Five-year clinical outcomes of metal-backed, hybrid, and polyethylene glenoid components in total shoulder arthroplasty.

Background: The glenoid components in total shoulder arthroplasty (TSA) are numerous and have both advantages and disadvantages. This study aimed to compare 5-year functional outcomes, patient-reported outcomes, and conversion rates between patients who underwent TSA using metal-backed glenoid (MBG), hybrid, and all-polyethylene glenoid components.

Methods: The patients who were eligible for this study were retrospectively identified using electronic health records. The subjects underwent TSA performed by a fellowship-trained attending physician from November 2017 to December 2018 at a single institution. The inclusion criteria from 5-year follow-up data were adult-age patients (≥18 years old) who underwent TSA using MBG, hybrid, or all-polyethylene glenoid components.

Results: A total of 77 patients was included: 44 patients with all-polyethylene glenoid components, 17 with hybrid glenoid components, and 16 with MBG components. The mean patient age was 66.9 years, with the all-polyethylene patients being significantly younger (P<0.001). The all-polyethylene glenoid patients experienced a significantly longer operative time at 120 minutes (P=0.005) compared to those with other components. At the 5-year follow-up, no significant difference was shown in American Shoulder and Elbow Surgeons (ASES) and visual analog scale scores. However, a trend was evident in which the all-polyethylene patients had lower ASES scores (all polyethylene 87.0 vs. hybrid 100.0 vs. 97.0 MBG, P=0.086). The hybrid components tended to require revision more often at 12% vs. 6.8% of polyethylene glenoid vs. 0% of MBGs (P=0.310). No dislocation was reported, and only two complications occurred, both in the all-polyethylene group (P=0.387).

Conclusions: At 5-year follow-up, patient-reported outcomes were similar when utilizing MBG, all-polyethylene, and hybrid glenoid components. Given the similar outcomes, MBGs and hybrid glenoid components could be considered favorable or preferred for potential surgical ease in a revision setting with conversion to reverse TSA. Level of evidence: III.