title: MRI findings of rotator cuff myotendinous junction injury.
abstract: OBJECTIVE
  The purpose of this article is to describe the MRI features of rotator cuff myotendinous junction injuries.
  
  
  METHODS
  We retrospectively identified MRI cases with myotendinous junction injury of the rotator cuff muscles and reviewed clinical, imaging, and surgical records. MR images were reviewed independently by two musculoskeletal radiologists to grade myotendinous junction injuries (strain, partial tear, or complete tear) and to assess for concurrent tendon tears (partial or full thickness) and bone changes (fracture or contusion).
  
  
  RESULTS
  The final study group comprised 16 subjects. The mean age was 38 years, with a majority of men (56%). The left shoulder was affected in 56% of subjects, with the dominant upper limb affected in 50%. The mean time between symptoms and MRI was 19 days. Subjects reported heavy lifting (19%), landing on the arm after a fall (19%), or prior shoulder therapeutic injection (25%). Myotendinous junction injuries affected the infraspinatus muscle (50%), followed by the supraspinatus (31%), subscapularis (25%), and teres minor (19%) muscles. About one fifth of subjects presented with more than one muscle affected, and 94% did not present with tears of the corresponding tendons. Most myotendinous junction injuries were strains (80%), followed by partial tears (20%). No complete tears were identified. There was no correlation between myotendinous junction injury and the presence of bone changes or the presence of tendon tears (p > 0.05).
  
  
  CONCLUSIONS
  Rotator cuff myotendinous junction injuries affect mostly the infra-spinatus and supraspinatus muscles, usually in a strain pattern and without tear of the corresponding tendon attachment.
authors: 1 Division of Musculoskeletal Radiology, Diagnostic Center, Hospital do Coração (HCor) and Teleimagem, São Paulo, Brazil.
authors: Atul K
authors: AK
authors: Taneja
authors: Susan V
authors: SV
authors: Kattapuram
authors: Connie Y
authors: CY
authors: Chang
authors: F Joseph
authors: FJ
authors: Simeone
authors: Miriam A
authors: MA
authors: Bredella
authors: Martin
authors: M
authors: Torriani
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D000070636:Rotator Cuff Injuries; D012421:Rupture / Q000175:diagnosis*
keywords: MRI; myotendinous junction; rotator cuff; strain; tear