Preventing Posttraumatic Osteoarthritis With Physical Activity Promotion
Condition: Anterior Cruciate Ligament Injuries; Exercise; Cartilage, Articular; Knee Injuries; Osteoarthritis; Osteoarthritis, Knee; Arthritis; Joint Diseases
MeSH terms: Osteoarthritis; Osteoarthritis, Knee; Joint Diseases; Wounds and Injuries; Knee Injuries; Anterior Cruciate Ligament Injuries
Study type: Interventional

Summary: 
      Osteoarthritis (OA) is a leading cause of disability worldwide that affects millions of
      Americans each year. Posttraumatic OA (PTOA) significantly impacts patients after anterior
      cruciate ligament (ACL) injury and ACL reconstruction (ACLR) with approximately 50% of
      patients developing PTOA within 20 years of injury or surgery. Knee joint mechanical loading
      measured via physical activity (i.e. daily steps) is insufficient in individuals after ACLR
      compared to uninjured individuals. Establishing the beneficial effects of physical activity
      to promote optimal free-living knee joint mechanical loading and improve knee joint health
      will aid in the development of cost-effective interventions that prevent PTOA and health
      burden of the disease.
    

Detailed description: 
      Osteoarthritis (OA) is a leading cause of disability worldwide resulting in severe
      limitations in daily activities and chronic pain. It is estimated that 35% of posttraumatic
      OA (PTOA) cases occur after knee injuries and surgeries such as anterior cruciate ligament
      (ACL) injury and ACL reconstruction (ACLR). Optimal free-living mechanical loading, which
      refers to the forces acting on the knee caused by daily activities, plays an essential role
      in maintaining knee articular cartilage health. After ACLR, individuals take fewer steps per
      day as compared to uninjured controls. This results in insufficient free-living mechanical
      loading to joint tissues and is associated with early PTOA development. Adequate physical
      activity (PA) is recommended to help reduce risk of PTOA, but it is unclear how changes in PA
      acutely impact knee joint cartilage health. The overall objective of this pretest-posttest
      experimental pilot study is to determine how optimizing free-living mechanical loading
      through PA promotion improves cartilage composition in individuals who demonstrate
      insufficient free-living mechanical loading after ACLR. PA promotion will be delivered over 8
      weeks using commercially available PA monitors and the patients' smartphone to provide daily
      personalized and achievable step goals to increase daily step counts to a level consistent
      with healthy PA participation. The hypothesis for aim 1 is that MRI markers of proteoglycan
      density associated with PTOA development will improve after 8-weeks of PA promotion exposure.
      Hypothesis for aim 2 is that greater changes in steps per day will be associated with
      improved proteoglycan density. Change in MRI markers of proteoglycan density and steps per
      day will be assessed using a pretest-posttest design in 8 adults who are 6 months to 5 years
      post-ACLR with insufficient mechanical loading (<8,000 steps per day)24 and suboptimal
      quality of life (quality of life survey<87.5). Outcomes will be collected before (pretest)
      and after (posttest) 8-weeks of PA promotion. For the PA promotion, participants will receive
      a text message each morning with a personalized, daily step count goal and a link used to
      confirm receipt of the goal. The preceding 10 days of step data will be rank ordered and the
      60th percentile step count will be set as the goal for the next day. The proposed work is
      innovative, in that this study will use a novel combination of outcomes that will lead to
      unprecedented insight into the influence of PA promotion in mitigating early PTOA
      development.
    

Intervention name(s): Physical Activity Promotion
Intervention type(s): Behavioral
Intervention description(s): After enrolling, participants will be outfitted with a Fitbit Charge 2 activity monitor. The monitor will be worn during all waking hours, and compliance will be considered as a day with ≥ 1,000 steps. Participants will complete a 14-day "run-in" observation period while wearing the Fitbit but no PA promotion will occur. Individuals who are noncompliant during the "run in" period (<10 days with <1,000 steps) will be removed. Participants will receive a text message each morning with a personalized, daily step count goal and a link used to confirm receipt of the goal. The preceding 10 days of step data will be rank ordered and the 60th percentile step count will be set as the goal for the next day.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment