allowing us to present our work on a CT-based algorithm for preoperative planning for Latter-J. We have no relevant disclosures. I'd like to thank my co-authors from HSS as this work was done during my fellowship. So the Latter-J is a commonly used procedure for critical bone loss. However, the kind of upper limit of what a Latter-J is able to achieve is largely unknown and based on expert opinion. So two major techniques have been described for Latter-J. Classic technique in which the wider undersurface is opposed to the anterior aspect of the glenoid. And as Dr. Brockmeyer discussed earlier, the congruent arc modification in which the graft is rotated 90 degrees and the wider undersurface is used to restore more glenoid diameter. Potential downside of the congruent arc modification is that patients with thin glenoids may be at risk for graft fracture during screw insertion. So the purpose of our study was twofold. First, to determine a reproducible method of coracoid graft measurement for preoperative templating using CT scan. And then to use that information to develop a preoperative planning algorithm with the goal of achieving a post-operatively on-track shoulder. So we had two hypotheses. First, that the classic Latter-J technique would reliably restore 100% of glenoid bone loss in patients with up to 30% anterior glenoid bone loss. Secondly, we hypothesized that the majority of females would have thin coracoids of less than one centimeter, which may put them at higher risk for graft fracture. So consecutive CT scans were analyzed in patients aged 18 to 45, which reflected a population that typically undergoes anterior stabilization surgery. A measurement protocol was developed with a fellowship-trained musculoskeletal radiologist. Briefly pictured here is our measurement protocol. The coracoid was aligned in all three dimensions. The length was measured, as depicted in the center, from the anterior aspect of the base along the central axis to the tip. And then the width and thickness of the coracoid were measured along the central axis on the coronal view, as depicted in the lower right. We analyzed 117 CT scans with a male predominance. We found that coracoid dimensions varied significantly among both males and females, and nearly 75% of females had a coracoid thickness of less than 10 millimeters. We had excellent inter- and inter-rater reliability for all measurements. We found that, as hypothesized, the classic Latter-day Technique did restore up to 30% bone loss in more than 90% of males and females, but was not reliable above 30% bone loss. So you may ask, when would I use this? So this is a 32-year-old male who failed to scope Bancart four years prior. He's since had recurrent subluxation events. Using our protocol, you can see his coracoid dimensions measured there. He has a preoperatively off-track shoulder. So using our evidence-based treatment algorithm, preoperatively, he has an off-track shoulder with a Hill-Sachs interval of 18.2 and a preoperative glenoid track width of only nine. If you proceed with a classic Latter-day, postoperatively, he's still going to be off-track. If, however, you proceed with a congruent arc modification, he will have an on-track shoulder postoperatively, but with a coracoid thickness of less than one centimeter, he's at risk for graft fracture. In this case, the decision was made to use a distal tibia allograft. And I'll defer to Mike Fu on the outcome of this patient, as I don't know if it's been done yet. So limitations, the coracoid dimensions were not verified intraoperatively, as this was a CT-based simulation study, and the algorithm did not consider how soft tissue procedures such as a REMPLISAGE may affect the postoperative glenoid track. In conclusion, both of our hypotheses were confirmed. The classic Latter-day reliably restored bone loss in up to 30% of patients. We found that the majority of females have thin coracoids that may put them at risk for graft fracture during screw insertion. So the take-home points are that the decision to use a congruent arc or a classic Latter-day or a Latter-day at all should depend on the amount of glenoid and humeral bone loss present, the patient's glenoid and coracoid dimensions, and most importantly, whether an on-track shoulder can be achieved with this procedure. We don't want any surprises in the OR. Thank you for your time. Thank you.

CT-based algorithm

Latter-J procedure

classic technique

congruent arc modification

bone loss