title: Effectiveness of Knee Injury and Anterior Cruciate Ligament Tear Prevention Programs: A Meta-Analysis.
abstract: OBJECTIVE
  Individuals frequently involved in jumping, pivoting or cutting are at increased risk of knee injury, including anterior cruciate ligament (ACL) tears. We sought to use meta-analytic techniques to establish whether neuromuscular and proprioceptive training is efficacious in preventing knee and ACL injury and to identify factors related to greater efficacy of such programs.
  
  
  METHODS
  We performed a systematic literature search of studies published in English between 1996 and 2014. Intervention efficacy was ascertained from incidence rate ratios (IRRs) weighted by their precision (1/variance) using a random effects model. Separate analyses were performed for knee and ACL injury. We examined whether year of publication, study quality, or specific components of the intervention were associated with efficacy of the intervention in a meta-regression analysis.
  
  
  RESULTS
  Twenty-four studies met the inclusion criteria and were used in the meta-analysis. The mean study sample was 1,093 subjects. Twenty studies reported data on knee injury in general terms and 16 on ACL injury. Maximum Jadad score was 3 (on a 0-5 scale). The summary incidence rate ratio was estimated at 0.731 (95% CI: 0.614, 0.871) for knee injury and 0.493 (95% CI: 0.285, 0.854) for ACL injury, indicating a protective effect of intervention. Meta-regression analysis did not identify specific intervention components associated with greater efficacy but established that later year of publication was associated with more conservative estimates of intervention efficacy.
  
  
  CONCLUSIONS
  The current meta-analysis provides evidence that neuromuscular and proprioceptive training reduces knee injury in general and ACL injury in particular. Later publication date was associated with higher quality studies and more conservative efficacy estimates. As study quality was generally low, these data suggest that higher quality studies should be implemented to confirm the preventive efficacy of such programs.
authors.affiliation: Orthopaedic and Arthritis Center for Outcomes Research, Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
authors.forename: Laurel A
authors.initials: LA
authors.lastname: Donnell-Fink
authors.affiliation: Orthopaedic and Arthritis Center for Outcomes Research, Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
authors.forename: Kristina
authors.initials: K
authors.lastname: Klara
authors.affiliation: Orthopaedic and Arthritis Center for Outcomes Research, Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.|Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Collins
authors.affiliation: Orthopaedic and Arthritis Center for Outcomes Research, Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
authors.forename: Heidi Y
authors.initials: HY
authors.lastname: Yang
authors.affiliation: Orthopaedic and Arthritis Center for Outcomes Research, Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
authors.forename: Melissa G
authors.initials: MG
authors.lastname: Goczalk
authors.affiliation: Orthopaedic and Arthritis Center for Outcomes Research, Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.|Harvard Medical School, Boston, Massachusetts, United States of America.|Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Katz
authors.affiliation: Orthopaedic and Arthritis Center for Outcomes Research, Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.|Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: Elena
authors.initials: E
authors.lastname: Losina
mesh_terms: D016118:Anterior Cruciate Ligament / Q000503:physiopathology; D000070598:Anterior Cruciate Ligament Injuries; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology / Q000517:prevention & control*; D011434:Proprioception