2025 ISAKOS Biennial Congress ePoster
An Imaging-Guided Posterior Working Portal: Technique And Radiologic Correlation
Benjamin Hoyt, MD, Chicago, IL UNITED STATES
Scott Feeley, MD, Bethesda, MD UNITED STATES
Conor F McCarthy, MD, Bethesda, MD UNITED STATES
Sarah Walsh, MD, PhD, Bethesda, Maryland UNITED STATES
Bobby Yow, MD, West Point, NY UNITED STATES
Lance LeClere, MD, San Diego, CA UNITED STATES
Robert Waltz, MD, Annapolis, MD UNITED STATES
Ivan Wong, MD, FRCSC, MACM, Dip. Sports Med, Halifax, NS CANADA
Jon F. Dickens, MD, Bethesda, MD UNITED STATES
Walter Reed National Military Medical Center, Bethesda, MD, UNITED STATES
FDA Status Not Applicable
Summary
Variation exists between instability patterns for accurate posterior working portal placement for arthroscopic shoulder labral repair and traditional landmarks may be inadequate as currently utilized.
ePosters will be available shortly before Congress
Abstract
Purpose
With increasing recognition of posterior shoulder instability, there is greater need for an accurate posterior portal to perform labral repair and allograft reconstruction. Therefore, we sought to present a novel technique for a patient-specific imaging-guided working portal to compare to standard approaches.
Methods
We retrospectively analyzed arthroscopic labral repairs with preoperative advanced imaging at a single institution between 2010-2020. We randomly selected 30 each of isolated anterior or posterior labral repairs. MRI measurements included posterior acromial height and acromial tilt. A novel imaging-guided posterior portal was measured along the glenoid equator with distances to the coracoid and posterolateral acromion measured. Then, unguided portal positions of 2 and 4cm from the posterolateral acromion were made and the distances and angles between the guided/unguided positions were measured. ANOVA analysis and linear regression models were used to evaluate differences.
Results
Sixty shoulders were included for analysis (30 anterior, 30 posterior). Instability patterns differed by acromial tilt (p=0.037). The guided portal distance to the acromion differed between instability types (p<0.001).
The 4cm unguided portal deviated less from the guided portal intersection with the glenoid in both instability patterns (p<0.0001) but did not differ between groups (p=0.990). However, the 4cm unguided portal angle deviated more compared to the guided portal in both instability patterns (p<0.0001).
Using the unguided 2 and 4cm portals aiming towards the coracoid, there was more than 5mm deviation from the guided portal at the glenoid and would require replacement of the portal 89.8% (86.2% anterior, 93.0% posterior) and 45.5% (37% anterior, 53.6% posterior) of the time, respectively.
Conclusion
Variation exists between instability patterns for accurate posterior working portal placement for arthroscopic shoulder labral repair. Traditional landmarks may be inadequate as currently utilized.