Gap Balancing Sacrifices Joint-Line Maintenance to Improve Gap Symmetry: A Randomized Controlled Trial Comparing Gap Balancing and Measured Resection

A total knee arthroplasty can be completed using two techniques; measured resection or gap balancing. A prospective blinded randomized controlled trial was completed with 103 patients randomized to measured resection (n=52) or gap balancing (n=51). Primary outcome measure was femoral component rotation. Secondary outcome measures were joint-line change, gap symmetry and function and quality-of-life outcomes. Gap balancing resulted in a significantly raised joint-line compared to measured resection. Gap symmetry was significantly better using gap balancing. Functional outcomes and quality-of-life were not significantly different at 24 months. Using computer navigation, gap balancing significantly raises the joint-line in order to improve gap symmetry. This does not result in a clinical difference in function or quality of life at 24 months.