title: The rate of subsequent surgery and predictors after anterior cruciate ligament reconstruction: two- and 6-year follow-up results from a multicenter cohort.
abstract: BACKGROUND
  Subsequent surgeries have a profound effect on patient satisfaction and outcome after primary anterior cruciate ligament reconstruction (ACLR). There have been no prospective studies to date describing the rate and predictors (surgical and patient variables) of all subsequent knee surgeries at short-term and midterm follow-up along with analyses of surgical and patient variables that are associated with subsequent surgeries.
  
  
  OBJECTIVE
  To report the rate and predictors of all subsequent surgeries at short-term and midterm follow-up along with associated patient variables.
  
  
  METHODS
  Case-control study; Level of evidence, 3.
  
  
  METHODS
  A total of 980 patients (540 male) were prospectively enrolled in a Multicenter Orthopaedic Outcomes Network (MOON) cohort from January 2002 to December 2003. The 2- and 6-year follow-up information for subsequent procedures was obtained. Operative reports were obtained, and all procedures were categorized.
  
  
  RESULTS
  One hundred eighty-five patients underwent a subsequent surgery on the ipsilateral leg (18.9%) and 100 on the contralateral knee (10.2%) at 6-year follow-up. On the ipsilateral knee, there was a 7.7% rate of ACL revisions, a 13.3% rate of cartilage procedures, a 5.4% rate of arthrofibrosis procedures, and a 2.4% rate of procedures related to hardware. For the contralateral knee, there was a 6.4% rate of primary ACL ruptures. Younger age at the index surgery and the use of allografts were predictors (risk factors) for subsequent surgery. Revision ACLR, female sex, body mass index, and surgical exposure were not significant predictors.
  
  
  CONCLUSIONS
  At 6-year follow-up, 18.9% of patients who had undergone ACLR underwent subsequent surgeries on the ipsilateral knee. The rates between an ipsilateral ACLR graft versus a contralateral normal ACL tear were similar (7.7% vs 6.4%, respectively). Younger age and the use of allografts were risk factors for subsequent surgery.
authors.affiliation: University of Iowa, Iowa City, Iowa, USA.
authors.forename: Carolyn M
authors.initials: CM
authors.lastname: Hettrich
authors.forename: Warren R
authors.initials: WR
authors.lastname: Dunn
authors.forename: Emily K
authors.initials: EK
authors.lastname: Reinke
authors.forename: Kurt P
authors.initials: KP
authors.lastname: Spindler
mesh_terms: D000293:Adolescent; D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000706:statistics & numerical data*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D011237:Predictive Value of Tests; D012086:Reoperation / Q000706:statistics & numerical data; D012307:Risk Factors; D055815:Young Adult
keywords: anterior cruciate ligament reconstruction; subsequent surgery