What Should the Surgeon Aim for When Performing Computer-Assisted Total Knee Arthroplasty?

Stability of the knee is a complex issue and involves ligaments that behave differently on the medial and lateral side. Correct positioning of the components and adequate soft-tissue balancing are critical steps in successful total knee arthroplasty1. A total knee prosthesis that is implanted “too tightly” may cause limited range of motion and compromise patient satisfaction. A total knee replacement that is implanted “too loosely” will be unstable2. Medial-lateral instability is the most common type of instability and may result from incompetent collateral ligaments, incomplete correction of a preoperative deformity, or incorrect bone cuts3. Separate studies have identified instability as a leading cause of early clinical failure of a primary total knee replacement, resulting in revision within three to five years4,5.