Heterotopic Ossification at an Unusual Site: A Case Report
Heterotopic ossification (HO) is the formation of ectopic bone at non-physiological location, such as soft tissues around a joint. HO is a common complication seen after trauma and certain surgeries (e.g., total hip arthroplasty) involving specific regions such as hip. In neurogenic HO, ectopic bone develops in patients sustaining a spinal cord injury or traumatic brain injury (incidence 20–30%). Neurogenic HO characteristically involves major joints with hip joint being the most common, followed by elbow, shoulder, and knee joint. No reported case of HO in wrists, ankles, legs, and feet has been documented, making these highly rare locations. The ectopic bone may be asymptomatic or can cause significant functional impairment of the involved joint presenting as erythema, warmth, swelling with loss of range of motion; however, this case is a rare presentation involving ankle joint with no signs of inflammation. Plain X-rays and CT scans diagnose the new bone. Management involves primary prophylaxis with NSAIDs, bisphosphonates (not commonly used), and radiation therapy. Surgical excision is the definitive treatment. Neurogenic HO cases should undergo comprehensive and extended follow-up with attention to even rarely involved sites such as ankle, wrists, hands, and feet.
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