Extensive Myositis Ossificans with Extra-articular Ankylosis of the Hip Joint

V Bagaria, DD Rasalkar, BK Paunipagar

Hong Kong J Radiol 2011;14:35-8

Myositis ossificans, also known as heterotrophic ossification, is characterised pathologically by the presence of lamellar bone at sites where bone normally does not exist. Its aetiology is unknown but is known to occur following damage to the muscle. The resultant proliferative connective tissue later differentiates into the mature bone mass.

Extensive myositis ossificans leading to a complete extra-articular bony ankylosis is rare. We report a case of post-traumatic myositis ossificans in a 27-year-old female following a head injury. The iliopsoas was involved in this case, and lead to extra-articular bony ankylosis of the hip causing severe functional impairment. Surgical excision of the mass as described resulted in a marked functional improvement.

中文摘要

大範圍骨化性肌炎伴發髖關節外骨性僵硬

V Bagaria、DD Rasalkar、BK Paunipagar

骨化性肌炎又稱為異位性骨化症，從病理學的角度來說，這種病是指在不應該長有骨的組織內出現了板狀骨。發病原因目前仍然不明確，但一般在肌肉受損後才發生。增生性結締組織分化至成熟的骨質。因大範圍骨化性肌炎而引致關節外的骨性僵直很罕見。本文報告一名27歲女性頭部受傷後引發創傷後骨化性肌炎。這病例牽涉骼腰肌而導致髖關節外的骨性僵直。病人髖關節活動度變小而導致功能嚴重受損。患者接受上述骨質切除手術後功能活動明顯恢復。