Incision Length in Small Incision Total Knee Arthroplasty: How Long of an Incision Is Needed?

Abstract

This prospective review studied incision length with a small incision TKA technique and compared measured incision lengths to various anatomic and clinical parameters. We prospectively reviewed 357 cases of primary total knee arthroplasty using a small paramedial incision and utilizing small incision instrumentation. By using linear regression analysis, we found that incision length was generally related to the width of the distal cut femur and the width of the proximal cut tibia. Incision length was not related to height, weight, BMI, or femoral implant width. Clinically based upon our data, a reasonable starting incision for small incision TKA (as measured in knee extension) is a length that is 1.6 times the measured width of the distal femur. The surgeon should always extend the incision if he/she encounters difficulty in exposure and/or placement of instrumentation.