title: Proprioception in Patients With Anterior Cruciate Ligament Tears: A Meta-analysis Comparing Injured and Uninjured Limbs.
abstract: BACKGROUND
  Because of a reduction in the number of mechanoreceptors or alterations of their characteristics, anterior cruciate ligament (ACL) tears lead not only to mechanical instability but also to impaired proprioception. Purpose/Hypothesis: This study analyzed whether ACL tears cause a greater decrease in proprioception in injured than in uninjured knees. The hypothesis was that knee proprioception after ACL tears would decrease more in injured than in contralateral uninjured knees, regardless of the method used to measure knee proprioception.
  
  
  METHODS
  Meta-analysis.
  
  
  METHODS
  We identified studies comparing proprioception in ACL-injured and contralateral intact knees using threshold for detection of passive motion (TTDPM) or joint position sense (JPS) tests. JPS was assessed by measuring the reproduction of passive positioning (RPP) or active repositioning (RAP) of the knee.
  
  
  RESULTS
  Sixteen studies were included in this meta-analysis. The pooled results of subgroup analyses of TTDPM for both 20° and 40° of knee flexion showed that mean angle of error was 0.23° (95% CI, 0.08°-0.37°) greater in ACL-injured than in contralateral intact knees ( P = .002). Pooled data RAP and RPP subgroup analyses also showed that the mean angle of error was 0.94° higher in ACL-injured than in contralateral intact knees. The mean difference in angle of error between ACL-injured and contralateral intact knees was 0.71° greater (95% CI, 0.68°-0.74°; P < .001) by JPS than by TTDPM.
  
  
  CONCLUSIONS
  Proprioception of ACL-injured knees was decreased compared with contralateral intact knees, as determined by both joint movement (kinesthesia) and joint position. The magnitude of loss of proprioception was greater in joint position than in joint movement.
authors.affiliation: Department of Preventive Medicine, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Sports Medical Center, Korea University College of Medicine, Anam Hospital, Seoul, Republic of Korea.
authors.forename: Jin-Hyuck
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Dae-Hee
authors.initials: DH
authors.lastname: Lee
mesh_terms: D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology* / Q000523:psychology*; D006801:Humans; D009068:Movement; D011434:Proprioception / Q000502:physiology*; D016059:Range of Motion, Articular
keywords: anterior cruciate ligament tear; joint position sense; proprioception; threshold for detection of passive motion