Abstract
Introduction
Although the “learning curve” in surgical procedures is well recognized, little data exists documenting the accuracy of surgeons in performing individual steps of orthopedic procedures. In this study we have used a validated computer-based training system to measure variations instrument placement and alignment in TKA, specifically those relating to tibial preparation.
Methods
Eleven trainees (surgical students, residents and fellows) were recruited to perform a series of 43 knee replacement procedures in a computerized training center. After initial instruction, each trainee performed a series of four TKA procedures in cadavers (n=2) and bone replicas (n=2) using a contemporary TKA instrument set and the assistance of an experienced surgical instructor. The Computerized Bioskills system was utilized to monitor the placement and orientation of the proximal tibial osteotomy and the tibial tray.
Results
The tibial component was implanted with an average posterior slope of 3.2°±2.7°. In 14% of cases the tibial resection sloped anteriorly, and in another 5%, the posterior slope exceeded 10°. In 83% of trials, the trainees cut the tibia with less posterior slope than intended, ranging from −10.0° to +5.6° (average:−2.0°±4.0°). The average rotational orientation of the tibial component was 5.4°±5.3°of external rotation, however individual values ranged from 7.6°of int rot to 14.4°of ext rot. Overall, 19% of components were placed in internal rotation.
Conclusions
Tibial preparation still presents significant difficulty to many less experienced surgeons, despite the use of modern instrumentation and careful didactic instruction. The errors measured in the computerized bioskills lab unfortunately replicate clinical cases often presenting with symptoms necessitating early revision,. Greater attention is needed to training of surgical skills and intraoperative assessment of component position to improve clinical outcomes of TKA.
