Trendelenburg Gait – Causes, Symptoms, Diagnosis, Treatment

Trendelenburg gait is an abnormal gait resulting from a defective hip abductor mechanism. The primary musculature involved is the gluteal musculature, including the gluteus medius and gluteus minimus muscles. The weakness of these muscles causes drooping of the pelvis to the contralateral side while walking. The gait gets its name from a German surgeon, Friedrich Trendelenburg, who first reported the test related to this gait in 1895. The physical examination test described by him is useful to uncover hip abductor weakness in a patient with developmental dysplasia of the hip.[rx]

The hip joint and its abductor mechanism behave like a class 3 lever with the effort and the load on the same side of the fulcrum.[rx]

Pathophysiology

The center of gravity of the body passes midway through the pubic symphysis. When one foot lifts off the ground, as during swing phase of the gait cycle, the body remains unsupported on that side, and the pelvis tends to drop to the unsupported side. To prevent the drop, the abductor muscles mainly the gluteus medius and minimus on the supported side contract, providing stabilization of the superimposed trunk.[rx] If there is any damage to the hip and its abductor mechanism due to the causes mentioned above, there will be drooping of the pelvis on the opposite side of the pathology.

Causes of Trendelenburg Gait

Any pathology of the fulcrum, load, effort, or the lever which binds all three will lead to a positive Trendelenburg gait.

Failure of the fulcrum presents in the following conditions

• Osteonecrosis of hip
• Legg-Calve-Perthes disease
• Developmental dysplasia of the hip
• Chronically dislocated hips secondary to trauma
• Chronically dislocated hips secondary to infections like tuberculosis of the hip

Failure of the lever is a feature in the following conditions

• Greater trochanteric avulsion
• Non-union of the neck of the femur
• Coxa Vara

Failure of effort presents in the following conditions

• Poliomyelitis
• L5 radiculopathy
• Superior gluteal nerve damage
• Gluteus medius and minimus tendinitis
• Gluteus medius and minimus abscess
• Post total hip arthroplasty

Symptoms of Trendelenburg Gait

The Trendelenburg sign is useful in identifying weak hip abductors as well as assessing other mechanical, neurological, and spinal disorders.

A positive Trendelenburg test is a finding in the following [rx]

Any condition that brings the origin and insertion of gluteus medius together

• Subluxation or dislocation of the hip
• Coxa vara
• Greater trochanter fractures
• Slipped femoral capital epiphysis
• Legg-Calve-Perthes disease

Abductor paralysis or weakness

• Polio
• Root-lesion
• Post-operative nerve damage
• Muscle-wasting disease
• Hemiplegic cerebral palsy
• Muscular dystrophy
• Any painful hip disorder which results in gluteal inhibition

Others

• Lower back pain
• Osteoarthritis of the hip
• Greater trochanter fractures
• Femoral neck fractures
• Short leg syndrome
• The initial time following total hip replacement
• Cleidocranial dysostosis

Diagnosis of Trendelenburg Gait

History and Physical

• A patient with a Trendelenburg gait often complains of a limp. The limp can be painful or painless depending on the etiology. If the limp is severe, there is compensatory bending or lurching to the side of pathology to balance the center of gravity of the body. This limp is called the lurching gait. When the pathology is bilateral, the pelvis droops to the unsupported side alternating with each step and is called a waddling type of gait. This gait, when present, provides clues regarding certain possible etiologies, such as non-union of the neck of femur and developmental dysplasia of the hip.
• On physical examination of gait, the lurching or waddling type of gait patterns should alert the physician to examine the abductor mechanism of the hip more closely.
• Mild Trendelenburg gait may be difficult to appreciate while examining the patient with full clothing. It is necessary to perform a Trendelenburg test to evaluate further.
• To perform the test, the examiner sits or stands behind the patient. The patient is then asked to lift each foot off the ground, and the opposite side pelvis is elevated as high as possible alternately for at least 30 seconds. [rx] This modification was suggested by Hardcastle et al. and is now practiced worldwide as a standard practice. In healthy individuals, the unsupported side stays at the same level or rises slightly. When the abductor mechanism is weak, the pelvis drops towards the unsupported side. In case of more serious weakness, the patient leans towards the affected side. This dropping of the pelvis in the standing position suggests a positive Trendelenburg test.

The prerequisites for doing the test are as follows

• The patient should have a painless hip pathology. In case of a painful hip condition, the patient will not be able to balance leading to spurious results.
• The must not have abduction or adduction (coronal plane) deformities of the hip. The presence of adductor deformity at the hip leads to the elevation of the pelvis leading to the false-negative result. The presence of abductor deformity at the hip leads to drooping of the pelvis on the contralateral side leading to the false-positive result.

Limitations of the Trendelenburg test

• Kendall et al. have shown that hip abductor weakness induced by superior gluteal nerve block does not correlate with the pelvis drop mainly in athletes and in patients who are asymptomatic but have hip pathology.[rx]
• In a patient with early stages of osteonecrosis, in spite of having an abductor mechanism defect Trendelenburg sign and therefore gait remain masked.[rx]
• Pelvis drop can occur even in healthy individuals with normal abductor mechanism when the abductor muscle is not working adequately.
• A detailed physical examination should be carried out to diagnose the condition leading to the abnormal gait. Other investigations include X-rays, ultrasonography, computed tomography (CT) scans and magnetic resonance imaging (MRI) to diagnose the primary condition. Blood tests may be performed to corroborate with the radiological findings.
• Differential Diagnosis
• Trendelenburg gait must be differentiated from other gait patterns including the following
  • Short limb gait
  • Antalgic gait
  • Extension lurch gait
  • High stepping gait
  • Stamping gait

  A thorough history and physical examination are essential to rule out other types of abnormal gait patterns.

The Trendelenburg sign is useful in assessing different hip dysfunctions, but the interpretation of the results remains controversial as there is no clearly established standard for a positive test. According to Bailey et al., only two authors have objectively defined the point at which pelvic drop can be considered a positive Trendelenburg test result: Asayama et al. established a positive Trendelenburg test result as a pelvic tilt angle of greater than 2 degrees, while Westhoff et al. (2005) considered “positive” to be a pelvic drop in the non-stance limb during the single-stance phase of over 4 degrees and/or a maximum pelvic drop in the stance phase exceeding 8 degrees.[rx][rx] In recent years, the Hardcastle modification of the Trendelengberg test (described above) can help to eliminate false positives.

Prerequisites of testing

• The patient can stand on the affected side for more than 30 seconds
• The patient can understand commands
• The patient has intact coordination
• The patient has free abduction movement; no fixed adduction deformity

Standing test

The patient stands on the affected leg in a single leg stance for up to 30 seconds. The provider stands behind the patient at the hip level and places their hands on the iliac crests on either side of the pelvis observing to see if it stays level during the single-leg stance. Repeat the test on the opposite side. A positive Trendelenburg sign is when the pelvis drops on the unaffected side.[rx]

Gait test

The examiner asks the patient to walk a short distance. In a normal gait, the body shifts the weight to the stance leg, allowing the center of gravity to shift as well, which stabilizes the body. In a patient with positive Trendelenburg sign constituting of abductor weakness, when they lift the unaffected leg, the shift does not occur; therefore, the patient is unable to maintain balance, leading to instability.

False positives can occur with

• Obesity
• Fixed adduction deformity
• Medialization of lower limb axis, such as coxa vara, genu varum, and malunited supracondylar femur with varus deformity
• Non-intact quadratus lumborum (pulls the pelvis on the unaffected side up if it is not intact)
• Pain
• Poor balance
• Lack of cooperation or understanding
• Costo-pelvic impingement
• Scoliosis
• Pelvic drop can occur even in healthy individuals with normal abductor mechanism when the abductor’s muscles are not working adequately.

 False negatives can occur with

• Use of supra-pelvic muscles
• Use of psoas and rectus femoris
• Wide lateral translocation of the trunk to allow balance over the hip as a fulcrum
• In patients with early stages of osteonecrosis, despite having an abductor mechanism defect, Trendelenburg sign and, therefore, gait remain masked.[rx]

Treatment of Trendelenburg Gait

The main focus of the treatment after identification of the etiology involves correction of the etiological factor resulting in the Trendelenburg gait and varies according to the pathology.

Trendelenburg gait by itself wears the hip joint, and appropriate treatment is essential.

Physical therapy is the mainstay treatment for gluteus medius and minimus weakness. Physical therapy involves strengthening weakened hip abductor muscles. This involves lying on the unaffected side while abducting the affected leg up towards the ceiling. A theraband can be applied on the lower limb to increase the resistance during the exercise. Other modalities include lateral side steeping and balance exercises.

Patients who have abductor weakness after an arthroplasty require specific exercises which include:

• Non-weight bearing standing abduction
• Weight-bearing standing abduction
• Side-lying abduction
• Resisted side-stepping exercises

Weight-bearing exercises have been shown to have a better functional recovery than non-weight-bearing exercises.

Alteration of the gait pattern after gait training can also compensate for the hip abductor weakness.[rx]

For gluteus medius tears, reports have shown that in patients with hip abduction manual muscle strength less than 4/5 along with the presence of gait dysfunction, surgical intervention is likely indicated. [rx]

Complications

Chronic untreated abnormal Trendelenburg gait may lead to the development of secondary pathology at the knees or ankles over the years. It is also known to accelerate the process of wear and tear at the hip joint. The wear and tear usually occur at the portions of the hip which are typically not used during normal gait, more so in athletes.[rx][rx] Untreated Trendelenburg gait can also lead to dynamic lower extremity valgus.[rx] The mechanism behind this is that the pelvis of the unaffected side will be elevated thereby having the trunk lean towards the affected side. The ground resultant force will, in turn, be directed to the lateral knee joint thereby producing a valgus knee on the affected side. This overtime can lead to knee pain.

References