title: Influence of glenosphere size on the development of scapular notching: a prospective randomized study.
abstract: OBJECTIVE
  The objective of the study was to evaluate the development of scapular notching in reverse shoulder arthroplasty by comparing larger glenospheres (42 mm) with smaller glenospheres (38 mm).
  
  
  METHODS
  This was a prospective randomized study of 81 patients who had undergone reverse shoulder arthroplasty with a 2-year follow-up. Patients were randomized to receive either a 42-mm glenosphere (38 patients) or a 38-mm glenosphere (43 patients). Scapular notching development was assessed with an anteroposterior radiograph at the end of the follow-up. Functional outcome was assessed with the Constant score before surgery and at the end of follow-up. An independent blinded observer carried out radiologic and clinical assessments.
  
  
  RESULTS
  Scapular notching was present in 48.8% of the patients receiving a 38-mm glenosphere and in 12.1% of the patients receiving one of 42 mm, with significant differences between both (P < .001). No significant differences were noted between the 2 glenosphere size groups in terms of the total Constant score. Patients with a 42-mm glenosphere had a mean glenoid-glenosphere overhang of 6.1 mm, whereas patients with a 38-mm glenosphere had one of 4.2 mm, with significant differences between them (P < .001). No significant differences in the total Constant score were found between the patients whether they had scapular notching or not.
  
  
  CONCLUSIONS
  Bigger glenospheres (42 mm) significantly reduce development of scapular notching compared with smaller glenospheres (38 mm). Glenosphere size has no significant influence on functional outcomes measured with the Constant score.
authors.affiliation: Department of Orthopedics, Hospital del Mar, Parc de Salut Mar, Barcelona, Spain. Electronic address: 86925@parcdesalutmar.cat.
authors.forename: Carlos
authors.initials: C
authors.lastname: Torrens
authors.affiliation: Department of Orthopedics, Hospital del Mar, Parc de Salut Mar, Barcelona, Spain.
authors.forename: Pau
authors.initials: P
authors.lastname: Guirro
authors.affiliation: Department of Orthopedics, Hospital d'Igualada, Consorci Sanitari de l'Anoia, Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Miquel
authors.affiliation: Department of Orthopedics, Hospital del Mar, Parc de Salut Mar, Barcelona, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Santana
mesh_terms: D000368:Aged; D000072228:Arthroplasty, Replacement, Shoulder / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011474:Prosthesis Design; D012540:Scapula / Q000000981:diagnostic imaging*; D012785:Shoulder Joint / Q000601:surgery; D000072227:Shoulder Prosthesis
keywords: Reverse shoulder arthroplasty; complications; cuff-deficient shoulder; glenosphere; glenosphere overhang; outcomes; scapular notching