Good afternoon everyone, it's a pleasure to be here. Thank you to the moderators and AOSSM for allowing us to share our work with you. So the main background to this study is based on the fact that there's a resurgence in interest in ACL repair. One of the main reasons for that is perceived advantages with respect to quicker recovery and return to sport. Here's an example of that, a case report we published a couple of years ago of an Olympic skier. She injured her ACL five months before the Olympic Games. At three months after ACL repair she was able to return to a competitive level and then she did compete in the Olympic Games coming 17th. However, the general literature doesn't bear out these findings and doesn't so far show significant advantages of ACL repair. So the purpose of this study was to retrospectively compare the clinical and functional outcomes of repair versus reconstruction using either BTB or hamstring tendon grafts at a minimum follow-up of two years. This is an example of a Sherman One tear, it's an avulsion from the femur. The way in which we repair it is to pass two cinch stitches through the ACL and then place an internal brace. Very briefly that's fixed on the lateral cortex with a button and the internal brace is fixed on the tibia with an anchor. The internal brace is fixed in full extension after the ACL has been fixed at 90 degrees of flexion. We use propensity matching because this is a retrospective study so we wanted to minimise the impact of treatment selection bias. So we propensity matched all the ACL repair patients that we had between 2017 and 2019 and I should mention that all procedures were performed by Bertrand Sonnery-Cote and Johannes Barth. We matched them in a one-to-one ratio to ACL reconstructions performed in the same time period. We performed isokinetic testing at six months post-operatively, we evaluated knee laxity parameters at 12 months and then PROMs and return to sport and failures at the final follow-up which is a minimum of 24 months. We're not going to go through the whole of this slide but the important points to note are that in that study period those two surgeons performed over 1,200 ACL reconstructions so we had a big pool with which to propensity match. After applying exclusion criteria which included revision ACLs, use of holographs and patients who'd had surgery beyond one month, sorry beyond one year from the time of injury, there was about 900 patients available. Of those only 8% underwent ACL repair so this reflects the fact that the indications are highly specific and that it's only applicable to a small number of patients. In the end we had 75 patients in each group. The criteria for repair were Sherman 1 or 2 which is an avulsion from the femur and Sherman 2 is when there's up to 20% of the remnant remaining on the femoral side. There had to be good quality tissue but the main indication for surgery for a repair was determined intraoperatively by the reducibility of the ACL. So on the left hand side you can see how we assess reducibility inflection so at 90 degrees of flexion but more importantly the PL bundle is slack inflection so what we want to do is assess it in the figure of four position and you can see at the top on the right it's reduced but on the bottom it didn't reduce so that one in the bottom right corner we didn't repair that one. These are the variables assessed in propensity matching, gender, age, BMI, the delay from injury to surgery, meniscus satus, laxity parameters and athletic level and all these were very well matched. You can see that mean differences were very small showing that the groups were highly comparable. So in terms of results there was a significant difference in isokinetic strength of the hamstring muscles with the ACL reconstruction group having a 10% deficit with no deficit in the repair group. That was statistically significant. There was also considerable deficits in both groups with respect to quadriceps 20% in each group but there was no statistical significance between them. We found that ACL repair was non-inferior with respect to side-to-side laxity differences or subjective IKDC at 12 months and then our main outcome measures assessed a mean final follow-up of 30 months, no significant difference between groups with respect to Lishome, Tegna, KOOS, ACL RSI or time to return to sport. Time to return to sport is one of the main areas of interest but even though there was a trend for an earlier return with repair at 10 months compared to 11 months that wasn't significant and there was also a greater proportion of patients in the repair group 75 compared to 60 in the reconstruction group who returned to the pre-injury level of sport but again that wasn't significant. Another significant finding though was the mean forgotten joint score was significantly better in the ACL repair group meaning that those patients were more likely to forget about their knee during activity and that was significant. Another important outcome is failure of the index procedure. There was actually no failures of ACL reconstruction during the study period or the follow-up period but there were four failures of repair representing 5.3% and that was significant. Within the ACL repair group patients experiencing failure were significantly younger than those that did not, also significant. When we excluded patients aged under the age of 21 there was no significant difference in failure rates between the group and that mirrors some previous studies. So in conclusion the failure rate is significantly higher after ACL repair compared to ACL reconstruction and younger patients are particularly at risk. ACL repair was associated with some advantages over reconstruction including superior hamstring strength at six months and significantly better FJS scores so it's a potentially useful treatment option but only in highly selected patients. Thank you.

ACL repair

ACL reconstruction

BTB graft

hamstring tendon graft

clinical outcomes