Hi everybody, my name is J.R. Cruz, and I'm going to be talking to you about transficial ACL reconstruction, what I do different in skeletally immature patients. I have no relevant financial disclosures. So we're going to talk about the growth plate and how we assess skeletal maturity. We'll talk about indications for transficial ACL reconstruction, some technical considerations when performing this procedure, alternatives to this procedure, and some outcomes and complications. So let's consider growth. As we know, this patient population is at very high risk for ACL tear, and also coincidentally, this is the population where a majority of your limb height velocity is going to be happening. So there's been multiple case reports as well as case series of growth disturbance after ACL reconstruction. This was a systematic review by Collins looking at 21 studies, a total of 313 patients. They showed about a 13% growth disturbance rate. 16 cases of these were angular deformity, a majority of which resulted in genu-malgum, and they showed 29 cases of limb length discrepancy, 62% were overgrowth. Now there are multiple methods to assess skeletal maturity, be this chronologic age, skeletal age, physiologic age via Tanner staging or estimating height based on parents and siblings, as well as menses in females. The traditional method to assess skeletal maturity is the Groyleg and Pyle Atlas, however, this can be a little bit cumbersome, and Hayworth et al at HSS developed the HSS shorthand method, which is a much more straightforward way to assess bone age. There's been more interest in assessing bone age via knee MRIs, and presumably you'll have the MRI from your ACL diagnosis. This is an alternative method of assessing bone age, which has been shown to be reliable, saves the extra radiograph, and again, utilizes the existing MRI. Finally, it's very important to get a full length standing alignment film preoperatively before performing any procedure. This can be uniplanar or biplanar with the EOS, and again, it's important to obtain it preoperatively as well as postoperatively so that you can follow any sort of limb length discrepancy or angular deformity that you may have caused. Now we know that there are multiple methods of performing ACL reconstruction in pediatric patients. We're going to talk about these last two, hybrid ACL reconstruction as well as transficial ACL reconstruction. Transficial ACL reconstruction is going to be closest to your, quote unquote, traditional ACL reconstruction. The indications here are these are going to be your older adolescents with less than two years of growth remaining, so you're not too worried about the physis. However, you still want to consider the physis, and we'll get into detail about that here. So this was a study getting a little bit old now, basically proving that it's okay to drill across the physis as long as you put something across it, and that something across it has to be a soft tissue graft. These authors drilled across the physis, put a soft tissue graft across a canine physis, and showed that there was a very little chance of growth disturbance. However, if they just drilled and left it open, the chance of forming a bone rebridge was very high. This is a study that we looked at basically looking at vertical tunnels versus oblique tunnels. Of course, vertical tunnels had less chance of drilling across a large percentage of physis, and the more vertical your tunnel got in order to get to your anatomic footprint, the tradeoff there was that you may be drilling more of the physis compared to a vertical tunnel. Along those same lines, this was an annual study basically showing that an oblique femoral tunnel also not just puts the physis at risk, but also the perichondrial ring. These authors showed that an oblique tunnel exited the perichondrial ring very close to it, and resulted in distal femoral valgus and distal femur procrobatum in this animal model. So if you are still worried about the distal femoral physis, another consideration that you can, another option that you can perform in these patients is the so-called hybrid ACL reconstruction. Indications here are these patients are a little bit younger, maybe more than two years of growth remaining. They don't quite meet the indication for a complete physio-sparing technique. The hybrid ACL reconstruction is an epiphyseal femoral tunnel with a vertical tibial tunnel. In the femur, you preserve the obliquity of the graft. You avoid the physis and avoid injury to the perichondrial ring. And this is still, you can still get to your quote-unquote anatomical footprint for your femoral tunnel placement with this technique. There's been a few case series looking at this technique, Chambers, 24 patients in 2019. They showed that the older patients did have some higher rate of growth disturbance. However, only one patient required guided growth. Wilson et al., 2018, described a series of 23 patients with growth disturbance, of which only one required an epiphyseal thesis. So in summary, it's going to be very important, as we know, to accurately assess bone age and growth remaining in this patient population. You want to, whatever method you utilize, you also want to obtain a preoperative assessment of limb alignment, whether that be with uniplanar long-leg or biplanar long-leg films. Transphyseal reconstruction, if you're going to perform that, you want to consider utilizing a vertical tunnel in order to minimize the risk to the physis as well as the perichondrial ring. You want to be mindful of that tunnel obliquity if you choose to perform a quote-unquote anatomic femoral tunnel. Always put a soft tissue graft across the physis if you're going to process the physis, and you don't want any fixation across the physis. And again, in older patients, where you're worried about the physis or the perichondrial ring, a hybrid ACL reconstruction with an all-epiphyseal femoral tunnel and a vertical tunnel remains an option. These are my references. Thank you.

transficial ACL reconstruction

skeletally immature patients

assessing skeletal maturity

growth disturbance

bone age assessment