Colloquia

Summary

 The number of Total Knee Arthroplasty (TKA) procedures is steadily increasing and is expected to continue rising in the coming years. Consequently, the incidence of revision surgeries is also growing, with instability being one of the leading causes. Patients experiencing knee instability are often prescribed knee braces to alleviate symptoms. However, despite their widespread clinical use, the underlying working mechanisms of knee braces remain poorly understood. Existing evidence is limited, frequently relying on subjective assessments or cadaver-based studies.

          To address this gap, a sensorized mock-up knee and dedicated test setup were developed to enable objective evaluation of the mechanisms of commercially available knee braces. The design requirements were derived from a comprehensive literature review on current methods for assessing knee instability and the state of the art in knee brace functionality. The mock-up knee replicates key anatomical structures, including the femur, tibia, knee joint, collateral ligaments, patellar ligament, quadriceps and hamstring muscles, and surrounding soft tissue.

          The system integrates multiple sensing modalities, including motion capture, a six-degree-of-freedom force–torque sensor, and a pressure sensing mechanism to quantify brace tightness. Additionally, a control system was implemented to simulate dynamic quadriceps actuation.

          The mock-up knee and test setup were designed, built, and verified and validated to determine whether the design requirements were met and whether they are suitable for objective evaluation of knee brace performance.