Hi, I'm Sheetal Parikh from Cincinnati Children's Hospital. I'd like to thank AOSSM and POSNA for allowing us to talk about guided growth. Nothing to disclose. I'll start with the case of a 14 and a two-year-old boy who was a competitive tennis player. At age nine, he had treatment for discoid meniscus at an outside hospital, and then the family had moved to Cincinnati. He didn't have any issues for the first five years until about a month ago when he presented with intermittent knee pain. These are his x-rays, and as we can see on the lateral side, he has a little bit of flattening and a small osteocondylation, and also has lesion on the medial side. His MRI shows loss of meniscus substance, decrease in joint space, and mild degenerative changes in the lateral compartment. His full-length x-ray shows mild valgus alignment, of the right lower extremity. He had opinion from two adult support surgeons who had recommended lateral meniscus transplant, along with an osteocondylalograft or autograft. When I saw the patient, we got a bone age, and the distal phalangeal fices were still open. That indicates that the patient has at least two years of growth remaining, so his bone age was less than his chronologic age. I scoped his knee. As you could see, there was some degenerative tearing of the remaining meniscus, which wasn't too much. It was excluded, and there were some changes of the lateral femoral condyle, as well as the tibial plateau. I did a pic in a small area and did a guided growth, as you could see here, using a transvasal screw. This is a pre-op and four-month x-ray, and then at a year and a half, you could see that his weight-bearing line has shifted a little bit towards the medial side, and that is how it stayed since he's finished his growth at that time, and he is four years out. When I saw him in December of last year, he had no pain. He was swimming. He did give up tennis, but the meniscus transplant was deferred till he was symptomatic, and right now, he was completely asymptomatic. So, the key point is that the limb alignment is as important as treatment of the condyle and the osteocondylation, and skeletal age is more important than chronologic age, and then guided growth allows for change of alignment without burning any bridges for future surgery, and it's less morbid than an osteotomy. If you look at alignment, the normal alignment of six-degree valgus is established by the age of around seven years. The mechanical axis is roughly in the center of the knee or just medial to it. If we look at the distal femoral angle and the proximal tibial angle, then it's around 87 degrees, and that would help us to find out what is contributing to the deformity. The origin of the malalignment, it is commonly known that valgus is usually femur-based and verus is tibia-based, so they could be combined or there could be some deformity from the knee joint as well. However, looking at this study in 2017, where they analyzed 420 full length x-rays with valgus, they found that only about 23% were femur-based, 41% tibia-based, and 26% were combined. What that means is it's important to find out where the deformity is coming from. Now, besides the verus and the valgus that we are talking, we also need to understand that if you have a fixed fraction deformity more than 10 degrees, it would influence the coronal axis. Same with the axial plane, even a three-degree rotation would alter all the measurement. Look at this example. The patella is not centered, and we have all been taught that the full alignment x-ray, the patella should be centered, but if you look at the MRI, the patient has fixed patella subluxation. So, in this case, if you try to center the patella, you are significantly internally rotating the leg, and you could see the valgus, which is not true valgus. So, internal rotation increases the valgus, external rotation increases the verus, so we have to keep in mind the rotation that can contribute to the coronal plane deformity. We saw the importance of the coronal plane alignment for the focal contradiction, as well as early degenerative changes in the lateral compartment in the first case. Besides this, meniscus tear, discoid meniscus, patellar instability, collateral ligament, and ACL tears, all these concomitant procedures, one has to keep in mind the alignment of the lower extremity. The goal is to restore the mechanical axis to the center of the knee, and for unique compartment degenerative changes, the goal is to offload it and put the weight-bearing line in the opposite compartment at 62.5% of the width of the knee joint. There are various types of guided growth, including the wires that were initially in 1945. The Blount staples, later on, were very popular for about 50 years, to the newer implants, which are the trans-visor screws, and the tension band plates became popular. I usually use the trans-visor screw in my adolescent practice, and the way I use it, or the way I insert the trans-visor screw, is I find it easier to put my guide pin in a retrograde fashion, so it intersects the visors at two-third, one-third junction, and then I put an anti-grade screw, which is usually a 6.5-millimeter screw, and then do the concomitant procedures as needed. Tension band plates are various types of plates, including hinge plates. Now, if you compare the screws versus the plates, multiple studies have shown that the rate of correction is more rapid with the screws than with the plates, and this is another study which shows a similar thing, that the screws provide a faster correction compared to the plates, and hence is considered to be a better technique. We need to know the complications of guided growth. Here is a seven-year-old Down syndrome boy with bilateral patellar instability and general valgus. I did trans-visor screw to correct his valgus, which it did, but then he presented late in follow-up, and it was difficult to remove the trans-visor screw. I had to use the reamer on top of the screw to remove it. So, he is five years post-op. Now, luckily, he did not have a growth arrest. You could see the track of the screw, so he has grown significantly after the removal of the screw, but we can see that he's overcorrected, and there is joint-line obliquity. He remains asymptomatic to date, but I'm concerned about his joint obliquity. Here is an example of a nine-year-old female who had a tension band plate back in 2013 for valgus, and once it corrected, I removed the plate. This is her x-ray in 2014. The following year, she came with a rebound valgus, and now the patient was nearing skeletal maturity, so I chose to use the screws on both the femur and the tibia, and so she did correct, and I overcorrected her a bit in 2016, then removed the screws, and this is a final follow-up on her, but the important thing to note here is that there is a rebound valgus or rebound deformity in about 5% of the patients. I showed an example of overcorrection and then an example of rebound. When we're using the plates, cadaveric studies have shown that out of the eight cadavers in four, the capsule was violated by the tension band plate, and in the other four knees, it compromised the MPFL, so one has to be careful when using the plate on the medial side. Other complications which are common with the plate are infection stiffness and swelling. There is hardware-related complications, including extrusion breakage of the screws and hardware prominence, and then undercorrection, overcorrection, rebound, and five-cell damage, especially with the screws. This is a study of 967 physis looking at complications, and they found eight complications were infections, some limited range of motion, and some screw breakage from the plate. So, to summarize, I have a low threshold correction of deformities, especially when I'm treating patellar instability, meniscal injuries, chondral injuries, and my threshold is more than five degrees of vagus, and two years or sometimes even one year of growth remaining, I would go with guided growth. My preference is a trans-physis screw, especially when the patient is nearing completion of growth, since it allows for faster correction, has low morbidity. I would use tension band plates in younger kids, though that's typically not our sports population, but if I have to use it, just like I showed the example of a Down's patient, then now I would prefer to use a tension band plate because of issues with violating the physis. The implants also need to be based on the concomitant procedures to make sure they don't interfere with any tunnel placement or other treatment of other diagnosis. Thank you.

guided growth

limb alignment

skeletal age

trans-vasal screws

deformities