Background/Purpose: Total knee replacement (TKR) is one of the most common elective surgeries and is effective for managing knee pain in osteoarthritis. However functional outcomes post TKR are variable. Exercise and physical activity (PA) improve functional outcomes post TKR, but little is known about the role of specific content and dosage of exercise and PA on outcomes. While most patients receive some physical therapy (PT) post TKR, PT exercise content and dosage vary widely and are poorly documented. Importantly, trends in healthcare show more patients are receiving less direct PT and are instructed to perform exercise and PA with no supervision or with “virtual” supervision at home. Our study describes the content and dosage of exercise and PA that patients performed at home post TKR and assesses patient attributes that may influence patient engagement in exercise and PA.

Methods: Patients from 3 US states and multiple outpatient PT sites post-TKR recorded home exercises and PA performed using daily logs.  Logs included exercise name, repetitions, sets, resistance, perceived difficulty (RPE), and PA per day. Three independent reviewers identified exercise type, total and weekly average of exercises, total and weekly average of progressions and total and weekly average of PA. Patient demographics, health status and joint-specific symptoms were collected at baseline through patient-reported assessment surveys. Descriptive statistics of patient and exercise factors are reported. Chi² and Fisher’s exact tests and linear regressions are used to identify patient factors associated with characteristics of exercise and PA.

Results: 74 patients returned exercise logs, 15 were excluded for incomplete or unclear responses; 50 records included 4 weeks of exercise logs; 9 included < 4 weeks. Patient characteristics are similar to those in a national registry of total joint replacement patients (FORCE-TJR) (Table 1). Amount of weekly exercise and PA varied widely (Table 2). On average (s.d.) patients performed 45.4 (23.3) exercises weekly, more strengthening than stretching (30.0 (18.8) vs 16.4 (9.2)). More strengthening exercises were non-weight bearing (OC) than weight bearing (CC). Average PA was 264.0 (264.0) minutes per week. We found no statistically significant associations between patients’ clinical attributes and types or quantity of exercise and PA, although trends existed suggesting sex, presence of low back pain (LBP) and pre-operative function may affect home exercise engagement.

Conclusion: Patient-reported amount of at-home exercise and PA varied widely. Exercise logs often overstate patient engagement, but our data show wide variations in quantity, with some patients reporting few exercises and little PA and others reporting extreme amounts. Patients’ clinical attributes did not help explain this variation. As post TKR rehabilitation trends suggest more dependence on home exercise and PA than on face-to-face PT, it is essential that we understand the source of variation in the type and quantity of at-home exercise and PA. Future research will examine the influence of patient engagement and variation in home exercise and PA on long term functional outcomes post TKR in order to optimize functional outcomes.

Table 1 Ex logs abstract

Table 2 Ex logs abstract

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/descriptive-analysis-of-patient-reported-home-exercise-and-physical-activity-and-their-associations-with-patient-baseline-characteristics-following-total-knee-replacement/