[Prophylaxis of heterotopic ossification in hip revisions with 7 Gy single-dose radiation]

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.

143 hips were irradiated with 7 Gy anterior-posterior applied single dose radiation, on one of the first four days after revision surgery.

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.

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.