High Failure Rates of Polyethylene Glenoid Components in Stemless Anatomic Total Shoulder Arthroplasty for Primary and Secondary OA.

Abstract

BACKGROUND Glenoid component loosening remains a challenge in anatomic total shoulder arthroplasty (aTSA). The aims of this study were to evaluate complications, implant survival, and revision rates in patients with primary and secondary osteoarthritis (OA) undergoing stemless aTSA using the Arthrex Eclipse humeral implant with a cemented pegged all-polyethylene glenoid component and to identify risk factors leading to revision. METHODS Of 211 patients who underwent primary stemless aTSA (using the Eclipse humeral component with a cemented pegged all-polyethylene glenoid) with prospectively documented data in a local registry, 197 were evaluated, grouped by OA pathology (primary OA, 153 patients; secondary OA, 44 patients). Demographic and functional data (e.g., age, sex, shoulder function) and the cause of OA were documented preoperatively in both groups. Comparative analyses were conducted to assess complications and implant revisions between the study groups. In addition, various radiographic parameters (e.g., glenoid morphology, critical shoulder angle, lateral acromion index, implant sizing [humeral component overhang], radial matching of the humeral and glenoid components, glenohumeral distance, and medial glenoid cement penetration) were evaluated to explore their potential association with revision. A subset of these parameters was subsequently included in the multivariable Cox model on the basis of clinical relevance. RESULTS After a median postoperative period of 72 months, the overall revision rate was 51%. The reasons for revision were glenoid component loosening (85%), periprosthetic humeral fracture (9%), early rotator cuff failure (3%), and low-grade infection (3%). The median implant survival in patients with primary OA (95 months; 95% confidence interval [CI]: 84 to 108) was significantly longer than that in patients with secondary OA (71 months; 95% CI: 60 to 88; p = 0.027). Female patients had a significantly shorter time to revision than male patients (p = 0.016). There were no significant differences in complications or revision rates by OA pathology. Secondary OA, the presence of medial glenoid cement penetration, and an anterior overhang of the humeral component were associated with an increased risk of revision. CONCLUSIONS Our findings indicate a high rate of glenoid component loosening as the primary cause of revision in patients with primary and secondary OA undergoing stemless aTSA with the Eclipse and a cemented pegged all-polyethylene glenoid component. This outcome emphasizes the need for careful consideration of implant design, patient selection criteria, and implant positioning and cementation in order to optimize implant survival. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.