Nonstandard glenoid components for bone deficiencies in shoulder arthroplasty

BackgroundGlenoid 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.Materials and methodsThirty-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.ResultsAt 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).ConclusionsThe 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.