Unique convertible shoulder modular replacement trabecular titanium hybrid glenoid component in anatomic shoulder arthroplasty: 5-7 year outcome data.

Background: Aseptic glenoid loosening and rotator cuff dysfunction remain major causes of revision after anatomic total shoulder arthroplasty (TSA). A unique convertible hybrid glenoid component has been designed to provide both durable glenoid fixation and conversion to reverse total shoulder arthroplasty (rTSA) without extraction of the central trabecular titanium peg, which serves as the foundation for the revision. Hybrid glenoid components have provided promising short-term results, but there is limited mid-/long-term data. This study provides minimum 5-year follow-up data on the convertible shoulder modular replacement trabecular titanium (SMR TT) Hybrid Glenoid. Methods: This study was a retrospective case series with prospectively gathered data. All patients with primary osteoarthritis treated with TSA utilizing the SMR TT Hybrid Glenoid implant (Enovis Surgical; formerly LimaCorporate, San Daniele del Friuli, Italy) with >5-year follow-up were screened. Patients with previous shoulder surgeries, rotator cuff tears, proximal humerus or glenoid fracture, or a septic arthritis were excluded. Pre-operative and post-operative range of motion, radiographic parameters, and complications were reviewed. Patient-reported outcomes, repeat clinical evaluation, and follow-up radiographs were collected >5 years from surgery. Radiographs were assessed for any signs of implant loosening, including radiolucent lines around the glenoid component. Survivorship of the central trabecular titanium glenoid peg was the primary outcome variable. Results: There were 94 patients who met inclusion criteria, with an average follow-up of 6.5 years (range, 5-8 years). Central glenoid peg survivorship was 98.9%, with one stable glenoid component removed due to infection. There were no cases of glenoid loosening, progressive aseptic glenoid radiolucency, or glenoid osteolysis. Sixty-seven patients were able to complete patient-reported outcomes at >5 years, with an average American Shoulder and Elbow Surgeons score of 91.1. Ninety percent of patients reported being "very satisfied" or "satisfied" with their clinical outcome. Four patients (4.3%) required reoperation: 3 (3.2%) had post-operative rotator cuff tears who underwent successful conversion to rTSA at an average of 43.1 months (range, 9-70 months) after index TSA, and1 (1.3%) patient underwent removal of all components due to deep, recalcitrant infection. All 3 conversions to rTSA utilized the well-fixed central trabecular titanium peg as the foundation for the glenoid base plate. Conclusion: This study represents the first midterm clinical and radiographic report of TSA utilizing the SMR TT Hybrid Glenoid component. The component remained stable in all patients at an average follow-up of 6.5 years. When conversion to rTSA was necessary, the central trabecular titanium peg was successfully used as a foundation for the glenoid baseplate.