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Clinical and ultrasonographic predictors of joint replacement for knee osteoarthritis: results from a large, 3-year, prospective EULAR study
  1. P G Conaghan1,
  2. M A D'Agostino2,
  3. M Le Bars3,
  4. G Baron4,5,
  5. N Schmidely3,
  6. R Wakefield1,
  7. P Ravaud5,
  8. W Grassi6,
  9. E Martin-Mola7,
  10. A So8,
  11. M Backhaus9,
  12. M Malaise10,
  13. P Emery1,
  14. M Dougados11
  1. 1Section of Musculoskeletal Disease, University of Leeds and NIHR Leeds Musculoskeletal Biomedical Research Unit Leeds, UK
  2. 2Rheumatology Department, Ambroise Pare Hospital, UVSQ University, Boulogne-Billancourt, France
  3. 3Bristol Myers-Squibb, France
  4. 4Epidemiology, Biostatistics and Clinical Research Department, Bichat Hospital, France
  5. 5INSERM E0357 and University Paris 7, Paris, France
  6. 6Rheumatology Department, Jesi Hospital, Jesi, Italy
  7. 7Rheumatology Department, La Paz Hospital, Madrid, Spain
  8. 8Rheumatology Department, Vaudois Hospital, Lausanne, Switzerland
  9. 9Rheumatology Department, Charité University Hospital, Berlin, Germany
  10. 10Rheumatology Department, Saint Tiltman Hospital, Liege, Belgium
  11. 11Paris-Descartes University, Medicine Faculty, UPRES-EA 4058 & APHP, Cochin Hospital, Rheumatology B Department, Paris, France
  1. Correspondence to Professor Maxime Dougados, Paris-Descartes University, Medicine Faculty, UPRES-EA 4058 & APHP, Rheumatology B Department, Cochin Hospital, 27, rue du Faubourg St Jacques, 75014 Paris, France; maxime.dougados{at}


Objectives To determine clinical and ultrasonographic predictors of joint replacement surgery across Europe in primary osteoarthritis (OA) of the knee.

Methods This was a 3-year prospective study of a painful OA knee cohort (from a EULAR-sponsored, multicentre study). All subjects had clinical evaluation, radiographs and ultrasonography (US) at study entry. The rate of knee replacement surgery over the 3-year follow-up period was determined using Kaplan–Meier survival data analyses. Predictive factors for joint replacement were identified by univariate log-rank test then multivariate analysis using a Cox proportional-hazards regression model. Potential baseline predictors included demographic, clinical, radiographic and US features.

Results Of the 600 original patients, 531 (88.5%), mean age 67±10 years, mean disease duration 6.1±6.9 years, had follow-up data and were analysed. During follow-up (median 3 years; range 0–4 years), knee replacement was done or required for 94 patients (estimated event rate of 17.7%). In the multivariate analysis, predictors of joint replacement were as follows: Kellgren and Lawrence radiographic grade (grade ≥III vs <III, hazards ratio (HR) = 4.08 (95% CI 2.34 to 7.12), p<0.0001); ultrasonographic knee effusion (≥4 mm vs <4 mm) (HR = 2.63 (95% CI 1.70 to 4.06), p<0.0001); knee pain intensity on a 0–100 mm visual analogue scale (≥60 vs <60) (HR = 1.81 (95% CI 1.15 to 2.83), p=0.01) and disease duration (≥5 years vs <5 years) (HR=1.63 (95% CI 1.08 to 2.47), p=0.02). Clinically detected effusion and US synovitis were not associated with joint replacement in the univariate analysis.

Conclusion Longitudinal evaluation of this OA cohort demonstrated significant progression to joint replacement. In addition to severity of radiographic damage and pain, US-detected effusion was a predictor of subsequent joint replacement.

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  • Competing interests None.

  • Funding This study was supported in part by an unrestricted grant from Bristol Myers-Squibb.

  • Patient consent Obtained.

  • Ethics approval All involved multinational centres had local approval.

  • Provenance and peer review Not commissioned; externally peer reviewed.