The Learning Curve and Alignment Assessment of an Image-Free Handheld Robot in TKA: The First Patient Series in Europe

Abstract

BACKGROUND: The typical goal of TKA is to obtain a neutral mechanical axis of the leg. The NAVIO® Surgical System (Smith & Nephew, Pittsburgh, PA, USA) is aimed at reducing technical errors and outliers. The aim of this study is to assess the surgeons’ learning curve and limb alignment in TKA.METHODS:The first sixty-nine patients who underwent TKA with the NAVIO system by two experienced surgeons were included in this study. Pre- and postoperative mechanical limb alignment and balancing was measured by the NAVIO system. Registration time, planning time and cutting time was monitored preoperatively by the NAVIO™ system. All data was analyzed retrospectively.RESULTS:The mean preoperative mechanical limb alignment was 3.18° varus (SD 4.28°, range 15.08° varus to 4.30° of valgus). The mean intraoperative planned angle was 0.59° varus (SD 0.97°, range 2.50° varus to 0.99° valgus). The mean postoperative alignment was 1.17° varus (SD 1.78°, range 4.52° varus to 4.33° valgus. The mean extra surgical time (EST) for registration and planning decreased from 23.4min (SD 3.7min) to 13.2min (SD 2.0) throughout the learning curve with a range of 10min05sec to 28min19sec.CONCLUSION: The NAVIO robotic system is a valuable tool in assisting total knee arthroplasty. It allows the surgeon to accurately determine optimal implant position for each patient and minimize statistical outliers in alignment.

Robotic Systems in Knee Surgery: Current Concepts and Future Perspectives

“…Many authors demonstrated that after an initial learning curve with a long operation time, surgeons could expect a significant reduction in operative time after a small number of cases with this system [43, 46,47]. In particular, the average surgical time for a surgeon approaching NAVIO ® TKAs was reported as 68.2 min, compared to an average of 51.7 min for cTKA [43].…”