title: Exercise, manual therapy, and use of booster sessions in physical therapy for knee osteoarthritis: a multi-center, factorial randomized clinical trial.
abstract: (1) Do treatment effects differ between participants receiving manual therapy (MT) with exercise compared to subjects who don't, (2) are treatment effects sustained better when participants receive booster sessions compared to those who don't over a one year period in subjects with knee osteoarthritis (KOA)?
  
  
  
  Multi-center, 2 × 2 factorial randomized clinical trial. 300 participants with knee OA were randomized to four groups: exercise-no boosters (Ex), exercise-with boosters (Ex+B), manual therapy+exercise-no boosters (MT+Ex), manual therapy+exercise-with boosters (MT+Ex+B). The primary outcome was the Western Ontario and McMaster osteoarthritis index (WOMAC) at 1 year. Secondary outcomes included knee pain, physical performance tests, and proportions of participants meeting treatment responder criteria.
  
  
  
  There were no differences between groups on the WOMAC at 1 year or on any performance-based measures. Secondary analyses indicated a) better scores on the WOMAC and greater odds of being a treatment responder at 9 weeks for participants receiving MT, b) greater odds of being a treatment responder at 1 year for participants receiving boosters. Exploratory interaction analysis suggested knee pain decreases for participants receiving boosters and increases for participants not receiving boosters from 9 weeks to 1 year.
  
  
  
  MT or use of boosters with exercise did not result in additive improvement in the primary outcome at 1 year. Secondary outcomes suggest MT may have some short term benefit, and booster sessions may improve responder status and knee pain at 1 year. However, the role of booster sessions remains unclear in sustaining treatment effects and warrants further study.
  
  
  
  gov (NCT01314183).
authors.affiliation: Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, USA. Electronic address: kfitzger@pitt.edu.
authors.forename: G K
authors.initials: GK
authors.lastname: Fitzgerald
authors.affiliation: Department of Physical Therapy, Associate Dean for Research, College of Health, University of Utah, Salt Lake City, UT, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Fritz
authors.affiliation: US Army-Baylor University, San Antonio, TX, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Childs
authors.affiliation: Rehabilitation Services, Intermountain Healthcare, Salt Lake City, UT, USA.
authors.forename: G P
authors.initials: GP
authors.lastname: Brennan
authors.affiliation: Center for Research on Health Care Data Center, Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: V
authors.initials: V
authors.lastname: Talisa
authors.affiliation: Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: A B
authors.initials: AB
authors.lastname: Gil
authors.affiliation: Henry M. Jackson Foundation for the Advancement of Military Medicine, Randolph Air Force Base, Schertz, TX, USA.
authors.forename: B D
authors.initials: BD
authors.lastname: Neilson
authors.affiliation: Centre for Musculoskeletal Outcomes Research, Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
authors.forename: J H
authors.initials: JH
authors.lastname: Abbott
mesh_terms: D015444:Exercise; D005081:Exercise Therapy; D006801:Humans; D026201:Musculoskeletal Manipulations; D009864:Ontario; D020370:Osteoarthritis, Knee; D026741:Physical Therapy Modalities
keywords: Booster sessions; Exercise; Knee; Manual therapy; Osteoarthritis; Physical therapy