title: Association between pre-operative magnetic resonance imaging and reparability of large and massive rotator cuff tears.
abstract: OBJECTIVE
  It is recognized that a percentage of large and massive rotator cuff tears (RCTs) cannot be anatomically repaired. We hypothesized that factors identified on pre-operative MRI would be associated with rotator cuff reparability.
  
  
  METHODS
  A single-surgeon retrospective study was performed on patients who had undergone either an anatomical or partial repair of a large or massive RCT. Pre-operative MRI images were evaluated by a fellowship-trained shoulder surgeon, blinded to the surgical outcome. Stump location, tear dimension in the coronal and sagittal plane, fatty infiltration, muscle atrophy (occupation ratio, tangent sign), and superior migration of the humeral head (acromion-humeral distance, inferior glenohumeral distance, and best-fit humeral circle technique) were assessed as the predictors of repair. Logistic regression and chi-square analyses were used.
  
  
  RESULTS
  A total of sixty patients with median age 63 (range 40-83) were included. On MRI, reparability was associated with increased medial-lateral (ML) tear size (p = 0.003), but not increased AP tear size (n.s.). An association was seen between partial repair and tendon retraction to or beyond the glenoid (p = 0.0005), positive tangent sign (p = 0.04), advanced supraspinatus fatty infiltration in isolation (p = 0.046), combined advanced supraspinatus and infraspinatus fatty infiltration (p = 0.04), and superior migration of the humeral head as measured by the inferior glenohumeral distance only (p = 0.004). Multivariable analysis identified increased ML tear size as the most significant factor associated with partial repair.
  
  
  CONCLUSIONS
  This study demonstrates that MRI findings of tendon retraction to or beyond the glenoid, increased inferior glenohumeral distance, and a positive tangent sign are associated with irreparability of large and massive RCTs.
authors.affiliation: Women's College Hospital, University of Toronto Orthopaedic Sports Medicine, 76 Grenville St, Toronto, ON, M5S 1B1, Canada, drtimdwyer@yahoo.com.au.
authors.forename: Tim
authors.initials: T
authors.lastname: Dwyer
authors.forename: Helen
authors.initials: H
authors.lastname: Razmjou
authors.forename: Patrick
authors.initials: P
authors.lastname: Henry
authors.forename: Simon
authors.initials: S
authors.lastname: Gosselin-Fournier
authors.forename: Richard
authors.initials: R
authors.lastname: Holtby
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001182:Arthroscopy; D003657:Decision Making; D005260:Female; D006801:Humans; D058430:Humeral Head / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009133:Muscular Atrophy / Q000473:pathology; D057234:Preoperative Period; D012189:Retrospective Studies; D017006:Rotator Cuff / Q000473:pathology*; D000070636:Rotator Cuff Injuries; D012421:Rupture / Q000473:pathology / Q000601:surgery