title: Radiographic joint space width is correlated with 4-year clinical outcomes in patients with knee osteoarthritis: data from the osteoarthritis initiative.
abstract: OBJECTIVE
  To evaluate if quantitative joint space width (JSW) measurements from radiographs correlate with 4-year Knee injury and Osteoarthritis Outcome Scores (KOOS) and clinical performance measures.
  
  
  METHODS
  The study group consisted of 942 patients with symptomatic knee osteoarthritis (OA). 4-year outcomes for six measures (KOOS Pain, Symptom, Quality of Life, and Function scores, 20-m walk pace, and chair stand time) were used to create six multiple linear regression models. Primary predictors were baseline minimum JSW and 4-year change in JSW measured from fixed flexion radiographs. Age, gender, body mass index (BMI), race, knee alignment, and baseline measures of the outcomes of interest were covariates.
  
  
  RESULTS
  Lower baseline minimum JSW and a greater decrease in 4-year JSW significantly correlated with worse 4-year KOOS Pain, Symptom, and Quality of Life. With all other factors constant, a 4.1, 4.8, and 5.6 mm lower baseline JSW correlated with a clinically significant eight-point drop in 4-year KOOS Pain, Symptom, and Quality of Life scores respectively. Additionally, a 3.5, 3.1, and 4.0 mm loss of JSW over 4 years correlated with a clinically significant eight-point drop in 4-year KOOS Pain, Symptom, and Quality of Life scores respectively.
  
  
  CONCLUSIONS
  Our results indicate quantitative radiographic JSW measurements correlate with 4-year clinical outcomes. Since patients with narrower JSW at the onset of study had lower KOOS scores at 4 years even after controlling for 4-year change in JSW and baseline KOOS scores, clinical outcomes in knee OA may be predetermined once the disease process begins. These findings suggest early treatment with disease modifying therapies may be necessary to influence outcomes.
authors: Cleveland Clinic Lerner College of Medicine, 9500 Euclid Ave, NA-21, Cleveland, OH 44195, USA. oaks@ccf.org
authors: S R
authors: SR
authors: Oak
authors: A
authors: A
authors: Ghodadra
authors: C S
authors: CS
authors: Winalski
authors: A
authors: A
authors: Miniaci
authors: M H
authors: MH
authors: Jones
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000628:therapy*; D015992:Body Mass Index; D016208:Databases, Factual / Q000706:statistics & numerical data; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000628:therapy*; D010147:Pain Measurement; D011788:Quality of Life; D011859:Radiography; D012307:Risk Factors; D016896:Treatment Outcome
keywords: Clinical progression; Joint space width; Knee osteoarthritis; X-ray