title: Prevalence and Incidence of Cartilage Injuries and Meniscus Tears in Patients Who Underwent Both Primary and Revision Anterior Cruciate Ligament Reconstructions.
abstract: BACKGROUND
  Previous studies have found differences in meniscus and cartilage injury rates between groups of patients after primary and revision anterior cruciate ligament reconstructions (ACLRs). This study examined a cohort of individual patients who underwent primary and subsequent revision ACLR to determine the incidence of cartilage and meniscus disease.
  
  
  OBJECTIVE
  To describe the prevalence and incidence of meniscus and articular cartilage injuries in patients who underwent primary and then subsequent revision ACLR as well as indicate differences in the management of these injuries.
  
  
  METHODS
  Case series; Level of evidence, 4.
  
  
  METHODS
  Patients who underwent primary and then revision ACLR from February 2005 to September 2011 were identified using a community-based registry. Patient and procedure characteristics were obtained, and descriptive statistics were used to evaluate the study sample.
  
  
  RESULTS
  There were 261 patients who underwent primary and then subsequent revision ACLR during the study period. The median age was 18 years at primary ACLR and 20 years at revision ACLR. Revision ACLR was performed for instability in 256 patients (98%) and for infection in 5 patients (2%). The prevalence of cartilage injuries increased from 14.9% at primary ACLR to 31.8% at revision ACLR. The prevalence of meniscus tears decreased from 54.8% at primary ACLR to 43.7% at revision ACLR. The prevalence of lateral meniscus tears was 32.2% at primary ACLR but only 18.4% at revision ACLR, while the prevalence of medial meniscus tears was the same at primary and revision ACLRs (32.6%). Patients who underwent meniscus tear treatment at primary ACLR had a 70.8% prevalence of meniscus tears at revision ACLR.
  
  
  CONCLUSIONS
  In this community-based sample followed from primary ACLR to revision ACLR, the prevalence of articular cartilage injuries increased, while the prevalence of meniscus injuries decreased. The higher prevalence of articular cartilage injuries at revision ACLR may represent new injuries. The lower prevalence of meniscus tears at revision ACLR may be caused by susceptible menisci being injured and treated at primary surgery or by changes in knee kinematics or injury exposure patterns.
authors.affiliation: Department of Orthopaedic Surgery, Kaiser Permanente, Walnut Creek, California, USA ronald.wyatt@kp.org.
authors.forename: Ronald W B
authors.initials: RW
authors.lastname: Wyatt
authors.affiliation: Surgical Outcomes and Analysis Department, Kaiser Permanente, San Diego, California, USA.
authors.forename: Maria C S
authors.initials: MC
authors.lastname: Inacio
authors.affiliation: University of California, San Francisco, San Francisco, California, USA.
authors.forename: Kate D
authors.initials: KD
authors.lastname: Liddle
authors.affiliation: Department of Orthopaedic Surgery, Kaiser Permanente, Baldwin Park, California, USA.
authors.forename: Gregory B
authors.initials: GB
authors.lastname: Maletis
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D002358:Cartilage, Articular / Q000601:surgery; D005260:Female; D006801:Humans; D015994:Incidence; D007718:Knee Injuries / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D015995:Prevalence; D012042:Registries; D012086:Reoperation; D012189:Retrospective Studies; D012421:Rupture / Q000601:surgery; D000070600:Tibial Meniscus Injuries; D055815:Young Adult
keywords: articular cartilage injury; knee anterior cruciate ligament; meniscus tear