Roundtable Insights On Adult-Acquired Flatfoot

   Adult-acquired flatfoot (AAF) is one of the more common conditions that podiatrists see in practice. With this in mind, some of the leading experts on this subject shared their views and experience on this subject. They discuss the role of diagnostic imaging, their use of conservative treatments and their perspectives on appropriate surgical procedures. Without further delay, here is what they had to say.    Q: What ancillary studies are required for proper diagnosis and treatment selection for the adult-acquired flatfoot?    A: Michael S. Lee, DPM, says AAF is generally a clinical diagnosis. Other than the physical exam, Shannon Rush, DPM, says a proper radiographic evaluation is the most important aspect of diagnosing AAF and arriving at an appropriate course of treatment. Dr. Rush emphasizes the inclusion of foot and ankle views as well as hindfoot alignment and long leg calcaneal views.    All the panelists agree that neutral position X-rays are helpful in determining the degree of the deformity and what procedure one should perform. Alan Catanzariti, DPM, says it is important to evaluate the talus-first metatarsal angle on both AP and lateral radiographs. He adds that the AP views also enable one to see the amount of talar head that is covered by the navicular. Standard radiographs also allow clinicians to assess the tritarsal complex for degenerative changes, according to Dr. Catanzariti. He says these degenerative changes may indicate an arthrodesis procedure as opposed to performing reconstructive osteotomies or soft tissue procedures.    The majority of the panelists recommend obtaining ankle X-rays in order to detect valgus deformity within the ankle. When there is valgus deformity within the ankle joint, Dr. Catanzariti will typically consider performing a medial displacement osteotomy of the calcaneus.     “This helps decrease the tension within the deltoid ligament and prevent further attenuation of medial soft tissue structures,” explains Dr. Catanzariti.    In cases of end-stage flatfoot deformity, Jordan Grossman, DPM, says AP ankle views are useful in evaluating for deltoid ligament insufficiency and valgus deformity of the talus within the ankle mortise.    Gerard V. Yu, DPM, and Dr. Catanzariti agree with Dr. Rush about the value of obtaining long leg axial films. Dr. Catanzariti says long leg axial views and Saltzman views allow one to evaluate the calcaneus, subtalar joint, ankle joint and tibia relative to one another. He adds that these views often facilitate appropriate procedure selection.    Lower-extremity alignment views may also be indicated in certain instances, according to Dr. Rush. Dr. Grossman concurs, noting that obtaining Cobey and hindfoot alignment views are useful in severe cases and with lower-extremity deformity.    When it comes to magnetic resonance imaging (MRI), Dr. Rush says he “rarely, if ever” uses it in his workup for AAF. Dr. Catanzariti agrees. However, if he is contemplating arthrodesis versus reconstruction, Dr. Catanzariti will sometimes obtain a MRI in order to detect early degenerative changes within the subtalar joint that are subtle on standard X-rays. Dr. Grossman concurs, noting that MRI is indicated in “select circumstances” in which the diagnosis is unclear.    Dr. Lee says one may employ MRI or ultrasound imaging to evaluate the posterior tibial tendon for attenuation or complete rupture. Dr. Yu emphasizes that MRI is most helpful when clinicians use a facility that has an experienced musculoskeletal radiologist, who is knowledgeable about the clinical entity and its primary and secondary manifestations.     “I believe the MRI should be part of the standard workup for AAF if you plan to do direct surgical repair alone or as part of the correction of the deformity,” maintains Dr. Yu.    Dr. Lee adds that a CT scan may have limited use in determining the degree of arthrosis in stage 3 or stage 4 deformities. Gait analysis may also be helpful in procedure selection, according to Dr. Catanzariti.    Q: What is the significance of the posterior tibial tendon in the adult-acquired flatfoot?    A: Dr. Yu says the primary purpose of the posterior tibial tendon is decelerating internal rotation of the tibia and accordingly limiting pronation of the foot following heel strike in gait.    The intrinsic pathology specific to the posterior tibial tendon is “insignificant once the deformity has occurred,” notes Dr. Rush. He says the most important overriding factor is that the tendon has functionally weakened and is unable to stabilize the midtarsal joint. Dr. Rush says this functional weakness may be due to posterior tibial tendon dysfunction (PTTD) or subluxation in the rearfoot.    The posterior tibial tendon plays “a primary role in the development of AAF,” according to Dr. Grossman. Dr. Lee says the posterior tibial tendon plays an important role early in the process but its importance diminishes as the deformity progresses. He notes the spring ligament may become attenuated in some situations.    While there are several possible causes of AAF, Dr. Grossman says insufficiency or rupture of the posterior tibial tendon is the most common cause. The posterior tibial tendon often may be attenuated or diseased in AAF, according to Dr. Catanzariti, but he says this can vary from patient to patient.    If patients have significant symptoms as a direct result of disease within the posterior tibial tendon, Dr. Catanzariti says they may require surgical intervention, which could include a tenosynovectomy, a partial tendon debridement or actual resection of an attenuated tendon. He notes these interventions may be supported by tendon transfers. In these cases, Dr. Catanzariti prefers a flexor digitorum longus tendon transfer.    Dr. Rush says the clinical view of the posterior tibial tendon or its appearance on MRI does not influence one particular reconstruction over another. When it comes to stage 3 and stage 4 AAF, Dr. Lee says the posterior tibial tendon plays little importance in function, diagnosis or surgical treatment selection.    If a patient has a predisposition to excessive pronation due to a specific foot structure, Dr. Yu says the posterior tibial tendon is “very significant.” When patients have a cavus foot, he notes the inherent stability of the foot will limit pronation. However, if a patient has hypermobile joint laxity syndrome, Dr. Yu says the posterior tibial tendon will be more important as it will “work harder to prevent excessive pronation.”    If one stabilizes the foot well with osseous procedures, especially fusions, the importance of the posterior tibial tendon for function decreases, according to Dr. Yu. When one performs a posterior tibial tendon transfer for other conditions (i.e., dropfoot deformity), Dr. Yu says the foot structure remains the same due to the inherent interlocking of osseous units. When performing a triple arthrodesis, Dr. Yu notes the surgeon can leave the PT tendon alone altogether unless the pain there is due to active inflammation around the tendon itself. In essence, the more inherently stable the foot is, whether by surgical fusion or anatomical stability, the less important the PT tendon is to overall foot function.    Q: What conservative measures have been successful in your hands in the treatment of AAF?    A: Employing orthotics in combination with antiinflammatory medications and posterior muscle group stretching provides relief in milder cases of AAF, according to Dr. Catanzariti. When it comes to stage 1 conditions, Dr. Lee notes he has had a fair amount of success utilizing figure-of-eight ankle braces along with rest, ice, NSAIDs and shoe gear modifications.    He notes that stage 2 deformities have responded well to prefabricated and custom orthotics, rest, activity modification and NSAIDs. Dr. Lee has also utilized ankle foot orthoses (AFOs). Depending on the presentation and degree of the deformity, Dr. Grossman says he has had success with the aforementioned modalities as well as physical therapy, cast immobilization and a removable walking boot.    Functional orthotics may be helpful in the early stage of AAF but Dr. Yu says he generally does not use them. Dr. Yu notes that some companies make a variety of orthotic devices that “are too flimsy and do not have enough substance to do the job.”    Essentially, one needs to ensure bracing of the foot to the leg, according to Dr. Yu, especially in the presence of other factors like obesity, genu valgum, etc. Dr. Yu says Aircast ankle braces and similar devices may provide good relief prior to using the more sophisticated and expensive devices like the Richie Brace and AFOs. With chronic conditions, Dr. Rush will use aggressive custom orthoses, Richie Braces and the Arizona AFO prior to surgical intervention.    With stage 3 and stage 4 deformities, Dr. Lee will brace them with either UCBL orthotics or AFOs. If these fail, he proceeds to surgical intervention. The other panelists concur that one can use conservative bracing for stage 3 and stage 4 deformities in patients who are not surgical candidates. In these patients, Dr. Rush has had success with the Arizona AFO while Dr. Catanzariti has utilized supramalleolar AFOs with good results.    In regard to conservative therapy, Drs. Rush and Yu say there are many factors to consider including the patient’s level of activity, weight loss, patient education, proper shoe gear and rehabilitation. Realistic expectations are essential and become more important as patients progress from stages 1 to 4, according to Dr. Yu. He says a patient with stage 3 or 4 deformity and low activity may respond surprisingly well to bracing but bracing is unlikely to be successful in a highly active patient with stage 2 AAF.    Q: At what point does AAF become a surgical foot?    A: The majority of the panelists consider surgical treatment when the deformity is progressive, grossly unstable and doesn’t respond to functional bracing. Dr. Rush says the potential progression of the deformity is a significant concern.     “Severe talonavicular and subtalar subluxation can have a devastating influence on the ankle joint,” emphasizes Dr. Rush. “If the lateral peritalar drift is left unabated, the ankle can also fall into valgus.”    Dr. Lee says he performs surgery for end-stage deformities such as stage 3 and stage 4 conditions. However, Dr. Yu notes that even severe deformities do not justify surgery alone.     “If the other foot is flat and asyptomatic, you may be able to manage the pathologic foot without surgery,” points out Dr. Yu. If bracing fails, one needs to turn to surgical options, according to Dr. Yu. He emphasizes that physicians should always remember to treat patients in conjunction with their disease or deformity and not the X-rays. He notes that clinical correlation is essential to effective treatment.    Q: When are calcaneal osteotomies indicated in the treatment of AAF?    A: Dr. Yu says these procedures are “rarely” indicated for treating AAF. He believes this approach has been abused in an attempt to avoid more time-tested techniques, such as the gold standard triple arthrodesis, especially in the later stages of AAF when the deformity can be quite severe.    In his experience, Dr. Yu says the calcaneal osteotomy has little impact in resolving severe AAF “when a fusion in conjunction with tibialis posterior repair and posterior lengthening would have worked out better.” While he notes that calcaneal osteotomies are very helpful in the earlier stages of the disease, Dr. Yu emphasizes that many of these patients will do well without surgery.    Drs. Grossman, Catanzariti and Lee believe calcaneal osteotomies are primarily indicated for flexible or reducible deformities. These procedures allow surgeons to correct various deformities while maintaining midtarsal and subtalar joint motion, according to Dr. Grossman. He says this will “most likely decrease the likelihood of adjacent joint demand and arthrosis that one commonly sees with an isolated or triple arthrodesis.”    Citing the versatility of calcaneal osteotomies, Dr. Catanzariti calls them an excellent alternative to arthrodesis procedures.     “These osteotomies spare the tritarsal complex and allow the hindfoot to function in a relatively normal fashion,” explains Dr. Catanzariti.    Dr. Lee concurs. If the flatfoot is supple, he says one can achieve correction with calcaneal osteotomies while preserving most of the hindfoot motion. When it comes to late stage 1 AAF, Dr. Catanzariti will consider posterior calcaneal displacement osteotomies and sometimes uses this approach to treat early stage 2 conditions. Dr. Lee utilizes posterior calcaneal displacement osteotomies for early stage 2 AAF and employs the Evans calcaneal osteotomy and double osteotomies for late stage 2 conditions. For mid- to late stage 2 AAF, Dr. Catanzariti considers performing an anterior open wedge osteotomy in combination with a posterior displacement osteotomy.    Dr. Rush says calcaneal osteotomies are a “wonderful surgical tool” for treating AAF. He performs a posterior osteotomy with any valgus malalignment of the subtalar joint when a subtalar arthrodesis is not indicated. Obtaining hindfoot alignment and long leg calcaneal axial views help in planning with this procedure, according to Dr. Rush.    He maintains that clinicians must be careful to evaluate the midtarsal joint and medial column for instability and supinatus. In the presence of instability or deformity, Dr. Rush notes one must add ancillary procedures in order to stabilize the medial column. Dr. Rush adds that naviculocuneiform arthrodeses serve to stabilize the medial column and address the naviculocuneiform fault if one exists. Dr. Grossman says he typically performs calcaneal osteotomies in combination with other bony and/or soft tissue procedures.    Dr. Rush does not utilize an isolated anterior calcaneal osteotomy for AAF. He says one must combine this procedure with the posterior osteotomy to correct the valgus and lateral translation in the subtalar joint. Dr. Rush strongly emphasizes paying close attention to the subtalar alignment when selecting these procedures.    Dr. Lee also notes that he prefers calcaneal osteotomies over isolated hindfoot fusions when treating AAF in smokers, more active patients and those with a normal or slightly elevated body mass index (BMI).    Q: When is an isolated or combined joint arthrodesis indicated in treating AAF?    A: According to Dr. Yu, these procedures are indicated when there is significant deformity with significant disability and symptoms, especially in cases that involve degenerative arthritis or excessive mobility that cannot be predictably controlled by other means.    When one considers performing three joint preservation procedures, Dr. Yu believes one joint fusion can achieve the same outcome. He says performing an isolated joint fusion is especially beneficial for patients who have a low level of activity and want relief of their pain and a stable foot. If one achieves the fusion in a neutral position without varus or valgus, Dr. Yu says the fusion provides “exceptional functional outcomes” with minimal stress on adjacent joints, which minimizes the risk of subsequent degenerative joint disease. “It’s all about the alignment and position of fusion,” emphasizes Dr. Yu.    Over the years, Dr. Yu notes anecdotally that he has observed, examined and analyzed a large number of adult patients who had congenital coalitions, realizing they had minimal to no symptoms until their late 40s and 50s or even later. Dr. Yu says the position of the fusion is key to minimizing stress on adjacent joints and structures. Tarsal coalition patients who present early in life invariably have peroneal spastic flatfoot deformities, creating a completely different clinical problem, according to Dr. Yu. However, he emphasizes that the technique one uses to perform these fusions is important.    Rigid deformities, a degenerative midtarsal or subtalar arthritis are the primary indications for using isolated or combined arthrodesis procedures, according to Dr. Grossman. He says one may also consider these procedures for obese patients with AAF or in cases of underlying inflammatory arthritis. Dr. Grossman says he typically combines an isolated arthrodesis procedure with soft tissue reconstruction and posterior muscle group lengthening. As with all arthrodesis procedures, Dr. Grossman says the position primarily predicates outcomes and patient satisfaction.    Dr. Lee utilizes isolated hindfoot fusions in late stage 2 deformities when there may be mild arthrosis in one or more of the hindfoot joints, when the deformity is severe on plain radiographs or in patients with a higher BMI.    A subtalar joint arthrodesis may be effective in the presence of isolated subtalar joint disease or arthritis, according to Dr. Catanzariti, but he rarely uses this procedure to treat AAF. In these cases, Dr. Catanzariti prefers a double calcaneal osteotomy for stage 2 AAF, a triple arthrodesis for stage 3 AAF and a combination of triple arthrodesis and posterior calcaneal displacement osteotomy for stage 4 AAF.    On the other hand, Dr. Lee says he tends to perform an isolated subtalar joint arthrodesis in many cases of AAF but will occasionally opt for talonavicular arthrodesis in more severe cases of AAF with significant talar declination.    Dr. Rush notes that painful degenerative joints and significant subluxation in the subtalar or talonavicular joints are general indications for arthrodesis. Arthrodesis of the non-essential medial column joints, such as the naviculocuneiform or metatarsocuneiform joints, can easily and effectively stabilize the medial arch, according to Dr. Rush. He adds that combining this procedure with calcaneal osteotomies can “correct most degrees of instability.”    While distraction fusions are effective for lateral peritalar subluxation, Dr. Rush cautions that they often do not address the valgus or translation in the subtalar joint. According to Dr. Lee, distraction arthrodesis of the calcaneocuboid joint is a powerful procedure but does have “some elevated risk of non-union.”    In the presence of supinatus or varus deformities, all the panelists agree that one must perform some type of ancillary medial column procedure, whether it is a medial column fusion or an osteotomy. Dr. Mendicino is Chief of the Division of Foot and Ankle Surgery at the Western Pennsylvania Hospital in Pittsburgh. He is a Fellow and Past President of the American College of Foot and Ankle Surgeons, and is a Clinical Professor of Surgery at the Western Campus of the Temple University School of Medicine. Dr. Catanzariti is the Director of the Residency Training Program within the Division of Foot and Ankle Surgery at the Western Pennsylvania Hospital in Pittsburgh. He is a Fellow of the American College of Foot and Ankle Surgeons. Dr. Grossman is Chief of the Section of Podiatry at Akron General Medical Center in Ohio. He is a Fellow of the American College of Foot and Ankle Surgeons, and a Diplomate of the American Board of Podiatric Surgery. Dr. Lee is a Fellow and serves on the Board of Directors of the American College of Foot and Ankle Surgeons. He is a Diplomate of the American Board of Podiatric Surgeons. He recently chaired the adult flatfoot panel and co-authored the ACFAS Clinical Practice Guidelines for Adult Flatfoot. He is in private practice at Central Iowa Orthopedics in Des Moines, Iowa. Dr. Rush is a Fellow of the American College of Foot and Ankle Surgeons. He is a Staff Surgeon within the Department of Orthopedics at Kaiser Permanente in Walnut Creek, Ca. Dr. Rush is also a Staff Surgeon with the San Francisco Bay Area Foot and Ankle Residency Program. Dr. Yu is the Director of the Podiatric Surgical Residency Program (PSR-36) and is the Chief of the Section of Podiatry of the Division of Orthopedic Surgery at the St. Vincent Charity Hospital, and at the Huron Hospital in Cleveland. He is a Fellow of the American College of Foot and Ankle Surgeons, and is a Diplomate of the American Board of Podiatric Surgery. Dr. Yu is also the Director of Program Development and a faculty member of the Podiatry Institute.