Radiation prophylaxis for heterotopic ossification of the knee.

Heterotopic ossification (HO) occurs in 42% of patients who have undergone total knee arthroplasty. Bone formation usually is found in the quadriceps expansion and causes minimal to no symptoms. Specific therapy usually is unnecessary, but cases have been reported in which manipulation under anesthesia or revision arthroplasty has been required. We report a small series of 5 patients (6 knees) who have undergone surgical intervention for HO of the knee with radiotherapy given postoperatively for prophylaxis against future HO. Although this series is small, it appears that the use of prophylactic radiation may reduce recurrence after resection of symptomatic HO after total knee arthroplasty. Further investigation is required to confirm these preliminary findings.