title: Changes in serum biomarkers of cartilage turnover after anterior cruciate ligament injury.
abstract: BACKGROUND
  Biomarkers of cartilage turnover and joint metabolism have a potential use in detecting early degenerative changes after a traumatic knee joint injury; however, no study has analyzed biomarkers before an anterior cruciate ligament (ACL) injury and again after injury or in comparison with a similar group of uninjured controls.
  
  
  OBJECTIVE
  Changes in serum biomarker levels and the ratio of cartilage degradation to synthesis, from baseline to follow-up, would be significantly different between ACL-injured patients and uninjured controls.
  
  
  METHODS
  Case-control study; Level of evidence, 3.
  
  
  METHODS
  This case-control study was conducted to examine changes in serum biomarkers of cartilage turnover following ACL injury in a young athletic population. Specifically, 2 markers for type II collagen and aggrecan synthesis (CPII and CS846, respectively) and 2 markers of types I and II degradation and type II degradation only (C1,2C and C2C, respectively) were studied. Preinjury baseline serum samples and postinjury follow-up samples were obtained for 45 ACL-injured cases and 45 uninjured controls matched for sex, age, height, and weight.
  
  
  RESULTS
  Results revealed significant decreases in C1,2C (P = .042) and C2C (P = .006) over time in the ACL-injured group when compared with the controls. The change in serum concentrations of CS846 from baseline to follow-up was also significantly different between the ACL-injured patients and uninjured controls (P = .002), as was the change between groups in the ratio of C2C:CPII over time (P = .013). No preinjury differences in the ratio of C1,2C:CPII or C2C:CPII were observed between groups; however, postinjury differences were observed for both ratios.
  
  
  CONCLUSIONS
  Changes in biomarker concentrations after an ACL injury suggest an alteration in cartilage turnover and joint metabolism in those sustaining ACL injuries compared with uninjured matched controls.
authors.affiliation: John A. Feagin Jr Sports Medicine Fellowship, Department of Orthopedic Surgery, Keller Army Hospital, West Point, NY 10996, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Svoboda
authors.forename: Travis M
authors.initials: TM
authors.lastname: Harvey
authors.forename: Brett D
authors.initials: BD
authors.lastname: Owens
authors.forename: William F
authors.initials: WF
authors.lastname: Brechue
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Tarwater
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Cameron
mesh_terms: D000293:Adolescent; D016118:Anterior Cruciate Ligament / Q000378:metabolism; D000070598:Anterior Cruciate Ligament Injuries; D015415:Biomarkers / Q000097:blood*; D002356:Cartilage / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000097:blood*; D008297:Male; D016032:Randomized Controlled Trials as Topic; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: ACL injury; biomarkers; cartilage metabolism; cartilage turnover; posttraumatic osteoarthritis