Prescribing Orthoses For Bunions, Hammertoe And Achilles Tendinosis
Our expert panelists discuss the beneficial effects that orthotics can have for conditions such as hallux valgus, hammertoes and Achilles tendinosis, and also provide insights into modifications including heel lifts.
Do you think orthotics can be helpful in the treatment of bunion deformities?
Jane Andersen, DPM, tells her patients orthotics will not take away the bunion deformity but they may control the pain and the progression of the deformity.
Orthotics never prevent tight shoes from pressing against prominent bunions, notes Gene Mirkin, DPM. In fact, both he and Bruce Williams, DPM, say the added space these devices occupy may make the shoe tighter, which increases pain. Accordingly, for tight dress shoes and heels, Dr. Mirkin says there is no chance of a patient benefiting from an orthotic.
“Bunions are one of the toughest things to effectively treat with orthotics,” concurs Dr. Williams. Since most bunion deformities need extra space inside a shoe, Dr. Williams says patients may gain some biomechanical advantage and lose out to the foot being cramped in the shoe and aggravating the bunion that way. He says one can have some success with some patients utilizing a properly sized first ray cutout with PPT or Poron backfill in conjunction with a digital skive under the hallux.
When a patient does have a prominent bunion, one prone to irritation from rubbing, Dr. Mirkin acknowledges that an orthotic can help in the right shoe. When pronatory forces exist, he says correctly posted orthotics can decrease the rubbing of the bunion against the shoe and provide relief. For athletes, in whom running and jumping aggravate bunions, Dr. Mirkin says orthotics can be useful to avoid a surgical approach and relieve symptoms.
How do you prescribe orthotics for flexible hammertoe deformities?
Dr. Mirkin says orthotics can sometimes stabilize flexible hammertoes due to flexor stabilization and prevention of excessive pronation. By preventing the collapse of the medial longitudinal arch and keeping the subtalar joint from pronating beyond perpendicular to the weightbearing surface, he says the pull of the flexor tendons can decrease. Dr. Mirkin uses a 10-12 mm deep heel cup and will sometimes use extrinsic forefoot posting if a forefoot varus deformity is responsible for hammertoes caused by excessive pronation. He always warns the patient that the toes will still look contracted but they may not rub the shoes as much and therefore will feel better.
For flexible hammertoe deformities, Dr. Andersen usually prescribes a rigid or semi-rigid device with a rearfoot post posted to 4/4 motion. If patients are having any forefoot symptoms, especially metatarsal pain, she will use a metatarsal pad.
Hammertoes, notes Dr. Williams, are tough to treat with orthotics. As he says, some people will benefit from the use of sulcus raises or pads that allow the toes to grip properly. Some patients can benefit from a digital skive or pad to raise the toes above the level of the metatarsophalangeal joints by 3 to 6 mm, according to Dr. Williams. Ultimately, he notes any increase in a foot platform from a full-length orthotic or a digital skive can irritate a fixed hammertoe deformity.
“Treat these with caution but keep in mind you can use digital padding at certain toes and not on others to maximize the potential of the orthotic modification,” advises Dr. Williams.
What are your orthotic prescription criteria for Achilles tendinosis?
Dr. Williams says the most current literature on biomechanics of the ankle joint suggests that a lack of dorsiflexion range of motion is the most likely culprit leading to Achilles tendinopathy.He feels that when the ankle joint stops dorsiflexion too early in midstance, the Achilles will not get to full extension during eccentric loading. As Dr. Williams explains, this stops any energy potential building up in the Achilles that would then assist late midstance and propulsive concentric contraction.
“This makes the Achilles insertion and tendon body work harder, and can lead to calcification and exostosis at the tendon insertion and trauma to the tendon itself,” says Dr. Williams.
All three panelists cite the use of heel lifts for the Achilles. More often than not, Dr. Mirkin finds that a heel lift does as much for Achilles tendinosis as a custom-molded orthotic. If rearfoot varus exists, he does not prescribe orthotics. For Achilles tendinosis, Dr. Andersen uses a rigid or semi-rigid device with a rearfoot post posted to 4/4 motion. She often adds a slight heel lift, especially if the patient responds to this clinically prior to orthotic scanning.
In cases with flexible rearfoot valgus, Dr. Mirkin most often uses a deep heel cup with 1/8 to ¼-inch of heel lift and posting to bring the rearfoot to perpendicular. If the hindfoot deformity is rigid, Dr. Mirkin has found that orthotics are not of much benefit. “In those patients, the heel lift rules in both result and cost savings to the patient,” he emphasizes.
When it comes to treating Achilles tendinosis, Dr. Williams says his goal is to get the ankle moving again via manipulation and the use of orthotics. He often uses a heel lift from 3 to 6 mm to accommodate the lack of motion at the ankle joint via dorsiflexion. If the patient cannot dorsiflex enough, Dr. Williams says he will “cheat” and lift the affected side to “fool the body” into thinking it did what it needed to do. Dr. Williams advises caution so one does not overload a long limb that way but says bilateral lifts will often keep that from happening and allow for proper function. He also emphasizes use of the ankle joint lunge test to measure flexed knee range of motion, saying it is the only test that is repeatable.
“When you start measuring this regularly, you will understand how many patients really have significant tightness in their soles and need to have heel lifts combined with orthotics to treat this effectively,” explains Dr. Williams.
Dr. Andersen is in private practice in Chapel Hill, N.C. She is a Past President of the American Association for Women Podiatrists and is a podiatric expert for Caring.com . She is board certified in surgery by the American Board of Foot and Ankle Surgery.
Dr. Mirkin is board certified in foot surgery by the American Board of Foot and Ankle Surgery and board certified in foot and ankle orthopedics by the American Board of Podiatric Medicine. He is a Fellow of the American College of Foot & Ankle Orthopedics & Medicine, and a Fellow of the American Society of Podiatric Surgeons. Dr. Mirkin is the President of Foot and Ankle Specialists of the Mid-Atlantic in Maryland, Washington, DC and Virginia.
Dr. Williams is the Director of Gait Analysis Studies at the Weil Foot & Ankle Institute. He is a Past President and Fellow of the American Academy of Podiatric Sports Medicine. Dr. Williams is a sports medicine professional specializing in the treatment of foot, ankle and movement disorders. He is the Director of Breakthrough Sports Performance, LLC in Chicago.