Thank you for allowing me to present. So I think this will be hopefully a complimentary discussion after the last presentations. So we're going to talk about anterior glenoid bone augmentation graft techniques as well as evolutions. So no disclosures relative to this. I think it's been previously described in the presentations there's been expanding indications for bone block procedures anteriorly, moving from critical bone loss, subcritical bone loss, perhaps off track and bipolar and maybe even collision athletes and revision scenarios. And there's a number of different ways in which we can reconstruct those and we'll go through each of these. I think the latter is where we can start. That's the standard for which many of these are measured against. The Bristow procedure is separate. So transfer of the tip of the coracoid and as originally described suture fixation. And really we're going to talk about the traditional latter J, which is horizontal transfer of the coracoid surface with screw fixation or the congruent arc, which is transfer of the medial surface. Either one of these has had generally good to excellent outcomes in terms of recurrence rates, patient reported outcomes and return to sport ratios. We mentioned the sling effect earlier and this is really a triple blocking effect of the increased track from the bone block. The dynamic sling of the conjoined tendon, especially in abduction, external rotation and capsular reinforcement with the CA ligament combined with good autographed healing potential. As we look at the sling, it's been considered to one extent, the main stabilizing effect of the latter J where others have said maybe it's not as important to the bone block and other biomechanical studies. Clinically, as we discussed, there's no difference in recurrence. There's no difference in return to sport rates. And in fact, patient reported outcomes are a little bit better in the free bone blocks versus the latter J. So where we stand today might best be summarized as it's important, but we don't know exactly to what extent. And there's some complications with the latter J we know. Short-term complications up to 25%, neurologic injuries in 10 to 20%, which can be severe. And long-term complications of nonunion as well as arthritis are certainly present. The iliac crest has been around as well for quite some time. A recent randomized controlled trial has looked at this comparing the latter J versus iliac crest again. No difference in recurrence, radiologic or clinical outcomes, decreased internal rotation in the latter J. And as you would expect, increased donor site morbidity with the iliac crest. It's even been performed arthroscopically with similar good to excellent outcomes. So if you look at the literature as a whole for the iliac crest, while you do have the ability to upsize potential large bone loss situations, you still have donor site morbidity, arthritis, and graft osteolysis that persists. So JT tokish has introduced the distal clavicle as one potential option and it does have similar reconstructed areas to a traditional latter J in biomechanical testing. Still the congruent arc offers a larger surface area. It is osteoarticular. It's easy to access autograft healing potential, but downsides in the AC joint arthritis patient, it's limited size and you potentially run into some mismatch areas and minimal articular surface. So that brings us to the distal tibia and this is obviously Matt Preventer's work that really kind of started this. And if you look at this biomechanically, it demonstrates when compared to a latter J, improved articular congruity, decreased contact pressures. And when we consider this in the concavity compression effect in the shoulder, it may actually enhance shoulder stability to some extent. And then comparing the latter J to the DTA specifically, no difference in recurrence or outcomes between the two. So these have all been considered as arthroscopic options, the latter J, distal clavicle, iliac crest, and distal tibia. The arthroscopic latter J is met with some significant learning curves and certainly in the best person's hands, 30 to 50 arthroscopic latter Js per year is what's really required to maintain proficiency and that's defined as optimal graft position, surgical efficiency, and a complication rate that hovers around 12%. If you expand this to talented surgeons in multiple different centers, overall complication rate is 24% and graft fracture is the most common complication. The arthroscopic distal tibia allograft has been recently proposed as well. This is a large part Ivan Wong's work who compared it to the arthroscopic latter J showing decreased surgical time, easier to learn and achieve a learning curve, six to nine cases approximately. And in general, most of those are achieving a good graft position at the inferior one third of the glenoid. There's a number of different ways to fix this. There's arthroscopic suture suspensory buttons as well as screw fixations. Initial outcomes demonstrated encouraging reports with suture-based constructs with 6% recurrent instability, 100% graft healing. Word of caution though, some recent work that's still coming out in the literature regarding screw fixation being superior than suture-based fixation in terms of WOSI scores and lower recurrence rate, and that's Ivan Wong's work. When we look at osteolysis, I think the take-home point here is that it's present regardless of what type of surgery you do, arthroscopic or open. The graft type as well as the fixation method, so suture-based or screw fixation, does not seem to affect recurrence rates or outcomes. And the work of DiGiacomo and others basically supporting Wolff's law that if you add a large bone block to a glenoid that has minimal bone loss, you're going to get more osteolysis. And if you add a large bone block to cases of larger glenoid bone loss, you'll get less glenoid bone loss. In terms of the outcome of this, the arthroscopic distal tibia, no recurrent instabilities in the largest series to date after five years, 100% graft union rate, the majority of these, vast majority, 97% are appropriately located, and the most common complication is screw removal. None of these patients have had nerve injury. So in summary, I think we can say today that the open Latter Jay remains the go-to for glenoid augmentation as the primary procedure. But free bone blocks are increasingly performed, both arthroscopically and open, with encouraging early outcomes. Thanks.

anterior glenoid bone augmentation graft

Latter Jay procedure

iliac crest

distal clavicle

distal tibia