Short-term outcomes of robotically assisted patello-femoral arthroplasty

The purpose of this study was to determine the outcomes in patients treated with robotically assisted patello-femoral arthroplasty (PFA).

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 pre-operative 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).

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 pre-operatively 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.

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.