The medial trivector approach in total knee arthroplasty.

Abstract

This study compares the clinical results of the medial trivector approach to the standard parapatellar approach in primary total knee arthroplasty. Ten patients undergoing simultaneous bilateral total knee arthroplasty were included in this study. Right and left knees were randomized for a standard medial parapatellar arthrotomy or a medial trivector approach. Patients were assessed by the number of days to achieve straight leg raising and range of motion at discharge. In addition, knee scores were obtained at 6 weeks and 6 months with careful assessment of any pain or tenderness around the quadriceps mechanism. At 6 months, patients were tested on a KINCOM machine assessing their concentric and eccentric quadriceps strength. While there was no difference in total range of motion at the time of discharge, patients undergoing a medial trivector approach achieved independent straight-leg raising 2 days sooner than patients undergoing a standard medial parapatellar arthrotomy. No significant differences existed in knee scores, pain scores, or range of motion at 6 weeks or 6 months. KINCOM testing at 6 months revealed the knees undergoing trivector approach to be 15% stronger in concentric contractions. No complications were encountered with the use of the medial trivector approach in these patients. Subjectively, patients reported less discomfort and more strength in the knees having undergone a medial trivector approach. The medial trivector approach may enhance postoperative recovery without adversely affecting the quadriceps function following total knee arthroplasty. The medial trivector approach to the knee does not weaken quadriceps muscle function or adversely affect clinical results of total knee arthroplasty.