title: Intra- and inter-rater reliability of the detection of tears of the supraspinatus central tendon on MRI by shoulder surgeons.
abstract: BACKGROUND
  The purpose of this study was to determine the intra- and inter-rater reliability of detecting full- and partial-thickness tears of the supraspinatus intramuscular central tendon on magnetic resonance imaging (MRI) by orthopaedic shoulder surgeons. Full-thickness tears of this tendon have previously been associated with the failure of nonsurgical management of rotator cuff tears.
  
  
  METHODS
  Shoulder MRIs from 40 patients entered into a prospective rotator cuff disease database were independently reviewed by two musculoskeletal (MSK) radiologists in order to determine if there was a partial- or full-thickness tear of the supraspinatus central tendon. The MRIs were randomly sorted and distributed to 16 fellowship-trained shoulder surgeons. The surgeons then similarly diagnosed each patient. After a 1-month interval, surgeons repeated the evaluation with the same set of randomly reordered MRIs. Surgeon intra- and inter-rater reliability was determined with the kappa statistic. Agreement and inter-rater reliability were also determined between the shoulder surgeons and MSK radiologists.
  
  
  RESULTS
  For full-thickness tears, the intra-rater reliability was excellent (0.86 ± 0.1, 95% confidence interval (CI): 0.81, 0.91) and the agreement was 93.4% ± 4.6, 95% CI: 91.1, 95.8. Inter-rater reliability for both rounds was also excellent (0.77 and 0.74). The agreement between the shoulder surgeons and MSK radiologists was 92.9% ± 3.9, 95% CI: 90.9, 94.9, and the kappa was 0.85 ± 0.08, 95% CI: 0.81, 0.89. Including partial-thickness tears resulted in agreement of 65-92% and kappa values of 0.59-0.72.
  
  
  CONCLUSIONS
  The reliability for the MRI detection of full thickness tears of the supraspinatus central tendon among shoulder surgeons and between shoulder surgeons and MSK radiologists was excellent.
authors.affiliation: MedSport, Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Grant
authors.forename: Bruce S
authors.initials: BS
authors.lastname: Miller
authors.forename: Jon A
authors.initials: JA
authors.lastname: Jacobson
authors.forename: Yoav
authors.initials: Y
authors.lastname: Morag
authors.forename: Asheesh
authors.initials: A
authors.lastname: Bedi
authors.forename: James E
authors.initials: JE
authors.lastname: Carpenter
mesh_terms: D000328:Adult; D002983:Clinical Competence; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012421:Rupture; D012782:Shoulder / Q000473:pathology*; D013708:Tendon Injuries / Q000175:diagnosis*