title: Determinants of knee replacement in subjects with a history of arthroscopy: data from the osteoarthritis initiative.
abstract: OBJECTIVE
  To investigate the risk and determinants of knee replacement (KR) in subjects with or at risk of osteoarthritis (OA) and a history of arthroscopy.
  
  
  METHODS
  Data from the osteoarthritis initiative cohort were analyzed (n = 4796, up to the seventh year of follow-up). Cox proportional hazard analysis was used to determine the risk of KR according to the history of arthroscopy. A multivariable model was used to determine the risk factors for KR among subjects with a history of arthroscopy (n = 842), including age, gender, body mass index, history of knee injury, and baseline physical activity scale for the elderly, Western Ontario and McMaster (WOMAC) total score, and radiographic Kellgren and Lawrence (KL) score.
  
  
  RESULTS
  History of arthroscopy was associated with risk of KR after adjustments for the mentioned determinants of OA (HR: 1.90 (1.49-2.44); P value <0.001). Female gender (HR: 1.86 (1.30-2.68); P value <0.001), higher WOMAC (HR: 1.02 (1.01-1.03); P value <0.001), and KL score (HR: 2.64 (2.08-3.35); P value <0.001) increased the risk of KR among subjects with a history of arthroscopy. Subjects with a history of knee injury had 50 % lower risk of KR (HR: 0.50 (0.35-0.72); P value <0.001) after arthroscopy.
  
  
  CONCLUSIONS
  Female gender, more clinical symptoms and radiographic signs of OA, was associated with higher risk of future KR in subjects with a history of arthroscopy. Subjects with arthroscopy in the setting of concomitant knee injury were 50 % less likely to undergo KR compared to subjects who underwent arthroscopy without a history of concomitant knee injury.
authors.affiliation: Department of Orthopedic Surgery, Johns Hopkins University, Baltimore, MD, USA. bzikria2@jhmi.edu.|Johns Hopkins Department of Orthopedics, Johns Hopkins University, 4924 Campbell Road Suite 130, Baltimore, MD, 21236, USA. bzikria2@jhmi.edu.
authors.forename: Bashir
authors.initials: B
authors.lastname: Zikria
authors.affiliation: Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Nima
authors.initials: N
authors.lastname: Hafezi-Nejad
authors.affiliation: Department of Orthopedic Surgery, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: John
authors.initials: J
authors.lastname: Wilckens
authors.affiliation: Department of Orthopedic Surgery, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Ficke
authors.affiliation: Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Shadpour
authors.initials: S
authors.lastname: Demehri
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods / Q000706:statistics & numerical data; D001182:Arthroscopy / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000601:surgery; D010147:Pain Measurement / Q000379:methods; D011859:Radiography / Q000379:methods; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index
keywords: Arthroscopy; Cohort study; Knee; Knee replacement; Osteoarthritis