Improving Rehabilitation Outcomes After Total Hip Arthroplasty

This study plans to learn more about the effects of physical therapy (PT) following a total hip arthroplasty (THA). The purpose of this study is to compare standard of care PT after THA with a physical therapy program specifically designed to integrate targeted core and hip muscle strength and functional training.

Over the next 20 years, the number of total hip arthroplasties (THAs) performed to alleviate pain and disability associated with osteoarthritis (OA) is expected to double to more than 500,000/year. Most patients report improved health-related quality of life following surgery; however, deficits in physical function and quality of life persist. Specifically, Veterans with THA have a higher prevalence of severe activities of daily living (ADL) limitations and report severe physical health-related quality of life deficits. The increased THA utilization, combined with long-term functional deficits which increase heath care utilization, suggests a need for targeted rehabilitation strategies to improve physical function for Veterans after THA.

Movement compensations are a biomarker of functional decline in a variety of older adult populations. For patients with THA, persistent movement compensations are seen in activities of daily living, such as level walking, sit-to-stand transitions, and stair climbing. These movement compensations likely stem from a combination of poor muscle strength and a failure to integrate available muscle strength into functional movement. Functional strength integration (FSI) during daily tasks refers to the ability of the body to produce stable, coordinated movements. At the hip joint, optimal FSI is largely dependent on the ability of hip abductor muscles to produce sufficient hip abduction moments to stabilize the pelvis during unilateral stance tasks. Thus, inability to integrate hip abductor muscle strength during functional tasks results in poor pelvic stability and movement compensations. Lack of FSI possibly explains the deficits in functional recovery after THA. However, current rehabilitation practices do not target the integration of strength and functional movement to resolve movement compensations.

Rehabilitation emphasizing functional strength integration after THA has the potential to substantially improve postoperative physical function by remediating movement compensations with greater hip abductor strength and recruitment during function, providing greater pelvic control and better movement quality. Therefore, the investigators propose a randomized controlled trial of 100 participants to determine if an 8-week functional strength integration (FSI) program after THA improves physical function and muscle performance more than control intervention (CON) after unilateral THA. The secondary goal is to determine if FSI improves movement compensations during functional activity (walking and stair climbing). Eight weeks of intervention will be initiated 2 weeks after THA to allow for early tissue healing. Outcomes will be assessed pre-operatively (PRE); intervention mid-point (after 4 weeks intervention; POST1); intervention end-point (after 8 weeks intervention; POST2) (primary endpoint); and late recovery (26 weeks after initiating rehabilitation; POST3).

Eligibility Criteria:
Inclusion Criteria:

* BMI less than or equal to 40
* Receiving unilateral primary total hip arthroplasty for osteoarthritis

Exclusion Criteria:

* Severe contralateral leg OA (\>= 5/10 pain with stair climbing)
* Other unstable orthopaedic conditions that limit function
* Neurological or pulmonary problems that severely limit function
* Uncontrolled hypertension or diabetes
* Use of illegal substances