Smart exoskeleton-assisted rehabilitation after fracture surgery: closed-loop control, personalized load management,...

Bone fractures represent a significant global health challenge, particularly with the aging population, where traditional post-operative rehabilitation often falls short of meeting increasingly personalized recovery needs. Smart exoskeleton technology is evolving from passive orthoses toward powered, sensor-rich systems that integrate multimodal sensing-including sEMG, IMUs, and pressure sensors-to enable closed-loop control and dynamic assistance. This review summarizes the system architecture and control strategies of smart exoskeletons in post-fracture rehabilitation, focusing on personalized load management through "assist-as-needed" (AAN) algorithms and progressive loading protocols. Clinical decision-making for exoskeleton use must integrate the patient's biological condition-such as bone quality, age, and trauma complexity-with surgical fixation stability to aim to indirectly regulate mechanical loading toward the beneficial mechanobiological window of 2%-10% interfragmentary strain. While current evidence suggests these devices are safe and can improve range of motion and hospital stay duration, the clinical base remains heterogeneous, and consistent superiority over conventional therapy for complex fractures is yet to be established. Significant hurdles remain, including high device weight (12-27 kg), cost, anthropometric incompatibility, and the lack of standardized clinical frameworks. Future directions point toward lightweight, adaptive systems enhanced by Digital Twin technology for biomechanical simulation and predictive healing modeling. Furthermore, the integration of telemonitoring and multimodal care pathways will be essential to transition these systems from laboratory settings into routine clinical and home-based care.