title: Hand osteoarthritis and MRI: development and first validation step of the proposed Oslo Hand Osteoarthritis MRI score.
abstract: OBJECTIVE
  MRI scoring systems for hand osteoarthritis (HOA) are currently not available. The present work proposes the Oslo HOA MRI (OHOA-MRI) score and examines the intrareader and inter-reader reliability.
  
  
  METHODS
  Relevant HOA features were included in the initial version of the OHOA-MRI score after literature review and informal group discussions. After a training session and two calibration exercises (with three readers), features with low reliability and/or low prevalence were excluded, and feature definitions/gradings were improved. In the reliability exercise 3 readers independently evaluated MRI scans of distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints in 10 patients with HOA according to the final proposed score. The reading was repeated after 1 week. Intraclass correlation coefficients (ICCs), percentage exact agreement/percentage close agreement (PEA/PCA) and smallest detectable difference were calculated.
  
  
  RESULTS
  The final proposed OHOA-MRI score includes assessment of synovitis, flexor tenosynovitis, erosions, osteophytes (OPs), joint space narrowing (JSN) and bone marrow lesions (BMLs) on a 0-3 scale, and absence/presence of cysts, malalignment (frontal/sagittal plane), collateral ligaments (CLs) and BMLs at CL insertion sites. Inter-reader reliability was very good for synovitis, erosions, OPs, JSN, malalignment (frontal) and BMLs (ICCs ≥ 0.83, PCA ≥ 89%), and good for flexor tenosynovitis (ICC 0.64, PCA 80%) and CL presence (ICC 0.79, PEA 63%). Cysts, malalignment (sagittal) and BMLs at CL insertion sites showed high PEA (≥ 85%), but poor to moderate ICCs (0.00-0.59). Intrareader reliability was similar. The reliability was generally highest in PIP joints.
  
  
  CONCLUSIONS
  The proposed OHOA-MRI score could reliably assess HOA features. However, further validation is needed.
authors: Department of Rheumatology, Diakonhjemmet Hospital, PO Box 23, Vinderen, 0319 Oslo, Norway. haugen_ida@hotmail.com
authors: Ida K
authors: IK
authors: Haugen
authors: Siri
authors: S
authors: Lillegraven
authors: Barbara
authors: B
authors: Slatkowsky-Christensen
authors: Espen A
authors: EA
authors: Haavardsholm
authors: Sølve
authors: S
authors: Sesseng
authors: Tore K
authors: TK
authors: Kvien
authors: Désirée
authors: D
authors: van der Heijde
authors: Pernille
authors: P
authors: Bøyesen
mesh_terms: D000368:Aged; D001855:Bone Marrow Diseases / Q000175:diagnosis / Q000209:etiology; D004487:Edema / Q000175:diagnosis / Q000209:etiology; D005260:Female; D050823:Hand Joints / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010003:Osteoarthritis / Q000150:complications / Q000175:diagnosis*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013585:Synovitis / Q000175:diagnosis / Q000209:etiology; D013717:Tenosynovitis / Q000175:diagnosis / Q000209:etiology