I'm going to talk to you about whether we need the scaffold. So I'm a consultant for Arthrex. I received grant funding for ACL repair for prospective investigation from Arthrex. So recent evidence suggests that suture-augmented ACL repair is a viable alternative to conventional ACL reconstruction in select patients. Though evidence quality is generally poor to date, there's increasing quality of evidence supporting modern ACL repair. I've been performing suture-augmented ACL repair since 2014 in select patients, specifically for proximal ACL tears. So looking at the first generation of ACL repairs in open technique, patients were casted for six weeks. All comers were fixed. And Fagan and Krell showed the 94% complaint of instability, 71% pain, and 66% had swelling. And as a result, this was basically cast out and replaced by ACL reconstruction as the gold standard. Looking at ligament augmentation, there were high rates of synovitis in this group, graft breakage, stress shielding was seen with the early ligament augmentation devices, thought they were too stiff and didn't allow the biology to do its job. And so the ligaments sort of degraded and there were a high rate of failure. Paulow's study in 1992 showed improvement in less than 50% and a 76% complication rate. So what's different now? So looking at Smith's study, 2019 second generation suture augmentation, braided high tensile suture strength alongside native ACL in dogs compared to conventional reconstruction, found no evidence of chemical synovitis or gross cartilage degradation, no foreign body reactions and superior histologic articular cartilage and synovial scores in suture augmented knees compared with ACL reconstructed knees. Murray's preclinical studies, Martha Murray's preclinical studies in Yucatan pigs at six and 12 months showed significantly less macroscopic cartilage damage with a bioenhanced ACL repair when compared with a conventional ACL reconstruction. So this is a study that I co-authored that we put out in 2020 in Orthopedic Journal Sports Medicine where we simulated in the lab what would happen after ACL repair with suture augmentation and we cycled the knee at different levels to simulate the immediate post-op rehabilitation, early post-op and late rehabilitation period. And what we found was that the dotted line represents the early function of the suture augment and how it fell within the stress strain curve early, but then eventually loosened, which is exactly what you want. So over time it loosened so that you sort of hand off to the biological structure. We also found that at the end of these cycles at 250 newtons and 400 newtons that the repair was still intact and had not moved away from its repair site. So this is our current generation technique. I actually use a button on the lateral cortex, whip stitches within the ligament itself, poke some holes in the bone to stimulate a healing response and then pass this button out in the lateral cortex, which you'll see on the x-ray, sort of mirror image x-ray. This is the suture augment running in the anterior aspect of the ligament so that I can see it and I can adjust tension. It should serve as a seatbelt. It should not be over tensioned. Again, we don't want it to take over the job of the ligament. The ligament repair is ultimately what we want to protect, but we want it to also serve its biological, biomechanical function. So promising new data, DeFelice study in 2019. When you look specifically, if we're talking about the scaffold here, he had failure rates that were 7.4% with the scaffold and 13.8%, almost double, without suture augmentation leading the author to abandon non-augmented repair. So talking about some of the other scaffolds that are out there other than the suture augmentation, this is Hugelsag's data of 2019, a randomized controlled trial, where he has a dynamic ligament stabilization device, a little bit different than the suture augmentation that I do, where the spring would actually move with the patient and kind of adjust according to the patient's motion and function. And he found with his device that there was an 8.7% failure rate with his device and a repair compared to conventional ACL reconstruction of 19%. This is a little bit higher than what we usually see in the United States, so it's kind of hard to comment on whether this would be comparable in our demographic patient population. Martha Murray's study with the BARE randomized controlled trial with 65 patients in the BARE group and 35 in the control group, where she used a proprietary scaffold that was used to bridge the defect between the tip of the ACL on the femoral side and the bony attachment site. And what they found was it was non-inferior based on IKD subjective scores, side-to-side difference in AP laxity was no different. They did not burn a bridge, but they did find a slightly higher rate of failure in the BARE group, even though this was not deemed statistically significant, 14% in the BARE group compared with the control conventional ACL reconstruction. So over the last six years, we've done a study at MedStar looking at prospective comparison of ACL to ACL reconstruction, ACL repair to ACL reconstruction. We had 30 patients in the suture-augmented ACL repair group, 30 in the conventional ACL reconstruction group, age less than 14, no PCL or PLC injury, no significant osteoarthritis. And what we found was that 55 out of 60 patients were available for follow-up, a 91% retention rate. We had three failures in the suture-augmented ACL reconstruction group, which was 10%. The average age was 19.6 years old. The total cohort average was 24.5 years old. So I think what you're seeing is a recurrent theme is that in younger patients, there seems to be a higher failure rate. Conventional ACL reconstruction, we had no re-tears, but we had one patient who was unable to return to a previous level of activity and was unsatisfied with this outcome. So looking more diligently at the patient-reported outcomes, statistically significant improvement in both the ACL repair and the conventional ACL reconstruction groups between pre-op and post-op at two years. Statistically greater improvement at the three-month and six-month mark for IKD subjective and Tegner scores, Tegner functional scores, for the ACL repair over the conventional ACL reconstruction group. But there ultimately were no significant differences between any of the PROs at two years. Return to previous level of activity in the suture-augmented ACL repair group, we had one professional athlete. We had multiple cops and people who needed their knee for daily activity, as well as three collegiate athletes and a number of high school athletes all were able to return to their previous level of activity. One in the reconstruction group was a recreational athlete dissatisfied with surgery and unable to return to previous level. KT1000 arthrometry at two-year follow-up involved versus uninvolved showed no significant differences between either cohort. We had 1.1 millimeter side-to-side difference with maximum tension using the KT1000 with the ACL repair and 1.2 with the conventional ACL reconstruction. So in conclusion, the overall quality of Evans is improving in support of ACL repair. Suture augmentation protects the repair. We've shown that in the lab and we're seeing reasonable outcomes in the ACL repair group clinically. Concerns remain over young pivoting and cutting athletes. There's a lower failure rate of ACL repair with suture augmentation, 8.7 to 16%. There's no significant difference in PROs, no arthrometric evaluation between suture-augmented ACL repair and ACL reconstruction at pre-op to two years. And there's promising short-term outcomes in comparison with the gold standard. But we need to do further study looking at RCTs, looking at long-term follow-up and investigating arthritis and return to play at the five and ten-year mark. Thank you.

suture-augmented ACL repair

conventional ACL reconstruction

bioenhanced ACL repair

suture augmentation

ligament function