Total Shoulder Arthroplasty in Patients with a B2 Glenoid Addressed with Corrective Reaming: Mean 8-year Follow-up.

Abstract

The management of Walch B2 glenoid deformities in primary glenohumeral osteoarthritis is frequently debated. Previous literature has shown that the treatment of B2 glenoids with high-side reaming and anatomic total shoulder arthroplasty (TSA) perform well in the short-term, but is associated with an increased glenoid component failure rate in severe deformities. Therefore, many have explored alternative options, including augmented anatomic glenoid components and reverse shoulder arthroplasty. Our goal in this study is to provide mid-term radiographic and clinical outcomes after high-side reaming and anatomic TSA for B2 glenoids. Patients were followed both clinically and radiographically. Preoperative CT scans were used for retrospective analysis of deformity. Both preoperative and postoperative VAS pain, ASES score, and SST scores were collected. Radiographs were analyzed preoperatively and postoperatively for humeral head decentering relative to the glenoid vault, immediate glenoid seating, and final glenoid peg radiolucency. Of the original cohort of 59 patients (6 now deceased) reported at a mean radiographic follow-up of 3.4 years, 34 shoulders in 33 patients with B2 glenoids (mean retroversion 18.9°, range 4°-32°) were available for follow-up at a mean of 8.6 years (range 5.5-11.2) after high-side glenoid reaming with anatomic TSA. Three (5.1%) of the original 59 shoulder were revised. At final follow-up, 3 of 30 (10.0%) shoulders had radiographic glenoid component failure, but were unrevised. Glenoid component failure was associated with worse initial glenoid component seating (mean Lazarus score 1.2 vs. 2.0, p=0.002). Glenoid failure was also associated with increased posterior humeral head subluxation at 2-4 year follow-up (mean 5.6% vs 12.6%, p=0.045) and at final follow-up (mean 7.0% vs. 21%, p=0.002). There was no association between glenoid component failure and preoperative retroversion, inclination, or humeral head subluxation (all p>0.05). Glenoid component failure was associated with worse ASES (88 vs. 73) and VAS pain (0.8 vs. 2.1) scores (both p=0.03). At a mean of 8.6 years, 88% of shoulders available for follow-up had well-fixed glenoid components. Glenoid component failure was associated with poor initial glenoid component seating, with failed components having an average of 25% of the glenoid component not seated. Preoperative deformity such as glenoid retroversion, inclination, or humeral head subluxation did not predict glenoid component failure. This study supports that initial glenoid component seating and recurrence of posterior humeral head subluxation may be the most important factors for mid-term glenoid component survival in anatomic TSA in patients with B2 glenoids.