Pelvic digit as a rare cause of chronic hip pain and functional impairment: a case report and review of the literature

INTRODUCTION Pelvic digit is a rare congenital anomaly where bone develops in the soft tissue adjacent to normal skeletal bone. The condition is benign and is usually discovered accidentally. On a plain radiography, pelvic digit typically appears as a rib- or phalanx-like bone structure with a clear cortex and medulla related to the pelvis, often with a pseudoarticulation at its base. CASE PRESENTATION We present the case of a 40-year-old Caucasian man who presented with chronic pain and tenderness over his right hip together with functional impairment in abduction and external rotation. Radiology identified a bony protuberance at the right anterior inferior iliac spine with fusion of the proximal bony nucleus to the adjacent bone. The pelvic digit was surgically removed and the patient was discharged free of symptoms and with complete range of motion in his right hip joint. CONCLUSION It is important to recognize and distinguish a pelvic digit from post-traumatic ossification and avulsion to avoid unnecessary additional investigations.