Paper 04: Acromial Morphology Differences in Primary versus Revision Posterior Shoulder Instability Patients

Objectives: Predisposing factors for failure of shoulder posterior stabilization surgery are not well defined. Characterization revision instability patients allows insight into potentially identifiable risk failure. Methods: A series who underwent as cases performed between 2005-2019 were identified. Patient demographics collected and glenoid morphology was quantified by measuring bone loss, acromial tilt, height on MRIs. Continuous variables compared with Student’s t-test. Results: 42 active duty servicemembers successful primary (primaries, P) 41 (revisions, R) Mean ages the primaries revisions at time 28.7 (±6.0; 18-39) 23.0 (±5.2; 18-41) years respectively (p < 0.005). Males made up 92.9% (P) 92.7% (R) each group. loss index MRI 4.5% (±7.2; 6.3% (±7.8; = 0.316). tilt (from horizontal) 40.9 degrees (±10.2; 28.8 (±10.6; Index 14.2 mm (±7.4; 19.8 (±7.6; 0.001). In group, progression from to pre-revision (±7.8) 6.6% (±6.2) 0.456). greater than 15% present in 5/41 patients; when excluding these, mean 3.4% (±3.3), significantly less that 0.038). Additional occurred 9.8% (4/41) 2/4 separated military. 17.1% (7/41) separated, while an additional 7.3% (3/41) remained upper extremity activity limitations. Conclusions: lower higher a population cohort stabilization. “high flat” may predispose standard procedures, justifying further study supplemental techniques decrease risk.