2023 ISAKOS Biennial Congress ePoster
Metal-Backed Glenoid Component For Total Shoulder Arthroplasty: A Systematic Review And Meta-Analysis Of Complications, Revisions, and Outcomes
Joseph Galvin, DO, Tacoma, WA UNITED STATES
Alexander J. Ment, BA, Farmington, CT UNITED STATES
Holt Zalneraitis, MD, Tacoma, WA UNITED STATES
Ryan Kim, MD, Boston, MA UNITED STATES
Patrick Magnus Neset Joslin, MD, Williamstown, ma UNITED STATES
David Novikov, MD, Boston, MA UNITED STATES
Ilya Voloshin, MD, Rochester, NY UNITED STATES
Joe Eichinger, MD, Daniel Island, SC UNITED STATES
Xinning Li, MD, Boston, Massachusetts UNITED STATES
Boston University, Boston, Massachusetts, UNITED STATES
FDA Status Cleared
Summary
The present review found the convex MBG with screw fixation to have a lower weighted rate of revision (5%) compared to the other MBG implants (18%). The weighted overall rate of revision with the metal-backed glenoid after an average of 8.5 years of follow-up is 17.0% with most revisions secondary to polyethylene wear and glenoid component loosening
ePosters will be available shortly before Congress
Abstract
Background
Total shoulder arthroplasty (TSA) is a proven treatment to decrease pain and improve function for patients with shoulder arthritis and an intact rotator cuff. A modular metal backed glenoid (MBG) consists of both a metal backside and a separate polyethylene insert. MBG were initially developed as an alternative to cemented polyethylene glenoid components, for which loosening was a problem and resulted in overall clinical failure and revision surgeries—it is accepted that good long-term outcomes are dependent on sustained glenoid fixation. The present systematic review is intended to provide an update on overall outcomes, complications, and revision rates of the MBG in shoulder arthroplasty. Additionally, we sought to compare outcomes after TSA, specifically comparing those using the convex MBG with screw fixation, to all other MBGs.
Methods
This review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by searching Medline (Pubmed). Inclusion criteria were clinical studies published in English that reported complications of primary TSA with a modular MBG with a minimum of 1-year follow-up. Case series with fewer than five patients and studies with the use of MBGs in TSA for revision, fractures, and tumor indications were excluded. Demographics, range of motion, outcomes, and complications were extracted, recorded, and analyzed from the included articles. In cases where more than one complication was associated with a revision, all complications were recorded. Additionally, convex backside MBG with screw fixation were grouped and compared to all other MBG designs.
Results
A total of 18 studies (4,138 shoulders) met final inclusion criteria after a Medline search for studies reporting complications with a minimum one-year minimum. The overall pooled weighted rate of revision after MBG was 17.0%. A sub-analysis demonstrated a 5% revision rate in the convex MBG with screws group, compared to 18% with other MBG designs. Common complications requiring revision included: polyethylene wear (7.3%), glenoid loosening (6.4%), and instability (4.0%).
Discussion
The present review found the convex MBG with screw fixation to have a lower weighted rate of revision (5%) compared to the other MBG implants (18%). The weighted overall rate of revision with the metal-backed glenoid after an average of 8.5 years of follow-up is 17.0% with most revisions secondary to polyethylene wear and glenoid component loosening. The convex MBG with screw fixation may serve as the basis for further innovation of MBG in TSA.