Serial change of sliding in intertrochanteric femoral fractures treated with sliding screw system.

We investigated the serial change of the extent of sliding of the compression screw in 42 intertrochanteric femoral fractures fixed with a sliding screw system. Neither age, gender, bone density, fracture type nor quality of fracture reduction could accurately predict healing time. There was a significant correlation between the extent of sliding at union and healing time (correlation coefficient r = 0.505). The average healing time in group B (the extent of sliding at union of 8 mm or greater) was 13.8 weeks postoperatively, and that in group A (the extent of sliding at union of less than 8 mm) was 8.9 weeks. There was a significant difference in the average healing time between groups A and B (P = 0.0004). The extent of sliding at union had a influence on the healing time. The phenomenon of sliding progressed mainly during the first 2 weeks postoperatively. There was a significant positive correlation between the extent of sliding at union and the extent of sliding at 2 weeks postoperatively (r = 0.977). An assessment using the extent of sliding at 2 weeks postoperatively can accurately predict the extent of sliding at union and the healing time. It is important to examine the phenomenon of sliding during the early postoperative course, especially until 2 weeks postoperatively, in order to predict fracture repair.