Aim of study: Radiation therapy is an established method for the prevention of heterotopic ossification. The aim of this study was to assess whether radiation therapy is also effective in revision arthroplasties.
Method: 143 hips were irradiated with 7 Gy anterior-posterior applied single dose radiation, on one of the first four days after revision surgery.
Results: After an average follow-up of 18 months, 107 hips were evaluated radiographically using Brooker's criteria. In comparison to the immediate postoperative findings (26 % showed no heterotopic ossification, 66 % had Brooker I, 5 % Brooker II, and 3 % Brooker III), at final follow-up 19 % showed no heterotopic ossification, 66 % had Brooker I, and 7.5 % Brooker II and III. New ossification or an increase of one grade was found in 12 %, of two grades in 4 %. Grade 0 showed significantly more ossifications. Gender (p = 0.43), age (p = 0.43), the type of revision surgery (p = 0.36), the day of radiation (1st day vs. 2nd, 3rd, 4th day; p = 0.46) had no significant influence on this increase. There was no correlation between pain score and Brooker grades (p = 0.755). There was a significantly (p < 0.01) negative correlation (r = - 0.31) between the Brooker grades and flexion.
Conclusion: Radiation therapy with 7 Gy single dose effectively prevents the new formation of heterotopic ossification or the progression of ossifications after revision surgery. To prevent a decrease in the range of motion due to HO after revision surgery, HO should be removed intraoperatively.