Influence of Gap Balance on the Sagittal Movement of a Specific Mobile Bearing Floating Platform Design in Total Knee Arthroplasty

Abstract

We analyzed 119 knees implanted with mobile bearing floating platform prostheses using the navigation-assisted gap balancing technique to analyze the relationship between intraoperative sagittal movement of floating platforms and soft tissue balancing. The 95 (79.8%) knees were classified into the positive rollback group (mean insert posterior rollback 5.86 +/- 1.24 mm), and the remaining 24 (20.2%) into the negative rollback group. Lateral flexion gap (LFG) differed significantly between knees with positive and negative rollback (20.5 +/- 1.7 mm vs 22.1 +/- 1.7 mm, P = .021). Only LFG significantly influenced the occurrence of bearing sagittal movement. Sagittal translation of the insert occurred in about 80% of knees implanted with mobile bearing floating platforms in TKA, and was affected by flexion gaps, especially on the lateral side. (C) 2013 Elsevier Inc. All rights reserved.