抄録
One hundred and sixty-five hip joints (159 patients) treated by femoral head replacement for femoral neck fracture were analyzed to identify predisposing factors to ectopic bone formation (EBF), its frequency, and its effect on outcome. EBF of varied extent was recorded in 37 hips outcome (22.4%) after femoral endoprosthesis, and the ossifications shown in the A-P radiographs were situated predominantly in the medial to the hip joint (51.4%) . Ossifications in 35 of the 37 hips (94.6%) were recognizable within three months. EBF had no influence on walking ability or pain postoperatively, but range of motion was significantly reduced in patients with Grade III ossification (P<0.01) .EBF did not correlate with the age at operation, gender, operative time, and amount of blood loss. In patients who developed EBF, erythrocyte sedimentation rate (ESR) before operation was significantly elevated in comparison with patients who did not develop EBF (P<0.05) .ESR was also elevated after operation, but there was no significant correlation.The level of alkaline phosphatase increased between two and three weeks after operation in patients with EBF, but there was no significant correlation. In our study it was not possible to demonstrate preoperatively which group of patients was more prone to develop EBF.