Short-term outcomes of robotically assisted patello-femoral arthroplasty

Abstract

Purpose The purpose of this study was to determine the outcomes in patients treated with robotically assisted patellofemoral arthroplasty (PFA). Methods This technique offers a safe, reliable, and reproducible way of obtaining correct implant positioning in patello-femoral arthroplasty, and as a result, reduces revision surgery due to implant malalignment. We evaluated 30 knees in 29 patients who underwent robotically assisted patello-femoral arthroplasty between June 2009 and May 2011. Mean follow-up was 15.9 months. This was a retrospective study that involved chart reviews and radiographic analysis. Radiographic analysis included preoperative and postoperative plain films for implant positioning. Functional outcomes were evaluated using the Oxford Knee Score (OKS), range of motion, University of California at Los Angeles (UCLA) patient activity-level ratings, visual analog pain scale (VAS), and the Knee Society Score (KSS). Results The patients had an average OKS of 21.7 pre-operatively and reached an average of 33.5 postoperatively (p = 0.0033). Pre-operative UCLA patient activity-level ratings was 3.1, compared with 4.8 postoperatively. Average VAS preoperatively was 8 and postoperatively it decreased to 2.1 (p = 0.0033). The average KSS final score pre-operatively was 56 and postoperatively it increased to 68.3 while the functional score pre-operatively was 47.2 compared to 68.1 postoperatively (p = 0.011). As a result, patello-femoral arthroplasty is an emerging knee resurfacing technique that is an alternative to the total knee arthroplasty. Conclusions The early retrospective data for robotically-assisted PFA show encouraging results. Advantages of this technique include a smaller incision, faster rehabilitation, preservation of bone stock, and implantation without malalignment.