The Design and Validation of a Device to Intraoperatively Measure Knee Stability During Total Knee Arthroplasty

The success of a total knee arthroplasty is determined, in part, by the ability of a surgeon to adequately manage (or balance) the soft tissues surrounding the joint. Postoperative malalignment or imbalance of the collateral ligaments can lead to a lax joint and result in early loosening and instability, and leaving the knee too tight may cause stiffness and limited motion [1,2]. The severity and location of wear patterns on the polyethylene insert are also associated with knee stability from ligament balancing [3]. Establishing a balanced soft tissue envelope remains a challenge that is not always achieved [4], and instability, tightness, and wear that result from unbalanced knees may necessitate revision surgery [2,5] or result in reduced patient satisfaction.