paper was developed in Connecticut Children's when I was a fellow there last year. So I would like to thank my co-authors, no disclosures. So there's multiple studies demonstrated that a quad tendon is a good option for ECL reconstruction with similar good clinical outcomes, less donor-side morbidity to cross-sectional area for the BTB. So we have seen an increased interest in quad tendon for ECL reconstruction. The quad tendon can be harvested with a bone block or all soft tissue. Advantage for bone block would be a stronger and faster healing and a great length, allowing the surgeon to use an aperture fixation if they would like to. All soft tissue, twice the time for healing. You can use in pediatric population when Pfizer is a consideration and less incidence of fracture. Atrophobosis after ECL reconstruction range from 2% to 8% in adolescent population. Multiple risk factors has been described in literature. So mechanism-derived grafts such as the BTB and quad tendon are indeed a risk factor greater than hamstrings. And systematic review comparing bone block and all soft tissue was done and they demonstrate similar results but no data regarding atrophobosis. Therefore with this study we would like to report and compare early clinical outcomes with focusing complication rates after ECL reconstruction with bone block versus all soft tissue autograft. And we think that they would have similar results. So this was a retrospective case control studies with patient under 20 years of age involving two surgeons. We exclude complex concomitant procedure but we include medical repair and we divide in two cohorts. Same graft fixation with adjustable loop cortical suspensory fixation of femur and tibia and same rehabilitation protocol. We collect the data with focus and reoperation rate specifically for lysis of adhesion. We defined our threshold was three months post-op with lack of full knee extension compared to the other side. So at three months post-op patient underwent isometric knee strength testing to measure the limb symmetry index, which is the ratio between the involved and unevolved limb expressed as a percentage and also a range of motion patient report outcomes. So we did a power analysis and we need to have 34 patients in each group. And so our data, our groups were similar in age, BMI, meniscus and chondropathology, pre-injured sports participation level. But there was a predominance in female in the bone block group, which could represent a confounding factor since female sex is indeed a risk factor for osteofibrosis. But our logistical regression exclude female as a risk factor in this particular cohort. The bone block group graft has a greater length and size, the diameter. And we have four cases of patella fracture, but there was small pieces that was not amenable for a fixation. The bone block group has four times higher rate of osteofibrosis and all of those patients underwent lysis of adhesion and recovered full range of motion at the final follow-up. A busy table regarding the strength testing, but I want to point out that the bone block group was stronger in the baseline. And this reflect the selection bias because the senior author would like to use bone block in more high-level competitive athletes. However, when you look to the LSI, I mean, those patients, they have like a greater increase in quadriceps shutdown. They have lower LSI at three months post-op, which is a significant, I mean, it was something interesting to find. And they have like a patient report outcomes was lower in the bone block group, but this was just the three months post-op, so they all catch up later. We did a logistic regression including multiple risk factors, and the only two significant risk factors for at fibrosis in this cohort was bone block, quad tendon, and inability to achieve a terminal extension. So the main findings of this particular cohort, we found a little bit of a high rate of osteofibrosis, but I don't think we can like generalize these findings for the other populations because I think we'd have two alters, and since our definition was the indication for surgery, this could vary, depends on the attending preference. However, it's fair to point out that all patients achieved full range of motion, which emphasized that early recognition and early action is important, you know, after fibrosis, especially after quad tendon ACL. We did agree the literature that inability to achieve terminal extension is paramount, like is indeed an important risk factor, especially in extensor mechanism-derived grafts. And this study failed to correlate larger graft size with the at fibrosis. Is also another important information, I think that even though the bone block group was stronger in the baseline, they did have lower asymmetry in three months. They will catch up in the future, but maybe this could be related to the extensive dissection to get the bone block, but this can influence the at fibrosis rate for sure. Patient report outcomes were also like a lower, but this was just three months. So in conclusion, in this particular cohort, bone block, quad tendon, and inability to achieve terminal knee extension was associated with lighter adhesion after ACL reconstruction. And this finding suggests, like emphasized the importance of achieved terminal knee extension after quad tendon ACL reconstruction. Thank you.

bone block

soft tissue autograft

ACL reconstruction

osteofibrosis

terminal knee extension