Quadriceps-sparing, minimal-incision total knee arthroplasty: a comparative study.

Our study was conducted to compare radiographic alignments and functional outcomes with 2 approaches to minimal-incision total knee arthroplasty (TKA): the minimal-incision medial parapatellar (MP) approach and the quadriceps-sparing (QS) approach with side-cutting instruments. Sixty patients (80 knees) with primary osteoarthritis were randomly assigned to receive MP or QS TKA. Postoperative alignment of the femoral component was significantly less valgus, and postoperative alignment of the tibial component was significantly more varus with the QS approach than with the MP approach. One tibial outlier and 3 femoral outliers were observed with QS TKA. The overall postoperative hip-knee-ankle axis was more varus, and surgical time was longer with QS TKA. Short-term isokinetic peak muscle torque, postoperative pain, and functional outcomes did not differ between the approaches.