Tibial shaft axis does not always serve as a correct coronal landmark in total knee arthroplasty for varus knees

Predicted postoperative knee alignment was calculated when total knee arthroplasty was performed after 1 of 3 different methods of tibia preparation in 30 osteoarthritic knees with varus deformity. In Method 1, the tibia was cut perpendicular to the tibial shaft. In Method 2, the tibia was cut perpendicular to a line connecting the center of the tibial plateau and the center of the talar dome. In method 3, tibial resection was determined with an original template so that tibial resection would be perpendicular to a line connecting the center of the resected tibial plateau and the center of the talar dome. Methods 1 and 2 caused significantly more valgus alignment than Method 3 (P<.0001). The postoperative weight-bearing ratio was in Method 1, 57.7%, in Method 2, 53.6% and 50.0% in Method 3. These results suggest that cutting the tibia perpendicular to the tibial shaft can cause valgus alignment in total knee arthroplasty for varus knees.