Conversion of anatomic total shoulder arthroplasty (aTSA) to reverse total shoulder arthroplasty (rTSA) is increasingly performed, particularly when glenoid or rotator cuff failure occurs in the setting of shoulder arthritis. Modular hybrid and metal-backed glenoid components may facilitate conversion compared with nonmodular all-polyethylene implants, but studies are limited. A retrospective review was conducted of patients who underwent conversion from aTSA to rTSA between 2014 and 2024 using modular hybrid/metal-backed glenoid components or cemented all-polyethylene glenoids. Demographics, operative time, revision indications, American Shoulder and Elbow Surgeons (ASES) scores, range of motion (ROM), and radiographic outcomes were analyzed. Between-group differences were assessed using ANOVA, Kruskal-Wallis, and dependent-samples t-tests as appropriate. Twenty-seven patients (mean age 65.7 ± 8.7 years, 37% female) were included, with 17 modular and 10 nonmodular conversions. The most common revision indication was atraumatic rotator cuff tear (41%). Median operative time was similar between groups (75 min modular vs 81 min nonmodular, p = 0.59). At 1-year follow-up, forward elevation averaged 141.8° (142.7° modular vs 140.0° nonmodular, p = 0.71) and external rotation averaged 23.0° (30.0° modular vs 21.0° nonmodular, p = 0.07). Final ASES scores were excellent in both groups (90.1 modular vs 79 nonmodular, p = 0.42), and visual analog scale (VAS) pain scores were low (modular 1.1 vs. 2 nonmodular, p =0.49). Conversion from aTSA to rTSA using modular versus nonmodular glenoid components yielded comparable short-term functional outcomes, pain relief, and operative times. While modular components offer theoretical benefits of bone preservation and implant retention, these advantages were not clearly demonstrated in this cohort. Larger studies with longer follow-up are needed to further clarify the role of modular glenoid components in revision shoulder arthroplasty. Level III; Retrospective Comparative Study.
Lachance et al. (Sun,) studied this question.