Short-term comparative outcomes of LIMA hybrid, metal-backed, and all cemented polyethylene glenoids

Background

This study aims to compare short-term functional outcomes and conversion rates to reverse shoulder arthroplasty between patients who underwent total shoulder arthroplasty (TSA) using a modular metal-backed glenoid component, a hybrid glenoid component, and an all-polyethylene component.

Methods

A retrospective review of individuals undergoing TSA between October 2014 and December 2020 was performed. Inclusion criteria included patients undergoing primary TSA for osteoarthritis during this time frame by 1 surgeon. Preoperative and postoperative variables included demographic information, American Shoulder and Elbow Surgeons score (ASES), and range of motion. Revision rates were also documented. Summary statistics were performed, using a 1-way analysis of variance with Tukey post hoc pairwise comparisons when the outcome reached significance.

Results

Fifty-two patients were included with age averaging 68 ± 8.1 years, with body mass index of 31 ± 5.8. 54% of patients were female with 12% having diabetes and only 2% were smokers. Follow-up averaged 42 months with patients undergoing metal-backed glenoid having longer follow-up at 56.5 months (P < .001). ASES, forward elevation, and external rotation (ER) for every implant type improved significantly postoperatively (P < .001) besides internal rotation and ER within the poly group (P = .072). No difference was found between the 3 groups for preoperative and postoperative ASES scores, forward elevation, internal rotation, and ER (P > .05). Two patients within the poly group required revision due to rotator cuff tear (P = .225).

Conclusion

At 2 years, functional outcomes and patient-reported outcomes are similar in all 3 glenoid groups. There were slightly higher revision rates within the all-polyethylene group. If outcomes are similar among all groups, modular implant systems may be favorable to make conversion to revision TSA easier.