Clinical and radiographic survival rates of the Arthrex Univers VaultLock uncemented central-peg all-polyethylene glenoid component in anatomic total shoulder arthroplasty at 2- and 5-years postoperatively

BACKGROUND: To evaluate radiographic and functional outcomes at 2 and 5 years postoperatively for anatomic total shoulder arthroplasty (aTSA) performed with an uncemented central-peg all-polyethylene glenoid (Univers VaultLock; Arthrex, Inc., Naples, FL) designed for an uncemented central-peg fixation with peripheral cement and central osseous interdigitation. METHODS: This was a multicenter retrospective case series of aTSAs identified from a prospectively maintained registry. All primary aTSAs with an intact rotator cuff using a VaultLock glenoid (uncemented central-peg all-polyethylene design) and available radiographic data were included for analysis at 2- and 5-years postoperatively. Primary outcomes included radiographic glenoid loosening (via Lazarus classification) and revision rates for glenoid loosening. Relevant changes in lucency were defined as change in Lazarus score ≥2 and an "at-risk" component for loosening was defined as Lazarus score ≥3. Secondary outcomes included range of motion, as well as patient-reported outcomes. RESULTS: and mean follow-up of 5.0 ± 0.4 years. All outcome measures significantly improved at 2- and 5-years compared to baseline. At 2 years, 111 patients (93.3%) demonstrated a grade 0-1 Lazarus score, while 8 patients (6.7%) had a grade 2 Lazarus score. No glenoids at 2 years were observed to have grade 3 changes consistent with being "at-risk" for radiographic loosening. At 5 years, 100 patients (84.0%) had a grade 0-1 Lazarus score, 13 patients (11.0%) had a grade 2 Lazarus score, and 6 patients (5.0%) had a grade 3 or greater Lazarus scores. Forty (33.6%) patients had an increase in Lazarus score from 2 to 5 years with mean increase of 1.2 (SD 0.42, range: 1-2). At 5 years, central peg humeral head bone grafting was associated with lower rates of Lazarus score ≥2 vs. no grafting (9.5% vs. 23.2%, P = .042). Clinical survival rate was 99.2% (132/133) at 5-years postoperatively, with radiographic survival of 95.0% (113/119) at 5-years postoperatively. CONCLUSIONS: The VaultLock glenoid has a 5-year clinical and radiographic glenoid survival rate of 99.2% and 95.0%, respectively. These findings are consistent with or superior to prior published reports of all-polyethylene glenoids and support the use of an uncemented central-peg all-polyethylene component in primary TSA.