title: Effects of humeral component retroversion on functional outcomes in reverse total shoulder arthroplasty for cuff tear arthropathy.
abstract: BACKGROUND
  The currently recommended 0° to 30° humeral component retroversion angle for reverse total shoulder arthroplasty (RTSA) is based on expert opinion rather than anatomical or clinical evidence.
  
  
  METHODS
  Sixty-two patients who underwent RTSA for cuff tear arthropathy were reviewed retrospectively. The humeral component was inserted with 20° retroversion in 30 patients (group A) and with 0° retroversion in 32 (group B). The mean age at the time of operation was 66.2 years and 68.9 years, and the mean follow-up period was 43.3 months and 38.4 months in groups A and B, respectively.
  
  
  RESULTS
  At the last follow-up, external rotation at the side was 47.2° ± 8.4° in group A and 43.9° ± 7.0° in group B, whereas internal rotation to the posterior was L3 and L2, respectively (P = .102 and P = .092). The ranges of motion between the 2 groups at the last follow-up were not significantly different. Most daily movements related to activities of daily living showed no significant differences between the 2 groups, with the exception of back washing/back doing up bra (1.5 ± 1.2 in group A vs 2.1 ± 0.8 in group B of 3 points, P = .026).
  
  
  CONCLUSIONS
  Range of motion after RTSA did not significantly differ between 20° and 0° humeral component retroversion angle. Most daily movements did not differ between the 2 groups, but patients in the 0° retroversion angle group scored better on activities related to internal rotation.
authors.affiliation: Shoulder & Elbow Clinic, Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University, Seoul, South Korea. Electronic address: shoulderrhee@hanmail.net.
authors.forename: Yong Girl
authors.initials: YG
authors.lastname: Rhee
authors.affiliation: Shoulder & Elbow Clinic, Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University, Seoul, South Korea.
authors.forename: Nam Su
authors.initials: NS
authors.lastname: Cho
authors.affiliation: Shoulder & Elbow Clinic, Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University, Seoul, South Korea.
authors.forename: Seong Cheol
authors.initials: SC
authors.lastname: Moon
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006811:Humerus / Q000601:surgery; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D012399:Rotation; D000070636:Rotator Cuff Injuries; D012785:Shoulder Joint / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome
keywords: Shoulder; activities of daily living; cuff tear arthropathy; humeral component; range of motion; retroversion; reverse total shoulder arthroplasty; rotator cuff tear