2025 ISAKOS Biennial Congress ePoster
Robotic-Assisted Total Knee Arthroplasty Improves Accuracy and Reproducibility Compared to Manual Instrumentation or Navigation.
Matt Lyons, FRACS, Mosman, NSW AUSTRALIA
Yoan Bourgeault-Gagnon, MD, FRCSC, Sherbrooke, Quebec CANADA
Lucy J. Salmon, PhD, Sydney, NSW AUSTRALIA
North Sydney Orthopaedic and Sports Medicine Centre, Sydney, New South Wales, AUSTRALIA
FDA Status Cleared
Summary
Tibial polyethylene insert thickness, as a surrogate of surgical accuracy, is more reproducible in robotic-assisted than in navigation-assisted or manual-instrumentation TKA. The learning curve to reach high levels of reproducibility with this technique is relatively short.
ePosters will be available shortly before Congress
Abstract
Background
Increased accuracy and lower rates of component positioning outliers have been associated with better long-term survival and functional outcomes of total knee arthroplasty (TKA). This study investigates the accuracy of robotic-assisted TKA compared to navigation-assisted and manual instrumentation techniques, using polyethylene tibial insert thickness as a surrogate.
Methods
Consecutive primary TKA by a single surgeon were retrospectively reviewed and divided in 3 groups: manual instrumentation (M-TKA), navigation-assisted (NA-TKA) and robotic-assisted (RA-TKA). Polyethylene insert thickness, deviation from planned thickness and rate of outliers were compared between the 3 groups using non-parametric ANOVA, Kruskal-Wallis tests, and Bonferroni corrections. Logistic regression analysis was performed to identify predictors of polyethylene thickness ≥9 mm. The learning curve for RA-TKA was evaluated with a box plot graph of groups of 10 consecutive cases.
Results
There were 474 patients in M-TKA, 257 in NA-TKA and 225 in RA-TKA, with median polyethylene thicknesses of 6.0 (IQR5.0–7.0), 6.0 (IQR 5.0–7.0) and 5.0 (IQR 5.0–6.0) millimeters respectively (p˂0.001 RA-TKA compared to both other groups). Polyethylene inserts with a thickness ≥9mm were used in 28(5.9%) M-TKA, 13(5.1%) NA-TKA and 1(0.4%) RA-TKA (p=0.004). Independent predictors for polyethylene thickness ≥9mm included surgical technique, left side and male sex. A learning curve of <30 cases was observed before consistent polyethylene thickness was achieved in RA-TKA.
Conclusion
Tibial polyethylene insert thickness, as a surrogate of surgical accuracy, is more reproducible in robotic-assisted than in navigation-assisted or manual-instrumentation TKA. The learning curve to reach high levels of reproducibility with this technique is relatively short.