Portable electronic devices for mechanotherapy and operative treatment of osteoarthritis

Knee osteoarthritis (KOA) is fundamentally driven by abnormal mechanical loading and the subsequent loss of joint homeostasis. Effective therapeutic strategies, whether conservative or surgical, depend on the precise restoration of physiological kinematics and load distribution. This review synthesizes recent advances in sensor technologies designed to quantify the mechanobiological environment of the knee. In non-surgical management, wearable systems utilizing inertial measurement units (IMU) and flexible pressure sensors enable the continuous monitoring of gait cycles, joint angles, and muscle activation, providing objective data for neuromuscular rehabilitation. In surgical contexts, we analyze the evolution of intraoperative sensing from rigid force-sensing spacers to emerging soft electronics in total knee arthroplasty (TKA). A critical challenge remains in developing sensors with mechanical compliance similar to biological tissues and minimal thickness to fit the constrained joint space during joint-preserving procedures. We highlight the potential of novel transduction mechanisms-including piezoresistive, capacitive, piezoelectric, and triboelectric systems-to overcome these limitations. The integration of these flexible, self-powered technologies with data-driven analytics offers a pathway toward an integrated data-driven treatment framework, which could facilitate optimal biomechanical alignment and functional recovery.