A comparison of the vastus splitting and median parapatellar approaches intotal knee arthroplasty

This prospective randomized study was undertaken to evaluate the vastus spl itting approach as an alternative to the median parapatellar approach in pr imary total knee arthroplasty, Fifty-one knees in 42 patients were randomiz ed preoperatively, Clinical parameters were evaluated preoperatively and at regular postoperative intervals. Electromyography was performed preoperati vely and postoperatively to evaluate each approach relative to its effect o n the innervation of the quadriceps mechanism. There were no significant pr eoperative differences. Postoperatively, there were no significant differen ces regarding strength, range of motion, knee scores, tourniquet time, prop rioception, or patellar replacement. There were significantly more lateral releases performed and greater blood loss in the patients in the parapatell ar group, The results of all preoperative electromyograms were normal, as w ere all of the results of postoperative electromyograms in the patients in the parapatellar group. However, the results of nine of 21 (43%) of the ele ctromyograms performed postoperatively on patients who had the vastus split ting approach were abnormal. Significantly fewer lateral releases were perf ormed and there was less blood loss in the patients in the vastus group. Ho wever, the postoperative electromyographic results revealed neurologic inju ries in the vastus medialis muscle that only were present after the vastus splitting approach. The clinical significance of denervation of the vastus medialis muscle by the vastus approach remains to be determined by longer t erm clinical and electromyographic studies.