Fractionated and single-dose radiotherapy for Heterotopic bone formation in patients with spinal cord injury a phase-I/II study

Heterotopic ossifications occur in about 20% of patients with spinal cord injury and may seriously compromise the rehabilitation process. Aim of the present study was to evaluate if radiotherapy administered early in the course of the disease prevents the manifestation of heterotopic ossification and if in patients whose bone formations have been resected recurrence can be avoided. 52 patients (44 males, eight females, median age 33 years) and 75 joints were irradiated between December 1989 and March 2000. 49 patients (70 joints, 65 hips, three knees, one shoulder, one elbow) were evaluable. Median follow-up was 11 months. In 58 joints radiotherapy was performed as a primary treatment in the inflammatory phase of soft tissue swelling that precedes manifestation of heterotopic ossifications. Twelve joints were treated after resection of manifest heterotopic bone, two patients had primary and postoperative irradiation in different joints. The dose was 10 Gy in single fractions of 2-2.5 Gy in 34 joints and 7.5-20 Gy in six joints. From July 1996 on, 30 joints received single-dose irradiation with 8 Gy. 50/70 joints (71%) remained free from progression. This was the case for 47/65 (72%) hips, whereas in 18 hips (27%) the Brooker score increased for 1-2 grades and caused a moderate decrease of mobility in five joints. Out of the other five joints, two knees developed progression. No relevant side effects occurred. The present results suggest that radiotherapy is an effective local treatment option for spinal cord injured patients with heterotopic ossifications.