A986. LATERAL EPICONDYLAR OSTEOTOMY USING COMPUTER NAVIGATION IN TOTAL KNEE ARTHROPLASTY FOR RIGID VALGUS DEFORMITIES

Abstract

Extensive release of postero-lateral structures may be required to correct rigid and severe valgus deformities during total knee arthroplasty. Current techniques are technically difficult, may not accurately restore soft tissue balance, and are associated with postoperative complications. We evaluated the results of using computer navigation for lateral epicondylar osteotomy during total knee arthroplasty for rigid severe valgus arthritis.

We had performed this procedure during navigated TKA in 10 valgus arthritic knees (2 bilateral TKAs) in 8 patients (1 male and 7 female). The mean age at the time of surgery was 65.7 years (range, 48–77 years) and the mean preoperative valgus deformity was 19.25° (range, 10°–36.5°). The mean postoperative limb alignment at the end of a mean follow-up of 20 months (range, 14–31 months) was 0.5° valgus (range, 2° varus–1.8° valgus). None of the patients had any complications related to the procedure with no obvious clinical mediolateral instability and complete union at the osteotomy site was noted in all patients radiographically at the last followup.

Computer navigation allows for precisely measuring the difference between medial and lateral gaps as well as the limb alignment and to determine the effect of sequential soft-tissue releases on both. Our technique takes advantage of this feature to accurately re-position the lateral epicondylar block in order to equalize medial and lateral gaps thereby ensuring a stable knee. Internal fixation with compression screws coupled with large contact surfaces of cancellous bone at the osteotomy site allow for early post-operative rehabilitation and ensure union at the osteotomy site.