title: Long-term follow-up of isolated ACL tears treated without ligament reconstruction.
abstract: OBJECTIVE
  The incidence of subsequent meniscal tears and arthritis among patients with isolated ACL tears treated without ligament reconstruction has not been clearly established. The purpose of this study was to (1) compare the risk of subsequent meniscal tears and osteoarthritis (OA) between patients with isolated ACL tears treated without ligament reconstruction and a matched cohort of individuals without ACL tears and (2) examine factors predictive of long-term sequelae after non-operative treatment of isolated ACL tears.
  
  
  METHODS
  This study compared a population-based incidence cohort of 364 patients with new-onset, isolated ACL tears between 1990 and 2000, to an age and sex-matched cohort of 364 individuals without ACL tears. A chart review was performed to collect information related to the initial injury, treatment, and outcomes. Subjects were retrospectively followed for mean follow-up of 14.3 years (±7.4 years) to determine the development of subsequent meniscal injury, arthritis, or total knee arthroplasty (TKA).
  
  
  RESULTS
  Patients treated without ligament reconstruction after ACL tears had a significantly higher risk of secondary meniscal tears (HR 18.0, 95 % CI 9.7, 33.3), arthritis (HR 14.2, 95 % CI 8.0, 25.2), and need of TKA (HR 5.0, 95 % CI 2.1, 12.2) than individuals without ACL tears. Lateral meniscal tear at diagnosis was associated with a higher risk of arthritis (HR 2.7, 95 % CI 1.4, 5.7) and TKA (HR 4.3, 95 % CI 1.3, 13.7). Treatment with meniscectomy was associated with an increased risk of additional meniscal tears (HR 51.5, 95 % CI 10.3, 936.8).
  
  
  CONCLUSIONS
  Patients treated non-operatively after isolated ACL tears are at a significantly higher risk of secondary meniscal tears, arthritis, and TKA when compared to age and sex-matched subjects without ACL tears. Additionally, baseline lateral meniscal tears were significantly associated with an increased probability of developing arthritis and the need for TKA. This information may be helpful when counselling patients about the natural history of ACL tears treated without ligament reconstruction.
  
  
  METHODS
  III.
authors.affiliation: Departments of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA. sanders.thomas@mayo.edu.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Sanders
authors.affiliation: Departments of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Ayoosh
authors.initials: A
authors.lastname: Pareek
authors.affiliation: Departments of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.|Health Sciences Research, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Hilal Maradit
authors.initials: HM
authors.lastname: Kremers
authors.affiliation: Departments of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Bryan
authors.affiliation: Departments of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Levy
authors.affiliation: Departments of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Stuart
authors.affiliation: Departments of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Diane L
authors.initials: DL
authors.lastname: Dahm
authors.affiliation: Departments of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Krych
mesh_terms: D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries / Q000453:epidemiology*; D019645:Arthroplasty, Replacement, Knee / Q000706:statistics & numerical data; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D020370:Osteoarthritis, Knee / Q000453:epidemiology; D000070600:Tibial Meniscus Injuries / Q000453:epidemiology
keywords: Anterior cruciate ligament; Arthritis; Meniscal tear; Non-operative; Total knee arthroplasty