Intraoperative Manipulation for Flexion Contracture During Total Knee Arthroplasty

Joint gap balancing during total knee arthroplasty (TKA) is important for ensuring postoperative joint stability and range of motion. Although the joint gap should be balanced to ensure joint stability, it is not easy to achieve perfect balancing during TKA. In particular, relative extension gap shortening can induce flexion contracture. Intraoperative manipulation is often empirically performed. This study evaluated the tension required for this manipulation and investigated the influence of intraoperative manipulation on the joint gap in cadaveric knees. Total knee arthroplasty was performed in 6 cadaveric knees from whole body cadavers. Flexion contracture was induced using an insert that was 4 mm thicker than the extension gap, and intraoperative manipulation was performed. Study measurements included the changes in the joint gap after manipulation at 6 positions, with the knee bending from extension to 120 degrees flexion, and the manipulation tension that was required to create a 4-mm increase in the gap. The manipulation tension needed to create a 4-mm increase in the extension gap was 303 +/- 17 N. The changes in the joint gap after manipulation were 0.4 mm, 0.6 mm, 0.2 mm, -0.2 mm, -0.4 mm, and -0.6 mm at 0 degrees, 30 degrees, 45 degrees, 60 degrees, 90 degrees, and 120 degrees flexion, respectively. Therefore, the joint gap was not significantly changed by the manipulation. Intraoperative manipulation does not resolve flexion contracture. Therefore, if flexion contracture occurs during TKA, treatment with additional bone cutting and soft tissue release is likely more appropriate than manipulation.