MedStar NRH Study Finds that Innovative Devices Did Not Provide Better Outcomes for Knee Replacement Patients Undergoing Outpatient Rehabilitation

Researchers from MedStar National Rehabilitation Hospital and MedStar Health Physical Therapy were a part of a large multi-center randomized clinical trial that found that newer and more expensive devices, increasingly seen in outpatient physical therapy centers, did not enhance outcomes for patients following their knee replacement relative to conventional care.

Study findings appear in  a recent issue of the Journal of Arthroplasty, one of the nation’s three leading orthopedic surgery journals and in  JAMA Network Open, JAMA’s on-line journal.

In the U.S., upwards of 1.0 million people obtain a primary total knee arthroplasty (TKA) per year. Most go on to use outpatient physical therapy—soon after discharge or following a stay at home or another facility. As part of a typical outpatient visit, the patient will initially participate in a warm-up exercise using a recumbent bike designed to increase blood flow and tissue pliability.

The trial compared 4 exercise interventions: (1) a recumbent bike (which is usual care) compared to the three newer exercise interventions: (2) a bodyweight-adjustable treadmill, (3) a patterned electrical neurostimulation (PENS) devise used with a recumbent bike, and (4) a PENS device used with a bodyweight-adjustable treadmill.

The study compared intervention outcomes using (1) walking speed, a performance-based measure, and (2) the Knee Injury and Osteoarthritis Outcome Score or KOOS, the most common patient-report measure used to evaluate TKA outcomes.

The study enrolled 363 patients with more than 90 participants in each of the study’s four arms across 15 MedStar Physical Therapy outpatient rehabilitation centers. Altogether 19 MedStar orthopedic surgeons referred patients to the study.

Jean Hsieh, PhD, of MedStar NRH’s research program served as the study’s principal investigator. Dr. Hsieh was assisted by Gerben DeJong, PhD as co-principal investigator. Michele Vita, DPT served as the chief clinical services coordinator with able assistance from Linda Briggs, EdD, AVP for the MedStar National Rehabilitation Network. Biostatistical support for the study came from Alexander Zeymo and Sameer Desale of the MedStar Health Research Institute. The study could not have succeeded without the strong support of John Brickley, VP, MedStar National Rehabilitation Network and John Rockwood, its president.

The study was funded internally by the MedStar National Rehabilitation Network with support from several outside sources including the company’s whose devices were evaluated.

Journal of Arthroplasty, Vol. 35 (08), 2054-2065. DOI: 10.1016/j.arth.2020.03.048