[Navigated implantation of total knee endoprostheses in secondary knee osteoarthritis of rheumatoid arthritis patients as compared to conventional technique].

INTRODUCTION: The operative treatment of a secondary gonarthrosis due to RA claims high quality in soft tissue balancing and accurate alignment in total knee arthroplasty (TKA) which are essential for good long-term results. The efficiency of an imageless computer-assisted implantation in TKA was evaluated and compared with conventional technique.
METHOD: The authors implanted each 40 TKA either using the imageless computer-assisted or classical surgeon-controlled technique. The quality of implantation was studied on postoperative long leg coronal and lateral x-rays.
RESULTS: A postoperative leg axis between 3 degrees varus and 3 degrees valgus was obtained in 37 patients (92.5%) in the study group and 30 patients (75%) in the control group. Complications influencing the clinical outcome did not occur.
CONCLUSION: The use of the imageless Vector-Vision navigation system provides the patient a good chance for longterm survival. Especially the ligament balancing tool appears to be useful. Cutting errors can be detected and intraoperatively corrected.