cause the knee dislocation to break, sometimes into many pieces, and often require surgical repair.
• Have osteoporosis –  a disease that weakens your bones
• Eave low muscle mass or poor muscle strength – or lack agility and have poor balance (these conditions make you more likely to fall)
• Walk or do other activities in the snow or on the ice – or do activities that require a lot of forwarding momenta, such as in-line skating and skiing.
• Previous fractures record.
• Wave an inadequate intake of calcium or vitamin D.
• Football or soccer, especially on artificial turf
• Athletic injury with a sports injury.

The ligamentum patellae. Attached above to the lower border of the patella and below to the tuberosity of the tibia. A continuation of the central portion of the common tendon of the quadriceps femoris muscle. The oblique popliteal ligament. A tendinous expansion derived from the semimembranosus muscle. It strengthens the posterior aspect of the capsule.

Symptoms of Knee Posterior Dislocation

• Symptoms include knee pain. The joint may also be obviously out of place. A joint effusion is not always present.^[rx]
• Hearing a “popping” sound at the time of injury
• Severe pain in the area of the knee
• A visible deformity at the knee joint
• Instability of the knee joint, or feeling like your knee joint is “giving way”
• Limitations in the range of movement of your knee
• Inability to continue with activities, whether they involve day-to-day tasks or sports
• Feeling the kneecap shift or slide out of the groove
• Feeling the knee buckle or give way
• Hearing a popping sound when the patella dislocates
• Swelling
• A change in the knee’s appearance — the knee may appear misshapen or deformed
• Apprehension or fear when running or changing direction.

Diagnosis of Knee Posterior Dislocation

Vascular exam (especially popliteal artery distribution)

Perfusion Assessment

• Dorsalis pedis pulse
• Posterior tibial pulse
• Capillary Refill
• Ankle-Brachial Index (ABI) – Normal ABI (as well as pulses, Capillary Refill) may not exclude popliteal artery disruption

Hard signs of vascular injury

• Distal pulse loss or ischemia (e.g. pallor, coolness)
• Active bleeding
• Expanding hematoma
• Palpable thrill or bruit over the popliteal artery

Neurologic Exam (especially peroneal nerve)

• First web space and dorsal foot sensation
• Ankle dorsiflexion

Multidirectional instability

• Multidirectional instability may be only finding if knee spontaneously reduced prior to presentation
• Three of four ligaments are likely injured (ACL Tear, PCL Tear, LCL tear, MCL tear)

Skin changes

• Dimple Sign – Anteromedial skinfold at medial joint line. Seen in posterolateral dislocation (not reducible without surgery)
• Skin necrosis – Entrapped skin at femoral condyle
• Overlying Laceration – Suggests open Knee Dislocation (accompanies 20-30% of Knee Dislocations)

Others exam may include

• Checking the pulse in several places on your leg and knee – This is called checking posterior tibial and dorsal pedal pulses, which are located in the region of the knee and foot. Lower pulses in your injured leg could indicate an injury to a blood vessel in your leg.
• Checking the blood pressure in your leg – Called the ankle-brachial index (ABI), this test compares the blood pressure measured in your arm to the blood pressure measured in your ankle. A low ABI measurement can indicate poor blood flow to your lower extremities.
• Checking your sense of touch or sensation – Your doctor will assess the feeling in the injured leg versus the unaffected leg.
• Checking nerve conduction – Tests like electromyography (EMG) or nerve conduction velocity (NCV) will measure the function of the nerves in your leg and knee.
• Checking your skin color and temperature – If your leg is cold or changing colors, there may be blood vessel problems.
• X-rays – These tests create clear pictures of bone. Your doctor may order x-rays to look for skeletal abnormalities in the knee, such as a shallow groove in the femur.
• Magnetic resonance imaging (MRI) scans – These scans create better pictures of the soft structures surrounding the knee, like ligaments. An MRI is seldom necessary because the doctor can usually diagnose a dislocated patella through an examination and x-rays. However, if your doctor needs additional, more detailed images, he or she may order an MRI.

^{Treatment of Knee Posterior Dislocation}

Nonoperative

• Immobilization – Your doctor may recommend that your child wear a brace for 3 to 4 weeks. This stabilizes the knee while it heals.
• Weightbearing –  Because putting weight on the knee may cause pain and slow the healing process, your doctor may recommend using crutches for the first week or two after the injury.
• Physical therapy – Once the knee has started to heal, your child’s doctor will recommend physical therapy to help your child regain normal motion. Specific exercises will strengthen the thigh muscles holding the knee joint in place. Your child’s commitment to the exercise program is important for a successful recovery. Typically, children return to activity 3 to 6 weeks after the injury.
• Emergent closed reduction followed by vascular assessment/consult – indications to considered an orthopedic emergency, vascular consult indicated if pulses are absent or diminished following reduction if arterial injury confirmed by arterial duplex ultrasound or CT angiography
• Immobilization as definitive management – successful closed reduction without vascular compromise, most cases require some form of surgical stabilization following reduction, outcomes of worse outcomes are seen with nonoperative management/prolonged immobilization will lead to loss of ROM with persistent instability.
• Rest Your Leg – Once you’re discharged from the hospital in a legislating, your top priority is to rest your and not further inflame the injury. Of course, the arm sling not only provides support, but it also restricts movement, which is why you should keep it on even during sleep. Avoiding the temptation to move your will help the bone mend quicker and the pain fades away sooner.

Medication

• Antibiotic – Cefuroxime or Azithromycin, or  Flucloxacillin or any others cephalosporin/quinolone antibiotic must be used to prevent infection or clotted blood remove to prevent furthers swelling and edema
• NSAIDs – Prescription-strength drugs that reduce both pain and inflammation. Pain medicines and anti-inflammatory drugs help to relieve pain and stiffness, allowing for increased mobility and exercise. There are many common over-the-counter medicines called non-steroidal anti-inflammatory drugs (NSAIDs). They include and Ketorolac, Aceclofenac, Naproxen, Etoricoxib.
• Corticosteroids – Also known as oral steroids, these medications reduce inflammation.
• Muscle Relaxants –  These medications provide relief from associated muscle spasms.
• Neuropathic Agents – Drugs(pregabalin & gabapentin) that address neuropathic—or nerve-related—pain. This includes burning, numbness, and tingling.
• Opioids – Also known as narcotics, these medications are intense pain relievers that should only be used under a doctor’s careful supervision.
• Topical Medications – These prescription-strength creams, gels, ointments, patches, and sprays help relieve pain and inflammation through the skin.
• Calcium & vitamin D3 – to improve bone health and healing fracture. As a general rule, men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day.
• Glucosamine & Diacerein, Chondroitin sulfate – can be used to tightening the loose tension, cartilage, ligament, and cartilage, ligament regenerate cartilage or inhabit the further degeneration of cartilage, ligament
• Dietary supplement-to remove general weakness & improved health.
• Antidepressants – A drug that blocks pain messages from your brain and boosts the effects of endorphins (your body’s natural painkillers).

Surgical Treatment

Open reduction

• irreducible knee
• posterolateral dislocation
• open fracture-dislocation
• obesity (may be difficult to obtain closed)
• vascular injury

External fixation

• vascular repair (takes precedence)
• open fracture-dislocation
• compartment syndrome
• obese (if difficult to maintain reduction)
• polytrauma patient

Delayed ligamentous reconstruction/repair

• instability will require some kind of ligamentous repair or fixation
• patients can be placed in a knee immobilizer until treated operatively
• improved outcomes with early treatment (within 3 weeks)

Arthroscopy +/- open debridement

• Arthroscopic or open debridement with removal of any loose bodies may be necessary for displaced osteochondral fractures or loose bodies.

MPFL re-attachment or reconstruction (proximal realignment)

• Proximal realignment constitutes the reconstruction of the MPFL. In brief, to repair the ligament, a longitudinal incision is made at the border of the VMO, just anterior to the medial epicondyle. The ligament is usually re-attached to the femur using bone anchors. If the patient has had recurrent dislocations, then reconstruction may be necessary by harvesting gracilis or semitendinosus which are then attached to the patella and femur.
• Isolated repair/reconstruction of the MPFL is not a recommendation in those with bony abnormalities including TT-TG distance greater than 20mm, convex trochlear dysplasia, severe patella alta, advanced cartilage degeneration or severe femoral anteversion.[rx]

Lateral release (distal realignment)

• A lateral release cuts the retinaculum on the lateral aspect of the knee joint. The aim is to improve the alignment of the patella by reducing the lateral pull.

Osteotomy (distal realignment)

• Where there is abnormal anatomy contributing to poor patella tracking and a high TT-TG distance, the alignment correction can be through an osteotomy. The most common procedure of this type is known as the Fulkerson-type osteotomy and involves an osteotomy as well as removing the small portion of bone to which the tendon attaches and repositioning it in a more anteromedial position on the tibia.

Trochleoplasty

• Trochleoplasty is indicated in recurrent dislocators with a convex or flat trochlea. The trochlear groove is deepened to create a groove for the patella to glide through; this may take place alongside an MPFL reconstruction. Studies suggest it is not advisable in those with open growth plates or severely degenerative joints. This procedure is uncommon except in refractory cases.

Complications of Knee Posterior Dislocation

Vascular compromise

• incidence of – 5-15% in all dislocations. 40-50% in anterior or posterior dislocations
• risk factors – KD IV injuries have the highest rate of vascular injuries
• treatment-emergent vascular repair and prophylactic fasciotomies

Stiffness (arthrofibrosis)

• incidence – most common complication (38%)
• risk factors – more common with delayed mobilization
• avoid stiffness with early reconstruction and motion
• arthroscopic lysis of adhesion
• manipulation under anesthesia

Laxity and instability 

• incidence – 37% of some instability, however, redislocation is uncommon
• treatment – arthroscopic lysis of adhesion, manipulation under anesthesia

Peroneal nerve injury 

• incidence- 25% occurrence of a peroneal nerve injury, 50% recover partially
• posterolateral dislocations

Treatment

• A to prevent equinus contracture
• neurolysis or exploration at the time of reconstruction
• nerve repair or reconstruction or tendon transfers if chronic nerve palsy persists
• a dynamic tendon transfer involves transferring the posterior tibial tendon (PTT) to the foot

References

Knee Anterior Dislocation/Knee Dislocation is a potentially devastating injury and is often a surgical emergency. This injury requires prompt identification, evaluation with appropriate imaging, and consultation with surgery for definitive treatment. Vascular injury and compartment syndrome are dreaded complications that the clinician should not miss in the workup of a knee dislocation. Note that this is in distinct contrast to patellar dislocations, which generally do not require immediate surgical or vascular intervention.[rx][rx]

A knee dislocation is a knee injury in which there is a complete disruption of the joint between the tibia and the femur. Symptoms include knee pain and instability of the knee. Complications may include injury to an artery around the knee, most commonly the artery behind the knee, or compartment syndrome.^[rx][rx][rx]

Types /Classification of Knee Dislocation

They may be divided into five types: anterior, posterior, lateral, medial, and rotatory. This classification is based on the movement of the tibia with respect to the femur. Anterior dislocations are the most common, followed by posterior dislocations. They may also be classified based on what ligaments are damaged.^[rx]

Kennedy classification based on the direction of displacement of the tibia

Anterior (30-50%)

• most common
• due to hyperextension injury
• usually involves tear of PCL
• an arterial injury is generally an intimal tear due to traction
• the highest rate of peroneal nerve injury

Posterior (30-40%)

• 2nd most common
• due to axial load to the flexed knee (dashboard injury)

The highest rate of vascular injury (25%) based on Kennedy classification

• has highest incidence of a complete tear of the popliteal artery

Lateral (13%)

• due to a varus or valgus force
• usually involves tears of both ACL and PCL

Medial (3%)

• varus or valgus force
• usually disrupted PLC and PCL

Rotational (4%)

• posterolateral is most common rotational dislocation
• usually irreducible
• buttonholing of femoral condyle through the capsule

Anatomic Classification System

The letters C and N can be added to denote arterial and neurologic injury, respectively.

Schenck Classification

• based on a pattern of multi ligamentous injury of knee dislocation (KD)

• Car accidents – If you bang your knee against a hard surface like your dashboard, the force of the blow may be strong enough to dislocate your knee.
• Sports injuries – This is less common than car accidents, but it’s possible to dislocate your knee if you collide with great force with another player or with the ground when your knee is bent, or if you over-extend your knee (bend it back farther than it’s supposed to go).
• Hard falls – It may happen to skiers or runners who lose control and fall on a bent or overextended knee. You may even dislocate your knee if you fall after stepping into a hole in the ground by mistake.
• Result of major trauma – and about half occur as a result of minor trauma.^[rx] Major trauma may include mechanisms like falls from a significant height, motor vehicle collisions, or a pedestrian being hit by a motor vehicle.
• Genetic Disorder – often have other injuries.^[rx] Minor trauma may include tripping while walking or while playing sports. Risk factors include obesity.^[rx] The condition may also occur in a number of genetic disorders such as Ellis–van Creveld syndrome, Larsen syndrome, and Ehlers–Danlos syndrome.^[rx]
• Sudden forceful  fall down
• Road traffic accident
• Falls – Falling onto an outstretched hand is one of the most common causes of the broken or dislocation knee.
• Sports injuries – Many cervical spine fractures occur during contact sports or sports in which you might fall onto an outstretched hand — such as in-line skating or snowboarding.
• Motor vehicle crashes – Motor vehicle crashes can cause the knee dislocation to break, sometimes into many pieces, and often require surgical repair.
• Have osteoporosis –  a disease that weakens your bones
• Eave low muscle mass or poor muscle strength – or lack agility and have poor balance (these conditions make you more likely to fall)
• Walk or do other activities in the snow or on the ice – or do activities that require a lot of forwarding momenta, such as in-line skating and skiing.
• Previous fractures record.
• Wave an inadequate intake of calcium or vitamin D.
• Football or soccer, especially on artificial turf
• Athletic injury with a sports injury.

The ligamentum patellae. Attached above to the lower border of the patella and below to the tuberosity of the tibia. A continuation of the central portion of the common tendon of the quadriceps femoris muscle. The oblique popliteal ligament. A tendinous expansion derived from the semimembranosus muscle. It strengthens the posterior aspect of the capsule.

Symptoms of Knee Dislocation

• Symptoms include knee pain. The joint may also be obviously out of place. A joint effusion is not always present.^[rx]
• Hearing a “popping” sound at the time of injury
• Severe pain in the area of the knee
• A visible deformity at the knee joint
• Instability of the knee joint, or feeling like your knee joint is “giving way”
• Limitations in the range of movement of your knee
• Inability to continue with activities, whether they involve day-to-day tasks or sports
• Feeling the kneecap shift or slide out of the groove
• Feeling the knee buckle or give way
• Hearing a popping sound when the patella dislocates
• Swelling
• A change in the knee’s appearance — the knee may appear misshapen or deformed
• Apprehension or fear when running or changing direction.

Diagnosis of Knee Dislocation

Vascular exam (especially popliteal artery distribution)

Perfusion Assessment

• Dorsalis pedis pulse
• Posterior tibial pulse
• Capillary Refill
• Ankle-Brachial Index (ABI) – Normal ABI (as well as pulses, Capillary Refill) may not exclude popliteal artery disruption

Hard signs of vascular injury

• Distal pulse loss or ischemia (e.g. pallor, coolness)
• Active bleeding
• Expanding hematoma
• Palpable thrill or bruit over the popliteal artery

Neurologic Exam (especially peroneal nerve)

• First web space and dorsal foot sensation
• Ankle dorsiflexion

Multidirectional instability

• Multidirectional instability may be only finding if knee spontaneously reduced prior to presentation
• Three of four ligaments are likely injured (ACL Tear, PCL Tear, LCL tear, MCL tear)

Skin changes

• Dimple Sign – Anteromedial skinfold at medial joint line. Seen in posterolateral dislocation (not reducible without surgery)
• Skin necrosis – Entrapped skin at femoral condyle
• Overlying Laceration – Suggests open Knee Dislocation (accompanies 20-30% of Knee Dislocations)

Others exam may include

• Checking the pulse in several places on your leg and knee – This is called checking posterior tibial and dorsal pedal pulses, which are located in the region of the knee and foot. Lower pulses in your injured leg could indicate an injury to a blood vessel in your leg.
• Checking the blood pressure in your leg – Called the ankle-brachial index (ABI), this test compares the blood pressure measured in your arm to the blood pressure measured in your ankle. A low ABI measurement can indicate poor blood flow to your lower extremities.
• Checking your sense of touch or sensation – Your doctor will assess the feeling in the injured leg versus the unaffected leg.
• Checking nerve conduction – Tests like electromyography (EMG) or nerve conduction velocity (NCV) will measure the function of the nerves in your leg and knee.
• Checking your skin color and temperature – If your leg is cold or changing colors, there may be blood vessel problems.
• X-rays – These tests create clear pictures of bone. Your doctor may order x-rays to look for skeletal abnormalities in the knee, such as a shallow groove in the femur.
• Magnetic resonance imaging (MRI) scans – These scans create better pictures of the soft structures surrounding the knee, like ligaments. An MRI is seldom necessary because the doctor can usually diagnose a dislocated patella through an examination and x-rays. However, if your doctor needs additional, more detailed images, he or she may order an MRI.

^{Treatment of Knee Dislocation}

Nonoperative

• Immobilization – Your doctor may recommend that your child wear a brace for 3 to 4 weeks. This stabilizes the knee while it heals.
• Weightbearing –  Because putting weight on the knee may cause pain and slow the healing process, your doctor may recommend using crutches for the first week or two after the injury.
• Physical therapy – Once the knee has started to heal, your child’s doctor will recommend physical therapy to help your child regain normal motion. Specific exercises will strengthen the thigh muscles holding the knee joint in place. Your child’s commitment to the exercise program is important for a successful recovery. Typically, children return to activity 3 to 6 weeks after the injury.
• Emergent closed reduction followed by vascular assessment/consult – indications to considered an orthopedic emergency, vascular consult indicated if pulses are absent or diminished following reduction if arterial injury confirmed by arterial duplex ultrasound or CT angiography
• Immobilization as definitive management – successful closed reduction without vascular compromise, most cases require some form of surgical stabilization following reduction, outcomes of worse outcomes are seen with nonoperative management/prolonged immobilization will lead to loss of ROM with persistent instability.
• Rest Your Leg – Once you’re discharged from the hospital in a legislating, your top priority is to rest your and not further inflame the injury. Of course, the arm sling not only provides support, but it also restricts movement, which is why you should keep it on even during sleep. Avoiding the temptation to move your will help the bone mend quicker and the pain fades away sooner.

Medication

• Antibiotic – Cefuroxime or Azithromycin, or  Flucloxacillin or any others cephalosporin/quinolone antibiotic must be used to prevent infection or clotted blood remove to prevent furthers swelling and edema
• NSAIDs – Prescription-strength drugs that reduce both pain and inflammation. Pain medicines and anti-inflammatory drugs help to relieve pain and stiffness, allowing for increased mobility and exercise. There are many common over-the-counter medicines called non-steroidal anti-inflammatory drugs (NSAIDs). They include and Ketorolac, Aceclofenac, Naproxen, Etoricoxib.
• Corticosteroids – Also known as oral steroids, these medications reduce inflammation.
• Muscle Relaxants –  These medications provide relief from associated muscle spasms.
• Neuropathic Agents – Drugs(pregabalin & gabapentin) that address neuropathic—or nerve-related—pain. This includes burning, numbness, and tingling.
• Opioids – Also known as narcotics, these medications are intense pain relievers that should only be used under a doctor’s careful supervision.
• Topical Medications – These prescription-strength creams, gels, ointments, patches, and sprays help relieve pain and inflammation through the skin.
• Calcium & vitamin D3 – to improve bone health and healing fracture. As a general rule, men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day.
• Glucosamine & Diacerein, Chondroitin sulfate – can be used to tightening the loose tension, cartilage, ligament, and cartilage, ligament regenerate cartilage or inhabit the further degeneration of cartilage, ligament
• Dietary supplement-to remove general weakness & improved health.
• Antidepressants – A drug that blocks pain messages from your brain and boosts the effects of endorphins (your body’s natural painkillers).

Surgical Treatment

Open reduction

• irreducible knee
• posterolateral dislocation
• open fracture-dislocation
• obesity (may be difficult to obtain closed)
• vascular injury

External fixation

• vascular repair (takes precedence)
• open fracture-dislocation
• compartment syndrome
• obese (if difficult to maintain reduction)
• polytrauma patient

Delayed ligamentous reconstruction/repair

• instability will require some kind of ligamentous repair or fixation
• patients can be placed in a knee immobilizer until treated operatively
• improved outcomes with early treatment (within 3 weeks)

Arthroscopy +/- open debridement

• Arthroscopic or open debridement with removal of any loose bodies may be necessary for displaced osteochondral fractures or loose bodies.

MPFL re-attachment or reconstruction (proximal realignment)

• Proximal realignment constitutes the reconstruction of the MPFL. In brief, to repair the ligament, a longitudinal incision is made at the border of the VMO, just anterior to the medial epicondyle. The ligament is usually re-attached to the femur using bone anchors. If the patient has had recurrent dislocations, then reconstruction may be necessary by harvesting gracilis or semitendinosus which are then attached to the patella and femur.
• Isolated repair/reconstruction of the MPFL is not a recommendation in those with bony abnormalities including TT-TG distance greater than 20mm, convex trochlear dysplasia, severe patella alta, advanced cartilage degeneration or severe femoral anteversion.[rx]

Lateral release (distal realignment)

• A lateral release cuts the retinaculum on the lateral aspect of the knee joint. The aim is to improve the alignment of the patella by reducing the lateral pull.

Osteotomy (distal realignment)

• Where there is abnormal anatomy contributing to poor patella tracking and a high TT-TG distance, the alignment correction can be through an osteotomy. The most common procedure of this type is known as the Fulkerson-type osteotomy and involves an osteotomy as well as removing the small portion of bone to which the tendon attaches and repositioning it in a more anteromedial position on the tibia.

Trochleoplasty

• Trochleoplasty is indicated in recurrent dislocators with a convex or flat trochlea. The trochlear groove is deepened to create a groove for the patella to glide through; this may take place alongside an MPFL reconstruction. Studies suggest it is not advisable in those with open growth plates or severely degenerative joints. This procedure is uncommon except in refractory cases.

Complications of Knee Anterior Dislocation

Vascular compromise

• incidence of – 5-15% in all dislocations. 40-50% in anterior or posterior dislocations
• risk factors – KD IV injuries have the highest rate of vascular injuries
• treatment-emergent vascular repair and prophylactic fasciotomies

Stiffness (arthrofibrosis)

• incidence – most common complication (38%)
• risk factors – more common with delayed mobilization
• avoid stiffness with early reconstruction and motion
• arthroscopic lysis of adhesion
• manipulation under anesthesia

Laxity and instability 

• incidence – 37% of some instability, however, redislocation is uncommon
• treatment – arthroscopic lysis of adhesion, manipulation under anesthesia

Peroneal nerve injury 

• incidence- 25% occurrence of a peroneal nerve injury, 50% recover partially
• posterolateral dislocations

Treatment

• A to prevent equinus contracture
• neurolysis or exploration at the time of reconstruction
• nerve repair or reconstruction or tendon transfers if chronic nerve palsy persists
• a dynamic tendon transfer involves transferring the posterior tibial tendon (PTT) to the foot

References

Types /Classification of Knee Dislocation/Knee Dislocation is a potentially devastating injury and is often a surgical emergency. This injury requires prompt identification, evaluation with appropriate imaging, and consultation with surgery for definitive treatment. Vascular injury and compartment syndrome are dreaded complications that the clinician should not miss in the workup of a knee dislocation. Note that this is in distinct contrast to patellar dislocations, which generally do not require immediate surgical or vascular intervention.[rx][rx]

A knee dislocation is a knee injury in which there is a complete disruption of the joint between the tibia and the femur. Symptoms include knee pain and instability of the knee. Complications may include injury to an artery around the knee, most commonly the artery behind the knee, or compartment syndrome.^[rx][rx][rx]

Types /Classification of Knee Dislocation

They may be divided into five types: anterior, posterior, lateral, medial, and rotatory. This classification is based on the movement of the tibia with respect to the femur. Anterior dislocations are the most common, followed by posterior dislocations. They may also be classified based on what ligaments are damaged.^[rx]

Kennedy classification based on the direction of displacement of the tibia

Anterior (30-50%)

• most common
• due to hyperextension injury
• usually involves tear of PCL
• an arterial injury is generally an intimal tear due to traction
• the highest rate of peroneal nerve injury

Posterior (30-40%)

• 2nd most common
• due to axial load to the flexed knee (dashboard injury)

The highest rate of vascular injury (25%) based on Kennedy classification

• has highest incidence of a complete tear of the popliteal artery

Lateral (13%)

• due to a varus or valgus force
• usually involves tears of both ACL and PCL

Medial (3%)

• varus or valgus force
• usually disrupted PLC and PCL

Rotational (4%)

• posterolateral is most common rotational dislocation
• usually irreducible
• buttonholing of femoral condyle through the capsule

Anatomic Classification System

The letters C and N can be added to denote arterial and neurologic injury, respectively.

Schenck Classification

• based on a pattern of multi ligamentous injury of knee dislocation (KD)

• Car accidents – If you bang your knee against a hard surface like your dashboard, the force of the blow may be strong enough to dislocate your knee.
• Sports injuries – This is less common than car accidents, but it’s possible to dislocate your knee if you collide with great force with another player or with the ground when your knee is bent, or if you over-extend your knee (bend it back farther than it’s supposed to go).
• Hard falls – It may happen to skiers or runners who lose control and fall on a bent or overextended knee. You may even dislocate your knee if you fall after stepping into a hole in the ground by mistake.
• Result of major trauma – and about half occur as a result of minor trauma.^[rx] Major trauma may include mechanisms like falls from a significant height, motor vehicle collisions, or a pedestrian being hit by a motor vehicle.
• Major trauma – often have other injuries.^[rx] Minor trauma may include tripping while walking or while playing sports. Risk factors include obesity.^[rx] The condition may also occur in a number of genetic disorders such as Ellis–van Creveld syndrome, Larsen syndrome, and Ehlers–Danlos syndrome.^[rx]
• Sudden forceful  fall down
• Road traffic accident
• Falls – Falling onto an outstretched hand is one of the most common causes of the broken or dislocation knee.
• Sports injuries – Many cervical spine fractures occur during contact sports or sports in which you might fall onto an outstretched hand — such as in-line skating or snowboarding.
• Motor vehicle crashes – Motor vehicle crashes can cause the knee dislocation to break, sometimes into many pieces, and often require surgical repair.
• Have osteoporosis –  a disease that weakens your bones
• Eave low muscle mass or poor muscle strength – or lack agility and have poor balance (these conditions make you more likely to fall)
• Walk or do other activities in the snow or on the ice – or do activities that require a lot of forwarding momenta, such as in-line skating and skiing.
• Previous fractures record.
• Wave an inadequate intake of calcium or vitamin D.
• Football or soccer, especially on artificial turf
• Athletic injury with a sports injury.

The ligamentum patellae. Attached above to the lower border of the patella and below to the tuberosity of the tibia. A continuation of the central portion of the common tendon of the quadriceps femoris muscle. The oblique popliteal ligament. A tendinous expansion derived from the semimembranosus muscle. It strengthens the posterior aspect of the capsule.

Symptoms of Knee Dislocation

• Symptoms include knee pain. The joint may also be obviously out of place. A joint effusion is not always present.^[rx]
• Hearing a “popping” sound at the time of injury
• Severe pain in the area of the knee
• A visible deformity at the knee joint
• Instability of the knee joint, or feeling like your knee joint is “giving way”
• Limitations in the range of movement of your knee
• Inability to continue with activities, whether they involve day-to-day tasks or sports
• Feeling the kneecap shift or slide out of the groove
• Feeling the knee buckle or give way
• Hearing a popping sound when the patella dislocates
• Swelling
• A change in the knee’s appearance — the knee may appear misshapen or deformed
• Apprehension or fear when running or changing direction.

Diagnosis of Knee Dislocation

Vascular exam (especially popliteal artery distribution)

Perfusion Assessment

• Dorsalis pedis pulse
• Posterior tibial pulse
• Capillary Refill
• Ankle-Brachial Index (ABI) – Normal ABI (as well as pulses, Capillary Refill) may not exclude popliteal artery disruption

Hard signs of vascular injury

• Distal pulse loss or ischemia (e.g. pallor, coolness)
• Active bleeding
• Expanding hematoma
• Palpable thrill or bruit over the popliteal artery

Neurologic Exam (especially peroneal nerve)

• First web space and dorsal foot sensation
• Ankle dorsiflexion

Multidirectional instability

• Multidirectional instability may be only finding if knee spontaneously reduced prior to presentation
• Three of four ligaments are likely injured (ACL Tear, PCL Tear, LCL tear, MCL tear)

Skin changes

• Dimple Sign – Anteromedial skinfold at medial joint line. Seen in posterolateral dislocation (not reducible without surgery)
• Skin necrosis – Entrapped skin at femoral condyle
• Overlying Laceration – Suggests open Knee Dislocation (accompanies 20-30% of Knee Dislocations)

Others exam may include

• Checking the pulse in several places on your leg and knee – This is called checking posterior tibial and dorsal pedal pulses, which are located in the region of the knee and foot. Lower pulses in your injured leg could indicate an injury to a blood vessel in your leg.
• Checking the blood pressure in your leg – Called the ankle-brachial index (ABI), this test compares the blood pressure measured in your arm to the blood pressure measured in your ankle. A low ABI measurement can indicate poor blood flow to your lower extremities.
• Checking your sense of touch or sensation – Your doctor will assess the feeling in the injured leg versus the unaffected leg.
• Checking nerve conduction – Tests like electromyography (EMG) or nerve conduction velocity (NCV) will measure the function of the nerves in your leg and knee.
• Checking your skin color and temperature – If your leg is cold or changing colors, there may be blood vessel problems.
• X-rays – These tests create clear pictures of bone. Your doctor may order x-rays to look for skeletal abnormalities in the knee, such as a shallow groove in the femur.
• Magnetic resonance imaging (MRI) scans – These scans create better pictures of the soft structures surrounding the knee, like ligaments. An MRI is seldom necessary because the doctor can usually diagnose a dislocated patella through an examination and x-rays. However, if your doctor needs additional, more detailed images, he or she may order an MRI.

^{Treatment of Knee Dislocation}

Nonoperative

• Immobilization – Your doctor may recommend that your child wear a brace for 3 to 4 weeks. This stabilizes the knee while it heals.
• Weightbearing –  Because putting weight on the knee may cause pain and slow the healing process, your doctor may recommend using crutches for the first week or two after the injury.
• Physical therapy – Once the knee has started to heal, your child’s doctor will recommend physical therapy to help your child regain normal motion. Specific exercises will strengthen the thigh muscles holding the knee joint in place. Your child’s commitment to the exercise program is important for a successful recovery. Typically, children return to activity 3 to 6 weeks after the injury.
• Emergent closed reduction followed by vascular assessment/consult – indications to considered an orthopedic emergency, vascular consult indicated if pulses are absent or diminished following reduction if arterial injury confirmed by arterial duplex ultrasound or CT angiography
• Immobilization as definitive management – successful closed reduction without vascular compromise, most cases require some form of surgical stabilization following reduction, outcomes of worse outcomes are seen with nonoperative management/prolonged immobilization will lead to loss of ROM with persistent instability.
• Rest Your Leg – Once you’re discharged from the hospital in a legislating, your top priority is to rest your and not further inflame the injury. Of course, the arm sling not only provides support, but it also restricts movement, which is why you should keep it on even during sleep. Avoiding the temptation to move your will help the bone mend quicker and the pain fades away sooner.

Medication

• Antibiotic – Cefuroxime or Azithromycin, or  Flucloxacillin or any others cephalosporin/quinolone antibiotic must be used to prevent infection or clotted blood remove to prevent furthers swelling and edema
• NSAIDs – Prescription-strength drugs that reduce both pain and inflammation. Pain medicines and anti-inflammatory drugs help to relieve pain and stiffness, allowing for increased mobility and exercise. There are many common over-the-counter medicines called non-steroidal anti-inflammatory drugs (NSAIDs). They include and Ketorolac, Aceclofenac, Naproxen, Etoricoxib.
• Corticosteroids – Also known as oral steroids, these medications reduce inflammation.
• Muscle Relaxants –  These medications provide relief from associated muscle spasms.
• Neuropathic Agents – Drugs(pregabalin & gabapentin) that address neuropathic—or nerve-related—pain. This includes burning, numbness, and tingling.
• Opioids – Also known as narcotics, these medications are intense pain relievers that should only be used under a doctor’s careful supervision.
• Topical Medications – These prescription-strength creams, gels, ointments, patches, and sprays help relieve pain and inflammation through the skin.
• Calcium & vitamin D3 – to improve bone health and healing fracture. As a general rule, men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day.
• Glucosamine & Diacerein, Chondroitin sulfate – can be used to tightening the loose tension, cartilage, ligament, and cartilage, ligament regenerate cartilage or inhabit the further degeneration of cartilage, ligament
• Dietary supplement-to remove general weakness & improved health.
• Antidepressants – A drug that blocks pain messages from your brain and boosts the effects of endorphins (your body’s natural painkillers).

Surgical Treatment

Open reduction

• irreducible knee
• posterolateral dislocation
• open fracture-dislocation
• obesity (may be difficult to obtain closed)
• vascular injury

External fixation

• vascular repair (takes precedence)
• open fracture-dislocation
• compartment syndrome
• obese (if difficult to maintain reduction)
• polytrauma patient

Delayed ligamentous reconstruction/repair

• instability will require some kind of ligamentous repair or fixation
• patients can be placed in a knee immobilizer until treated operatively
• improved outcomes with early treatment (within 3 weeks)

Arthroscopy +/- open debridement

• Arthroscopic or open debridement with removal of any loose bodies may be necessary for displaced osteochondral fractures or loose bodies.

MPFL re-attachment or reconstruction (proximal realignment)

• Proximal realignment constitutes the reconstruction of the MPFL. In brief, to repair the ligament, a longitudinal incision is made at the border of the VMO, just anterior to the medial epicondyle. The ligament is usually re-attached to the femur using bone anchors. If the patient has had recurrent dislocations, then reconstruction may be necessary by harvesting gracilis or semitendinosus which are then attached to the patella and femur.
• Isolated repair/reconstruction of the MPFL is not a recommendation in those with bony abnormalities including TT-TG distance greater than 20mm, convex trochlear dysplasia, severe patella alta, advanced cartilage degeneration or severe femoral anteversion.[rx]

Lateral release (distal realignment)

• A lateral release cuts the retinaculum on the lateral aspect of the knee joint. The aim is to improve the alignment of the patella by reducing the lateral pull.

Osteotomy (distal realignment)

• Where there is abnormal anatomy contributing to poor patella tracking and a high TT-TG distance, the alignment correction can be through an osteotomy. The most common procedure of this type is known as the Fulkerson-type osteotomy and involves an osteotomy as well as removing the small portion of bone to which the tendon attaches and repositioning it in a more anteromedial position on the tibia.

Trochleoplasty

• Trochleoplasty is indicated in recurrent dislocators with a convex or flat trochlea. The trochlear groove is deepened to create a groove for the patella to glide through; this may take place alongside an MPFL reconstruction. Studies suggest it is not advisable in those with open growth plates or severely degenerative joints. This procedure is uncommon except in refractory cases.

Complications of Knee Dislocation

Vascular compromise

• incidence of – 5-15% in all dislocations. 40-50% in anterior or posterior dislocations
• risk factors – KD IV injuries have the highest rate of vascular injuries
• treatment-emergent vascular repair and prophylactic fasciotomies

Stiffness (arthrofibrosis)

• incidence – most common complication (38%)
• risk factors – more common with delayed mobilization
• avoid stiffness with early reconstruction and motion
• arthroscopic lysis of adhesion
• manipulation under anesthesia

Laxity and instability 

• incidence – 37% of some instability, however, redislocation is uncommon
• treatment – arthroscopic lysis of adhesion, manipulation under anesthesia

Peroneal nerve injury 

• incidence- 25% occurrence of a peroneal nerve injury, 50% recover partially
• posterolateral dislocations

Treatment

• A to prevent equinus contracture
• neurolysis or exploration at the time of reconstruction
• nerve repair or reconstruction or tendon transfers if chronic nerve palsy persists
• a dynamic tendon transfer involves transferring the posterior tibial tendon (PTT) to the foot

References