In addition to discussing the most common problems they see with orthosis irritation and how they remedy these issues, the expert panelists weigh in on two recent studies and their potential impact.
Q: What is the most common orthosis irritation problem that you see in your practice and how do you solve it?
A: The most common problem that Paul Scherer, DPM, encounters is longitudinal arch pain. He says the most common cause is improper casting. If the podiatrist leaves the midtarsal joint supinated, he warns that the contour of the finished orthotic will not match the corrected position of the foot and the point of maximum tenderness will be just proximal to the arch apex.
Dr. Scherer says one can easily avoid this problem by checking if a cast has a forefoot varus component and being sure the foot has a forefoot varus. Dr. Scherer points out this false forefoot varus in the cast results from the forefoot having a more inverted position during casting. This occurs frequently with foam box casting or inadvertent contracture by the patient of the tibialis anterior during plaster casting, according to Dr. Scherer.
Kevin Kirby, DPM, notes that orthotics can commonly cause discomfort or pain on the medial band of the plantar fascia. He says some patients will have significant bowstringing of the plantar fascia into the dorsal orthosis plate during weightbearing activities. Patients with higher medial arch heights or tight Achilles tendons are particularly prone to this, according to Dr. Kirby. Dr. Kirby says this bowstringing will cause increased compression force on the fibers of the medial band of the plantar fascia onto the orthosis plate. This may lead to a type of mild contusion to the mid-portion of the plantar fascia, notes Dr. Kirby.
When patients have plantar fascial irritation, Dr. Kirby grinds a plantar fascial groove into the dorsal orthosis plate in his office. He says this process should take one minute per orthosis for the experienced clinician.
“Plantar fascial grooves often make an orthosis that is barely tolerable become an orthosis that the patient never wants to take out of his or her shoe,” notes Dr. Kirby.
For the majority of patients, Bruce Williams, DPM, uses full-length EVA devices. He says problems with these devices usually arise from too much stiffness at the medial or lateral midfoot arch, and thinning these areas usually takes care of the problem.
In some instances, Dr. Williams notes that what may appear to be a medial arch irritation is actually caused by a lack of proper accommodation from a heel lift on the opposite limb. If the heel lift is not high enough, Dr. Williams says patients will often pronate more on the opposite limb.
Charles Mutschler, DPM, most commonly sees the irritation of heel cup impingement. To avoid this, he measures the fat pad displacement while the patient is weightbearing and then records it on the prescription form. As he explains, the lab can then add the correct amount of expansion based on his impression.
Q: Given the recent Evans study in the Journal of the American Podiatric Medical Association (JAPMA), when should a podiatrist treat or not treat pediatric flatfoot?1
A: Dr. Kirby praises Evans’ study as “a must-read for every clinician who treats children’s flatfoot.” Although he does not necessarily agree that one should not treat asymptomatic pediatric flat feet with foot orthoses, he agrees with Evans that many asymptomatic pediatric flat feet do not need any
treatment. He feels such patients require close monitoring rather than orthotic treatment.
Dr. Scherer cites the significance of Evans’ study, saying it revives the decades-old question of whether there is value to treating children with hypermobile flatfoot. He notes the author develops a very clear algorithm that all doctors can follow, combined with a single case experimental design.