2025 ISAKOS Biennial Congress ePoster
Biomechanical Evaluation and Surface Analysis of Glenoid Reconstruction Using the Subtalar Joint Allograft for Significant Glenoid Bone Loss in Recurrent Shoulder Instability: A Novel Alternative Graft Option
Phob Ganokroj, MD, Bangkok Noi, Bangkok THAILAND
Justin Hollenbeck, MS, Vail, Colorado UNITED STATES
Marco Adriani, MD, Brescia, Brescia ITALY
Ryan J. Whalen, BS, Vail, Colorado UNITED STATES
Amelia Drumm, BA, Vail UNITED STATES
Wyatt Buchalter, BS, Vail UNITED STATES
Trevor McBride, MD, Vail UNITED STATES
Marco-Christopher Rupp, MD, Munich, Bavaria GERMANY
Matthew T. Provencher, MD, Vail, CO UNITED STATES
Steadman Philippon Research Institute, Vail, Colorado, UNITED STATES
FDA Status Cleared
Summary
Subtalar joint allograft (STA) showed comparable contact mechanics and surface geometry to the distal tibial allograft (DTA), which improved over the traditional Latarjet procedure.
ePosters will be available shortly before Congress
Abstract
Background
As glenoid and humeral head bone defects are common in chronic shoulder instability. Talus has been proposed as a unique allograft from which bipolar bone loss can be addressed. However, the is little biomechanical data or joint reconstruction analysis of the glenoid using subtalar joint allograft (STA).
Purpose
To compare the contact mechanics of the STA versus the coracoid graft (Latarjet procedure) versus distal tibial allograft (DTA) for anatomic glenoid reconstruction
Study design: Controlled laboratory study.
Methods
Eight fresh-frozen, unpaired, cadaveric specimens underwent biomechanical testing in five stages: intact state, glenoid bone defect (30% defect), and randomized for Latarjet, glenoid reconstruction using DTA or STA. A compressive load of 440 N was applied to the GH joint when the humerus was mounted to a dynamic tensile testing machine in three humerus positions: 30° of abduction, 60° of abduction, and 60° of abduction with 90° of external rotation (ER). Average GH contact pressure, contact area, and peak pressure were calculated from the sensors. The surface analysis and surface congruency were calculated using a custom script. Data was analyzed using the variance analysis (ANOVA) method. Pairwise group comparisons were made using Tukey’s method.
Results
The study exhibited a significantly higher DTA surface area than STA and Latarjet (p=0.005 and p<0.001, respectively). Anatomic glenoid reconstruction using DTA or STA yielded improved congruency across Latarjet (p=0.003 and p=0.004). In all shoulder positions, the average contact pressure in the bone loss state was significantly higher than in the native state. (p<0.05) All repair states restored average pressure to the native state at 60° of abduction and with 90° ER. There was lesser contact area after Latarjet than the native state at 30-degree and 60-degree of shoulder abduction, p=0.009 and p=0.04. There was no significant difference in contact area and peak pressure after reconstruction with DTA or STA compared with the native state.
Conclusion
Anatomic glenoid reconstruction using DTA or STA restored average contact pressure, peak pressure, and contact area at 60° abduction and 60° abduction with 90° ER. In addition, surface congruency and contact area restoration improved over the traditional Latarjet procedure.
Clinical Relevance: Subtalar joint allograft (STA) showed comparable contact mechanics and surface geometry to DTA. Further research is needed to determine the in-vivo clinical outcomes of this new alternative graft (STA).