Seth Sherman from Stanford University will talk to us about meniscus. Thank you very much. I'm excited to be here talking about biologics for meniscus repair. My disclosures are available online. I think we're in an era where we're all in this room trying to save that meniscus. And we know that meniscus repair is on the rise. We know that our patients actually care about the development of osteoarthritis. That's a primary concern of theirs as we follow them over time. And we're really advancing the field from those classic vertical longitudinal tears to all sorts of different patterns that I'm sure we'll go through today in our case presentations. However, we know that these success rates of repair remain suboptimal. And so I think this definitely is a field that is ripe for biologic augmentation. We can see pictures like this ideal tear in the setting of an ACL. We can do hybrid inside out, vertical sutures, and we can get good results with great healing for this tear. It's not exactly the problem. However, when we think about other tear patterns, complex, horizontal, older patients, red-white tears, revisions, that's where the problems start to exist, especially in isolation without ACL reconstruction. And there's many factors that go into meniscus healing. We're going to laser focus on biologic augmentation for the next several minutes. When we think about healing, we need to think about cells. We can think about blood supply. We can think about tear patterns and configurations of repair. We have seen a real rise in articles talking about techniques for meniscus repair and thinking about biologics. We need to be thinking about what are the targets of our interventions. Is this for vascularization? Is it for recruitment of cells? Inflammatory control, extracellular matrix deposition, or other targets to augment healing? Here's kind of the five areas that we might utilize in our practices these days to improve meniscus healing. The first one is fairly straightforward, either rasping the meniscus or trepanation. We can see several studies dating back to the 90s on this. We typically want abrasion-induced stimulation of local vascularity and growth factors. There's really no RCTs, but good results in K-series of small tears. This can increase local cytokines and growth factors, peaking at 7 to 14 days. It's very easy to do. It's fast to add to the repair. It has a long track record and really little downside or risk. So I would certainly consider utilizing one or both of these in your meniscus repair strategies. As we move on towards fiber and clot, this becomes a little more challenging. We can see some of the data supporting clots dating back to the 80s and 90s. You can get good defect fill, but it's fibrous tissue rather than true meniscal tissue. You can see the classic Henning article, failure rates going from 40% to 8% with the clot and those isolated meniscus tears. The concept is this is a localized scaffold and stimulation, primarily PDGF and fibronectin. Unfortunately, again, K-series only, improved failure rates with the clot, but it's really challenging. It requires a blood draw. It's difficult to maintain localization of that clot. I think we're starting to consider utilizing this, particularly perhaps in these degenerative horizontal cleavage tears, this kind of sandwich technique. But there is limited high-quality evidence. It's K-series only and still challenging whether we should consider bone marrow clots versus peripheral blood clots. I still think is ripe for investigation. And then can we use fibrin clots as a vehicle for cell-based therapy? Certainly not game ready in 2023. Here's a young patient of mine, horizontal cleavage tear treated with circumferential compression sutures and trying the best that I could to get the clot where it belongs and to get it to stay there. But I'm certainly not perfect at this technique, but I do think there is an increasing role for this over time. Which leads us to this athlete, 17-year-old. He had a flap tear of the lateral meniscus. You can see here that we do an all-inside repair strategy. This is an isolated tear without an ACL reconstruction. And I think for this and for the majority of my cases, this is where I'm going towards marrow venting. You can see making small perforations in the notch. And then with experience, you can train the bone marrow to go exactly to the site of the meniscus repair. I can tell you offline how I do that. It's a veteran move. But you can see here, there is some growing data for marrow venting. Improved healing rates in isolated repairs, similar to the rates in concomitant ACL reconstruction. And that's really my workhorse these days for repair. PRP, similar issues that I'm sure we'll discuss in other fields and use cases. We definitely have varying formulations, different cytokine chemokine profiles. So it really hasn't been perfectly standardized, and I think the literature reflects that. The bottom line, when looking at the paucity of literature for meniscus, we can perhaps get improved failure rates in isolated repairs, but really no benefit with ACL. And there is a risk of stiffness when you combine PRP with ACL reconstruction. We looked at several of these articles a couple of years ago and found that those failure rates were reduced in the five studies in 274 patients. In our series, there are other systematic reviews, meta-analyses, and I think we are somewhat limited by the quality of the evidence that we're synthesizing and reviewing, and the jury's still not out on this. Lastly, cell-based augmentation. I think the bottom line is this is promising but still experimental. There's emerging basic science literature, no high-level studies. Challenges remain. Cell viability, localization. There are different sources of MSCs that we can consider, and so hopefully I've summarized this evidence for you in your packet with the available studies, and there are not very many of them. We certainly have expanding indications for repair. Our healing rates remain suboptimal. There's a clear rationale here for biologic augmentation and no consensus on what to utilize. I want to keep it simple in 2023. No augmentation alongside my ACLs, marrow venting for most isolated repairs, selective use of PRP for complex cleavage and or revision situations. We should all follow the evidence and collect our outcomes together, and thank you very much for your attention. Thank you.

biologics

meniscus repair

complex tear patterns

biologic augmentation

marrow venting