The ROSA robotic-arm system reliably restores joint line height, patella height and posterior condylar offset in total knee arthroplasty

Abstract

IntroductionThere is growing interest in the use of robotic TKA to improve accuracy of component positioning in Total Knee Arthroplasty (TKA). The aim of this study was to investigate the accuracy of implant component position using the ROSA® knee system with specific reference to Joint Line Height, Patella Height and Posterior Condylar Offset (PCO). MethodsThis was a retrospective review of a prospectively-maintained database of the initial 100 consecutive TKAs performed by a high volume surgeon using the ROSA® knee system. Both the image-based and imageless workflow were used and two prosthesis types were implanted. To determine the accuracy of component positioning, the immediate post-operative radiograph was reviewed and compared with the immediate pre-operative radiograph with regards to Joint Line Height, Patella Height and Posterior Condylar Offset. Results100 consecutive patients undergoing TKA using the ROSA system were included; mean age 70 years (range 49–95 years). Mean change in joint line height was 0.2 mm, patella height (Insall-Salvati ratio) 0.01 and posterior condylar offset 0.02 mm; there was no statistically significant difference between the pre and post-operative values. No difference was demonstrated between image-based or imageless workflows, or between implant design (Persona versus Vanguard) regarding joint line height, patella height and PCO. ConclusionThis study validates the use of the ROSA® knee system in accurately restoring Joint Line Height, Patella Height and Posterior Condylar Offset in TKA surgery. No significant differences were found between imageless and image-based groups, or between implant designs (Persona versus Vanguard).