Early Results of TKA with Electromagnetic Navigation

Kang, Dong Joon; Suh, Jeung Tak; Shin, Won Chul; Ahn, Jae Min; Kim, Tae Wan

Abstract

PURPOSE
We compared the results of electromagnetic navigation assisted total knee arthroplasty (TKA) with that of conventional TKA from the viewpoint of the postoperative limb alignment and the implant position.
MATERIALS AND METHODS
We retrospectively analyzed 115 consecutive total knee arthroplasties that were done between September 2006 and June 2007. There were 65 navigation assissted cases and 50 conventionally implanted cases. We analyzed the postoperative radiologic results, the clinical results over one year follow up after surgery and the range of motion (ROM).
RESULTS
The postoperative mechanical axis deviation showed no significant difference between the two groups. However, the tibial zone, as assessed by Kennedy and White's method were at zone C for 60 cases (92%) in the navigation group and for 40 cases (80%) in the conventional group (p=0.01). On the coronal plane, the implant position of the femoral component was 89.4+/-4.1degrees in the navigation group and 87.6+/-4.3degrees in the conventional group (p<0.01), and the implant position of the tibial component was 89.7+/-1.1degrees and 91.9+/-1.8degrees in each group, respectively (p<0.01), and this shows the better result in the navigation group.
CONCLUSION
Electromagnetic navigation assisted TKA had similar clinical results on the short-term follow up as compared with conventional TKA. However, it radiologically showed a more satisfactory position of the implant and it displayed superiority in locating the precise position of the femoral and tibial components, and especially on the coronal plane.