The Study of Physical Activity Rewards After Knee Surgery

Physical activity (PA) has been shown to improve pain and function in persons with knee
osteoarthritis (OA), reduce obesity, and prevent the onset and progression of heart disease,
diabetes, and chronic pulmonary disease. The US Department of Human and Health Services
(DHHS) guidelines recommend that adults engage in >150 minutes of moderate physical activity
per week. However, adherence to PA guidelines is poor in the general population, particularly
in persons with knee OA.

Total knee replacement (TKR) is widely used in patients with symptomatic, advanced knee OA.
While the vast majority of persons undergoing TKR experience considerable reduction in pain
and improvement in functional capacity, far fewer take this opportunity to become more
physically active. Since physical activity has a direct relationship with quality of life and
with prevention and amelioration of many chronic conditions, many TKR recipients do not
derive maximum benefits from the procedure.

The focus of this proposal is to conduct a proof of concept RCT to establish the efficacy of
a behavioral economics-based intervention that would facilitate engagement in physical
activity and improve adherence to PA guidelines in the growing population of TKR recipients.
We address the innovative hypothesis that the period following TKR presents a window of
opportunity to fundamentally change attitudes and beliefs regarding PA, and that tangible
economic incentives will effectively induce behavior change and facilitate adherence to PA
guidelines.

Inclusion Criteria:

- Scheduled to undergo primary TKA at BWH

- Osteoarthritis is the principal underlying diagnosis

- Age >=40 at the projected date of TKA

- English-speaking

- Willing and able to access the internet to complete study related questionnaires

Exclusion Criteria:

- Osteoarthritis is not the principal underlying diagnosis (e.g. inflammatory arthritis)

- Dementia (can not fill out forms)

- Psychological issues that preclude participation, as identified by participating
surgeons

- Does not have access to a computer and/or the internet.

- Non-English speaker (instruments are not validated in Spanish); very few non-English
speakers (<5%) are otherwise eligible

- Age <40 at the projected date of TKA (TKA is usually due to major trauma, juvenile
onset or congenital disease)

- Lives in a nursing home (difficult to track costs)

- Implantation of Unicompartamental Knee Arthroscopy (different clinical features and
different costs)

- Bilateral TKA in same admission (simultaneous), staged or within 6 months

- Uses a wheelchair or walker to ambulate

- Has been told by a physician that he/she has a heart condition and should only do
physical activity recommended by a doctor

- Has pain in his/her chest when doing physical activity

- Loses balance because of dizziness

- Loses consciousness

- Unable/unwilling to wear Fitbit® accelerometer for 5 or more days during baseline
visit