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BLANK SLIDE
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Hello! Welcome to this online educational present program. The topic for this lecture is âComprehensive Offloading in the Diabetic Foot.â My name is John S. Steinburg, Assistant Professor at the University of Texas Health Science Center, San Antonio, Texas.
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So, as we begin to look into the details of offloading, it is important first to understand the general pathways of diabetic neuropathic ulcer healing. In general, we want to establish first control of diabetes and general heath in these patients, and in bringing this multidisciplinary team together, we are also going perhaps involve nursing or dietary staff to assist in adequate diet and nutrition for these patients; perhaps vascular surgery hyperbaric oxygen might be necessary for adequate blood supply and oxygenation of the tissues, and then podiatry, orthopedics, perhaps even infectious disease is going to involved in the absence of infection from these possibly contaminated or infected wounds. Once this first part of equation has been solved, the remaining portions of regular debridement, offloading of pressure, and moist wound environment are the 3 key principles of standard wound care in the neuropathic diabetic foot ulceration. In fact, many studies have shown that following these principles of debridement, offloading, and maintaining a most wound environment will heal upwards of 60 to 80% of newly presenting diabetic foot ulcers in 6 or 8 weeks.
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It is important, when discussing offloading, to differentiate what is true pathology and what is perhaps just a clinical observation. The pathology that you are seeing in this particular patient is noticed after many years of having an asymptomatic callus, but now the key change that is noticed here is hemorrhagic tissue or bleeding underneath of the callus, which signifies that the pressure have further increased in this neuropathic diabetic patient to the point at which the skin below this hyperkeratotic or callus tissue is breaking open and therefore yielding a plantar ulceration. It is import that we keep in mind the principle that is often times more important what we take off of a wound rather than what we put on to a wound. In this era of advanced healing technologies and advanced healing science, sometimes we jump the gun just a bit when we look at some of the topicals that can be applied to these wounds because these topicals are certainly going to fail if we have not first addressed the principles of debridement and offloading.
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There are numerous mechanisms of injury that can yield to a foot ulceration in the diabetic population. Probably, the most common that we seen in clinical practice is that of repetitive moderate pressure or the type of ulcer that is caused from weightbearing and gait exposure to the lower extremity. However, it should be noted that high pressure such as a single exposure or a puncture wound, as well as low pressure such as a constant exposure to bed pressure in the form of a decubitus ulceration can be also yield to lower extremity and foot ulcerations. The 2 images on the right side of the screen show a high pressure in the red peaks and valley, and low-pressure foot mapping in the blue and black areas of the screen. It is important to distinguish between this abnormal gait pressure of the forefoot noted on the left photo versus the fairly normal pressure distribution noted on the right photo.
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It is important to understand the role of gait analysis and plantar pressure mapping in the neuropathic diabetic patient. This is a clinical example involving in a 36-year-old male who has a history of partial first ray amputation on the contralateral limb, but here you see the pressure mapping of the unaffected limb, giving a relatively normal distribution pattern, showing a significant weight on the heel at the heel strike and then transferring as the line of progression shows his weight through the forefoot and out the first ray. This is a fairly normal appearing plantar pressure assessment, and can certainly be accommodated well in a prescriptive shoe device. However, you look centrally here; this is the contralateral limb of the same patient. You can see here is the amputation that I spoke of just movement ago, and when you look his plantar pressure assessment, you can see that after sustaining this partial first ray amputation and now experiencing the changes consistent with Charcot disruption of his midfoot, you can see there is almost no heel strike and weightbearing of significance, yet the majority of weight is coming right through this midfoot lateral ulcer site and then progressing throughout the subsecond metatarsal region. These 2 high areas of focal pressure; that of the sub cuboid region and that of sub second metatarsal region, are certainly strong predictors for poor outcome and ulcer recurrence and nonhealing.
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If we are going to look and try to find the actual term of offloading, I think it is important to break that into sub sections. First of all, comprehensive offloading to me involves 4 points.
1. Debridement: We must débride an ulcer including its periphery and base if we are to successfully attempt relieve of pressure at that area and the immediate surrounding tissue.
2. The second segment of offloading in my opinion includes acute pressure relief devices such as a cast; as shown here, a total contact cast or perhaps a patellar tendon bearing brace or a removable cast walker type of acute pressure relief device.
3. The third area of offloading includes accommodation. This is going to be more of a long-term approach involving prescriptive shoe wear, custom orthoses, and devices design to reduce the pressure at the plantar foot in a long-term accommodative manner.
4. Finally, comprehensive offloading in my opinion has to include some level of surgical prophylaxis. If shoes and other devices are unsuccessful in showing and proving long-term pressure relief to these areas of concern in your diabetic patient, then you should address this surgically if it all possible to relieve this pressure and treat the actual etiology demanding the offloading to the extremity.
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So, we now break each of these segments and look at them individually. Let us look closely at debridement for just a moment, and here you can see the patient who has a sub first metatarsal head ulceration. This has already been débrided. You can see that obviously, a large amount of tissue, hyperkeratotic and macerative tissue, has been removed from the wound periphery and the wound border, and the wound base has been curetted and débrided to a bleeding area. The concern here, however, is that a cotton tip applicator or curette would easily probe underneath this lesion several millimeters surrounding the conference, indicating that there is a significant amount of undermining. This, as we know, must be aggressively treated and débrided if you are to successfully treat an ulceration, and here we can see the same ulceration after use of the tissue nipper to debride this undermining tissue.
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Another case example showing the importance of early and appropriate debridement is this patient who has had a history of prior ulceration underneath the first metatarsal head as well as the first intermetatarsal space. This patient has had prescriptive shoe wear and orthoses of a custom moulded nature prescribed for greater than 2 years; however, has worn the same pair of insoles and shoes for those entire 2 years. As you can imagine when this patient presents now complaining of some new drainage present to the plantar aspect of the foot, that upon debridement, this patient actually has now a recurrent ulceration in an area that simply needed appropriate a long-term accommodation.
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In this slide what you are watching is a brief video clip of ulcer border debridement. Here, utilizing either a tissue nipper or a bone cutting forceps using one jaw underneath the edge of the ulcer and another jaw on the top of the ulcer rim, we are able to adequately debride these ulcers and rid them of the undermining tissue and surrounding macerated and hyperkeratotic border.
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In this segment, what you are watching is a curettage or debridement of an ulcer base utilizing a large surgical curette or bone curette. This instrumention is very effective in providing a level of debridement and also helpful for weekly maintenance débridements so that you debride off this surface layer, activate angiogenesis, and stimulate some bleeding to these tissues; yet, you are not removing the underlying progression of granulation tissue, which the patient and yourself have worked hard to produce.
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There are numerous devices that we can employ when we are looking at mechanical means to offload the foot in plantar foot ulceration in the diabetic. Pictured here is a CROW walker and listed to the left are several devices such as the possibility of bed rest for your patients, wheelchair confinement, crutch assistance, total contact casting, felted foam applications plantarly, wedge or half-shoe type devices, therapeutic or prescriptive custom shoes, custom splints, as well as removable cast walkers. This is just a sampling of some of the off-loading devices that are available, but it gives you a perspective how this can range from something that is as aggressive as bedrest for these patients to something as simple as a foam pad applied to the plantar aspect of the foot.
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One of the key points that you can do for you patient when clinically assessing them for offloading and issuing a prescriptive device is to understand what it is that your patient will be able to tolerate in their particular lifestyle and in their particular home environment. While wheelchair and crutches are certainly important adjunctive offloading devices, for many of our elderly diabetic patients with poor upper body strength and poor balance function, these are simply not an affective option for independent offloading. Rather, we combine these type of secondary devices with a primary device that can be applied directly to the foot, most likely a total contact cast or a removable type cast walker boot.
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Since we practice in an era of evidence-based medicine, it is certainly important that you understand the differences and scientific rationale for why one offloading device may be more advantageous than the other. The study published in 1997 by Fleischli and others at the University of Texas in San Antonio looks at the difference between total contact casting, DH walker or a removable cast walker device, half shoe, felted foam, and postoperative shoe in peak pressures for ulcerations underneath the great toe. This study helps to show that really the 2 devices that effectively relieve that pressure and relieve it on a consistent basis are the total contact cast and the removable cast walker.
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Additional clinical data and research published at the University of Texas Health Science Center San, Antonio, have continued to prove that total contact casting and the removable cast walkers in general help to offload the plantar forefoot more consistently and more effectively than do the shoe type of devices.
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In putting some of this healing time and offloading data together and side by side, this illustration shows the number of days to wound healing and several different studies with their authors and devices utilized, showing, in majority case, total contact casting being the consistent facilitator to offloading and wound healing of the lower extremity diabetic foot ulceration.
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On looking a little bit closer at total contact casting as an offloading modality, the indications would include noninfected plantar ulcerations, acute or reparative phase Charcot arthropathy, and noncompliance on the patient. Contraindications for total contact casting include an actively infected ulceration, significant peripheral arterial disease, an ulcer that has a highly exudative nature that cannot be controlled, the patient who experiences claustrophobia when casted, or the patient who is just not in tolerance of perhaps a casting course.
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In continuing to look further at total contact casting, and in particular paying attention to some of these distinct advantages of this offloading technique, you would have to include that total contact casting forces a level of the patientâs compliance on the sometimes difficult patients category. Total contact casting also has the advantages of shortening the stride length, and therefore decreasing peak plantar pressures in the area of ulceration. Patients also experience a decreased cadence and again look in to just slow these individuals down with this bulky cast device. The reduced activity also translates the fact that when they are ambulatory, they are constantly wearing their device and they do not have the option to wear or not wear the offloading device.
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Looking at some technical points about how to apply a total contact cast, our general University of Texas approach in San Antonio is to first apply a small wound dressing as necessary, a stockinette is then utilized in addition to some protection at the toe level utilizing lambs wool and/or foam. At that point, a moleskin is utilized at the medial and lateral aspect to facilitate by bivalving and removal of the cast, and felt is used to path the anterior aspect of the tibia as well as medial and lateral malleoli. After the appropriate minimal padding has been placed, the initial layer of plaster is used in an anatomic conformity such that you can get the offloading on to the leg and therefore take advantage of the cast nature. This plaster is then reinforced with fiberglass including a posterior splint, and then a final over wrap is utilized to complete the total contact cast. Care should be taken to keep the ankle generally at a 90-degree angle with the leg in addition to keeping a flat plantar surface to the cast to facilitate weightbearing.
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This is looking at one consideration and option of total contact casting is to continue the cast up proximally into the leg and approaching the knee, such that there is pattellar bearing section to this total contact cast. This, perhaps, would be important to consider in the face of a heel ulceration, in which offloading of the rear foot is off a challenge despite the use of a total contact cast. You can see here looking from the forward portion how a significant amount of this cast weights and the ground reactive forces are transferred directly to the patellar bearing segment of the device.
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The removable cast walker devices or cast boot device have become very popular in standard offloading for diabetic foot ulceration. Part of the rationale is that this requires less manpower, less supplies, and perhaps less time out of the clinical environment to apply than with a total contact cast. Removable cast walkers are easily stocked in a limited supply clinic, and you can see here they come in many shapes, forms and, designs. Many manufacturers now have a version of their removable cast walker that is specifically marketed for use in diabetic foot ulcerations, and these generally will include some type of a plastizote or moldable insole segment, a rocker bottom sole to facilitate offloading plantarly, and many come with an inflatable air chamber to further offload and provide anatomic conformity to the leg and offloading to the foot.
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There are certainly many advantages for incorporating removable cast walkers in your practice and utilizing them for diabetic foot ulceration. You can see here again as one such example of these removable cast walker devices, this particular one utilizing air chambers to provide anatomic conformity to the leg and a better fit. These devices are user friendly, both to the patient and to your practice; they allow a good wound surveillance such that these can be removed, the wound can be dressed or inspected on a daily basis or perhaps even more often; they allow for continual wound care to be supervised and apply to this in a home care environment; removable cast walkers generally are cost effective; many of them ranging from $40 to $50; range and they generally have a very good patient acceptance. The patients prefer these devices greatly over a total contact cast, probably because they have the control and ability to perhaps remove it when it is appropriate.
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Another, although less commonly utilized offloading device, is the CROW or Charcot Restrained Orthotic Walker. The CROW device is a custom-molded piece that is composed of an anterior and posterior shell that is made from the cast impression of your patientâs leg. You can see here a couple of different views the CROW walker boot here showing the device in place together, and the device separated into its anterior and posterior components. Similar to a total contact cast, this device utilizes strict anatomic conformity to the foot and leg to allow for appropriate offloading of plantar pressure, and incorporates it a round rocker bottom sole with plastizote liner.
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Continuing to look at the CROW walker device here looking from top to bottom, you can see the anterior segment on the left and the posterior segment including the foot bed and plantar apparatus at the right hand side of your photo. Here, with the patient and lower extremity in place, you can see the anatomic conformity extending above the ankle into the leg which facilities the offloading of this device of plantar pressure.
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Although these generally are not the first line devices, modifications can be made to postoperative shoes to make them an appropriate off loading device for superficial ulceration or for a patient who is unable to tolerate a more aggressive offloading device. You can see here a simple postoperative shoe has been fitted with a half-inch plastizote liner with an appropriate cutout for the area of peak plantar pressure. Other examples of how insole modifications and accommodations can be utilized in making a simple postoperative shoe into a more appropriate and slightly customized offloading device.
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There certainly are a multitude of devices than can be utilized for offloading; this picture here shows a removable posterior splint which can be combined with an appropriate dressing and the advantage is that with the posterior splint, you still are limiting the ankle range of motion and therefore perhaps eliminating the some of the effect of the equinus that might play an influential role in the recurrence and nonhealing of the plantar ulceration. Another device that is seldom used, but is certainly worth mentioning, is a wedge shoe device; this is designed for the forefoot ulceration. You can see that the concept here is that the forefoot from the mid metatarsal level becomes nonweightbearing and apropulsive such that this patient is experiencing full weightbearing for the rear foot and mid foot. These devices, however, can present a problem in patients with limited balance function and also present a significant noncompliance concern in the patient population.
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A lot of attention is put into appropriate and aggressive accommodative devices, both in the short term and long term when we are talking about offloading the diabetic foot. This is one example of long-term offloading that shows accommodative device for a mid foot or transmetatarsal level amputation patient. You can see the multiple densities of the foam in the rear foot, progressing from a higher density to a more accommodative and formative layer at the level of the actual extremity, and then distally looking at the multiple bands and layers, colors of different density forms such to mimic that of the forefoot distribution so that this patient can be fitted into a normal appearing shoe.
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This is a clinical example looking at patient who has experienced a mid foot amputation and looking at what can be done long term to properly accommodate this extremity and prevent or decrease the risk of recurrent ulceration or contralateral amputation. You can see here this patient has received prescriptive extra-depth shoes with accommodative custom molded insole, which incorporate a toe filler device to the right lower extremity. Looking at the shoes, in particular you can see the rocker bottom apparatus, which has been added to the outer sole of these shoes, thus yielding a more gradual progression of weight form heel to the distal aspect towards toe off.
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The fourth component to comprehensive offloading that we mentioned earlier in this discussion includes surgical offloading or surgical prophylaxis for high peak plantar pressures. This is one clinical example that I want to share with you of a patient who has had diabetes and progressing lower extremity sensory neuropathy. He has plantar hyperkeratotic lesions underneath each of his metatarsal heads in the forefoot, and you can see the significants lesser digital contractor which is becoming semi-rigid in nature. This patient was also identified to have an ankle equinus, which further accentuated his forefoot peak plantar pressures. You can see some of this illustrated in the lateral view clinically of this patient and you can see the prominence of the forefoot in sub metatarsal head region from the retrograde buckling of the lesser digital contracture.
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Clinically now looking at some case studies for offloading, I want to share with you one particular patient. This gentleman, whose first name is Herbert, has experienced a chronic plantar forefoot ulceration for greater than 2 years. In reviewing his medical history, we see that this gentleman is 45-year-old, he has a medical history that includes diabetes for the past 12 years, surgical history includes what you can see here the partial first ray amputation as well as a second toe amputation, both on this affected left lower extremity. His medications include Paxil and glipizide, and his wound history as we shared earlier, is a greater than 2-year-old duration ulceration to this planter central aspect of his left forefoot. He has been to multiple treatment centers and seen many specialists for this, each time seeing some progression and improvement of the ulcer, and then recurrence of the ulcer upon return to weightbearing. Previous treatments for this patient have included local wound care, extensive use of the total contact casting and other offloading devices, he has used topically applied growth father in the form of Regranex, and also has attempted a long course of hyperbaric oxygen therapy with no success.
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In clinically evaluating this patient for his chronic ulceration, it was identified that he had significant ankle equinus, and this was addressed then through a percutaneous surgical tendo Achilles lengthening. A 3-incisional hemisection was utilized; you can see the outline of the Achilles tendon was drawn. The patient is kept in a prone position and then in these 3 notch areas, the Achilles tendon is severed approximately 50% of its width. At the same time, this patient was treated with bioengineered tissue grafting which was applied to the plantar ulcer site, and he was maintained in a total contact cast application. This is a cadaver example showing what was accomplished by using a percutaneous tendo Achilles lengthening. You are looking here at the cadaver foot in a prone position, looking at the posterior aspect of the leg and Achilles tendon, and you can see the effect of the 3-incisional hemisection performed in a percutaneous manner and ________ cadaver example than open fully to visualize the effect of the procedure. Approximately, 3 cm of lengthening was achieved in this cadaveric example of the percutaneous tendo Achilles 3-incision hemisection.
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In looking at the some of the technical points of the percutaneous tendo Achilles lengthening, you can see here the clinical photo showing the immediate post procedure effect and 3 incisional hemisection approach. The patient is generally kept in a prone position to facilitate exposure to the posterior aspect of the leg. Local anesthetic is achieved utilizing 1% lidocaine with epinephrin for hemostasis, a surgical prep and drape is utilized for aseptic technique, and generally a #11 surgical blade is utilized at each of the 3 incision sites. The patients are then maintained in a cast, a walker device or a splint in slight dorsiflexion, and they are generally kept nonweightbearing for 2-3 weeks, although these patients can sometimes be maintained in a walking cast if necessary.
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Returning now to our patient Herbert who had experienced the long-term ulceration to his planter forefoot. The equinus has been addressed now with the percutaneous tendo Achilles lengthening, and what we are looking at now is approximate 1-week post procedure upon changing of his gentlemanâs cast. He was kept in the cast for a period of a total of 3 weeks. Looking now at this gentleman and his progress at the 2-week mark, you can see significant wound filling in with granulation tissue and neo epithelization progression from the margins.
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Finally now with this patient comparing the pretreatment photo and the 2-year duration ulceration to the healed site with use of the percutaneous TAL bioengineered tissue grafting in total contact casting which was able to achieve complete closure of this wound in 33 days.
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In followup to this discussion clinically of utilizing percutaneous or open tendo Achilles lengthening in patients with equinus, one possible complication of this procedure that should be made note of is the possibility of over lengthening or rupture of the Achilles tendon which could then result in increased pressures to the rear foot or heel, yielding a calcaneus position and possible calcaneal ulceration and the tissue breakdown. In literature, this has been sited to occur in upwards of 17% of tendo Achilles lengthening cases, although clinically we have experienced this to a very minimal amount at UT, San Antonio in our experience.
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This next medical example involves a patient with severe equinus and significant sensory neuropathy. This is a 40-year-old male whit history of diabetes. He has ulcerations underneath his first and fifth metatarsal heads as you might predict from this type of a foot.
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Clinically looking at this gentlemanâs foot in the plantar aspect, you can see the ulcerations which are moderately severe in nature, but chronic for several years. The patient has attempted multiple types of offloading, debridement, and other devices, which have been unsuccessful in relieving his recurrence of ulceration. Here, you can see the lateral view of the same extremity, seeing the significant concern for the prominence of the forefoot and the cavus architecture as well as digital contractures.
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Looking now at the same patient from the anterior view, you can see that the digits are completely non-purchasing to the weightbearing surface, and that they are causing indeed a significant retrograde buckling pressure onto the forefoot. Dorsally, you can see the contracture of the extensor tendons as well as the deviation of the digits.
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There was a significant amount of discussion as to the appropriate treatment for this patient. It certainly could be argued that the root of the deformity is his cavus foot type, and that treatment of this deformity is necessary for ultimate correction. However, we identified that there was some mobility in the patientâs first ray, and also combining that with our concern for the Achilles tendon contracture, we were able to come up with a more ambulatory procedure for this patient. As you can see, a Jones tenosuspension was performed routing the extensor hallucis longus, detaching this from its insertion on to the hallux, and transferring it back then into a drill hole through the first metatarsal and suturing it back.
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An open frontal plain tendo Achilles lengthening was utilized as an adjunctive procedure for this patient and you can see that the choice was made for using an open TAL over a percutaneous tendo Achilles lengthening because of the significant amount and nature of the lengthening that was necessary to alleviate this patientâs equinus deformity.
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Here, you can see the completed Jones tenosuspension with the extensor hallucis longus sutured upon itself at the level of the first metatarsal neck. You can also see that the hallux interphalangeal joint has been resected and arthrodesed utilizing internal screw fixation. A radiograph of the same forefoot, you can see the evident drill hole traversing from medial to lateral at the level of the first metatarsal neck and the cancellous fully threaded screw across the hallux interphalangeal joint.
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Postoperative course for this patient included a walking cast at approximately 90 degree to maintain the Achilles at length, as well as provide some offloading for the plantar ulcer sites and immobilization to the forefoot. At approximately 6 weeks postoperatively, we noticed complete healing of the first and fifth plantar ulcerative sites, and the patient maintained good correction of his equinus upon clinical examination.
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In this segment, you see a rolling video clip of this patient. Here, you can see he is walking towards us and remember the affected extremity is the left lower extremity, and the purpose of observing this gait is to see that despite an aggressive open tendo Achilles lengthening in this patient, he still has a propulsive gait with excellent balance.
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Looking now at the same patient walking away from us, again, the left lower extremity is the postoperative extremity. You can see a significant propulsion and heel-toe gait noted in this patient.
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Continuing now with the surgical offloading of complicated patients, what you see is a gentleman who has sustained mid foot amputation and has chronic ulceration at the plantar lateral surface of his mid foot amputation. The patient is in a fixed contracture of his tendo Achilles as well as his tibialis anterior tendons which are unbalanced in nature because of the mid foot amputation. The chief weightbearing surface of his foot is now this plantar lateral mid foot area, and the chronic ulceration has remained despite continued offloading and debridement. The decision was made to proceed with surgical offloading for this patient, and a tibialis anterior tendon release was performed and harvested through an anterior leg accessory incision, and this was then transferred through a lateral incision onto the lateral cuneiform. You can see here the harvesting of the tibialis anterior tendon in toto, and then transferring of this with tendon passers onto the distal lateral surface of the mid foot amputation.
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Looking now at the 4-week postoperative result for this patient in combining the tendo Achilles lengthening with the complete tibialis anterior tendon transfer, you can see that we now have a rectus foot type eliminating the equinus and also on this view showing majority of the varus deformity eliminated with pressure relief to the plantar lateral aspect of this mid foot.
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As you can see from several of these clinical samples that we have just shown, equinus can play a very significant role in chronic ulceration in the diabetic neuropathic patient. It is important that we examine these patients who have forefoot ulceration for ankle equinus, and that if this cannot be conservatively treated and addressed, that this be surgically managed for these patients in a rapid fashion.
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In addition to evaluating patients who have active ulceration for ankle equinus, it is important to also examine patients who have diabetes and a history of amputation for the role of equinus. The unbalancing of tendons that has often caused from a forefoot or mid foot amputation, can cause a significant fixed equinus contracture, which might be easily addressed through conservative or surgical means.
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In addition, it is important to examine the patients who have active or quiescent Charcot for the role of ankle equinus. This clinical diagnosis of ankle equinus and its subsequent treatment are imperative to the successful management of Charcot and mid foot breakdown.
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The primary deformity in the diabetic neuropathic foot must be examined such as the possibility of prominent metatarsal heads or digital deformities, but it is also important to identify that when treating these digital deformities with conservative or surgical means, that we identify and test for ankle equinus as this may be accentuating the primary deformity and its subsequent plantar pressure.
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As we increasingly understand the mechanics of Charcot mid foot neuropathic osteoarthropathy, we understand that there is a significant relationship between neuropathy, elevated forefoot pressure, and Achilles tendon contracture. This will often times lead to mid foot breakdown as you can see from the diagram on the right showing that the Achilles tendon has a significant pull on the calcaneus and rear foot, leading to a breakpoint at the mid foot which is the most location of Charcot presentation clinically.
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Here, you can see a radiograph depicting exactly what we saw on the previous diagram in a clinical scenario. You can see the decreased amount of calcaneal inclination; in matter of fact, a clinically evident calcaneal declination. When you look at the effect of the Achilles tendon, you can see how this significant Achilles contracture or equinus is yielding an elevation of the posterior portion of the calcaneus, and therefore significant breakpoint is created and a fulcrum point is created at the mid foot and secondary Charcot breakdown in this clinical example.
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Highlighting now one particular clinical study, which I think, helps to summarize much of the information we have discussed over the past half hour. This is an article that was published in the Orthopedics Journal in 1996, and looks at plantar forefoot ulceration in combination with equinus deformity of the ankle. These patients who had diabetes were treated with total contact casting. Ninety three patients were treated who had present foot ulcerations, and they received 9 week of total contact casting with which 15 patients remained with an active ulceration. These 15 patients were further examined and found that they had ankle dorsiflexion of negative 10 degrees on average, consistent with their Achilles tendon equinus. A percutaneous tendo Achilles lengthening was performed followed by repeat of the total contact casting of these patients, and of these 15 patients, 93% of them healed within 39 days of treatment. There was no recurrence.
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Some very significant and confirmatory clinical information published by David Armstrong shows that the Charcot arthropathy is directly related to peak plantar forefoot pressure. In this clinical example, we can look at pressure in N/cm2 measured on the left hand side of this graph and then increasing diabetic neuropathic pathology along the base of the graph. As we traveled from left to right, on the base of the graph, you can see that the patients who presented who had diabetes but no neuropathy were in the approximate 45 N/cm2 plantar pressure range. Those patients with diabetes, however, that presented with active sensory neuropathy were in approximately the 65 N/cm2, while those who had diabetes and ulceration presented at approximately 90 N/cm2, and finally those who had Charcot arthropathy presented as the highest plantar forefoot peak pressure in this study group at approximately 100 N/cm2.
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Clinical data presented by Dr. Armstrong shows that there was an approximate 27% reduction in the peak plantar forefoot pressure when a percutaneous tendo Achilles lengthening was performed. You can see in the graph the left column measuring the N/cm2, and then following the base of the graph showing the preoperative patient range of pressure versus the post TAL range.
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Prevention of recurrence in patients with diabetes and history of ulceration, amputation, and neuropathy is a very significant and strong problem. The offloading devices that we have discussed, the offloading mechanisms and surgical procedures that we have discussed, are certainly a significant help in this patient population and technology has advanced significantly in this regard recently. However, it should be kept in mind that probably, the underlying source and cause for patient recurrence and ulceration is noncompliance; noncompliance to shoe gear, noncompliance to activity and lifestyle modifications, and noncompliance to appropriate podiatric followup. Therefore, patient education remains at the center point in the prevention of recurrence in combination with the best possible combination of the mechanical deformity, and early recognition and possible surgical management of the underlying etiology which cause the ulceration and amputation in the beginning.
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I certainly want to thank you for your attention and your interest in this topic of offloading in the complicated diabetic foot. This is an area that is partly basic science and partly an evolving science as we become more astute at diagnosing, treating, and properly managing the concept of increased plantar forefoot pressure. It is certainly apparent that once the patient has undergone treatment and management for ulceration or once the patient has undergone treatment and management for partial foot amputation, that offloading becomes even more paramount to their long-term outcome and success as without proper offloading and proper mechanical assistance, these patients are destined for future and recurrent amputation and limb loss. Thank you very much again for your attention. Please note our department website and my e-mail address should you have any questions. Thank you.
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