Essential Pearls On Effective Orthotic Modifications

Guest Clinical Editor: Patrick DeHeer, DPM

   Orthotic modifications can play a valuable role in the treatment of various lower extremity ailments. Accordingly, these expert panelists offer their insights on the use of orthoses and key modifications within the treatment plan for turf toe injuries, posterior tibial tendon dysfunction (PTTD) and lesser metatarsal stress fractures.

   Q: What is the preferred treatment for turf toe injuries in terms of orthotic modifications?

   A: Bruce Williams, DPM, notes turf toe injuries are challenging as they are usually hyperextension injuries so one should protect the joint first. Over time, he says one should help return proper extension to the first metatarsophalangeal joint (MPJ). Generally, Dr. Williams says most physicians will suggest a Morton’s extension and he concurs.

   Kevin Kirby, DPM, agrees. He says one can often initially treat turf toe injuries by using an orthosis with a Morton’s extension to help restrict motion at the first MPJ. As the pain gradually improves over time, Dr. Kirby says one may remove the Morton’s extension to allow more normal joint motion and gait mechanics.

   After a certain amount of time has passed with no improvement, Dr. Williams advises DPMs to consider other modifications to get the hallux to extend again. He notes such modifications include first ray cutouts with Poron or PPT backfill, reverse Morton’s extensions and forefoot valgus wedging. Once the patient can extend the hallux without pain, Dr. Williams says using a digital pad, such as a Cluffy Wedge (Cluffy Biomedical), to elevate the hallux can be very helpful if one uses it in moderation or gradually increases the wedge’s use.

   Charles Mutschler, DPM, says his most commonly used modification is a rigid extension of the orthotic plate under the hallux. For some patients with severe turf toe, he will use a rigid graphite plate to decrease motion at the first MPJ. If the patient also has sesamoiditis, Dr. Mutschler suggests using a reverse Morton’s extension in conjunction with a rigid extension to offload the area.

   Q: What is the preferred orthotic modification for PTTD in a patient who refuses an AFO type product?

   A: Dr. Kirby, who has treated hundreds of patients with PTTD in 24 years, does not use AFOs as an initial treatment. Instead, he initially prescribes specially modified, custom-made foot orthoses for patients to wear with shoes or boots with a stable sole.

   He prefers using an orthosis with a 4- to 6-mm thick polypropylene shell, a 2- to 6-mm medial heel skive and a 2- to 4-mm heel contact point thickness. His preferred orthosis also includes a 2- to 4-degree inverted balancing position, 16- to 20-mm heel cups and a 4-degree/4-degree rearfoot post. Dr. Kirby places the patients with milder PTTD into a low-cut motion-control shoe. Patients with more severe PTTD wear a high top hiking or dress boot.

    “I prefer foot orthoses with shoes/boots for the initial treatment of PTTD,” explains Dr. Kirby. “In my clinical experience, patient satisfaction is high for this treatment and the results are excellent, except for the more severe cases of PTTD.”

   When it comes to patients with PTTD, Dr. Mutschler often tries to use an orthotic device with a deep heel cup and a medial and lateral clip.

   Dr. Williams uses a 6- to 10-degree Kirby skive and posts the heel as high into varus as the patient can tolerate. He extends the height of the medial portion of the device, similar to a flange if necessary. For many patients, Dr. Williams will use a first ray cutout.

   Q: What type of orthotic do you recommend for lesser metatarsal stress fractures? Is it better to offload the areas or provide total contact and support?

   A: Dr. Williams usually places such patients in a Cam Walker or surgical shoe. If patients cannot wear such devices, he will utilize a metatarsal pad of soft material and an accommodation under the head of the affected metatarsal. Although he feels it is probably better to give total contact and support, Dr. Williams notes a lack of published data on this approach.

   For a patient with a plantarflexed metatarsal head, Dr. Mutschler prefers offloading the area via accommodation.

   As Dr. Kirby notes, metatarsal stress fractures result from excessive bending of the metatarsals during weightbearing activities. He says such fractures will nearly always occur at the most narrow portion of the metatarsal shaft, the metatarsal neck, where the bending stresses within the bone are at their greatest magnitude.

   Therefore, Dr. Kirby notes the best foot orthoses to heal or prevent metatarsal stress fractures are constructed with a metatarsal pad or other similar modification. The metatarsal pad should be directly plantar to the fracture site. He says this placement will decrease the bending moments on the metatarsal shaft by reducing the ground reaction force on the metatarsal head and increasing the ground reaction force on the plantar metatarsal neck.

Dr. Kirby is an Adjunct Associate Professor within the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt University in Oakland, Ca. He is in private practice in Sacramento, Ca.

Dr. Mutschler practices at Advanced Footcare in Miami, Fla. He is a member of the American Academy of Podiatric Sports Medicine and is board certified by the American Board of Podiatric Orthopedics and Primary Podiatric Medicine. Dr. Mutschler is the team podiatrist for St. Thomas University in Miami.

Dr. Williams is a Fellow of the American College of Foot and Ankle Surgeons, and is board certified by the American Board of Podiatric Surgery. He is a Fellow and the current Secretary/Treasurer of the American Academy of Podiatric Sports Medicine. Dr. Williams practices in Merrilville, Ind.

Dr. DeHeer is a Fellow of the American College of Foot and Ankle Surgeons, and is a Diplomate of the American Board of Podiatric Surgery. He is also a team podiatrist for the Indiana Pacers and the Indiana Fever. Dr. DeHeer is in private practice with various offices in Indianapolis.

Editor’s note: For further reading, see “A Closer Look At Orthotic Technologies And Modifications” in the October 2005 issue of Podiatry Today.

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