Abstract
Polyclinique le Languedoc, avenue de la Côte-des-Roses, 11100 Narbonne 7885
Purpose of the study: The goal of navigation for TKA is to improve the precision of the frontal alignment. Continuing this objective, we were interested in a different option than navigation: we wanted to optimise traditional instrumentation and associated an implantation procedure with a rigorous radiographic planning system.
Material and methods: This was a consecutive series of 100 TKA all implanted by the same operator; pre- and postoperative goniometry was performed in the same radiology unit and controlled by the same radiologist. Preoperative planning was based on the weight-bearing goniometry with a femoral valgus varying from 3 to 11, in order to obtain a distal femoral cut strictly orthogonal to the mechanical axis. The tibial cut, independent of the femoral cut was also orthogonal to the tibial axis. The instrument sent enabled in situ correction, with 1° precision, of the angle of the femoral and/or tibial cut if it was different from the preoperative measurement; tibial insertion was mixed (centromedullary and controlled by an extramedullary system).
Results: Mean patient age, male-female ratio and varus/valgus were comparable with other series. The mean postoperative HKA angle was 180±2.3°. Alignment varied from 0 to 2° in 70 patients. Defective alignment of 2 to 3° was observed in 14 patients, i.e. 92% of knees within 3°. Eight patients were misaligned at 3 to 5° which was the greatest deviation in this series.
Conclusion: These results demonstrate that the quality of TKA implantation can be improved, in particular implant alignment, by optimising the operative technique and the surgical material and associating simple radiographic planning, without necessarily using navigation systematically.
Correspondence should be addressed to Ghislaine Patte at sofcot@sofcot.fr
