Severe Heterotopic Ossification After Revision Total Knee Arthroplasty: A Case Report and Review of the Literature.

The incidence of primary and revision total knee arthroplasty (TKA) is increasing worldwide. Heterotopic ossification is a common and concerning complication of TKA. There are few described cases of severe heterotopic ossification after revision TKA and no known cases of heterotopic ossification causing functional ankylosis after revision TKA. We describe a case of extensive heterotopic ossification in a patient who underwent right TKA for extensive adhesions and stiffness. After early range of motion improvement postoperatively, the patient discontinued a physical therapy regimen. The patient presented 13 years after revision TKA with radiographically evidenced severe heterotopic ossification resulting in a functional ankylosis. The patient elected for nonsurgical management. This case demonstrates a delayed finding of severe heterotopic ossification. The case prompted an applied literature review of several topics: heterotopic ossification as a complication of revision arthroplasty, the contribution of autoimmune and inflammatory conditions to heterotopic ossification; the use of medication, radiation, and physical therapy as prophylaxis against heterotopic ossification; and the range of treatment strategies for severe heterotopic ossification at the knee joint. Consent by the patient involved in this case report was obtained.