Early clinical and radiographic outcomes of an augmented baseplate in reverse shoulder arthroplasty for glenohumeral arthritis with glenoid deformity

Abstract

Background: Glenoid deformity is commonly encountered in patients undergoing reverse shoulder arthroplasty (RSA). Augmented baseplates can correct glenoid deformity while potentially avoiding certain complications encountered with structural bone graft. Limited evidence exists to support the use of metallic augmented baseplates in RSA. Methods: We performed a retrospective review to identify all patients treated with an augmented baseplate during primary RSA with a minimum of 1 year of clinical and radiographic follow-up. Preoperative radiographs and advanced imaging were used to determine glenoid morphology and deformity. Postoperative radiographs were used to evaluate for deformity correction, radiographic complications, and early baseplate loosening or failure. Prospectively collected clinical data and patient-reported outcome scores were determined. Results: Primary RSA was performed with an augmented baseplate in 44 patients (mean age, 72 AE 6 years; 15 half-wedge and 29 fullwedge augmentations). Glenoid retroversion was significantly improved for the entire cohort (P ¼ .001). Among the 22 patients with either Walch type B2, B3, or C glenoid morphology, glenoid version improved from 28 AE 8 to 16 AE 8 (P ¼ .001). Glenoid inclination, as determined by the b angle, was significantly improved for the entire cohort (P < .001). Among the 18 patients with Favard type E2 or E3 glenoid morphology, glenoid inclination improved from 67 AE 7 to 81 AE 8 (P < .001). Postoperative range of motion and functional outcome scores including the American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, Single Assessment Numeric Evaluation score, and visual analog scale score for pain significantly improved within the entire cohort (P < .05). No patients had evidence of baseplate loosening or failure of the glenoid component. Acromial stress fractures developed in 5 patients (11.4%), and 2 patients (4.5%) underwent a reoperation unrelated to the glenoid component. Discussion and conclusion: Primary RSA with an augmented baseplate results in excellent short-term clinical outcomes and significant deformity correction in patients with advanced glenoid deformity. There were no complications related to the augmented baseplate or glenoid component. The rate of acromial stress fractures appears higher than typically reported and warrants further investigation.This study was approved by the Thomas Jefferson University Institutional Review Board (no. 19D.732).

Treatment of Glenoid Wear with the Use of Augmented Glenoid Components in Total Shoulder Arthroplasty

“…In another retrospective descriptive analysis of 67 patients with Walch B2, B3, or C glenoids treated with the 8-degree posterior augmented baseplate, Virk et al demonstrated good functional outcomes, low rates of scapular notching, and no evidence of glenoid loosening with a mean follow-up of 3.3 years 55 . A review of 44 patients treated with half-wedge or full-wedge augmented baseplates further supports the favorable short-term functional outcomes reported in the preceding studies, although they did note an 11% rate of acromial stress fracture 53 .…”

“…At final follow-up, the posteriorly augmented group demonstrated superior shoulder function and greater active forward elevation compared with the superiorly augmented group. Although this study has been cited as evidence that posterior augments perform better than superior augments 53 , it is important to note that the analysis is essentially a comparison of 2 distinct indications for RSA. The group treated with superior augments for superior glenoid wear likely represented a cohort of patients with rotator cuff arthropathy, while the group treated with posterior augments for posterior glenoid wear likely represented a cohort of patients in which primary osteoarthritis was the predominant diagnosis.…”

Considerations for Shoulder Arthroplasty Implant Selection in Primary Glenohumeral Arthritis With Posterior Glenoid Deformity

“…38 Clinically, both augmented constructs and autogenous bone grafting between the backside of the baseplate and the native glenoid have generally been associated with good clinical outcomes. 34,39 However, bone graft constructs are subject to resorption in some cases and are more at risk for micromotion compared with metallic offset. 40,41 One study suggested that baseplate failures were more common with higher degrees of preoperative deformity (226°in failures versus 215°in successes), although this difference did not reach statistical significance (P = .06).…”

Management of glenoid bone loss in primary reverse shoulder arthroplasty

“…2 However, acquired glenoid bone loss and deformity is encountered in up to 40% of patients undergoing shoulder arthroplasty. 3,4 Increased complication and revision rates may be seen in this cohort due to compromised soft-tissue tensioning, glenoid instability and malalignment leading to early loosening, component impingement, and ultimately failure with reduced bone stock for subsequent revision. 5-10 Thus, the optimal surgical technique to reconstruct glenoid anatomy in rTSA remains an ongoing challenge in orthopaedic surgery.…”