title: Nonstandard glenoid components for bone deficiencies in shoulder arthroplasty.
abstract: BACKGROUND
  Glenoid bone deficiencies may be addressed by specialized components. The purpose of this study is to evaluate the clinical and radiographic outcomes of 3 different types of nonstandard glenoid components.
  
  
  METHODS
  Thirty-eight patients with a mean age of 65 years (range, 34-84 years) underwent a primary or revision anatomic shoulder arthroplasty with one of 3 nonstandard glenoid components: a polyethylene component with an angled keel for posterior glenoid wear without posterior subluxation; a polyethylene component with 2 mm of extra thickness for central glenoid erosion; or a posteriorly augmented metal-backed glenoid component for posterior glenoid wear and posterior subluxation. Average clinical follow-up was 7.3 years (range, 2-19 years) or until revision surgery.
  
  
  RESULTS
  At the most recent follow-up, 24 patients had no, mild, or occasionally moderate pain. Mean elevation improved from 91° to 126°, and mean external rotation improved from 24° to 53°. Thirteen patients had moderate or severe subluxation preoperatively, and 11 had subluxation at follow-up. On radiographic evaluation, 3 glenoid components had loosened and 3 were at risk for loosening at an average 5.5 years of follow-up. Seven patients had revision surgery: 4 for instability, 1 for osteolysis, 1 for component loosening with osteolysis, and 1 for a periprosthetic fracture. Three additional patients had removal of glenoid components, 2 for infection and 1 for loosening. Ten-year survival rate free of revision or removal of the angled keel component was 73% (95% CI: 75.3-70.7); of the extra thick (+2 mm) component, 69% (95% CI: 65-73); and of the posteriorly augmented metal-backed glenoid component, 31% (95% CI: 35.6-26.4).
  
  
  CONCLUSIONS
  The effectiveness of nonstandard glenoid components in addressing glenoid bone deficiencies is compromised by an increased rate of component loosening and by only partial success in eliminating subluxation.
authors: Department of Orthopaedics, University of Missouri, Kansas City, MO, USA.
authors: Akin
authors: A
authors: Cil
authors: Department of Orthopedic Surgery, Mayo Clinic and Mayo Foundation, Rochester, MN, USA.
authors: John W
authors: JW
authors: Sperling
authors: Department of Orthopedic Surgery, Mayo Clinic and Mayo Foundation, Rochester, MN, USA. Electronic address: cofield.robert@mayo.edu.
authors: Robert H
authors: RH
authors: Cofield
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement / Q000295:instrumentation*; D001672:Biocompatible Materials; D001862:Bone Resorption / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D007593:Joint Instability / Q000209:etiology / Q000517:prevention & control / Q000601:surgery; D007595:Joint Prosthesis; D008297:Male; D008670:Metals; D008875:Middle Aged; D010014:Osteolysis / Q000000981:diagnostic imaging / Q000601:surgery; D011095:Polyethylenes; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation; D012189:Retrospective Studies; D012540:Scapula / Q000601:surgery; D012785:Shoulder Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; D008670:Metals; D011095:Polyethylenes
keywords: Glenoid components; bone deficiency; shoulder replacement