One main perceived drawback for the adoption of computer assisted orthopedic surgery (CAOS) during total knee arthroplasty (TKA) relates to the increased surgical time compared to the use of standard mechanical instrumentation [1]. This study compared the time efficiency between a next generation CAOS system (ExactechGPS®, Blue-Ortho, Grenoble, FR) and conventional mechanical instrumentation, and assessed the impact of surgeon experience level on the efficiency. Surgical time was retrospectively reviewed on 63 primary TKAs performed by a board-certified orthopedic surgeon (PP) using a cemented postero-stabilized knee system (Optetrak Logic PS, Exactech, Gainesville, FL), grouped as 1) Group I (control): 21 TKAs using conventional mechanical instruments; 2) Group II: 21 TKAs performed using the CAOS system with an early experience level (first 21 cases); and 3) Group III: 21 TKAs using the CAOS system with an advanced experience level (beyond 30 cases). Surgical time was compared across the three groups (with significance defined as p<0.05).Introduction
Materials and methods
One main perceived drawback for the adoption of computer assisted orthopaedic surgery (CAOS) during total knee arthroplasty (TKA) relates to the increased surgical time compared to the use of standard mechanical instrumentation. This study compared the time efficiency between a next generation CAOS system (ExactechGPS®, Blue-Ortho, Grenoble, FR) and conventional mechanical instrumentation, and assessed the impact of surgeon experience level on the efficiency. Surgical time was retrospectively reviewed on 63 primary TKAs performed by a board-certified orthopaedic surgeon (PP) using the Optetrak Logic® PS knee system (Exactech, Gainesville, FL), grouped as 1) Group I (control): 21 TKAs using conventional mechanical instruments; 2) Group II: 21 KAs performed using the CAOS system with an early experience level (first 21 cases); and 3) Group III: 21 TKAs using the CAOS system with an advanced experience level (beyond 30 cases). Patient condition (age, BMI, gender, etc.), surgical technique, and post-operative guidelines were similar across the three groups. No cases were lost and no patient had any intra-operative complications. Surgical time was compared across the three groups (with significance defined as p<0.05). Compared to the TKAs using conventional mechanical instrumentation, the average surgical time for the navigated TKAs performed with an early experience was 7 minutes longer. However, with an advanced experience level, the average surgical time was 2 minutes less than the time required using conventional mechanical instrument. Further, navigated TKAs with an advanced experience level exhibited the least variability among the three groups. None of the time differences were significant (p>0.20). No significant difference in TKA surgical time was found between the evaluated CAOS system (both within or pass the learning curve) and the conventional instrumentation. Nevertheless, once the learning curve was reached, the system decreased the time variability compared to conventional mechanical instrumentation. The comparable efficiency reported in this study to the conventional mechanical instrumentation may be attributed to the unique features of the ExactechGPS system, such as indication for use inside the sterile field, blood occlusion-resistant tracker design, customisable operative technique tailored to the surgeon's preference, and compact and reduced number of instruments.
