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.