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Hip and knee replacement surgeries are among the most common orthopedic procedures performed worldwide. While these surgeries can dramatically improve quality of life by relieving chronic pain and restoring mobility, the recovery journey is often challenging. Patients must rebuild strength, regain range of motion, and relearn fundamental movement patterns — all while protecting healing tissues. This is where robotic lower limb exoskeletons are changing the game, offering a new approach to post-surgery rehabilitation that is both more effective and more personalized than traditional methods alone.
A lower-limb exoskeleton is a wearable robotic device that attaches to the legs, providing powered assistance and support to facilitate movement. Equipped with sensors, motors, and intelligent control systems, these devices detect the user's movement intentions and deliver precise torque at the hip, knee, or ankle joints. Unlike traditional mobility aids such as crutches or walkers, exoskeletons distribute mechanical support directly to the lower limbs, allowing patients to practice natural gait patterns during the critical early stages of recovery. This makes them particularly valuable for lower limb rehabilitation exoskeletons used in clinical settings.
After hip or knee replacement surgery, patients are typically advised to limit weight-bearing on the operated leg for a period of time. This protective phase is necessary but can slow down recovery if prolonged. Lower-limb exoskeletons solve this dilemma by enabling early mobilization with adjustable support — offloading the healing joint while still allowing the patient to perform walking exercises. This early activity is crucial for preventing complications such as deep vein thrombosis, muscle atrophy, and joint stiffness, all of which are associated with extended immobility. By getting patients moving sooner, exoskeletons help break the cycle of decline that can follow major joint surgery.
Regaining full knee flexion and extension is one of the primary goals after joint replacement. A 2024 meta-analysis published in Medicine examined eight studies involving 302 patients and found that those using robotic exoskeletons after total knee replacement achieved significantly greater improvements in active range of motion (SMD: 10.98, 95% CI: 7.81–14.16) and passive range of motion (SMD: 4.11, 95% CI: 1.02–7.20) compared to conventional rehabilitation. The same analysis reported higher Hospital for Special Surgery (HSS) scores and shorter hospital stays for exoskeleton-assisted patients, suggesting that these devices not only improve functional outcomes but may also reduce healthcare costs.
Following hip or knee replacement, many patients develop compensatory movement patterns — such as limping or uneven weight distribution — that can lead to secondary issues in the back, hips, or opposite leg. Exoskeletons equipped with biomechanical modeling, such as the Bear Adult lower-limb exoskeleton robot, simulate a natural human gait and guide the patient through correct movement patterns. The Bear Adult delivers continuous torque output of up to 50Nm and supports various functional training modes, making it suitable for repetitive high-frequency walking training. This type of guided practice helps correct abnormal gait and improves overall walking ability, which is especially important in the weeks following surgery when movement habits are being re-established.
Not every patient recovers at the same pace, and rehabilitation programs must adapt accordingly. The Gait Assist exoskeleton robot uses multi-sensor fusion technology to identify the user's movement intentions in real time and deliver personalized training. Its high-power electric control system provides strong yet controlled power output, while the comfortable human-machine interaction design ensures safety during each session. Key features include motion intention recognition for active walking, individualized parameter adjustment for precise training, and training data export for clinical assessment and research. This level of customization helps ensure that each patient receives the right amount of support at the right stage of recovery.
Joint replacement and corrective surgery are not limited to older adults. Younger patients and those with congenital conditions may also require surgical intervention. The Rabbit Kid children's lower-limb exoskeleton provides safe and comfortable human-machine interaction with multiple training modes designed to enhance active motor skills. It has been successfully deployed in several Hong Kong institutions, including the Hong Kong Christian Service's Pui Yi School, the Hong Kong Red Cross' Margaret Trench School, Haven of Hope Sunnyside School, and the Duchess of Kent Children's Hospital. All three devices — Bear Adult, Rabbit Kid, and Gait Assist — are IEC 60601 certified for safety and reliability.
The evidence base supporting exoskeleton-assisted rehabilitation continues to grow. Beyond the meta-analysis by Wu et al. (2024), a clinical trial using the Honda Walking Assist hip-wearable exoskeleton found that patients who underwent total knee arthroplasty and received exoskeleton-assisted gait training maintained their walking speed during the early postoperative period, while the control group experienced a temporary decline. Another study on the Hybrid Assistive Limb (HAL) demonstrated that single-joint exoskeleton training helped reduce extension lag and pain during early postoperative knee rehabilitation. These findings collectively point to a clear conclusion: lower limb exoskeletons for assistance can accelerate recovery, improve outcomes, and reduce the burden of post-surgical rehabilitation.
Key Benefits at a Glance
Lower-limb exoskeleton robots are suitable for a wide range of post-surgical and rehabilitation patients, including:
These devices are used in rehabilitation departments, neurology wards, neurosurgery units, intensive care units, and increasingly in home-based care settings under professional supervision.
The integration of lower-limb exoskeleton robots into post-surgery rehabilitation represents a significant advancement in orthopedic recovery. By enabling early mobilization, restoring natural range of motion, correcting gait abnormalities, and providing personalized training, these devices help patients recover faster, more safely, and with better long-term outcomes. For anyone facing hip or knee replacement surgery, discussing robotic exoskeleton options with their rehabilitation team could be a meaningful step toward a smoother and more confident recovery journey.