[Ectopic bone formation in neurological lesions (author's transl)].

The authors have operated on seventy instances of para-articular ectopic bone formation in fifty patients. Seventeen were paraplegic or tetraplegic, thirty were the result of trauma, two resulted from meningitis and one was a sequel of burns. The ectopic bone was located at the hip (thirty-three cases), the elbow (twenty-three cases), the knee (twelve cases) and the shoulder (two cases). The clinical, radiological and pathological features are reviewed. Several hypotheses on the mechanism of ectopic bone formation are put forward. The surgical procedures have included arthrolysis, arthrodesis, wide resection of the epiphysis, and total prostheses. There were ten recurrences. The authors conclude that the most extensive lesions occur in paraplegia and when the bone formation is situated at the hip.