Dear faculty, dear colleagues, my name is Maria de Hasra, I'm from Germany and unable to travel at the moment, so I'm very grateful to be able to present my pre-recorded talk. The anterior labral circumferential onlay technique, ALCOT, reconstructs the anterior labrum and biomechanically restores glenohumeral joint stability. The background anterior shoulder instability results are still reported with high recurrence rates and the purpose of this study was to present an innovative technique for labral reconstruction using the long head of the biceps tending on side and possibly delay or prevent bony procedures for recurrent instability. The hypothesis was that the ALCOT technique would restore glenohumeral joint stability in a cadaveric model and therefore be comparable to the native state and comparable to a lateral procedure. The study design was a controlled laboratory study and ten fresh frozen cadaveric shoulders were tested on a six degrees of freedom robotic arm in five consecutive states. The first was native, the second capsular repair, the third labral tear, the fourth ALCOT technique and then this was compared to the lateral technique. Biomechanical testing consisted of 80 newtons of anterior inferior force and 50 newtons of compression at a 90 degrees humeral to thoracic abduction angle. Lateral displacement and a dislocation force ratio were measured. The surgical idea was just to use the long head of the biceps tendon on side and to lay it on the anterior rim of the glenoid to recreate a bumper for glenohumeral joint stability. A short explanation of the surgical technique which was done openly since it was a cadaveric setting. So the subscapularis muscle was opened or tendon was opened along its fibers between the upper third and lower two thirds and then the joint was opened and the long head of the biceps tendon was cut subpectorally as if to perform a biceps tenodesis subpectorally. Then forceps was used to pull the tendon into the joint and then three anchors, knotless or suture anchors were placed at the anterior glenoid rim and then the tendon was pierced with a piercing device. The sutures were shortened and pulled into the anchors and then the tendon was secured and came to lay on the anterior rim. Here we can see the native setting where we just opened the capsule and can look at the labrum and the humeral head and the joint from an anterior perspective. And then the second picture shows the ALCO technique where we can see the long head of the biceps tendon laying on the glenoid anterior rim and recreating this bumper. Results, the lateral translation of the humeral head during dislocation in the native state was 6.5 and decreased to 5.4 in the labral tear state. So the lateral translation of the humeral head could be restored showing no difference to the native state by the ALCO technique. The force ratio as well was restored by ALCO. The LATERGY technique in comparison restored the force ratio to 1.3, so not significantly different from native, but failed to restore the lateral translation with a value of 5.6. Lateral translation by state is shown here in this box plot and force ratio as well. Limitations of the study are missing muscle and capsule ligamentous tension. This could not be evaluated. The cadaveric setup did not include muscle forces. Additional in vivo studies are needed to interpret the healing response of the long head biceps in the ALCO technique and the subsequent changes which may or may not occur and failure definition in biomechanical settings is challenging. Conclusion, the ALCO is an innovative technique for labral reconstruction that may have a role in the treatment of anterior glenohormel instability in the setting of a deficient labrum. It might only be a rescue technique if other techniques fail, but in this study the ALCO technique brought forces back to the native stability and native amount of the humeral translation. Thank you very much.

Maria de Hasra

anterior labral circumferential onlay technique

ALCOT

labral reconstruction

anterior shoulder instability