Neurogenic gluteus medius and minimus muscle atrophy with Trendelenburg's sign after a displaced acetabular fracture of the posterior column – A case report

Traumatic or iatrogenic sciatic nerve injury, but not superior gluteal nerve injury, is a well described complication after acetabular fractures. Most often, sciatic nerve injuries occur in fractures involving the posterior column/wall with a hip dislocation and posterior fracture displacement resulting in narrowing of the greater sciatic foramen and injuring the sciatic nerve passing through. In this case report, a case of abductor mechanism deficiency with positive Trendelenburg's sign after an acetabular fracture of the posterior column with hip dislocation is presented. Postoperative clinical and MRI examination revealed a neurogenic atrophy of gluteus medius and minimus muscles suggesting a superior gluteal nerve injury due to initial subtotal incarceration of the greater sciatic foramen by a displaced posterior fracture fragment. An additional mild sciatic nerve injury resolved in the early postoperative course, while intensive physiotherapy improved the patient's complaints and muscular atrophy caused by the superior gluteal nerve injury within 12 months. This case report intends to raise awareness for rare neurological complications after acetabular fractures for their early detection.