Combination of Accelerometer-Based Navigation and Force Sensor for Precise Bone Resection and Appropriate Soft Tissue Balancing in Total Knee Arthroplasty

Background: Precise bone resection and appropriate soft tissue balancing are considered indispensable in total knee arthroplasty (TKA). However, in most TKAs, only the experienced-based subjective physical “feel” of the surgeon, or either a computer-based navigation system or a soft tissue balancing system are applied to improve the results. In the present study, a combination of both an accelerometer-based navigation system and an electronic knee balancing force sensor were applied to attempt to obtain optimal outcomes. Materials and Methods: An accelerometer-based navigation system and an electronic knee balancing force sensor were applied in combination in 5 TKAs. Thereafter, the incidence of radiographical outliers of the lower-extremity mechanical axis and the alignments of femoral and tibial components, and the incidence of intraoperative lateral retinacular release were evaluated and compared against those of 5 TKAs performed with the force sensor alone as a control. Results: The posterior slope of the tibia was significantly improved in the TKAs performed with the combination of both devices (P=0.004). No lateral release was performed in any TKAs of either group. Conclusion: TKAs performed under the combination of an accelerometer-based navigation system and an electronic knee balancing force sensor can obtain greater the accuracy of bone resection and appropriate soft tissue balancing.