Pathological Hip Dislocation in a Neurofibromatosis Patient Secondary to Capsular Hemangioma

Abstract

Neurofibromatosis is an autosomal-dominant multi-system disease affecting the nervous, integumentary, ocular, and musculoskeletal systems. In the small number of reported cases, the cause was either atraumatic or an intra-articular neurofibroma. Only a couple of articles in medical literature have reported synovial and capsular hemangioma originating within the hip joint. In this article, we present a rare case of pathological hip dislocation in a neurofibromatosis patient secondary to capsular hemangioma that would be reported for the first time in medical literature. We present the case of a 20-year-old female, resident of Karachi, who presented to the outpatient clinic with pain in the left hip join and inability to bear weight on left leg for 1 week. Diagnosed as a case of posterior hip dislocation after physical examination and imaging, her dislocation was reduced by the Allis method. This maneuver, however, was unsuccessful. Ultimately, the joint was reduced with open reduction via Steinmann pin because post-reduction hip joint was unstable to be contained into the acetabulum; therefore, Steinmann pin was used. The biopsy specimen taken from joint capsule and femoral neck during the surgery revealed cavernous hemangioma within the capsule. Hence, the etiology of posterior hip dislocation was attributed to the presence of capsular hemangioma within the hip joint. The surgery proved successful. The patient had remarkable recovery. The Steinmann pin was removed at 6 weeks, full weight-bearing started at 3 months, and range of motion extended from 0 to 90 degrees at 1 year with imaging studies showing a normally placed hip joint. The presented case reports an unusual etiology of a rare pathology occurring in association with a common genetic disease. It focuses on the importance of thorough examination and extensive relevant investigations in patients presenting with rare pathologies. These practices not only expedite the diagnosis and treatment of such patients, but can also reveal unusual etiologies responsible for uncommon pathologies. This case would help widen the differential diagnosis and treatment strategies of the physicians while dealing with neurofibromatosis patients with pathological hip dislocation. Level of Evidence This is a case report having Level of Evidence 4 in accordance with the levels developed by the Centre of Evidence Based Medicine (CEBM) for treatment.

Keywords: Cavernous hemangioma; Hip dislocation; Hip joint; Neurofibromatosis; Orthopedics.

Fig. 1

Pre-operative radiological investigations. a X-ray full pelvis (AP view) showing posterior hip dislocation with erosions at the posterior lip. b CT scan pelvis showing shallow acetabulum with long tapered neck of femur. c MRI pelvis showing left hip dislocation with ipsilateral partial acetabular labral tear and abnormal marrow signals involving the head and neck of the left femur. Hyperintense shadows visible around the acetabulum and head and neck, maybe because of infective collection (abscess), most likely due to tuberculosis

Fig. 2

Condition of the patient post-operatively. a, b X-ray full pelvis showing left hip joint reduced by Steinmann pin, and the same joint at the 9th post-operative month. c, d Photographs showing the patient walking normally (c), and having difficulty in sitting (d) at 1 year post-operatively