Accuracy and precision in resection alignment: Insights from 10,144 clinical cases using a contemporary...

Studies on total knee arthroplasty (TKA) with computer-assisted orthopedic surgery (CAOS) are limited by sample size or overlooked longitudinal performance of the system. This study aimed to assess resection accuracy across the entire TKA application history of a modern CAOS system considering multiple factors.

A retrospective analysis was performed based on a database that archives technical logs of all TKAs performed using a CAOS system. Coronal resection errors and percentage of outliers (<2° alignment error) in the proximal tibia and distal femur were assessed. Multilevel modeling was used to understand whether and where the resection error variability was located in the grouping categories, which included geographic region, individual established surgeon, preoperative alignment, adoption phase (learning/proficient), and version of the CAOS software application.

A total of 10,144 cases were reviewed. The accuracy (mean) and precision (standard deviation) of the coronal alignment for both the tibia and femur were at the sub-degree level. High percentages of acceptable resections were observed across the pooled and each grouping category. The accountability for the amounts of total variability in tibial and femoral resection errors was negligible for all grouping categories, demonstrated by ICC values less than the common variations in observational studies.

The study applied advanced analyses to assess alignment outcome in TKA bony resection alignment across the history of a specific CAOS system. The results demonstrated high resection alignment accuracy insensitive to geographic region, CAOS software application, adoption phase, preoperative alignment, and inter-surgeon differences.