Comparison of Treatments Following Total Knee Replacement

Although total knee replacement (TKR) improves pain in numerous patients, it does not resolve many of the substantial functional limitations and physical inactivity that existed for a long time prior to the surgery. Exercise is an intervention that could improve these long-term limitations. To promote these improvements, exercise should be implemented at later stage post TKR when patients can tolerate doses of exercise sufficiently high to promote substantial changes. To date, we just don't have enough good research to tell us which type of exercise works best for which patients and under which circumstances at later stage post TKR. This research study will provide evidence for recommended interventions during the later stage post TKR. The specific research questions are: (1) How do group exercise in the community and individual exercise in rehabilitation clinic compare with usual medical care on physical function and activity outcomes? (2) Who are the patients most likely to respond to each exercise intervention? (3) Are the approaches safe?

This is a comparative effectiveness study, designed as a 3-group single-blind randomized clinical trial. Two hundred forty older adults who underwent TKR at least 2 months prior and are otherwise eligible will be randomized into one of three treatment approaches: 1) clinic-based individual outpatient rehabilitative exercise; 2) community-based group exercise classes; or 3) usual medical care. Subjects will be treated for 3 months. Data will be collected before intervention, after intervention (3 months), and 6 months after randomization. Physical function is a primary outcome and will be assessed by the Western Ontario and McMaster Universities Arthritis Index and a battery of performance-based tests germane to patients post TKR that includes ability to walk, manage stairs, lift from the floor and the chair, and one-leg balance. We will also use an accelerometer-based monitor that provides a real-time measure of physical activity during normal daily living and is able to accurately capture most levels of activity. Linear mixed models will be fitted to compare the changes in outcome across groups. Logistic regression will identify patient characteristics that predict functional recovery in the exercise groups. Survival analysis and instrumental variable methods will be used to compare attrition, adherence and adverse events between groups.

Subjects will participate in supervised sessions (clinic-based) of exercise followed by a home exercise program 2 times per week during 3 months. Each exercise session will last about 60 minutes. Treatment sessions will utilize a pragmatic approach and will include the exercises designed to increase muscular strength, low impact cardiovascular exercise, range of movement, and activity for daily living skills.

Subjects will attend to exercise classes (community-based) 2 times per week during 3 months. The exercise classes last approximately 60 minutes. The group exercise classes consists of a variety of exercises designed to increase general muscular strength, low impact aerobic exercise, range of movement, and activity for daily living.

Subjects will participate in supervised sessions (clinic-based) of exercise followed by a home exercise program 2 times per week during 3 months. Each exercise session will last about 60 minutes. Treatment sessions will utilize a pragmatic approach and will include the exercises designed to increase muscular strength, low impact cardiovascular exercise, range of movement, and activity for daily living skills.

Subjects will attend to exercise classes (community-based) 2 times per week during 3 months. The exercise classes last approximately 60 minutes. The group exercise classes consists of a variety of exercises designed to increase general muscular strength, low impact aerobic exercise, range of movement, and activity for daily living.

WOMAC-PF is a patient reported outcome with 17 items. Each item is scored on a 5-point Likert-type Scale with descriptors from 0-4 (none, mild, moderate, severe, and extreme difficulty) and summed for a maximum score of 68. Higher scores indicate worse physical function.

Scores on 6 performance-based tests (i.e., the 6-minute walk test, 40-meter gait speed, stair ascend/descend test, single leg stance balance test, chair stand test, and floor sitting-rising) were combined into a composite score formed with the unit-weighted Z scores of constituent tests to provide a more representative and stable measure of the subjects' underlying functional performance. The unit weights refer to averaging standardized scores (e.g., the scores for each performance-based test are converted to Z-scores before applying equal weights). Higher Z-scores represent better functional performance. The Z-scores for each participant can be interpreted as deviations from the baseline average of the whole group. We considered a change in Z-score of 0.2 as clinically important because it represents approximately 20% of a standard deviation relative to the baseline average of the whole group.

Real-time measure of daily energy expenditure physical activity assessed by portable activity monitor.

Inclusion Criteria: Unilateral TKR 2 to 4 months prior Older than 60 years of age Experience functional limitation in daily activities (score in WOMAC-PF of at least 9 points) Speak sufficient English to understand study instructions Have medical clearance to participate in the study Are willing to be randomized to one of the 3 treatment arms Exclusion Criteria: Have absolute or relative contraindications to exercise Have history of uncontrolled cardiovascular disease or hypertension Are unable to walk 50 meters without an assistive device Have history of muscular or neurological disorder that affect lower extremity function Regular participation in exercise Terminal illness Planning to have another joint replacement during the next 12 months Plan not to be around during the next 12 months

Piva SR, Schneider MJ, Moore CG, Catelani MB, Gil AB, Klatt BA, DiGioia AM, Almeida GJ, Khoja SS, Sowa G, Irrgang JJ. Effectiveness of Later-Stage Exercise Programs vs Usual Medical Care on Physical Function and Activity After Total Knee Replacement: A Randomized Clinical Trial. JAMA Netw Open. 2019 Feb 1;2(2):e190018. doi: 10.1001/jamanetworkopen.2019.0018.

Piva SR, Moore CG, Schneider M, Gil AB, Almeida GJ, Irrgang JJ. A randomized trial to compare exercise treatment methods for patients after total knee replacement: protocol paper. BMC Musculoskelet Disord. 2015 Oct 16;16:303. doi: 10.1186/s12891-015-0761-5.