CPME (Credits: 1.25)
Complete the 4 steps to earn your CE/CME credit:
CPME (Credits: 1.25)
PRESENT eLearning Systems, LLC is approved by the Council on Podiatric Medical Education as a provider of continuing education in podiatric medicine.
PRESENT eLearning Systems, LLC has approved this activity for a maximum of 1.25 continuing education contact hours.
Release Date: 03/16/2018 Expiration Date: 12/31/2020
Douglas Richie, Jr, DPM
Clinical Associate Professor, Department of Biomechanics
California School of Podiatric Medicine
Clinical Associate Professor of Podiatric Medicine and Surgery
Western University of Health Sciences
Past President, American Academy of Podiatric Sports Medicine
To view Lectures online, the following specs are required:
It is the policy of PRESENT e-Learning Systems and it's accreditors to insure balance, independence, objectivity and scientific rigor in all its individually sponsored or jointly sponsored educational programs. All faculty participating in any PRESENT e-Learning Systems sponsored programs are expected to disclose to the program audience any real or apparent conflict(s) of interest that may have a direct bearing on the subject matter of the continuing education program. This pertains to relationships with pharmaceutical companies, biomedical device manufacturers, or other corporations whose products or services are related to the subject matter of the presentation topic. The intent of this policy is not to prevent a speaker with a potential conflict of interest from making a presentation. It is merely intended that any potential conflict should be identified openly so that the listeners may form their own judgments about the presentation with the full disclosure of the facts.---
Douglas Richie, Jr has nothing to disclose
Male Speaker: Part 3 of this lecture series will focus on non operative treatment options available to patients diagnosed with adult acquired flatfoot. Radiographic assessment of flatfoot deformity is interesting but not always helpful in directing specific treatment options. We have certainly learned a lot from various studies made of patients with adult acquired flatfoot to come up with certain measurement findings which are reproducible and accurate particularly when comparing the symptomatic to the asymptomatic foot. We have learned that various angles drawn on the anterior, posterior and lateral weight bearing radiographs will give us indicators that one foot is pathologic when compared to the opposite contra-lateral foot. One of those measurements is depicted in this drawing showing what is called the talonavicular uncoverage angle which is depicted in number 8 in this drawing and will give a better example in a moment. On the lateral weight bearing X-rays, various angles can be used to measure the extent or severity of flatfoot but some of these angles are difficult to draw and reproduce on a regular basis and have very poor intra observer and inter observer reliability.
In this photograph of an anterior-posterior radiograph, the amount of coverage of the head of the talus is considered critical in detecting adult acquired flatfoot, specifically as the talus adducts and the navicular abducts. We see this uncoverage as it is described of the articular surface of the head of the talus which seems to be quite peculiar to the adult acquired flatfoot. In this particular study measurements were made of patients with various stages of adult acquired flatfoot to determine inter observer correlation accuracy. Hind foot views have been described to look at the position of the calcaneus and the talus and from these views we see these marked shift of the tibia and talus over the calcaneus as the midtarsal joints severely deforms in the transverse plane. These parameters that we can look on both A, P and lateral X-ray through various research studies have allowed us to determine with measurement technique various levels of deformity of the hind foot that might require correction such as using the medial displacement calcaneal osteotomy to realign the calcaneus under the tibia and the talus.
In this photograph, clearly the foot marked left which is actually on the right hand side of the drawing shows a much more marked deformity and shifting of alignment of the calcaneus relative to the talus demonstrating the marked asymmetry of hind foot alignment seen in the symptomatic left foot. Going back to this reliability factor and looking at what angles or measurements can we take on a radiograph which are reproducible and reliable on a day to day basis. We find from this particular paper that the medial cuneiform height relative to the base of the 5th metatarsal as well as the calcaneal pitch angle had the highest inter observer reliability. Also Meary’s angle or the talus first metatarsal angle on the lateral weight bearing radiograph were also found to be extremely predictive and reliable in detecting adult acquired flatfoot.
In my own experience I have found that this simple linear measurement, a line measured measuring the distance from the inferior edge of the medial cuneiform to the inferior edge of the base of the 5th metatarsal is very easy to measure and demonstrate to a patient when looking at their contra-lateral foot and demonstrating to them how their arch has collapsed and how their symptomatic foot has become deformed. Meary’s angle is a little more difficult to draw and measure and demonstrate to a patient, but it is still important in determining the level of deformity of first ray elevation and first ray deformity in forefoot supinatus. We know that watching patients walk gives us great insight into all three planes of deformity and various changes that occur in both the swing phase and the stance phase of gait. We know that in the frontal plane we will see valgus positioning of the hind foot. We will see a reciprocal supination of the forefoot on the rear foot as the rear foot everts.
And we will notice that as the patients progress in adult acquired flatfoot deformity, the forefoot becomes more and more abducted on the rear foot which is harder to detect sometimes in just a visual evaluation of the patient in static stance. But these gait studies show that these changes are actually quite significant and need to be addressed even in the conservative treatment with foot orthoses and ankle foot orthoses. If we look at this patient with a freeze frame photo taken from an actual video walking in the clinic, we can appreciate not only the significant hind foot valgus on the left foot but the significant abduction of the entire forefoot where we can see digits one through five clearly abducted from the plane of the leg. This is an even more dramatic example of that forefoot abduction deformity. In this particular patient the forefoot abduction is not as dominant but the rear foot pronation or rear foot valgus deformity clearly is the dominant plane of collapse in this stage 3 adult acquired flatfoot. From the interior view the abduction of the forefoot can be clearly demonstrated comparing to the contra-lateral foot and in this case not only is the forefoot abducted but you can look at the hallux and look at the toes and appreciate the valgus rotation of the forefoot in the frontal plane.
In stage 4 adult acquired flatfoot, the radiograph shows the deformity within the talocrural joint which occurs when the deep deltoid ligament has ruptured. When this occurs the talus moves into significant valgus rotation within the ankle mortise. And another key radiographic finding is the abutment of the calcaneus on the fibular malleolus, which accounts for the movement of pain laterally in these patients. And so to summarize these frontal plane changes, they are not just in the hind foot but we will see the forefoot undergo a supinatus along with rear foot valgus. In a sagittal plane, we will see the breakdown across the midtarsal joint. The sagittal plaint collapse of the midtarsal joint which we will see when the patient tries to perform a single foot heel rise, and this has also been described during gait as to be demonstrated by a delay of tibial progression where the tibia will not move forward over the talus but the talus and tibia will plan or flex together across the midtarsal joint.
This leads to a progressive contracture of the gastroc-soleus musculature. The flexibility of the mid foot joints is really what causes these observed changes in tibial progression. Here is a flexible or unlocked midtarsal joint and the forward motion of the tibia and the talus as one unit, the rear foot plantar-flexing on the forefoot across an unstable midtarsal joint. And finally as has been mentioned already with the rupture of the posterior tubular tendon nerves are significant internal rotation of the tibia. This carries the talus significantly internally rotated and subluxes the talonavicular joint. The navicular and the forefoot moves laterally as the forefoot abducts on the rear foot.
Inman was one of the first to describe this linkage mechanism where the tibia carries the talus. And there is a reciprocal motion through the mid piece subtalar joint where internal and external rotation of the tibia convert to inversion and eversion of the foot itself across the subtalar joint. The tibia is the more massive of the two levers they connect the leg to the foot. Kelikian [phonetic] gives an interesting observation about the dominance of the leg over the tibia or the leg including the tibia connecting to the talus compared to the weaker lever of the foot itself which contains multiple bones intercepted by multiple joints. The massive tibia connected to the talus dominates the motion of the talus. There are no muscular insertions on the talus itself. The talus is carried passively either by the tibia connected proximal or the foot connected distal. But according to Kelikian and many others the tibia is the dominant lever.
Internal rotation of the tibia translates directly to internal rotation of the talus. This is why patients with adult acquired flatfoot show a marked internal rotation of both the tibia and the fibula. And in this patient’s right foot we can see the anterior positioning of the fibular malleolus on the right foot compared to the asymptomatic left foot illustrating the planal dominance of internal rotation and transverse plane deformity of the adult acquired flatfoot. This is demonstrated on the interior, posterior radiograph where the tibia and the talus are markedly internally rotated and the navicular and the forefoot are abducted at the talonavicular joint. Here again is a close up of that previous patient looking carefully at the fibular malleolus on the right foot and the difference in position of the medial and lateral malleolus of the patient’s right foot compared to the asymptomatic left foot.
This gait study published in Foot and Ankle International suggests that there is a significant high or vertical axis of the motion of the forefoot on the rear foot leading to significant abduction of the forefoot in the transverse plane. And so if we look at this patient at mid stance, the challenge becomes how we could control this forefoot abduction in the transverse plane. So when we have a patient who has presented and gone through all the evaluation protocols described previously, we finally have to formulate a treatment plan and when we formulate a treatment plan we need to prioritize what our goals are for the patient with symptomatic adult acquired flatfoot.
Certainly one of the priorities for the patient is to eliminate pain but almost as important particularly for the older patient is the quality of life issue known as mobility. And for the older patient with debilitating foot and ankle pain restoring mobility to that patient can become an extremely gratifying outcome for both the patient and the practitioner. Certainly we want to prevent progression of deformity and the sooner we can intervene in early stage adult acquired flatfoot the more likely we are to prevent progression and ultimate surgical intervention.
If we take a patient with asymmetrical flatfoot deformity, a clear difference in the right foot compared to the left foot, we already realized that the patients left foot in the stage 2 adult acquired flatfoot because in stage 1 there is no asymmetry and no visible collapse. And so this patient is in stage 2 and the fore foot has already abducted on the rear foot and we see the classic “too many toes” sign. We have learned that patients in stage 2 deformity have already undergone ligamentous attenuation and disruption. And we therefore have learned that functional foot orthotic therapy usually fails. And that once the patient has moved in the stage 2 deformity with ligamentous disruption, we must implement ankle foot orthotic therapy to literally reconnect the tibia to the foot. And ankle foot orthotic therapy has now become the main stay of treatment of stage 2 and stage 3 deformity.
Finally the utilization of supportive footwear is critical to the success of ankle foot orthotic therapy. In this particular picture the patient has been fitted for motion control running shoes which might be most ideal for the use of ankle foot orthosis and resisting the medial compressive forces that dominate in the hind foot of adult acquired flatfoot. In stage 1 deformity there hasn't been significant visible collapse and we are really treating an acute or perhaps chronic tenosynovitis of the foot and ankle. And treatment here may be just a simple matter of temporary support while other interventions are implemented to calm down symptoms.
Temporary supports have often used things such as an Unna boot or taping of the foot and ankle for short periods of time to off load the inflamed posterior tibial tendon while other treatment modalities are implemented. Lace-up ankle braces are very helpful in the treatment of stage 1 adult acquired flatfoot because they are inexpensive and they can be adjusted to off load the posterior tibial tendon in the direction of inversion. Physical therapy is almost mandatory when treating all stages of adult acquired flatfoot not only to reduce the inflammation seen in stage 1 deformity but to bring in muscular strengthening, balance and appropriate reception and gait training for stage 2 and stage 3 deformities. All patients who present with stages of adult acquired flatfoot should be counseled and directed towards selection of proper footwear and many patients are candidates for modification of footwear to further enhance the outcome with foot orthotic or ankle foot orthotic therapy.
Custom function of foot orthosis are definitely the preferred intervention for stage 1 adult acquired flatfoot because in this particular level of deformity there has not been ligament disruption, breakdown of the midtarsal joint or disconnect of the foot to the leg. In stage 2 deformity, patients often need temporary support to address their pain, edema and disability arising from tenosynovitis ligament attenuation and rupture.
But because these patients are more severe, the intervention usually requires a walking boot anywhere from 1 to 6 weeks and then a decision has to be made on picking a more appropriate long term support because patients in stage 2 deformity are going to require external support for a minimum of 6 months and often for 1 year or more to recover from their disability. It is here in stage 2 deformity that a decision is made to implement a custom hinged ankle foot orthosis or perhaps a gauntlet type orthosis. Again footwear modification, selection of footwear are critical to successful outcome. And patient should be enrolled in and should complete what is known as a functional rehabilitation physical therapy program over a period of 12 weeks to restore strength and balance. The essential parts of this program include range of motion, e-centric strengthening of the lower leg musculature along with balance training.
Stage 3 deformity may also require temporary immobilization but normally these patients are over the acute phase and are really doomed to a long period of immobilization if not permanent. These patients require more rigid bracing, often a more rigid type of non hinged ankle foot orthosis or perhaps with a more rigid lace up leather gauntlet with a flexible polypropylene shell. Stage 4 deformity almost always mandates control with a rigid lace up leather gauntlet solid ankle foot orthosis polypropylene shell. I am going to go into a little more detail about how we implement these various interventions for stages of adult acquired flatfoot. I mentioned some initial immobilization and treatment for the first office visit, the first time evaluation to basically try to calm down the symptoms associated with the either tenosynovitis or ligament rupture. And in a sense we actually employ the same intervention for the older patients with symptomatic adult acquired flatfoot that we do for a patient with an acute ankle sprain because essentially we are dealing with a patient who has undergone rupture of key ligaments of the ankle or hind foot. And so this treatment paradigm using the pneumonic PRICE - protection, rest, ice, compression, elevation is very relevant in treating adult acquired flatfoot.
Protection, as mentioned for stage 1 or even stage 2, initially can be some form of soft mobilization with an Unna boot cast or taping or even a removable lace up ankle brace. A walking boot may be more appropriate for patients in stage 2 who might need to have their symptoms calmed down for 1 to even 6 weeks before considering cast in for a custom ankle foot orthosis. Foot wear modification is something that’s discussed on the initial office visit and must be agreed upon with the patient because if they are not going to comply with changing shoes to more appropriate footwear, all of the treatment options will most likely fail. Discussion with the patient about the importance of completing a functional rehabilitation program should be carried out on the initial office visit.
A walking boot is an excellent way of immediately mobilize the symptomatic adult acquired flatfoot at the time of initial office visit because it allows a complete, almost complete off loading of the injured structures. It reduces the patient’s pain and hopefully gains their confidence that the practitioner is going to be able to help them. We know from various studies that patients with adult acquired flatfoot do not all have to undergo surgery.
In fact there is compelling evidence as will be shown here that the majority of patients in stage 2 deformity can be treated non-surgically. In almost every case the treatment protocol calls for a combination of ankle foot orthotic therapy along with supervised long term physical therapy. This is one example of a paper published in 2009 by Kulig, et al, where patients in earlier stage of posterior tibial tendinopathy were able to avoid surgery by being treated with foot orthosis and specialized e-centric and concentric strengthening. In this research study, patients were studied to determine what type of exercise would best recruit stimulation and strengthening of an injured Tibialis posterior muscle. And so the researchers asked which particular motion of the foot in an exercise program would activate the Tibialis posterior. Would it be a foot abduction exercise as shown in the previous picture? A foot planner flexion inversion which is more of a supination moment or motion or a single foot heel rise?
So in this particular exercise the patient is moving the foot purely in the transverse plane in the direction of abduction against the resistance of a rubber band. In the next picture the patient is moving their foot more in the frontal plane in the direction of supination. And in the final pictures we are showing the single foot heal rise. Which of these three tests in this study actually recruited the Tibialis posterior best? What was interesting about this study was the measurement technique utilized by the researchers to determine changes in muscle activity. And it’s been shown that MR study of the leg or any part of the body can actually measure changes in the muscle itself, that occur when muscles have been adequately exercised. And they can take a cross sectional image of the leg and look at the water content which changes in intensity based upon the level of exercise. They can actually measure the change of intensity with a cursor and objectively quantify the muscular activity changes. And so from this picture taken from Kulig’s article, we can see in the top right hand picture a cross section of the leg and then we compare to the lower picture where after exercise the color of the Tibialis posterior has actually moved to a lighter shade where there is a consistent change associated with activity or exercise. So using that measurement technique, Kulig and co-workers found that the foot a-deduction exercise recruited the Tibialis posterior approximately 50%.
The heel rays actually only recruited the Tibialis posterior 27% while activating other muscles such as the Gastroc Soleus. The supination exercise recruited only 26%. So therefore looking at the three different exercises, it’s the peer transverse plane movement of the foot in to the direction of adduction which most likely will isolate and recruit Tibialis posterior. The next question, and this is quite interesting, in another research paper by Kulig and co-workers, was the effect of wearing foot orthosis and improving recruitment of these exercises for the Tibialis posterior.
And so they took 10 subjects with flat feet and they had them perform strictly the foot adduction exercise which is known to preclude Tibialis posterior the best. And they compared muscle recruitment in a bare foot condition versus wearing shoes with a pre fabricated orthosis. Again MRI was utilized to quantitate the amount of objective muscle activity. So here is the condition with shoes inside the shoe is the pre fabricated foot orthosis and the patient is performing peer adduction exercise. The direction of adduction in the transverse plane, compared to a bare foot condition.
Very interesting results were shown again with MRI looking at changes of activity of the Tibialis posterior where people or the subjects wearing shoes with foot orthosis had better recruitment of the Tibialis posterior at a level two fold higher compared to the bare foot condition. This is quite interesting because the exercises are actually done off weight bearing and one has to ask why the use of the shoe with foot orthosis stimulated muscle activity better than being bare foot. And the patients were truly bearing weight. It may suggest appropriate ceptive influence of placing an object under the foot that contours to the arch and stimulates activity against the cutaneous mechanoreceptors and perhaps augmenting muscle stimulation particularly of the Tibialis posterior. It emphasizes the importance of proper contouring of the arch of custom foot orthosis when treating patients with poster tibial tendon pathology.
There are enhancements that can be made to foot orthosis to further augment inversion stability or inversion movement arm to the hind foot in the treatment of adult acquired flatfoot. We have learnt that modification of the positive cast as shown in the right hand drawing can create a varus wedge effect to the heel cup of the orthosis to provide even more stability of the hind foot and resistance to pronation. These positive cast modifications must be made in a way that the arch conformity is preserved as emphasized by the study by Kulig, where we can get better neuromuscular stimulation to the foot and leg.
We will discuss these foot orthotic modifications further including the use of flanges to contour to the arch in just a few minutes. But first of all we need to look at and address all three planes of deformity when treating adult acquired flatfoot, the frontal plane, the sagittal plane and the transverse plane. This becomes a challenge with foot orthosis alone which rely on the contour of the device to the planter surface of the foot, but do not have direct control over the ankle joint or the Tibia which as has been shown earlier are essential components of the adult acquired flatfoot deformity. Footwear is extremely important whether using foot orthosis or ankle foot orthosis and a properly designed shoe particularly an athletic shoe with motion control features such as shown in this picture where there is medial postin under the hind foot to prevent compression of the foam under the device and resist the tremendous pronation movements that occur in the adult acquired flatfoot. So as we mentioned earlier a custom hinged ankle foot orthosis is preferred over a foot orthotic in stage 2 deformity.
In stage 3 deformity, a more controlling ankle foot orthosis such as will be shown in a few moments using either a restricted hinge ankle foot orthosis or an arch suspender have to be brought into play in treating the more severe deformity. And in some cases a more rigid gauntlet type AFO device for stage 3 and certainly for stage 4. This is a picture of a specialized ankle foot orthosis with a medial arch suspender which can be used in stage 3 deformity to achieve better correction and control to the sagittal plane collapse of the talonavicular joint. In stage 4 deformity where the talocrural or ankle in have rotated into severe valgus, a more restrictive gauntlet type ankle foot orthosis is required.
Here is a radiograph of that patient in stage 4 deformity where now a combination restraint across both the ankle, the subtalar and the midtarsal joint must be accomplished with both a solid shell AFO and the gauntlet type closure to provide a rigid control over the entire ankle and hind foot complex. Gauntlet style braces are similar to using a Pantalar arthrodesis approach to severe ankle and foot deformity. Hinged ankle foot orthosis are more appropriate and more similar to surgical approaches that involve osteotomies rather than fusions. Inside into the comparison of hinged ankle foot orthosis versus gauntlet style foot orthosis in the treatment of stage 2 adult acquired flatfoot was provided by Neville and Houck in this paper published in 2009. And this was a very interesting case report where 3 different types of orthosis were tested in a patient with stage 2 adult acquired flatfoot.
On the right hand side is an over-the-counter air-bladder type prefabricated ankle brace. The middle picture is an articulated ankle foot orthosis and the left hand picture is the traditional leather gauntlet used for treating adult acquired flatfoot. This particular paper studied how each of the 3 devices best achieved not only correction of alignment but patient satisfaction in relieving symptoms. It was interesting in the study that the best improvement of gait pattern was found in the articulated ankle foot orthosis. And the researchers felt that the articulated device more accurately controlled abduction of the forefoot on the rear foot and that both custom devices definitely achieved correction better than the off the shelf air-bladder type device. Although at a considerably higher cost than the off the shelf orthosis, the custom articulated orthosis produced similar improvement in hind foot inversion and forefoot planner flection than the gauntlet device. However the solid ankle foot orthosis which was a gauntlet provided only minimal improvement of forefoot abduction. In the end it was the articulated AFO device that performed better than the gauntlet device.
We are going to go back to these enhancements that we can provide to both custom foot orthosis and ankle foot orthosis. The first is the Kirby medial heels skive and the other is the Blake modification. Both developed by podiatrists who attended the California College of Podiatric Medicine. The right hand positive cast is a Blake modified device which has a 30 degree inverted cast correction.
The left hand picture is a Kirby medial heels skive which is a very subtle change on the heel cup of the orthosis where it has been formed into more of a varus wedge effect on the medial aspect of the planner surface of the heel of the orthosis. A better description of it is in this drawing where on the right hand picture, the heel cup has been modified or raised medially to give a varus wedge effect and a shifting of the ground reaction forces to the medial side of the subtalar joint access providing more supination moment arm. If we compare the two positive casts, the right hand side with the Blake modification, the left hand side with the Kirby medial heels skive, it’s preferred to do the medial heels skive simply because the arch of the cast is better maintained and better preserved with a medial heel skive. We can incorporate medial heels skive into custom articulated ankle foot orthosis and this has proven to be a very popular and effective method of enhancing pronation control with not only foot orthosis but ankle orthosis.
It is popular as well with both foot orthosis and AFO devices to apply flanges to improve control over the foot. But we must remember how to use these flanges and the first important rule to follow is the fact that a lateral flange will help prevent forefoot abduction. In order to do so, it must extend to the mid shaft of the 5th metatarsal. Medial flanges although popular for flatfoot deformity can actually cause a pronatory force on the foot. When we apply a medial flange, we have to be careful to accommodate a deformed talonavicular joint. This is a set of orthosis where the right orthotic has been modified with a medial flange and the assumption is this helps improve support of the adult acquired flatfoot. And while it might increase surface area under the medial side of the arch, the effect of the design may actually make the foot pronate off the orthotic device. Because the adult acquired flatfoot has so much tendency towards abduction in the transverse plane, any orthosis that pushes against the medial aspect of the foot will tend to make the foot abduct further.
A medial flange tends to provide a lateral directed force to the mid foot and the fore foot and in this case it may actually cause more forefoot abduction. Kevin Kirby showed how these subtalar joint access progressively becomes more medially deviated in flatfoot deformity. And as the foot is more abducted and the access of the subtalar joint is more medially deviated, a medial flange on a foot orthotic can actually fall lateral to the subtalar joint access and cause a pronatory moment across the subtalar joint. Another way to look at this deforming force of the medial flange is the simple direction of ground reaction forces that results from the media flange. The medial flange almost never is perfectly flat but it is inclined slightly to shape to the arch of the foot and the ground reaction forces will be exerted perpendicular to the surface of the medial flange which may therefore direct the foot lateral. So we often will see a patient on a foot orthotic or an AFO device that appears to be abducting off of the device or slipping off the device. And this may simply be the result of inappropriate use of a medial flange which is pushing against the medial edge of the mid foot or forefoot and causing the foot to abduct.
The better choice is actually a lateral flange which pushes against the lateral aspect of the mid foot and prevents abduction. So here is the patient with severe adult acquired flatfoot wearing a custom articulated AFO device with a lateral flange. And the lateral flange acts like a blocker to prevent abduction of the foot. Don’t forget that a shoe can provide a very important restraint for transverse plane motion of the foot. And so you will see a patient who appears to be abducting on their AFO device out of the shoe but when you put them in the shoe the shoe upper restrains forefoot abduction. Here is a picture of a patient being controlled in stage 2 adult acquired flatfoot with a foot orthosis and the abduction of the forefoot is being controlled by the use of a lateral flange that’s been applied to the foot orthosis providing, as can be seen in the right hand picture, excellent control over abduction of the forefoot and pronation of the hind foot.
So when we do our clinical testing described in part 2 of this lecture series we normally would find evidence of ligament disruption such as loss of the single foot heel rise or loss of the Hubscher maneuver. And once we see that we definitely would want to recommend a custom articulated AFO device. But if the ligaments are intact we can start with a custom function of foot orthosis, if the ligaments are disrupted custom ankle foot orthosis. We prefer as seen by the Neville study on articulated hinged AFO device if possible. By stage 3 and stage 4 it would be a solid AFO device. So here is a patient with a flexible reducible stage 2 adult acquired flatfoot deformity, fitted for a custom hinged AFO device and proper motion controlled running shoes. On the contra-lateral foot often a practitioner will treat with a custom foot orthosis since most of these patients have a flatfoot deformity already on the asymptomatic contra- lateral foot. The ankle foot orthosis applies force primarily against the medial malleolus causing the tibia and the medial malleolus to be restrained from a-deduction and also preventing a transverse plane rotation of the tibia and fibular which dominate in the adult acquired flatfoot.
The uprights of the AFO device when tightened against the tibia and fibular with Velcro straps can literally grip the leg and prevent the leg from internally rotating in and driving the talus in to adduction. As the patient’s leg internally rotates here there is very little, if not any, motion of the line drawn on the posterior aspect of the leg. Studies done of patients with custom hinged ankle foot orthosis show significant control of tibial rotation in the transverse plane, which is essential to controlling the adult acquired flatfoot deformity.
Here is an excellent presentation of a patient being treated with custom ankle foot orthosis on the symptomatic right foot and a standard custom foot orthosis on the left foot with appropriate athletic shoes. We can look at these so called before and after photos of patients with of patients with adult acquired flatfoot being treated with custom hinged ankle foot orthosis and we can appreciate how the transverse plane and the sagittal plane and the funnel planer being controlled with the devices.
Here is a patient in stage 3 deformity being significantly corrected with a fixed hinged ankle foot orthosis with a medial arch suspender under the talonavicular joint. If we compare the before and after we can appreciate the tremendous correction of the forefoot in the transverse plane which is achieved through the control of the tibia and fibular of the ankle foot orthotic device. Another patient in stage 2 deformity with significant forefoot abduction fitted this time with an industrial work boot and we see correction of alignment of the tibia inside of the work boot which is compatible and easily worn with a hinged ankle foot orthosis. In the before and after photo, we see the alignment of the tibia corrected inside the boot with the gapping now of the tibia away from the medial counter of the boot as the tibia is straightened in the frontal plane.
Finally a patient in stage 4 adult acquired flatfoot with rupture of the deep deltoid ligament and severe valgus deformity of both the subtalar joint and the ankle joint is controlled in the right hand picture with a custom hinged ankle foot orthosis with a medial arch suspender not requiring correction with a gauntlet device. We can see the significant sagging of the talonavicular joint in the left hand picture corrected in the right hand picture with the brace. Probably the most gratifying part of ankle foot orthotic therapy for adult acquired flatfoot deformity is the realization that many of these patients can avoid surgery and furthermore many of these patients can actually move out of their AFO device after one year of treatment and maintain good control with a foot orthosis and remain asymptomatic. This has been shown in multiple studies published over the past 20 years beginning in 1996 and continuing to this day. Studies, peer reviewed and published in the medical literature some of which are shown in this slide.
How is it the patients can be treated with a ankle foot orthosis and eventually become pain free? If you think about it we treat athletes with an ankle sprain who have torn ligaments and with bracing and with a functional rehabilitation program, they too become pain free and can move out of their brace. We have seen the same outcome treating patients with ligamentous disruption and even tendon disruption with stage 2 and stage 3 adult acquired flatfoot. The first study pointing this out was conducted at the Mayo Clinic by Chow, et al, where they treated patients with different types of ankle foot orthosis and foot orthosis and they found that about 70% of the patients had good to excellent results and were able to avoid having surgery. 50% of the patients had discontinued use of the brace after follow up of 20-months. This study by Augustine evaluated a lace up gauntlet AFO device in patients with posterior tibial tendon dysfunction and after a 12-month follow up, significant improvement in functional scoring was measured and patients for the most part were able to avoid surgery.
Alvarez in another prospective or actual retrospective study found that 89% of patients were fully satisfied with treatment with a short articulated ankle foot orthosis in stage 1 and stage 2 adult acquired flatfoot. And only 11% of these patients had to go on and have surgery. 80% of patients not only avoided surgery but moved out of their AFO brace after one year and remained pain free.
This was the foot orthosis patients moved into after moving out of their ankle foot orthosis and note that these foot orthosis had a larger lateral flange. Another study published by Johnny Lind [phonetic] treated patients with stage 2 deformity and in this case followed them for over 8 years. Over 60% of the patients were fully satisfied with the study and very few of the patients ended up having to go on and have surgery. But most important the patients who were satisfied and who avoided surgery were observed to be brace free at 7 to 10 year follow-up. In the podiatric literature Neilson et al at Western Pennsylvania Hospital followed, this study like many previous studies again showed that with custom ankle foot orthotic therapy combined with physical therapy and other interventions, the vast majority of patients can avoid surgery and in this case 87% of the patients avoided surgery over a 27-month observational period.
Now, how do surgical patients fare compared to conservatively treated patients for stage 2 adult acquired flatfoot? Well if we look at the outcomes with treatment for stage 2 deformity particularly in this study by Myerson the results look very good. A satisfaction rate of 91% significant pain relief and improvement of function. Another study by Vander Krantz using functional scoring found that patients functional scores improved significantly when treated with a lateral column lengthening procedure in stage 2 adult acquired flatfoot. And in both of those surgical studies, the AOFAS functional scoring was used as the determinant of successful outcome.
That same scoring has been used in AFO studies and essentially if you can move a patient up to a scoring of 70 or higher the patients are functioning very well and you would consider that as successful outcome. And indeed in the AFO studies by Augustine and Lynn and Kraus [phonetic], the AOFAS scores are all 70 or higher and if we compared to the surgical studies of Myerson and Vander Krantz, they are pretty similar. So if we can achieve functional scoring equivalent to surgical treatment using AFO therapy which intervention would be preferable particularly when looking at cost, potential disability and potential long range complication. Certainly we would pick conservative intervention first.
Keep in mind that a successful outcome isn’t just improvement of functional scoring but as has been shown by previous studies, a significant number of patients can discontinue wearing their AFO brace after one year and remain very functional and relatively pain free by wearing proper shoes and proper foot orthosis. And so it’s important to tell our patients when we are treating them initially with adult acquired flatfoot deformity that the medical literature and experience has verified that there is a significant chance that they will succeed with ankle foot orthotic therapy to the point that they not only avoid surgery, but they can move out of their AFO brace after one year and function very well simply wearing proper shoes and properly designed custom foot orthosis.
And in summary as we look at all 3 of these lectures relevant to the adult acquired flatfoot, we can make the following conclusions.
The adult acquired flatfoot is a condition which represents a cascade of events not just rupture the posterior tibial tendon but attenuation and tear of key ligaments which support the ankle and the hind foot and it’s this culmination of events that leads to dysfunction and loss of mobility. The progression of deformity and disability can be evaluated and monitored by a accurate clinical examination which includes gait analysis and may actually include imaging studies. We have learned now from multiple retrospective reviews that ankle foot orthosis have become the gold standard of treatment in the United States and should be considered before surgical intervention is recommended.
From these studies we have learned that the majority of patients with stage 2 deformity can be expected to be successfully treated with a combination of ankle bracing which would mainly include custom hinged ankle foot orthotic devices along with a physical therapy program that includes balance training, range of motion and specific muscular strengthening. And if the patients adhere to this program they can reasonably expect a positive outcome after 12 months where they can move out of their brace and remain pain free for long periods of time simply wearing proper shoes and proper foot orthotic devices. This is certainly a much more favorable outlook for these patients than what we could give them 20 years ago.
Keep in mind that no surgical intervention has proven to be significantly more successful than conservative treatment while surgeries have risk of complications and potential long term disability and therefore it’s incumbent on us to consider conservative intervention first before recommending debilitating surgery. Thank you very much.