Functional recovery of muscles after minimally invasive total hip arthroplasty.

Whether mini-incision total hip arthroplasty is associated with accelerated postoperative recovery is a subject of considerable controversy. A study was conducted to compare objective outcomes using gait analysis as a measure for recovery of function in patients treated with three different minimally invasive surgical approaches and the traditional posterior approach. Sixty-nine patients underwent instrumented gait analysis at self-selected and fast velocities preoperatively and at 6 weeks and 3 months postoperatively. Four surgical groups were studied-30 treated with posterior mini-incisions, 11 anterolateral, 10 anterior Judet, and 18 traditional posterior long incisions. Overall, gait velocity increased slightly at 6 weeks and significantly at 3 months. However, there were no significant differences between groups for velocity, cadence, stride length, single-limb support time, or double-limb support time at 6 weeks or 3 months postoperatively. These data indicate that patients undergoing total hip arthroplasty with any of these surgical approaches recover muscle function, as measured by gait analysis, to preoperative levels within 6 weeks postoperatively. No advantage was shown with the use of any of the three different small-incision approaches. This finding suggests that the amount of muscle, or the particular muscle cut, does not have a significant effect on the recovery of postoperative gait function.