Glenoid augments and revision risk following reverse and anatomic total shoulder arthroplasty

Abstract

Background

Augmented glenoid implant usage in shoulder arthroplasty bone loss cases has increased over the past decade. While safe in the short term, there are insufficient studies on longer term survivorship data on the newer generation of implants. We sought to determine whether there was a difference in survivorship for patients treated with glenoid augmentation vs. those with traditional total shoulder arthroplasty (TSA).

Method

A retrospective cohort study was conducted using data from a US integrated health-care system's shoulder arthroplasty registry. Patients ≥18 years who underwent primary shoulder arthroplasty for arthritis, inflammatory arthritis, and rotator cuff tear were included (2018-2024). Augmented and nonaugmented glenoids were compared separately for anatomic (aTSA) and reverse (rTSA) TSA. All-cause, aseptic, and revision risk due to infection were evaluated through cause-specific Cox proportional hazard regression with confounder and operating surgeon adjustment. Reason for revision was recorded. Hazard ratios (HRs) and 95% confidence intervals (CIs) are presented, a P < .05 was considered statistically significant.

Results

Augmented glenoid implants were identified in 11.9% (n = 500) of aTSA and 55.8% (n = 2,641) of rTSA procedures. All-cause 5-year cumulative revision probability was 2.3% for rTSA and 2.6% aTSA. Average follow-up time for aTSA was 3.4 years (standard deviation [STD] = 2.0 years) and 2.6 years for rTSA (STD = 2.0 years). Mean time to first revision in aTSA was 2.1 years (STD = 1.8 years). The most common reason for aTSA revision was rotator cuff tear. We observed a 27% decreased risk of aseptic revision in aTSA patients with augmented glenoids (HR = 0.73, 95% CI = 0.56-0.93, P = .012) and no difference in all-cause or revision for infection (HR = 0.64, 95% CI = 0.32-1.29, P = .209 and HR = 0.79, 95% CI = 0.53-1.18, P = .253, respectively). The mean time to first revision in rTSA was 1.8 years (STD = 2.0 years). The most common reason for rTSA revision is chronic dislocation (instability). In rTSA, we failed to detect a difference in all-cause, aseptic, or revision for infection in augmented compared to nonaugmented glenoids (HR = 1.01, 95% CI = 0.80-1.28, P = .919, HR = 0.99, 95% CI = 0.78-1.26, P = .929, and HR = 0.98, 95% CI = 0.74-1.30, P = .885, respectively).

Conclusions

We found a lower 5-year risk of aseptic revision in aTSA and no-difference by augment status for rTSA. Augmented glenoid implants have several advantages when addressing glenoid wear, and our data support the use of these implants in the toolkit to address glenoid pathology.