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

Abstract

IntroductionPelvic 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 presentationWe 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.ConclusionIt is important to recognize and distinguish a pelvic digit from post-traumatic ossification and avulsion to avoid unnecessary additional investigations.

Dyspareunia associated with a pelvic digit

“…Literature reports have suggested various origins of the pelvic digit, including congenital formation, myositis ossificans, or traumatic avulsion. (1-3,5,6) In this case, the defining features were that it was well corticated with a pseudoarticulation between bony segments, resembling a digit. This is most consistent with a congenital etiology.…”

“…Pandey et al and Maegele report the only other cases of symptomatic pelvic digits in a 35 and a 40 year old man, respectively. (6,9) These patients both experienced chronic hip pain, tenderness to palpation of the affected region and limited range of motion. (6,9) Surgical excision was curative for chronic pain and increasing range of motion in both instances.…”

“Pelvic ribs”: A rare congenital abnormality

“…Clinical symptoms have only been found in athletes, consisting of sacral pain triggered by movement of the hip [4]. Only if these symptoms are present is therapeutic management required, and this would usually consist of surgical ablation.…”

Benign osseous and articular abnormalities of the pelvis: a review of CT imaging findings

“…18). Pelvic digits are asymptomatic but should be distinguished from avulsion injuries of the pelvis or post-traumatic heterotopic ossification [61,62].…”