Hi, this is Dr. Laurence Lowy, Professor of Pediatrics at the New York College of Podiatric Medicine, where I am also Dean for student services. This is Part II of Serial Casting on the 21st Century. In Part I, I covered some of the general considerations and built a foundation for serial casting. Here in Part II I will be covering detailed instructions on how to achieve Serial Cast for four of the major pathologies that we see in Pediatric Orthopedics. Before I get started it's important to bear in mind two considerations, the first consideration is that you are not going to be proficient in serial casting unless you have practiced it on a live patient. And I hardly recommend that it not be done through lecture or a book but at the tutelage of a practitioner who does significant amount of serial casting. The other consideration is while I am very detailed in how to achieve each serial cast for each of the pathologies, there may be other equally valid methods and approach the key is to bear in mind how to avoid iatrogenic problems.
The first pathology that we are going to discuss with respect to serial casting is talipes calcaneal valgus or some practitioners will just say calcaneal valgus. Bear in mind this is a congenital flat foot and it is considered talipes it is an 'up and out' club foot rather than a 'down and in' talipes equino varus. What's good in calcaneal valgus is it's one of the easiest to correct through serial casting as it's all soft tissue and generally very flexible. In discussing serial casting for calcaneal valgus it's important to bear in mind that most of the pathologies confined to the rear foot. That is you have a significantly everted calcaneus and subtalar joint, that's where the ligaments and musculature is going to be the tightest. There is a forefoot component but that's easily corrected.
So we need to protect the rear foot while we are manipulating it. To get started the calcaneus should be cupped in-between your index finger and your thumb in the web space of your hand. Your index finger should be curled laterally along the calcaneal cuboid joint in order to project it throughout a manipulation. Your thumb should be plantar to this talar head on the medial aspect, this thumb will be protecting the talipes as we go through a manipulation so we are not inducing a worst flatfoot as we stretch the ligaments musculature and to some degree the bottom. With the heel well cupped and our fingers positioned we now want to invert the heel maximally, that is to resistance as I pointed out in Part I the child may cry but you should not be inducing any pain. While you are inverting the heel proximally, the thumb should be dorsiflexed in the talar head again protecting it from plantar flexing and become more sort of flatfoot.
Once we have achieved a looseness or flexibility in the rear foot, we can move onto the forefoot, here we want to place a thumb plantar to the metatarsal heads and our index finger dorsally, so that we are basically sandwiching the metatarsal head between our fingers, this prevents a logjam effect or having the metatarsals at an alignment with each other. Then it's a matter of just plantar flexing and slightly everting the forefoot. And underlying that slightly, you don't want to induce a forefoot valgus in comparison to the rear foot. Once you have achieved a looseness in both the rear foot and the forefoot you can move on to padding. As I noted in Part I of serial casting in the 21st century, the best way to test for the effectiveness of your serial cast that is the manipulation before putting on plaster and underpadding is to shake the limb.
So here with talipes calcaneal valgus if we shake the limb and we find that it's 'down and in' and that the rear foot is slightly inverted we know we have achieved the correction that we need. From there you can start applying your padding and again it can be Webril roll specialist cast padding. And the general rule of thumb no pun intended is to pad as you are going from medial to lateral, that is you are as you are rolling on your cast padding you are ending up pulling the foot down and in. Then you should continue and remember we want to do four layers here and then have two to three layers as we are going up through the proximal tibia. Then it's just a matter of applying the plaster evenly making sure that we leave some soft material that that is the Webril roll or whatever padding you are using proximally and distally so that toes and the proximal portion of the tibia is protected.
Generally you only need a short leg cast for talipes calcaneal valgus but bear in mind if you look at this picture you are creating almost a straight limb with the foot pulled down and in on the tibia. So you may have to go to a long leg cast because these casts sometimes will slip off easily. Generally I will try the short leg cast if the parents report that the cast came off immediately I will go to a long leg the next casting session.
The next pathology that's common in pediatric orthopedics and relatively easy to serial cast for is metatarsus adductus this is a congenital deformity of the metatarsus adducted on the lesser tarsus it's an all transverse plane problem we generally do not have any rear foot pathology. Here you see the classic concavity on the medial aspect and the convexity on the lateral aspect. We want to keep in mind that there is no rear foot pathology in metatarsus adductus, so we want to protect it at all costs. When we are talking about the rear foot we are talking about the subtalar joint in particular but also the midtarsal joint. Remember that this pathology is at Lisfranc Joint so we need to protect the rear foot as much as possible from subluxing.
Our positioning will be very similar to calcaneal valgus in that we will place the heel the web space of our hand but here the fingers are going to be reversed. The thumb is going to be placed along the calcaneal cuboid joint in line with the fibula. The index finger is going to be curled plantar and medial to the talus to prevent it from subluxing as we do our abductory force. We also will find it advantageous to invert the heel slightly, this will protect us from pronating the rear foot as we do our abdution, sort of a check because as you do your manipulation on the forefoot or the metatarsals to be specific, it's very easy to not be paying attention to the proximal portion and inducing a flatfoot.
Once the rear foot is appropriately protected we can move on to our actual manipulation of the forefoot and again specifically at the metatarsals. We want to place the first metatarsal head in the web space of our opposite hand. We need to protect the metatarsals and keep them in the same alignment to avoid any sort of logjam effect, in order to do that you want to place your fingers, the lesser digits on the dorsal aspects of the metatarsal heads and then our thumb is going to be placed plantarly in order to maintain alignment. Once we are comfortable that the rear foot is slightly inverted and protected and the forefoot is in alignment with itself in the transverse plane we want to create a force transversely, that is we are pushing on the metatarsals and you should feel a little resistance at the calcaneal cuboid joint with your opposite hand.
Once you have achieved some correction that is there is less adductus or you see some abduction in the metatarsals you can move on to padding and casting. The padding is applied by rolling dorsally from lateral to medial that is your abducting the foot as you are applying. It's important to keep in mind, something that I stressed in Part I, you need to keep body parts in the right position as you are applying your materials. You don't want to apply the material and then position the body part. So here we want to maintain the ankle at 90 degrees rather than putting the padding on and then applying it at 90 degrees. We then want to carry this to the proximal tibia again protecting the proximal tibia or the tibial tuberosity which hasn't ossified but in that particular area.
Once again applying the plaster is a simple matter of applying it from distal to proximal, maintaining some soft material at the proximal and distal ends. For metatarsus adductus a short leg cast is generally acceptable as we have kept the ankle at 90 degrees and these casts don't tend to slip off.
Now we move on to one of the more difficult pathologies to serial cast for that is Talipes Equino Varus or the club foot. And there are many methodologies that have been implemented over the years I will cover the major ones including the most recent. Classically coming from higher Hiram Kite there was a stepwise way of achieving a serial cast on Talipes Equino Varus this was handed to Dr. James Ganley in Podiatry and one of my mentors Dr. Ganley actually trained under Dr. Kite and adapted some of his methods. And then little later [Indiscernible] [0:09:52] and I will talk about the differences in these techniques and then most recently and it's not truly recent but just has gotten recent press so to speak is the Ponseti method and I will be talking about that in detail.
There have been many serial casting techniques over the years but Kite's was adopted in the 40s and 50s and for long time considered the way to serial cast for TEV. Kite also advocated as with most serial casting 5 to 10 minutes per limb, per manipulation. And for Kite it was always a stepwise correction first you would correct the forefoot adductus varus once that was achieved there was true correction then you moved on to the rear foot varus and once that was achieved you moved on to the equinus. Kite believed that if you didn't do it in that sequence you could breakdown the foot. This was something that Dr. Ganley also stressed over the years.
Dr. Kite also believed in a stepwise sequence of TEV casting with the difference that once you had achieved some correction in the rear foot and the forefoot in the same session you combine those two manipulations as you are applying your plaster. Once they were corrected that is the forefoot and the rear foot then he would approach the equinus. And if there was no appreciable change in the equinus over a few cast, he was a strong advocate of tendo Achilles lengthening or tenotomy so that the foot didn't get subluxed and sequential manipulation of the rear foot.
We want to keep in mind that TEV is generally stiffer or more rigid pathology in comparison to some of the other pathologies that we serial cast for. It's particularly important to protect the various joints from being deranged iatrogenically. So here again we are going to place the heel in the web space of our hand and place the index finger along the talus plantarly and medially to protect it. We place laterally the thumb along the calcaneal cuboid joint, again to protect the metatarsal joint as we do our manipulations. So it's also important so that we have full control of the rear foot as we evert it maximally. And when I say maximally again it's going to be to resistance. We want pure rear foot eversion and not having the forefoot involved, that's why at this point we are not involving our other hand. We should do this for 5 minutes so we get significant amount of stretch on the medial structures.
The next step is not always followed by some practitioners and I believe it leads to under-correction no-correction or worse iatrogenic pathology. Some points to understand the anatomy in TEV the talus is held either a locked or stiffly lateral to the navicular. So we need to align the talus proximal to the navicular so we have our normal minibone socket joint of the talonavicular joint. In order to achieve this we need to distract the forefoot as much as possible to soften all the soft tissue, dorsal, plantar, medial and lateral. Now in this picture you just see one hand pulling or distracting the forefoot and the other one holding the tibia sometimes you do need the other hand to be holding the rear foot but for picture sake we thought this was a better shot.
Once we feel appreciable give then we abduct the forefoot applying counter pressure with our thumb of the other hand to the lateral aspect of the talus, this counter pressure will allow the navicular to slip in laterally or another way to look at the talus slipping in medially. Once we have that we want to manipulate for the 5 minutes so that we get correction of the forefoot that's appropriate. Once you have achieved appreciable correction then you can combine the two manipulations prior to casting and this is done for another one to two minutes. So here we are everting the rear foot and abducting the forefoot.
The next step is another one where some practitioners I believe get a little sloppy. In trying to correct to the equinus they may just dorsoflex the foot but even maintaining a subtalar joint neutral position you could have a plantarflexery force on the calcaneus due to the significant contracture of the Achilles tendon. So the way to avoid this is to be mindful of what you are trying to achieve, you are really trying to stress the Achilles basically reducing the equinus and you are trying to dorsoflex or increase the calcaneal inclination. So the best way to achieve that is with your thumb plantarly dorsoflexed the anterior aspect of the calcaneous basically you are dorsoflexing the calcaneous itself. And then with your index finger and middle finger, distracting plantarly on the posterior aspect of the calcaneous. This will achieve significant amount of soft tissue release if effective. You may need to do a tenotomy or lengthening if you really don't get any response over time and there is no magic number but as a practitioner I would say if after 2 to 3 cast you don't see any appreciable change in the amount of dorsoflexion rather than maintaining that child in sequential cast, better to do the tenotomy or the lengthening and at this stage I would advocate the tenotomy as it heals very quickly and you get the most result.
Unlike casting for metatarsas adductus or calcaneous vargus TEV casting is a little more involved we do have to go with a long leg cast and in order to achieve that there are two schools of thought, mine is just is that you distal segment first so you hold the correction at the foot and then extent it proximally through the knee joint and try to maintain the knee joint at about 90 degrees. Other practitioners will say do a distal segment, a proximal segment and then connect them. Some will go proximally and distal again as I said earlier there are many variations the key though is to maintain your correction throughout the casting. Once you have gotten your correction and you have stuck your serial casts that's when you want to get them into a device for maintenance and the Dennis Brown Bar with Straight Last Boots will work very well but you do have to be mindful that the Dennis Brown Bar probably should be in a valgus bend in order to prevent any more varus from occurring.
The Ponseti method of TEV casting and treatment has actually been around for sometime, Dr. Ponseti started writing about in the 50s, 60s and 70s but recently and I am going to say over the last 10 to 20s year it has actually become popularized. His method was always at odds with Dr. Kite's and they tended to be rivals at least in the literature, but if you look at the Ponseti Method it certainly is appealing especially to the practitioner who has as busy practice. The manipulation is really only one to two minutes per foot, that's pretty sexy compared to the five to ten minutes per area that rear foot than forefoot that we saw with the Kite versus Ganley versus [Indiscernible] [0:017:22] method.
At the first encounter with the patient you doreflex the first metatarsal to reduce the varus component to coincide with Ponseti. All other encounters are directed at the rear foot and the forefoot as one manipulation. So in that manipulation we use a talus as a fulcrum and with the counter pressure on the talus we abduct the forefoot and with the forefoot goes the rear foot. So with that counter pressure and here you are seeing Dr. Ponseti himself applying that pressure with his index finger to lateral aspect of the talus and then abducting the forefoot with his thumb, so the forefoot is being abducted and then the rear foot is being pulled out of varus with the same manipulation. And then you would cast it once you have done that for one to two minutes.
So here you see a cast that's child did have TEV but it's a significantly abducted cast for the correction. Once you have achieved correction of the rear foot that is the calcaneous has [Indiscernible] [0:18:28] slightly everted you can move on to the percutaneous Achilles tenotomy. Some practitioners will do this in the OR but I believe that that's a little too much for a child and it really only takes a few minutes. Here we are doing it in a clinical setting you can see that my assistant isn't even gloved, the surgeon in me I do believe in a sterile drape around the area and sterile gloves but you can see that I am in my white coat and it's not really a fully sterile procedure as far as I am concerned.
So after administering a little lidocaine posteriorly you just end up snapping the Achilles with a stab incision and you can see appreciable amount of dorsoflexion than you will achieve. And early practitioners were always nervous how is the Achilles going to repair itself? Remember you are talking about babies and they grow very rapidly and believe me that Achilles finds itself again and it reattaches.
Once you perform the Achilles tenotomy the caster applied and maintained for 3 weeks, you don't change anything so my tendency is to use steristrips remember it's a stab incision it will heal uneventfully. Once that cast comes off Dr. Ponseti advocated applying a Dennis Brown Bar Set 70 that's 70 degree abducted with a valgus bend and that child would wear it for 24 hours a day, 7 days a week for 3 months. Now many are using the Dobbs Brace now including Dr. Dobbs who invented it who has been an advocate of Dr. Ponseti but it really doesn't matter the key is that there is some bar in the valgus position at 70 degrees abducted. Again 24x7 for 3 months and thereafter the child should be sleeping in it for 2 to 4 years.
This is what you will generally achieve if you have done the Ponseti method well, that is it's abducted and slightly everted there is no hint of talipes equinovarus left. When I lecture about Ponseti I am one of the few practitioners I believe, maybe the only who does point out some of the downsides of the method. It's not that I believe that it's a bad method and I do advocate it but as with any modality there are pluses and minuses. One of the real pluses I believe is that early tenotomy I have been an advocate of this for many years although in my early days having learned under Dr. Ganley I often put off the Achilles tenotomy and unfortunately that dooms the patient to many casts where you are not really achieving any true correction of the rear foot, but what I have also experienced in the after care of Ponseti is that Dennis Brown Bar whatever bar you want to use for 70 degrees for so long, I have seen a very low compliance. When you look at Ponseti literature and many of the advocates they don't note that much non-compliance but they do note when there were failures that it's been due to non-compliance. I believe that 70 degrees of abduction is pretty significant, there is a lot of torque that goes on at the knee and I believe that this could be an uncomfortable position for a child.
I have also seen many post Ponseti treatments my own and other practitioners and often I do see all the hallmarks of a flatfoot even when there is some appreciable arch. So are we creating flatfeet? It's possible. If you look at the Ponseti literature you will see flatfoot after flatfoot of what we would term a flatfoot both off weight bearing and non-weight bearing it maybe that this is more advantageous than the more destructive long term TEV but it's something we should be considering when we are doing the Ponseti method.
We move on to our last pathology for serial casting and probably the most controversial. There are some practitioners who don't believe that you can cast for internal tibial torsion that is a low malleolar position, but I don't agree, I have been very successful with casting for internal tibial torsion, literary changing a malleolar position that's negative than to one that's positive. One key thing to bear in mind is the younger the patient the more successful you are going to be that makes sense because the bone is going to be more malleable. If you are going to cast for internal tibial torsion please remember that the correction should not be at the knee joint. I have seen early practitioners who will just laterally or externally rotate the tibia and the fibular on the knee and there you gain soft tissue correction and you could be deranging the knee itself. So if we are going to protect the knee, the best way to do that is to grasp the tibia and again to a lesser degree the fibula, posteriorly at the proximal aspect just distal to the knee, that's with one hand and then while you are stabilizing that the other hand is going to grab the distal aspect and again posteriorly is a better and more comfortable position at the malleolar. Here the posterior aspect of the tibia is being held in a web space of your hand.
And then you are going to externally rotate that distal aspect so you are maintaining that proximal aspect in the right position you are not moving that at all and you are just mildly twisting to resistance the distal aspect. And again it seems counter intuitive how can you move bone like that but once you have done it you will see that it's very easily achieved again in a younger patient.
Once you have achieved the correction again it's a simple matter of casting from distal to proximal it's going to be a long leg cast and we want to maintain that distal torsion before we apply our more proximal portion we want that short leg cast to maintain the correction. Now some people will question why do a long leg cast? And the simple answer is we do have a lot of soft tissue structures crossing the knee joint that could affect our overall outcome. So by doing a long leg cast you are maintaining the correction and not allowing the hamstrings and the Achilles to have any affect. Once we get them out of the cast and we have got our correction we want to maintain that with a Dennis Brown Bar abducted to some degree, generally I will go with 45 degree abduction as much as possible if the child is non-ambulatory throughout the day if they are ambulatory at night and during naps. Here again the Dobbs Brace allows motion so it might be an appropriate choice as well.
In conclusion I think it's important to recognize that when you do serial casting without the need for any surgery outside of maybe minor Achilles tenotomy you have actually changed the overall quality of that child's life you have given them a low extremity that they can depend on that won't break down and will allow them to do whatever activities they want to do and you have done it very early in their lives. Tangentially you have also improved the quality of life of the family, once a child is made whole so to speak the family is very appreciative. And often this is where I get my greatest reward in private practice. These are families that will often even if the moved away will stay in touch with me because they are so grateful for what I have done for their child. Nothing beats that.
And the as they say tangentially well tangentially it's also a practice builder, you treat one child and those parents will talk to other parents and lo and behold you become the practitioner who does this sort of thing and end up economically although sometimes serial casting is a lost leader you will end up doing well in the long run by having more patients appreciative of your services. And then for those of us who are surgically oriented and I certainly am I think this is one of the true ways that you see the effect of your treatment almost immediately after that first casting you will see an improvement and that's a great reward as practitioner because you really feel like you are accomplishing something.
So that concludes Part II of serial casting in the 21st century, hope you have had the opportunity to see Part I as well and with the two combined I think that you have got a very practical guide to serial casting and I hope that you are able to start applying this in the real world. Thank you for your attention.
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