This prospective randomized clinical trial assessed a novel device for initial management of knee range of motion (ROM),
pain, and function after
total knee arthroplasty (TKA). Primary TKA patients with preoperative ROM of at least 5° to 115° were randomized to initial knee motion management: Mizzou BioJoint Flex-novel motion-
assistive device with prescribed
physical therapy or standard
physical therapy-prescribed
physical therapy. ROM,
pain score, and
knee injury and
osteoarthritis score for
joint replacement (KOOSjr) were obtained preoperatively and 2 weeks, 6 weeks, and 3 months postoperatively. Patient satisfaction for both cohorts and subjective assessments of the MBF device were assessed at 3 months. Readmissions, reoperations, and complications were assessed through 1 year. Nineteen patients were randomized to each cohort, with no significant preoperative differences in demographics,
pain score, KOOSjr score, or ROM. Six SPT (31.6%) and 3 MBF (15.8%) patients failed to regain preoperative ROM (p = 0.044). One SPT (5.3%) and eight MBF (42%) patients exceeded 125° ROM (p = 0.019) by 3 months. Total ROM (p = 0.039),
pain (p = 0.0068), and function (p = 0.0027) were significantly better for MBF at 3 months. MBF patients reported significantly higher satisfaction (mean, 9.4 ± 1.1 vs. 8.0 ± 1.8, respectively; p = 0.0084). One patient in each group underwent manipulation under
anesthesia. No other readmissions, reoperations, or complications were reported. A novel
durable medical equipment device can provide a safe and effective patient-controlled method for initial management of knee ROM,
pain, and function after primary TKA with potential clinically meaningful advantages over
physical therapy alone. In conjunction with
physical therapy, management with this novel knee flexion device more effectively restored knee ROM and early patient function when compared with
therapy alone and was associated with higher proportions of patients regaining minimum (115°) and desired (125°) levels of knee ROM and clinically meaningful differences in
pain scores, knee function, and patient satisfaction. This is a Level 1, prospective trial study.