Abstract
BACKGROUND: Early rehabilitation within 4 h following total knee arthroplasty involves passive exercise with manual therapy. OBJECTIVE: The aim was to determine the beneficial effects of the single-joint hybrid assistive limb for rehabilitation within 4 h after total knee arthroplasty. METHODS: This single-blinded randomized controlled trial included 68 participants who underwent primary total knee arthroplasty for knee osteoarthritis and were assigned to the early single-joint hybrid assistive limb (n = 22), HAL-SJ (n = 23), and control (n = 23) groups. RESULTS: The Knee Injury and Osteoarthritis Outcome Score quality of life (p = 0.007) scores of the early single-joint hybrid assistive limb group showed significantly higher values than the control groups at 12 months. The recovery time for extension lag was significantly improved in the early single-joint hybrid assistive limb group compared with the single-joint hybrid assistive limb (p = 0.006) and control (p < 0.001) groups. Additionally, the knee flexion range of motion of the early single-joint hybrid assistive limb group showed significantly higher values than the single-joint hybrid assistive limb (p = 0.029) and control (p = 0.031) groups at 1 week. CONCLUSIONS: Early single-joint hybrid assistive limb rehabilitation may improve patient-reported quality of life at 12 months without exacerbating postoperative pain or swelling. These results suggest that the single-joint hybrid assistive limb may be a feasible adjunct to early postoperative rehabilitation after total knee arthroplasty, while further studies are required to clarify its clinical relevance and long-term benefits.