The influence of preoperative deformity on valgus correction angle: an analysis of 503 total knee arthroplasties.

We prospectively studied variations in valgus correction angle (VCA) and the influence of preoperative limb deformity on VCA in 503 consecutive total knee arthroplasties done in 393 patients. The percentage of limbs that had VCA values less than 5° was 10.9%, and that with VCA values greater than 7° was 44.9%. The percentage of limbs with VCA greater than 7° was significantly more in varus knees, and that with VCA less than 5° was significantly more in valgus knees; preoperative deformity showed a significant correlation with VCA. Choosing a fixed-routine VCA of 5° to 7° may cause an unacceptable planning error that may be minimized by individualizing VCA or using computer navigation.