Okay, thanks very much. Disclosures are in the program. So we're all familiar that a quad tendon autograft is becoming a more popular graft choice for ACL reconstruction, in part due to studies suggesting perhaps lower anterior knee pain and donor site morbidity than BTB grafts, and preserved flexor muscle strength and potentially lower re-tear rates compared to hamstring grafts, as well as comparable or potentially superior functional outcome measures. There's been very little, however, on the adolescent subpopulation, which is the highest risk group, as well as complications. Here's one important study from a high ACL volume center, where 25% of their grafts were quadriceps tendon grafts, and they looked at risk factors for manipulation under anesthesia and lysis of adhesions, finding the quad tendon autograft to be 2.7 times relative risk, and among the strongest univariate and multivariate risk factors for this arthrofibrosis phenomenon. The goal of the current study was to investigate a series of adolescent soft tissue quad tendon ACL reconstructions, and look at the rate and nature of postoperative complications and early functional outcomes. This is not a long-term functional outcome measure study. We also wanted to assess a conversion from other graft techniques to quad tendon to see if there might be an effect of a learning curve or any adverse effects. We included patients 12 to 19 years old over a two-year period. This is a single surgeon series at a tertiary care pediatric center in sports medicine division. We excluded those under 12 months of follow-up and multiligamentous knee reconstructions, and used PROs validated for this age group. Based on prior studies, we assessed an initial 25 cases as a sort of learning curve period, and compared these to the subsequent 68 cases using various analyses. So we had 90 patients, 93 knees, 70% were female, the mean age was 16, mean follow-up was just under two years, 57% meniscus tears in this cohort, which is similar to this age group's rate in other studies. Over half of those underwent repair. So in the full cohort, there were 38 complications of varying degrees of clinical severity or significance, but there was no difference between the learning curve and the post-learning curve in terms of complications. The ACL retear was 6% at this early time point, but it was different in the learning curve compared to the post-learning curve period. The key finding of the study, however, was the relatively high rate of arthrofibrosis or cyclops lesions. This wasn't different in diagnosis between the learning curve and post-learning curve period, but the additional or secondary surgeries performed for these, the lysis of adhesions and cyclops debridements constituted the bulk of these 23 additional surgeries done for any reason, and this was different between the learning curve and post-learning curve period. So 15% overall and 20% in the learning curve, 13% for cyclops debridement in the post-learning curve period. Functional outcome measures were expectedly improved from pre-op to six months and further improved at one year and two years with high activity levels at one and two years in this group. Expectedly, there was an adverse effect. Patients with complications had significantly lower PROs compared to those without complications, though significance was lost by the two-year point. There was no difference in the functional outcome measures between the learning curve and the post-learning curve populations. So in conclusion, quad tendon ACL reconstruction in adolescence shows an early graft retear rate that's similar to other graft choices for this young high-risk subpopulation, though a technical learning curve may be important. And one and two-year PROs and activity levels are similar to normative values, though are adversely affected by complications such as retear or cyclops lesions. And in this age group, there appeared to be a relatively high rate of arthrofibrosis, up to 20%, mostly in the form of cyclops lesions, most of which require arthroscopic surgery in the form of a cyclops debridement. The cause of this is somewhat unclear, though may be related to the enhanced biologic or fibroblastic activity in this young tissue with three cut tendon surfaces up to 9 to 10 millimeters compared to no cut tendon surfaces in the hamstring or minimal surfaces in the BTB. We know that quad tendon has higher fibroblastic concentration than other graft options. Or maybe other demographic factors such as the young age, female sex, the high rate of meniscus repair, or technical factors related to notchplasty or graft position or rehab-related factors, but certainly warrants more study. Thank you.

quad tendon autografts

ACL reconstruction

adolescents

complications

functional outcomes