Radiotherapy in the prevention of recurrence of paraarticular ossification in total hip prostheses.

Ectopic bone formation or paraarticular ossification after total hip arthroplasty can be a very disabling factor. In patients with this problem, range of motion and walking ability may be reduced and pain can occur. In severe cases it seems logical to remove this paraarticular ossified tissue, but without measures to prevent its recurrence this will be of no real value. This study shows the effectiveness of irradiation soon after excision of the ectopic bone mass, with a total dosage of 20 Gy (2000 rad) given in ten fractions, in preventing, or at least inhibiting, the recurrence of paraarticular ossification in 16 patients. A dramatic improvement in hip function, walking ability, and relief of pain is demonstrated.