title: The effect of glenosphere size on functional outcome for reverse shoulder arthroplasty.
abstract: OBJECTIVE
  Reverse shoulder arthroplasty (RSA) is an effective surgery for a variety of patients with difficult shoulder pathology. Since postsurgical outcomes are often variable, there has been great effort made to optimize the design and use of these implants. Previous studies demonstrated an association between increased glenosphere size and improved range of motion. The purpose of this study is to assess the relationship between glenosphere size, range of motion, and functional outcome scores.
  
  
  METHODS
  This is a retrospective cohort study of 140 patients (148 shoulders) undergoing reverse shoulder arthroplasty. All patients were assessed pre- and postoperatively for range of motion, Constant score, ASES score, and Subjective Shoulder Value. Improvements in these variables were compared for patients treated with three different glenosphere sizes (36, 40, 42 mm).
  
  
  RESULTS
  All groups had a mean improvement in range of motion and functional outcome scores, but there were no statistically significant differences between groups when controlling for preoperative differences.
  
  
  CONCLUSIONS
  Our findings do not support a strong role for glenosphere size as a singular factor affecting range of motion or patient-reported outcome following RSA. These problems are most likely due to the multifactorial nature of shoulder dynamics. For this reason, assessing the effect a single surgical or biomechanical parameter on function has been challenging.
authors: Department of Orthopaedic Surgery, Wayne State University School of Medicine, 18100 Oakwood Blvd. Suite 305, Dearborn, MI, 48124, USA. Sabes001@gmail.com.
authors: V J
authors: VJ
authors: Sabesan
authors: Department of Orthopaedic Surgery, Wayne State University School of Medicine, 18100 Oakwood Blvd. Suite 305, Dearborn, MI, 48124, USA.
authors: D J
authors: DJ
authors: Lombardo
authors: Department of Orthopaedic Surgery, Wayne State University School of Medicine, 18100 Oakwood Blvd. Suite 305, Dearborn, MI, 48124, USA.
authors: R
authors: R
authors: Shahriar
authors: Department of Orthopaedic Surgery, Wayne State University School of Medicine, 18100 Oakwood Blvd. Suite 305, Dearborn, MI, 48124, USA.
authors: G R
authors: GR
authors: Petersen-Fitts
authors: Department of Orthopaedic Surgery, Oakland University William Beaumont School of Medicine, Royal Oak, MI, USA.
authors: J M
authors: JM
authors: Wiater
mesh_terms: D000072228:Arthroplasty, Replacement, Shoulder; D005500:Follow-Up Studies; D006801:Humans; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012189:Retrospective Studies; D000070636:Rotator Cuff Injuries / Q000601:surgery; D012540:Scapula / Q000473:pathology; D012720:Severity of Illness Index; D012783:Shoulder Dislocation / Q000453:epidemiology / Q000209:etiology; D000072227:Shoulder Prosthesis / Q000009:adverse effects; D016896:Treatment Outcome
keywords: Glenosphere size; Prosthesis design; Reverse shoulder arthroplasty; Shoulder range of motion; Surgical outcomes