Comparison of early postoperative rehabilitation outcome following total knee arthroplasty using different surgical approaches and instrumentation.

PURPOSE To assess early postoperative rehabilitation outcome following computer-assisted total knee arthroplasty (TKA) or standard instrumentation TKA using a medial parapatellar or subvastus approach. METHODS A prospective controlled trial of 70 consecutive patients undergoing TKA with a low contact stress rotating platform prosthesis was conducted. Patients were randomised to receive surgery with either computer navigation or standard instrumentation. A medial parapatellar or subvastus approach was used according to the surgeons' preference. Outcome measures included preoperative knee function, intra-operative factors, and postoperative rehabilitation. RESULTS Duration of surgery was significantly longer when using computer navigation; however, operating time decreased with greater experience. A higher incidence and duration of early postoperative quadriceps dysfunction was associated with computer-assisted TKA through the medial parapatellar approach than through the subvastus approach or TKA performed with standard instrumentation. No patient who received surgery through the subvastus approach had a lag of more than 20 degrees, at 48 hours postoperatively, regardless of the instrumentation used. CONCLUSION Computer-assisted TKA through a medial parapatellar approach was associated with delayed recovery of the quadriceps during early postoperative rehabilitation. This was due to the additional quadriceps dissection required to place the femoral tracking array. The subvastus approach is therefore recommended for computer-assisted TKA.