Robotic-arm assisted total knee arthroplasty improves precision and delivers early outcomes superior to manual approach

Haptic robotic-arm assisted technology improves accuracy in unicompartmental knee replacement through utilizing a preoperative 3-D plan, optical navigation for real-time intraoperative feedback on soft tissue laxity, and robotic arm for precise bone preparation. This technology became clinically available for total knee arthroplasty (TKA) in 2016. We present outcomes from the early adoption of this technique. A retrospective chart review compared data from the first 120 robotic-arm assisted TKAs performed December 2016 through July 2018 to the last 120 manually instrumented TKAs performed May 2015 to December 2016, prior to robotic technology adoption. Robotic surgery was associated with significantly increased anesthesia (212 vs 187 mins, p < 0.01) and operative (135 vs 112 minutes, p < 0.01) time. The robotic group had a lower hospital length-of-stay (2.7 vs. 3.4 days, p < 0.001). Discharge to home was not statistically different between robotic and manual groups (89% vs. 83%, p = 0.2). Robotic technology was associated with decreased variability in implant positioning, with smaller variances in the lateral distal femoral angle (LDFA; 3.5 vs 6.6 degrees, p < 0.01) and posterior tibial slope (1.8 vs. 5.3 degrees, p < 0.01). Mean limb alignment, as measured by tibiofemoral angle, was slightly less valgus in the robotic group (3.9 vs 4.4 degrees, p = 0.09). Postoperative range of motion was significantly increased for robotic-arm assisted TKA patients, with less flexion contracture at 2-weeks (1.8 vs. 3.3 degrees, p < 0.01), 7-weeks (1.0 vs. 1.8 degrees, p < 0.01), and 3-months (0.6 vs 2.1 degrees, p = 0.02) post-surgery. Postoperative Knee Society scores were similar between groups. Preliminary findings demonstrate robotic-arm assisted TKA is safe and efficacious with outcomes comparable, if not superior, to that of manually instrumented TKA.