The Varus Osteoarthritic Knee Has No Coronal Contractures in 90 Degrees of Flexion

Abstract

< 0.0001) whereas the measured lateral laxity displayed a nonsignificant difference compared with healthy knees. The mean difference in medial-lateral laxity was 1.5 ± 1.1 degrees. A medial-lateral difference of ≤2.5 degrees was present in 91.6% of knees. We found no evidence of contractures in the coronal plane tissue of the end-stage OA knee at the time of TKA. Absolute medial-lateral balance is not typical of the end-stage OA knee in 90 degrees of flexion with a small medial-lateral difference typically present. Careful examination of the soft tissues in flexion at the commencement of TKA may help guide surgery to optimize the coronal plane soft tissue envelope. Our findings would suggest that large releases during either a gap-balanced or a measured-resection TKA would not typically be necessary, and that releases that increase laxity in flexion may increase often already lax medial tissue or increase laxity within lateral tissues that typically already have physiological tension.