Comparison of Early Postoperative Rehabilitation Outcome Using Total Knee Arthroplasty Using Different Surgical Approaches and Instrumentation

Introduction Computer Assisted Total Knee Arthroplasty (CA-TKA) has been demonstrated to provide more reproducible implant positioning compared to standard instrumentation, with potential benefits for prosthesis survival. When performing CA-TKA through a medial parapatellar (MPP) incision, proximal extension of the quadriceps dissection is frequently required for appropriate placement of the femoral tracking array. This study assesses early postoperative rehabilitation after CA-TKA using MPP and subvastus approaches. Materials and Methods A prospective controlled trial of 70 consecutive patients undergoing TKA with the LCS Rotating Platform prosthesis was conducted with patients randomised to receive to surgery with the use of computer navigation or standard instrumentation. Medial parapatellar and subvastus approaches were employed according to surgeon preference. Outcome measures included preoperative knee function, intraoperative factors and postoperative rehabilitation. Results Duration of surgery was significantly longer when using computer navigation, however with greater experience operative times decreased. CA-TKA performed through the MPP approach was strongly associated with a greater incidence and duration of early postoperative quadriceps lag compared to CA-TKA through a subvastus approach and TKA performed with standard instrumentation. No patient who had surgery performed through subvastus approach had a lag >20 degrees after 48 hours post surgery regardless of instrumentation system employed. Discussion This study demonstrates that CA-TKA is associated with delayed early postoperative rehabilitation when performed through the MPP approach. This observation is explained by the additional quadriceps dissection that is frequently required to place the femoral tracking array in CA-TKA. This data supports the use of a subvastus approach when performing CA-TKA due to a demonstrated quadriceps sparing effect. KEY WORDS Knee. Arthroplasty. Approach. Computer. Rehabilitation