Step-by-step measurements of soft tissue balancing during total knee arthroplasty for patients with varus knees.

Using a step-by-step procedure, we measured joint gap during surgery using a simple device with a torque meter in 45 osteoarthritis knee joints (43 patients) with varus deformity. The effects of specific cuts or releases of the anatomic portion on joint gaps were investigated. Each cut or release resulted in various increases in the medial gap from 1.2 to 3.8 mm on average. The final gap measurements averaged 24.1 mm medially and 27.6 mm laterally in extension, and 24.6 mm medially and 27.2 mm laterally in flexion. The results of the measurements showed that each step-by-step procedure had a tendency of gap increase. The results led us to measure soft tissue balancing in a step-by-step procedure during total knee arthroplasty.