LEARNING CURVES FOR NAVIGATION FOR IMPLANTATION OF TOTAL KNEE ARTHROPLASTY: A COMPARISON BETWEEN EXPERIENCED AND NEW OPERATORS

Abstract

Purpose of the study: Navigation systems have proven efficacy for implantation of total knee arthroplasty (TKA). Navigations have been accused of being complex, requiring a long learning curve. We compared the results obtained with the same navigation system in centers with experienced operators and centers with new operators.

Material and methods: Thirteen European centers participated in this prospective consecutive study. Inclusion criteria was indication for a TKA using a gliding prostheis with preservation of the posterior cruciate ligament. Four experienced cents(group A) with a mean experience of four years, and nine new centers (group B) with no prior experience participated in the study. The study concerned 403 TKA (182 in group A and 221 in group B). The main indications were primarily lateralized osteoarthritis. The navigation system was an imageless system based on intaoperative kinematic anatomic and kinematic analysis. A mobile plateau prosthesis was inserted. The following items were compared between the two groups: overall operative time and its variation over time, postoperative HKA, orientation of the femoral and tibial components in the ap and lateral views, complications and revisions.

Results: No significant difference was observed between the two groups for the preoperative items so comparison between the groups was licit. Correction of the frontal mechanical axis was satisfactory in 90% of patients in group A and 88% in group B (p> 0.05). There was no difference between the groups in quality of implantation for each prosthetic element on the ap and lateral views. There was no difference for rate of complications or reoperations. Longer operative time in group B disappeared after 15 implantations.

Discussion: The results from centers using navigation systems for prosthetic implantations shows that the performance in centers starting use is the same as in experienced centers. The only difference is an operative time slightly longer for the first 15 cases.