Posterior Hip Dislocation – Causes, Symptoms, Treatment

Posterior Hip Dislocation in approximately 90% of hip dislocation patients, the thighbone is pushed out of the socket in a backward direction. This is called a posterior dislocation. A posterior dislocation leaves the lower leg in a fixed position, with the knee and foot rotated in toward the middle of the body.

What Is Hip Dislocations?/Hip Dislocations after trauma are frequently encountered in the emergency setting. A significant force is generally required to dislocate a hip as this ball and socket joint is quite stable due to its bony structure and the associated muscular and ligamentous attachments. Due to the required force, hip dislocations often are associated with other significant injuries; for example, fractures are found in over 50% of these patients. The majority of all hip dislocations are due to motor vehicle accidents. Posterior hip dislocations are the most common type, with anterior occurring only about 10% of the time. These injuries are true orthopedic emergencies and should be reduced expediently. The majority will resolve with a closed reduction in the emergency department.[rx][rx][rx]

Hip instability is a loose or wobbly hip joint that’s usually caused by problems with the ligaments (the bands of connective tissue that hold bones or joints together).

Causes of Hip Dislocations

• Acquired – Acquired hip dislocation is normally associated with high-speed trauma, with motor vehicle collisions account half of the dislocation with other causes such as falls and sports injuries, less common. Hip dislocation is the second most common complication of hip joint replacements and occurs in ~5% (range 0.5-10%) of patients with ~60% of dislocations being recurrent.
• Congenital – Congenital hip dislocation is now considered part of the spectrum of developmental dysplasia of the hip (see the article for further information).
• Forceful thrust – Anterior hip dislocations are usually the result of a significant force, such as trauma, or from a poorly positioned total hip arthroplasty.
• In a traumatic setting – the hip is forced into abduction with external rotation of the thigh and often related to a motor vehicle accident or fall. [rx]
• Falls – Falling onto an outstretched hand is one of the most common causes of hip dislocation.
• Sports injuries – Many hip dislocation occurs 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 dislocation of the hip.
• 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
• Wave an inadequate intake of calcium or vitamin D
• Football or soccer, especially on artificial turf
• Rugby
• Horseback riding
• Hockey

Symptoms of Hip Dislocations

In an accident victim, a traumatic hip dislocation can cause the following symptoms

• There is severe hip pain, especially when the leg is moved.
• The injured leg is shorter than the uninjured leg.
• The injured leg lies in an abnormal position. In most cases, the leg is bent at the hip, turned inward and pulled toward the middle of the body.
• There can be swelling at the site of the injury. The surrounding skin is puffy.
• Hip immobility Patients can experience difficulty moving the affected hip and so the inability to walk because of the pain and swelling.
• Hear snapping, clicking or popping sounds or sensations (crepitus) in any part of the hip
• Experience hip pain or pain in the groin
• Can’t put weight on your hip
• Can no longer walk normally
• The affected limb is shortened, adducted, and internally rotated, with the hip and knee in slight flexion
• Pain in the hip, buttock, and posterior leg
• Loss of sensation in posterior leg and foot
• Loss of dorsiflexion (peroneal branch) or plantar flexion (tibial branch)
• Loss of deep tendon reflexes (DTRs) at the ankle
• Local hematoma

Diagnosis of Hip Dislocations

History and Physical

Patients with hip dislocations generally arrive in severe pain in the hip area; however, reports of pain in the knee, lower back, thigh, or even lower abdomen or pelvis are not uncommon. It is important to note that additional bony leg injuries may alter this classic presentation.

• Neurovascular exam –  is also required. Injuries to the femoral artery, vein, or nerve may rarely occur with anterior dislocations and should also be sought out. Femoral nerve motor function may be difficult to assess fully due to pain and the nature of this injury; however, sensory deficits over the anteromedial aspect of the thigh and medial side of the leg and foot should raise suspicion. Sciatic nerve injuries occur more often with posterior dislocations; however, they should be ruled out in any hip dislocation or fracture. Due to the required mechanism of injury related to these dislocations, a full trauma evaluation for other associated injuries should be considered.

Imaging

• X-rays – Hip dislocations usually are obvious on standard AP (anteroposterior) images of the pelvis. However, complete imaging usually includes a cross-table lateral of the affected joint.  On a normal AP pelvis, the femoral heads should appear similar in size with symmetric joint spaces. The joint with an anterior dislocation will project a larger-appearing femoral head. A femoral neck fracture should be ruled out by this image prior to attempting reduction. Judet views (45 degree internal and external oblique views) may be of some help in evaluating for bone fragments and occult acetabular and femoral head and neck fractures.
• Arthrogram – An arthrogram uses dye injected into the hip joint before X-rays or other scans. This dye helps your doctor clearly see details of the joint’s condition.
• Computed tomography – CT (Computed tomography) is recommended after a successful, closed hip reduction to evaluate for occult fractures. It may also further elucidate the cause of postreduction joint space widening and find intra-articular bone fragments or soft tissue injury that may prevent appropriate joint articulation. Moreta et al. found loose bodies in 20% of the hips that underwent post-reduction CT.[rx]
• MRI – MRI may be indicated to evaluate for soft tissue injuries and cartilaginous bodies that continue to cause issues after the acute period. Osteonecrosis also may be seen in the subacute period (4 to 8 weeks), and some have suggested that MRI is superior to CT for children with hip injuries as CT may miss unossified labrum and acetabular fractures.
• Other Testing – Laboratory studies should be tailored to the individual patient; however, if significant blood loss is suspected due to femoral vessel injury, serial hemoglobin/hematocrit and a type and screen may be requested.

Treatment of Hip Dislocations

Non – Pharmacological

Immediately following the injury, the RICE method is recommended

• Rest – Activities that cause hip pain, such as running or walking for long periods of time, should be avoided until pain and swelling go away. The activity that caused the injury should be avoided until fully recovered.
• Ice – A person may wish to apply ice packs to the area to help reduce pain and swelling. Ice packs can be applied several times throughout the day for about 10 to 20 minutes at a time.
• Compression – Swelling can be managed by wearing an elastic bandage around the affected hip.
• Elevation – Keeping the knee elevated and supported above the waist—for example, sitting in a recliner or lying down with the knee propped up on pillows—may help with swelling.
• Use crutches – to avoid weight-bearing. Crutches are not needed in all cases. Dispense crutches; allow weight-bearing as tolerated.

Medication

If pain is severe and intolerable following medicine may be considered to prescribe to control pain and healing.

• Antibiotic – Cefuroxime or Azithromycin, or  Flucloxacillin or any other 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.
• 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).
• Glucosamine & Diacerein, Chondroitin sulfate – can be used to tightening the loose tension, cartilage, ligament, and cartilage, ligament regenerates cartilage or inhabits the further degeneration of cartilage, ligament. They are structural components of articular cartilage, and the thought is that a supplement will aid in the health of articular cartilage.
• Vitamin C – It essential to healing fracture and soft tissue infection.

Open Reduction

Indications for Open Reduction

• A nonconcentric reduction (indicating a retained loose body or significant soft tissue injury preventing proper reduction)
• An associated acetabular or femoral head fracture that will require an open repair
• Femoral neck fracture
• A dislocation that is not reducible by closed reduction techniques

Patients who do not warrant an open reduction should have an urgent closed reduction in the emergency department under procedural sedation.

Anterior Hip Dislocation Reduction Techniques

Allis Maneuver

The Allis Maneuver is the most common method performed and differs slightly from the Allis maneuver used for posterior hip reductions. The patient lies supine with the practitioner standing over them. An assistant stabilizes the pelvis by applying pressure over the bilateral anterior superior iliac spines. The practitioner holds the affected leg just below the knee and, while slightly flexing the hip, applies constant traction to the hip joint along the long axis. The hip may be internally rotated and adducted. A gentle lateral force to the thigh may be of some assistance. The reduction is performed until an audible click is heard, suggesting a successful reduction.

“Captain Morgan” Technique

The “Captain Morgan” Technique is a more novel approach named after the character on the spirit bottle. The patient lies supine with both the knee and hip flexed. The practitioner positioned their foot on the patient’s stretcher with their knee bent (hence the “Captain Morgan” moniker) and positioned behind the patient’s knee. The practitioner places a hand under the patient’s knee and the other on their ankle. With the first hand, the practitioner lifts the patient’s femur while plantar flexing their ankle to raise the patient’s femur. The practitioner then applies gentle downward pressure over the patient’s ankle. This “leverages” the hip back into place. Stabilization of the pelvis by a strap or an assistant may be helpful.

Reverse Bigelow Maneuver

The patient is positioned supine with the hip partially flexed and abducted. A firm jerk is then applied to the thigh. Another variation has the practitioner apply traction longitudinally with hip adducted and apply abrupt internal rotation and extension of the hip

Stimson Maneuver

This technique also is less frequently used due to difficult patient positioning; however, it is often suggested to be a less traumatic process. The patient is placed in the prone position with the affected leg allowed to hang from the side of the bed; the knee and hip are flexed while an assistant stabilizes the patient’s lower back. Traction is applied downward by the practitioner who is holding the leg just below the knee. This allows gravity to assist with the traction. Internal and external rotation are applied until a successful reduction is felt.

Open Reduction

• Multiple surgical approaches for reducing an anterior hip joint are possible; however, all require joint irrigation to remove any bony or soft tissue structures that would prevent a concentric reduction. Postoperatively reduced hips should be held in traction for 6 to 8 weeks, until definitive fixation, or until the pain has entirely resolved.

Rehabilitation

Hip dislocation rehabilitation can take anywhere from two to three months, depending on the person. Complications to nearby nerves and blood vessels can sometimes cause loss of blood supply to the bone, also known as osteonecrosis. The protective cartilage on the bone can also be disturbed by this type of injury. For this reason, it is important for people to contact a physician and get treatment immediately following injury.^[rx]

• The first step to recovering from a hip dislocation is a reduction. This refers to putting the bones back into their intended positions. Normally, this is done by a physician while the person is under a sedative. Other times, a surgical procedure is required to reduce the hip bones back into their natural state.^[rx]
• Next, rest, ice, and take anti-inflammatory medication to reduce swelling at the hip.
• Weight-bearing is allowed for the type one posterior dislocation, but should only be done as pain allows and the person is comfortable.^[rx]
• Within 5–7 days of the injury occurrence, people may perform passive range of motion exercises to increase flexibility.
• A walking aid should be used until the person is comfortable with both weight-bearing and range of motion.^[rx]

Exercises

Individuals suffering from hip dislocation should participate in physical therapy and receive professional prescriptive exercises based on their individual abilities, progress, and overall range of motion. The following are some typically recommended exercises used as rehabilitation for hip dislocation. It is important to understand that each individual has different capabilities that can best be assessed by a physical therapist or medical professional, and that these are simply recommendations.

• Bridge- Lie flat on the back. Place arms with palms down beside the body. Keep feet hip-distance apart and bend knees. Slowly lift hips upward. Hold the position for three to five seconds. This helps strengthen the glutes and increase the stability of the hip joint.^[rx]
• Supine leg abduction – Lie flat on the back. Slowly slide leg away from the body and then back in, keeping the knees straight. This exercises the gluteus medius and helps to maintain stability in the hip while walking.^[rx]
• Side-Lying Leg abduction – Lie on one side with one leg on top of the other. Slowly lift the top leg towards the ceiling and then lower it back down slowly.^[rx]
• Standing Hip abduction – Standing up and holding on to a nearby surface, slowly lift one leg away from the midline of the body and then lower it back to starting position. This is simply a more advanced way to do any of the lying hip abduction exercises and should be done as the person progresses in rehab.^[rx]
• Knee raises – While standing and holding onto a chair, slowly lift one leg off the ground and bring it closer to the body while bending the knee. Then lower the leg back down slowly. This helps to strengthen the hip flexor muscles and retain stability in the hip.^[rx]
• Hip flexion and extensions – Standing, hold on to a nearby chair or surface. Swing one leg forwards away from you, and hold the position for three to five seconds. Then swing the leg slowly backward and behind your body. Hold for three to five seconds. This exercise helps to increase range of motion, as well as strengthening the hip flexor and hip extensor muscles that control much of the hip joint.^[rx]
• Adding ankle weights – to any exercises can be done as progress is made in rehabilitation.

Complications

• Femoral head trauma – Anterior hip dislocations commonly are associated with femoral head trauma and therefore have a higher incidence of long-term decreased functional outcomes and post-traumatic arthritis. Moreta et al. found that 13.3% of patients that suffered a complex dislocation had radiographic signs of osteoarthritis.[rx] Approximately 50% of all anterior dislocations have femoral head indentation fractures; however, patients without these associated fractures often have an excellent, long-term outcome.
• Osteonecrosis – This complication ranges from 5% to 40% of all hip dislocations but is related to the time before the joint’s reduction, with over 6 hours increasing the risk. Up to 20% of all traumatic hip dislocations will suffer osteonecrosis of the hip. [rx]
• Thromboembolism – Patients are at an increased risk of thromboembolism due to both immobility post-injury and due to vascular intima injury related to traction. Rezaie et al. found a 0.5% risk of venous thromboembolism after a surgical hip dislocation. Prophylaxis should be the standard for this group. [rx]
• Recurrent dislocation – This occurs in approximately 2% of patients. Itokawa et al. found that 40% of patients who dislocated after total hip arthroplasty, suffered repeat hip dislocations. [rx]
• Neurovascular injury –  Although the injury to the femoral nerve or vasculature has been reported, it remains relatively rare. Cornwall et al. found 10% of adults and 5% of children will suffer neuropraxia following hip dislocation. Fortunately, 60-70% of patients had partial resolution of symptoms. [rx]

References