title: A positive tangent sign predicts the repairability of rotator cuff tears.
abstract: OBJECTIVE
  We hypothesize that patients with a positive tangent sign will have rotator cuff tears that are not able to be repaired primarily.
  
  
  METHODS
  We performed a retrospective review of the charts of patients who had undergone surgery for repair of a rotator cuff tear. The operative note was reviewed to determine whether the cuff tear was primarily repaired. The magnetic resonance imaging study of each patient was reviewed to assess for a positive or negative tangent sign. The reviewer was blinded to the result of each measurement.
  
  
  RESULTS
  Eighty-one patients met the inclusion criteria. Of the 79 included in our analyses, 17 had a positive tangent sign and 62 had a negative tangent sign. There was only 1 patient with a negative tangent sign who had an irreparable rotator cuff tear. There were 3 patients with a positive tangent sign who had a repairable rotator cuff. With a pretest prevalence of irreparable tears of 18.9%, a positive finding suggested a post-test probability of 82.3% with a positive tangent sign and a post-test probability of only 1.6% when the tangent sign was negative.
  
  
  CONCLUSIONS
  Our results showed decision-making value in both a negative tangent sign and a positive tangent sign. The tangent sign is an easily performed and reproducible tool with good intraobserver and interobserver reliability that is a powerful predictor of whether a rotator cuff tear will be repairable.
authors.affiliation: Steadman Hawkins Clinic of the Carolinas, Greenville Hospital System, Greenville, SC, USA. Electronic address: mkissenberth@ghs.org.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kissenberth
authors.affiliation: North Mississippi Sports Medicine and Orthopaedic Clinic, Tupelo, MS, USA.
authors.forename: Gabriel J
authors.initials: GJ
authors.lastname: Rulewicz
authors.affiliation: Steadman Hawkins Clinic of the Carolinas, Greenville Hospital System, Greenville, SC, USA.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Hamilton
authors.affiliation: Hawkins Foundation, Greenville, SC, USA.
authors.forename: Hannah E
authors.initials: HE
authors.lastname: Bruch
authors.affiliation: Steadman Hawkins Clinic of the Carolinas, Greenville Hospital System, Greenville, SC, USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Hawkins
mesh_terms: D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D017006:Rotator Cuff / Q000473:pathology / Q000601:surgery; D000070636:Rotator Cuff Injuries; D012421:Rupture; D013708:Tendon Injuries / Q000175:diagnosis* / Q000601:surgery
keywords: MRI; Tangent sign; rotator cuff tear