Improving Rehabilitation Outcomes After Total Hip Arthroplasty
Condition: Total Hip Arthroplasty; Osteoarthritis
MeSH terms: Osteoarthritis
Study type: Interventional

Summary: 
      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.
    

Detailed description: 
      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).
    

Intervention name(s): Functional Strength Integration (FSI); Control Group (CON)
Intervention type(s): Behavioral; Behavioral
Intervention description(s): FSI intervention involves strengthening of the hip musculature combined with focused techniques emphasizing early initiation of hip muscle recruitment to stabilize the pelvis, integrating strength and movement pattern training to maximize functional recovery. The FSI program consists of therapeutic exercise in 3 domains: pelvic stability (PST) training, functional training (FT), and strength training (ST). PST includes early surgical-limb weight bearing and core muscle strengthening, progressively increasing in difficulty based on performance benchmarks and therapist monitoring. FT focuses on gait and stair climb exercise, progressing to higher level agility training. ST includes progressive, resistance exercise to improve lower extremity muscle strength. The ST exercises include use of weighted pulleys/weight-training machines. Therapists will determine an 8-rep max for muscle groups and weight will be increased by 10% every 2 weeks to maximize hypertrophy and strength gains.; Observed practice patterns from previous investigations and discussion with physical therapists indicate that patients receive rehabilitation services during the 2-3 day hospital stay after THA, but not routinely after hospital discharge. Yet, to control for attention and volume of rehabilitation for the FSI group, patients in the control group will attend outpatient physical therapy for 14 visits (40 minute sessions) over 8 weeks. This control program will mimic the typical postoperative experience for patients in our community, in which patients independently manage their activity. This program will focus on patient education, functional ADL training, and therapeutic exercise. However, the activities in the exercise domain will be limited to low load exercise such as isometric muscle exercise, range of motion (ROM), and flexibility activities. These activities are specifically designed to mirror usual care activity.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Functional strength integration; Rehabilitation; Hip arthroplasty; Physical function; Muscle performance; Movement compensations