What is gluteal muscle contracture?

Gluteal muscle contracture refers to a clinical condition where fibrosis and contracture of the gluteus maximus or gluteus medius and their fascia occur due to various causes, leading to impaired hip joint function and resulting in characteristic gait and postural signs. It can occur unilaterally or bilaterally, often caused by repeated intramuscular injections in the buttocks over time.

What are the causes of gluteal muscle contracture?

The exact cause remains unclear but may be related to the following factors:

1. Repeated intramuscular injections in the buttocks for infectious diseases, with local manifestations of myofibrositis.
2. Predisposing factors in children (abnormal immune function, special scar constitution, congenital genetic factors, etc.).
3. Trauma, infections, and other factors (postoperative complications of congenital hip dislocation, sequelae of gluteal compartment syndrome, local infections in the buttocks, etc.).
4. Idiopathic factors.

Who is most susceptible to gluteal muscle contracture?

It commonly occurs in individuals who have received multiple injections in the buttocks, particularly in Asian populations. It is more prevalent in children and adolescents, with males affected more frequently than females.

What are the main symptoms of gluteal muscle contracture?

The disease progresses slowly, usually without significant local pain. Patients exhibit characteristic gait and abnormal postures:

• Walking often shows an outward "duck-like" swaying gait. When walking quickly or running, the lower limbs appear slightly externally rotated and abducted, resembling a hopping motion, known as the "hopping sign."
• When standing, the lower limbs cannot fully close and remain slightly externally rotated.
• When sitting, the knees are abducted and separated, forming a typical "frog-leg" posture, making it impossible to cross the legs.
• When squatting, the knees first separate and then come together.
• Hip clicking and snapping.

How is gluteal muscle contracture diagnosed?

1. A history of repeated injections in the buttocks, combined with the above clinical manifestations.
2. Physical examination may reveal loss of normal buttock contour (referred to as the "pointed buttock sign"), local skin depressions, palpable fibrous bands along the gluteus maximus fibers with a tight sensation, and local tenderness. Ober's sign is positive.
3. Pelvic X-rays are usually normal but may show secondary changes such as "pseudo-bilateral hip valgus," pelvic tilt, femoral neck-shaft angle >130°, prominent lesser trochanter, and increased center-edge angle.
4. Ultrasound shows echo loss in contracted muscles and thickened fascia with enhanced echoes.
5. CT reveals reduced gluteal muscle volume and fibrous contracture bands.

How is gluteal muscle contracture treated?

• Non-surgical treatments include medication, rehabilitation exercises, and micro-needle knife release of the contracted gluteal muscles.
• Surgical treatments include gluteus maximus contracture band resection, gluteal muscle contracture release, and arthroscopic gluteal muscle contracture release.

Most experts recommend early surgical intervention if no contraindications exist, with generally favorable outcomes.

What is the prognosis for gluteal muscle contracture?

Early diagnosis and treatment are crucial. Complete surgical resection or release of the contracted tissue, followed by appropriate rehabilitation exercises, can lead to recovery in most patients, restoring normal gait and reducing recurrence. In severe cases with complications like pelvic tilt or leg length discrepancy, abnormal gait may be difficult to correct, affecting daily activities.

How can gluteal muscle contracture be prevented in daily life?

• Maintain a balanced diet and strengthen immunity.
• Avoid frequent intramuscular injections in the buttocks.
• Engage in active postoperative rehabilitation.
• Avoid trauma and infections.