title: Factors involved in the development of osteoarthritis after anterior cruciate ligament surgery.
abstract: BACKGROUND
  The incidence of osteoarthritis after anterior cruciate ligament reconstruction is disturbingly high, with reports of nearly 50% of patients developing mild to moderate osteoarthritis 6 years after surgery. Few studies have assessed the factors involved in the development of osteoarthritis.
  
  
  OBJECTIVE
  The following 10 factors will be found to be predictive of osteoarthritis: meniscectomy, chondral damage, patellar tendon grafting, age at surgery, time delay between injury and surgery, type and intensity of postsurgery sport, quadriceps strength, hamstring strength, quadriceps-to-hamstring strength ratio, and residual joint laxity.
  
  
  METHODS
  Cohort study (prognosis); Level of evidence, 1.
  
  
  METHODS
  Fifty-six subjects with anterior cruciate ligament reconstruction were followed for 6 years after surgery. Assessment included KT-1000 arthrometer testing, isokinetic strength testing, a return-to-sport questionnaire, and a radiograph assessment. A discriminant analysis was performed to assess which of the 10 factors could discriminate between those patients who developed tibiofemoral and patellofemoral osteoarthritis and those who did not.
  
  
  RESULTS
  Five factors were found to be predictive of tibiofemoral osteoarthritis. Meniscectomy (r = .72) and chondral damage (r = .41) were the strongest discriminators, followed by patellar tendon grafting (r = .37) (chi(2) [7, n = 56] = 25.48; P = .001). Weak quadriceps (r = .39) and low quadriceps-to-hamstring strength ratios (r = .6) were very close discriminators (chi(2) [8, n = 42] = 15.02; P = .059). For patellofemoral osteoarthritis, meniscectomy (r = .45), chondral damage (r = .75), and age at surgery (r = .65) were predictors or close predictors (chi(2) [7, n = 54] = 13.30; P = .065).
  
  
  CONCLUSIONS
  As not all 10 factors studied were predictive of osteoarthritis, the hypothesis was only partially proven. Preventing further meniscal and chondral damage in patients with anterior cruciate ligament deficiency is critical. Grafting using the hamstring tendons and restoration of quadriceps-to-hamstring strength balance are associated with less osteoarthritis.
authors.affiliation: School of Health and Sport Sciences, The University of the Sunshine Coast, Queensland, Australia. slkeays@optusnet.com.au
authors.forename: Susan L
authors.initials: SL
authors.lastname: Keays
authors.forename: Peter A
authors.initials: PA
authors.lastname: Newcombe
authors.forename: Joanne E
authors.initials: JE
authors.lastname: Bullock-Saxton
authors.forename: Margaret I
authors.initials: MI
authors.lastname: Bullock
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Keays
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001315:Australia; D050376:Bone-Patellar Tendon-Bone Grafting; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000601:surgery; D008297:Male; D020370:Osteoarthritis, Knee / Q000209:etiology*; D017060:Patient Satisfaction; D019651:Plastic Surgery Procedures; D020127:Recovery of Function; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult