Thank you for the opportunity to present our work today. I'd like to give a special thanks to co-authors Ryan Rock and Andreas Contaxis who put in tremendous effort. There are no relevant disclosures. So you know, here we are and our understanding of bone loss has come a long way, but if I presented these two images to everybody here, we would reach, probably reach close to consensus that in a revision setting with 18% bone loss, most people would lean towards the latter J and in massive bone loss like you see on the right, we would look for alternative grasp sources. That said, the real problem kind of lies in the middle and this was a patient of mine early in practice. And I went to search the literature to find out, you know, how much, how much bone loss can I actually overcome with the latter J and found essentially nothing. So I did what any young surgeon would do. I turned to the wizards in our field, my mentors, and I asked, I asked that question. What did I get? Some said over 25, some said 30, 35, 40. So thanks a lot guys, really appreciate you. And the answer, you know, was essentially largely unsubstantiated level five dogma. So in order to answer this question, we asked a couple of questions. So first was, can we preoperatively determine the magnitude of bone loss after latter J? Excuse me. And this was published in arthroscopy. Joe Lamplot did a lot of the work here, showed that we could reliably look at the size of the coracoid and determine how much bone we could restore and that there was tremendous variability in the size of the coracoid. And as you see in the chart to the right, up to 30%, the vast majority of cases could be restored to a hundred percent with a traditional latter J that said it dropped off precipitously after that. So you know, yes, we can determine preoperatively how much bone loss we can accomplish with the latter J, but how much of the native glenoid do we need to restore? And so the purpose of this was to provide a biomechanical analysis to determine the percentage of native glenoid with restoration necessary to restore stability and force distribution. We hypothesized that a hundred percent was what we were looking for. We use nine cadaveric shoulders. These were denuded down to the rotator cuff, biceps, conjoint, tendon, and latissimus. Translation tracking system was used to record translation and we used a tech scan to determine and measure force distribution. Previously validated shoulder simulator was then used. The cuff was loaded in accordance with other studies. Coracoid graft was sized to 10 millimeters thickness. This is a traditional latter J technique. We used a lesser tuberosity osteotomy in order to create a precise glenoid bone removal, which was done with a burr and then created progressive resections of bones such that a latter J would restore 110%, 190, and 80% of the native width. This is an example of the experimental setup here. You can see the lesser tuberosity osteotomy and the latter J coracoid graft transfixed with two screws, the tech scan placed in the middle, and then the lesser tuberosity osteotomy repaired. The seven testing states you can see here were performed in that order. The first two were equivalent, showing that the LTO did not have an effect on this process. We recorded translation with 44 Newtons in 90 degrees of abduction in neutral and 45 degrees of external rotation and force distributions were measured in the loaded but non-translated state. Translation you can see here in neutral rotation varied significantly. The 100 and 110% glenoid restoration was similar to the intact state, while you can see significant translations in even 90% restoration. In external rotation, we didn't quite reach significance, but you can still see the trends here towards increased translation compared to the intact state. That's essentially what we showed from a translation standpoint, but you can see the numbers are pretty impressive that the difference between 100% restoration and 90% was translation of 6 plus millimeters. You also see within the force distribution here in neutral rotation that a precipitous increase in graft loading at 90% and 80% with the bulk of the contact pressure being on the graft at 80% is fairly similar in external rotation. So there were several limitations. Obviously we did a less tuberosity osteotomy, which is not consistent with standard technique. We did do the traditional Latter-Jay as opposed to a congruent arc. We're not accounting for any of the humeral sided lesions. And we also, this study was performed with loading the conjoint tendon. So the sling effect imparted here does potentially limit extrapolation to other bone block operations. So in conclusion, yes, we've got some answers. We can preoperatively determine the magnitude of bone loss and we should really aim for a hundred plus percent of our glenoid restoration. And so the real question you need to ask yourself is, can I restore a hundred percent of the native glenoid width? And if you can't, you should really consider alternative graft sources. Thank you.

bone loss

shoulder surgeries

glenoid restoration

Latter-Jay technique

stability and force distribution