• LecturehallCentral Metatarsal Surgery
  • Lecture Transcript
  • Male Speaker: Good morning. So I'm going to talk to you about the topic, Central Metatarsal Surgery. I find this to be rewarding if it goes well and very perplexing when it doesn't. It's one of the difficult things that we do in podiatry in my opinion. These are your learning objectives, and I'm going to move forward. The definition of a normal parabola is very important. You need the second metatarsal protrusion distance to be a plus or minus two millimeters to the first metatarsal head when comparing the disarticular surfaces of the cartilage. So you want to see that you have a normal parabola and that's what you're really trying to achieve when you're doing central metatarsal surgery. Ideologies of lesser metatarsal symptoms can be many by a mechanical structural dermatologic inflammatory and there are systemic disease and metabolic processes that can also cause ideology to the western metatarsals. Biomechanical deformities of the western metatarsals are usually due to hyper-mobility of the medial and lateral column of the foot with abnormal pronation of the foot and you'll commonly see it with the patient with a -- associated with a bunion deformity, a collapse in the medial longitudinal arch and then pressure in the metatarsals 2, 3 and 4, most commonly because you have met primus elevatus with pressure under the second, third or fourth metatarsal. Cavus foot deformity is -- also can come with metatarsal phalangeal joint deformities and central metatarsal problems due to the cavus -- four-foot equinus and actually there is a real foot equinus component as well extensive substitution with additional weight bearing causing stress on the metatarsals. This is a little bit more in detail. I'm going to move on but I want you to know that there's a metatarsal cavus equinus as well as a four-foot cavus equinus and then there's a transverse plane condition. And this is why, because it's truly a biomechanical problem more than a surgical problem when you look at the metatarsals especially 2, 3 and 4 because they work as one unit. The first metatarsal and the fifth metatarsal work on independent axis. The second, third and fourth metatarsals work together. Structurally, what we do in the surgery is correct the structural problems, the long and the short metatarsals, the prominent metatarsal heads or the disease in the metatarsal head and/or elevated or displaced metatarsals. A long first metatarsal structurally is actually a very infrequent finding but a nice osteotomy that was developed, it's called the Weil osteotomy which I'm sure you have all performed in your residency. What is interesting is that you avoid the rotation and dorsal displacement. When I started doing metatarsal surgery when I was resident, we just take a bone run or crunch the metatarsal and let it seek to its own position. Well, that came with lots of other problems although it was kind of fun to do. We weren't really helping too many people in reality. Fibroids disease [phonetic] is a disease of the -- on the osteochondral defect of the second metatarsal phalangeal joint and that leads with a lot of different problems and surgical considerations. Now, they have hemi-implants for this metatarsal head resections and also total implants. This is something as a surgeon you would want to look at and determine what is the most realistic approach for this problem but it is very painful, usually with weight bearing and it actually has a limited range of motion and later onset, there's a complete collapse of the joint with joint destruction. Plantar plate or plantary positioned metatarsals, you'll see commonly caused due to a contracture of a digit, particularly this -- at the metatarsal phalangeal joint with subluxation. Many times you'll have proximal phalangeal joint of the digit being also a contributing factor. It's usually cause-associated with dislocation at the level of the proximal phalanx with increased retrograde force to the metatarsal head itself. You also have dermatology or dermatopathologies that sometimes get confused with something that's due to a boney prominence. I can tell you that if you try to correct these deformities, these keratomas and these lesions with surgery, you're going to fail because it's really a dermatologic problem. These lesions are best biopsied and sent off to a podiatric lab like Bako and find out exactly what it is before you're starting to do surgery. Many times I'll put lesion markers on these lesions and you'll see that they're not over-boney prominences. There's also inflammatory conditions which result in a direct mechanical overload of the forefoot.


    You have psoriatic rheumatoid arthritis as well as osteoarthritis and gouty deformities that can contribute. Here's a patient with psoriatic arthritis with a complete subluxation of the first through fifth metatarsal phalangeal joints particularly the third metatarsal phalangeal joint. And although you're asking, well, that looks like rheumatoid, you can get a penciling and cup type deformity and you can also have psoriatic arthritis that mimics rheumatoid arthritis. So you need to have a good differential diagnosis when you're looking at these problems. Clinically, you want to evaluate not only the hyperkeratotic lesions and spend associated soft tissue swelling, you want to see them in gait, you want to actually evaluate the -- palpate the forefoot along the metatarsal area, find out if there are -- is an area of prominence. I use lesion markers many times and I'm taking x-rays over the area of pressure to assure that it's a boney deformity before I do surgery. Radiographically, of course, you have your standard views where you can assess the metatarsal parabola, the sagittal plane alignment of the lesser metatarsals and you would like to see if there's a super-imposed, supranatus [phonetic] of the forefoot on the lateral view as well. Remember that you have many systemic conditions which cause destruction at the level of the metatarsal phalangeal joints and therefore you should also be very aware of that, get a good patient history and make sure that you rule out the arthrodesis. In lesser metatarsal surgery, the goal is to restore the normal parabola of the metatarsal in order to realign the forefoot and stabilize the foot to the ground during stance phase of gait with relief of the forefoot symptoms. That's a lot of words to say and it's also one -- as I've said, one of the more difficult things that we have tried to achieved in foot surgery. You have many types of ways to approach the metatarsals, you have distal metatarsal osteotomies, basilar osteotomies, diaphyseal osteotomies, plantar condylectomies, lengthening procedures, shortening procedures, dorsal reflectory [phonetic] osteotomies. So you can see that when you have a whole army of tools that you can use after you evaluate keyword, evaluate the patient properly for the ideology. Here's an example of distal osteotomy and Weil type osteotomy in third metatarsal, the slide 2, you're right, I guess it is -- your left, is actually a lesion marker showing where there's pressure over that third metatarsal and then the osteotomy being made. The Weil osteotomy is an excellent procedure to help reduce the deformity at the metatarsal head and shaft and it also gives you availability to fixate it properly. It's indicated for -- with dislocated toes, metatarsal salgia and early [indecipherable] [0:08:09]. You want to have an -- your goal, again, is to reach that normal parabola where you have one a little shorter than two than three, four and five. A realignment of that normal parabola is your goal. Here's an example of someone who has had a foot surgery many times around that third toe with shortening and elevation of the toe. This would be called your podiatry nightmare and you wouldn't want to have that. But if you do, you have to sort of confront it and then try to fix it and the idea is to get that third toe back in alignment onto the metatarsal phalangeal joint. You can do that in several ways. Of course, you want to stage your procedures and fixate them so that you have good alignment of one, two, three, four and five when you're done. And in a patient like this, you know that there's definite soft tissue destruction and the plantar plate is nonfunctioning and a fusion maybe or answer especially at the proximal phalangeal joint if not at the metatarsal phalangeal joint. Again, here's an example of the patient's foot with -- before surgery then after surgery with severe subluxation. Prior to her surgery, she had minimal type incision surgery and there was complete destruction of the third metatarsal phalangeal joint. This second toe became more subluxed and then the story just begins with the toe, third toe becomes elevated. So you can see here that -- I don't know if you could see it well enough, but what we did is realign that second toe onto the metatarsal phalangeal joint, pinned it and fused it so that it would stay stable. The reason why I'm showing you this, although, I don't know if you could see them well enough, but you want to -- the dissection is very simple especially the second and third metatarsals, you get -- there's not a lot of ideologies, there's not a lot of tissue that you have to dissect through.


    Get down onto the metatarsal phalangeal joint and open it up. Now, what you're going to do is you're going to actually do a Weil type osteotomy, you can do a screw fixation. I've used absorbable screws, I've used headless screws. I've used all types of fixation. It really doesn't matter. Whatever is easiest in your hands. The idea is to make sure they're fixated. As I've said, in early days, we used to just cut the bones and let them float and then you would have that toe like you saw in the earlier picture. The key here is that -- I'm just going to move through that, you want to get good stable fixation. The nice thing about the Weil osteotomy is that way -- the way you cut it, you can determine how much you want to shorten or elevate that metatarsal, I mean, or lengthen that metatarsal. It's a very easy osteotomy to make and the fixation is very easy to do as well. Make sure that if you're going from proximal to distal with your screw, you're not getting into the [indecipherable] [0:11:07] of the metatarsal head. I think that's the only thing that you have to really watch out for when you're fixating it. This is just putting in a screw just to make sure it's stabilized. And you can see here, this patient needed -- had a very short first metatarsal and what was elected to do is shorten two and three and leave one alone. Patient refused any more bunion surgery. Therefore, we shortened two and three minimally enough that the parabola was more realigned. And again, here's another procedure with an Acutrak type screw, it's a headless screw. I particularly like that screw because it's headless, there is no prominence to it, it has good fixation and bites well. I can actually ambulate these patients very quickly. Again, if you look at a metatarsal phalangeal joint like this, it's difficult because you know a couple of things are happening. Number one, we have a pain at the joint. You actually have subluxation at the joint, you also have destruction of the collateral ligaments, especially laterally, you have the toenail leaning onto the first fist toe, if it's the second toe. You also have the other toes overtime will pull in a various position and you'd have a plantar plate disruption. So with all that in mind, there's a lot going on and many people go in there and simply say, "Well, I'll just do an arthroplasty and put the toe back on top of the metatarsal." It's a very unstable problem. You want to realign that joint as if you had a bunion and you would realign it with an Austin or Burton or a Chevron [phonetic] or whatever and you have to consider realigning the joint onto the base of the proximal phalanx. And that's what we did, we actually fused the second toe and realigned the metatarsal phalangeal joint but utilizing an osteotomy to do so. But also I did a plantar plate reconstruction and also fixed the collateral ligament. For completeness sake, the fifth metatarsal, there's a diaphyseal osteotomy, you can do that in your metatarsals. Although, I don't do much in the line of diaphyseal osteotomies unless I'm doing some type of lengthening procedure. Plantar condylectomy is also another approach to a very simple problem of a prominent big large metatarsal head with large condyles. I used this procedure in the elderly population where you want to relieve some of the pressure under the metatarsal and not put them through an extensive reconstruction and you're doing it from one isolated problem. You have a problem with this procedure though is that you unstabilize the plantar plate many times and you can get a floating toe. So be aware. Lengthening procedures, there's all types of osteotomies early on. We could slide osteotomies. And now, with the advent of external fixation, you can do lengthening procedures with external fixators. One caution -- and this is not the lecture on breaking metatarsia -- but if you do lengthen a metatarsal that much, make sure you put a pin in the metatarsal phalangeal joint because you definitely will sublux the toe, which I have. Shortening osteotomies, I like this picture because in the middle there you see this big round hole and you wonder what the heck that is. That's an absorbable screw and now we did a shortening osteotomy and then overtime, you can see where the absorbable screw. This is about a year later where you really now have healing and the absorbable screw begins to absorb. So don't get worried if you use absorbable screws. You will see that hole for a while. Hammer toe correction also is very important when you're realigning the metatarsal phalangeal joints and make sure that you take out the deformity of the proximal interphalangeal joint due to the buckling and subluxation onto the metatarsal phalangeal joint area.


    Just a quick view. Here you have a subluxation at the proximal end, proximal interphalangeal joint and the metatarsal phalangeal joint and both need to be realigned. Metatarsal head resection is definitely a very good procedure for someone who has rheumatoid arthritis, who has severe subluxations and then you do metatarsal head resection, one -- two through five. On -- the very elderly in my area, if they have a very severe pain, fifth metatarsal, I will do an isolated fifth metatarsal head resection. Again, here we fused the first metatarsal and took out heads two through five for this rheumatoid patient. The beauty of a patient with rheumatoid arthritis and being able to address this problem utilizing metatarsal head resections is they have a very apropulsive gait anyway and it's not really changing the way they walk. What you are is changing the pain and prominence of the problem so that they don't breakdown, ulcerate and have further debilitating other disease processes or debilitating problems. A long second metatarsal with deviation, make sure that you address the deviation. If you only address the metatarsal with osteotomy, you won't get success and you'll still have deviation. So in conclusion, you want to do restoration of the problem by maintaining a normal parabola and assure that you have -- you can do less amount of osteotomies to alleviate the forefoot symptoms. And as I said, it's a problem that actually is something that we have to really perfect. I think we have a lot more in our profession that we can do to make this a more successful type surgery. We're getting very close. Thank you very much. Go heat.