Klinische und radiologische Ergebnisse der operativen Entfernung von periartikulären Ossifikationen nach Hüftendoprothese

The occurrence of heterotopic ossification (HO) is a well-recognized problem after total hip replacement. In a retrospective study, we investigated 32 patients who had undergone surgical excision of symptomatic HO followed by radiation with 7 Gy and nonsteroidal anti-inflammatory drug therapy between 1994 and 1999. The mean follow-up was 20 months (range: 12-60).Clinical and radiographic follow-up examinations included Harris hip score and classification according to Brooker. The preoperative Brooker class was III in 16 cases and IV in 16 patients. Comparison of the Brooker classification at follow-up revealed a statistically significant improvement (p<0.0001; class 0: 3, class I: 14, class II: 8, class III: 7 patients). In one case with symptomatic Brooker class III ossification, surgical reexcision of HO was necessary. A statistically significant increase (p<0.05) in mean range of motion (ROM) was observed in flexion [preoperative:57° (±26), follow-up: 83° (±21)], in abduction [preoperative:17° (±12), follow-up: 24° (±9)], and in rotation (preoperative: 16° (±17), follow-up: 31° (±18)]. Comparison of preoperative Harris hip score (60±11) and Harris hip score at the time of follow-up examination (73±17) revealed a statistically significant increase (p<0.0001) after treatment. At the time of follow-up examination, 18 patients (56%) assessed their pain symptoms as low but 6 patients (19%) reported strong pain symptoms. Nevertheless, the score at the time of examination (35±10) was statistically improved (p<0.02) when compared to the preoperative score (30±8). Surgical excision of Brooker class III or IV heterotopic ossification with limited ROM followed by irradiation and anti-inflammatory prophylaxis results in significant improvement in flexion,abduction,and rotation arc and significant reduction of HO in radiographic examination at follow-up, but pain relief was only satisfactory.