Intraoperative Comparison of Measured Resection and Gap Balancing Using a Force Sensor: A Prospective, Randomized Controlled Trial.

Document Type


Publication Date


Publication Title

The Journal of arthroplasty


FuZion balancer; TEA; TKA; eLIBRA sensor; gap balancing; measured resection


BACKGROUND: For establishing femoral component position, gap-balancing (GB) and measured resection (MR) techniques were compared using a force sensor.

METHODS: Ninety-one patients were randomized to undergo primary total knee arthroplasty using either MR (n = 43) or GB (n = 48) technique using a single total knee arthroplasty design. GB was performed with an instrumented tensioner. Force sensor data were obtained before the final implantation.

RESULTS: GB resulted in greater range of femoral component rotation vs MR (1.5° ± 2.9° vs 3.1° ± 0.5°, P < .05) and posterior condylar cut thickness medially (10.2 ± 2.0 mm vs 9.0 ± 1.3 mm) and laterally (8.5 ± 1.9 mm vs 6.4 ± 1.0 mm). Force sensor data showed a decreased intercompartmental force difference at full flexion in GB (.8 ± 2.3 vs 2.0 ± 3.3u, 1u ≈ 15 N, P < .05).

CONCLUSION: GB resulted in a greater range of femoral component rotation and thicker posterior condylar cuts resulting in an increased flexion space relative to MR. Intercompartmental force difference trended toward a more uniform distribution between full extension and full flexion in the GB vs MR group.

Clinical Institute

Orthopedics & Sports Medicine