Retrospective analysis of early functional and radiological outcomes between robotic, navigated and conventional total knee arthroplasty: A single Surgeon's series

Achieving a neutral mechanical axis alignment (MAA) in Total Knee Arthroplasty (TKA) is associated with increased implant longevity and patient satisfaction, and robot-assisted (robotic) TKA is touted to improve implant placement accuracy and alignment. This study aims to analyse the functional outcomes and implant positioning between robotic, navigated, and conventional TKA in a single surgeon series.

A total of 196 consecutive primary TKAs (49 robotic, 97 navigated, and 50 conventional) performed by a single surgeon were retrospectively reviewed. Post-operative Oxford Knee Score (OKS), Knee Society Scores (KSS), Visual Analogue Score (VAS), and EuroQol-5 Dimension (EQ-5 D) taken at 3 months and 1 year were analysed, while post-op radiographs taken at 1 year were reviewed. Statistical analysis was performed using SPSS software version 26 (IBM, Armonk, NY, USA).

Robotic TKA leads to better (1) MAA compared to navigated and conventional TKA (p = 0.001 and, p = 0.047 respectively), (2) tibiofemoral angle compared to navigated TKA (p = 0.043), (3) femoral coronal angle compared to both navigated and conventional TKA (p = 0.008 and, p = 0.037 respectively), (4) tibial coronal angle compared to conventional TKA (p = 0.037), and (5) femoral sagittal angle compared to conventional TKA (p = 0.042).Improvements in functional scores were noted for all 3 groups. Robotic TKA did not result in better OKS compared to other groups whereas navigated TKA resulted in better OKS than conventional TKA (p = 0.027 at 3 months, p = 0.010 at 1 year). Comparing all three groups, there was no statistically significant difference in KSS, VAS, and EQ-5D.

While robotic surgery leads to more accurate implant positioning, it did not translate to improved functional outcomes compared to navigated or conventional TKA.