Can Orthoses Have An Impact For Bunions, Hammertoes And Morton’s Neuromas?

Author(s): 
Guest Clinical Editor: James Clough, DPM, FACFAS

   When using orthotics to reduce flexible hammertoe contractures in cavus feet, Dr. Richie says the key is conforming the device as close as possible to the arch of the foot. Both he and Dr. Clough support the use of minimal arch fill. Dr. Richie advises against using rearfoot posting or plaster fill across the balance platform. He suggests adding a metatarsal pad to ensure support of the distal transverse metatarsal arch. Although he will observe lesions from hammertoes reduce in these types of patients, he will not see the deformity reverse.

   Dr. Williams finds that patients tend to flex the digits due to an inability to get proper stable pressure/force under the first MPJ in most instances. However, he cautions that using the usual modifications on orthoses does not mean that the flexible hammertoes will go away. He usually uses a digital wedge (usually 3 to 5 mm thick, similar to a Cluffy wedge) across all the digits to assist with this.

   Dr. Williams adds that dorsiflexing the digits can help decrease the need to flex, especially if a cutout allows the first metatarsal head to plantarflex. Equalizing the pressure and forces under all the metatarsal heads will often decrease the need for the lesser digits to flex at the proximal interphalangeal joint and distal interphalangeal joint, according to Dr. Williams.

Q:

Can the use of orthotics effectively treat Morton’s neuroma?

A:

“Treatment of Morton’s neuroma is one of my most successful applications of foot orthotic therapy. Success can be achieved in all forms of footwear if the practitioner is creative in the prescription criteria,” says Dr. Richie.

   As he elaborates, the key to success is identifying and capturing a forefoot valgus deformity, which almost always accompanies this condition. Dr. Richie notes that balancing the forefoot valgus with intrinsic cast correction will reduce loading of the lateral column of the foot and offload the Morton’s neuroma.

   For patients with Morton’s neuroma, Dr. Williams notes it is helpful to accommodate the area or use a metatarsal pad. In contrast, in Dr. Richie’s opinion, adding a metatarsal pad or “neuroma bump” is rarely helpful and often these pads cause too much pressure on the neuroma.

   Dr. Richie avoids rearfoot posting and tries to avoid full-length orthotics to allow preservation of the volume of the shoe. He also notes the importance of arch contour, especially for “dress orthotics,” in which simply supporting the arch can have very positive effects on relieving neuroma pain.

   Dr. Williams says one will often need to add a 3 mm heel lift if the problematic foot suffers due to ankle joint equinus and/or a leg length discrepancy. As he explains, the heel lift will help equalize the forefoot and rearfoot pressures in a timely manner, and decrease the predominance of the forefoot pressures that occur in patents with neuromas.

   Dr. Clough removes very few neuromas surgically, finding a neuroma is mainly a functional problem with lateral weightbearing on the forefoot in propulsion. This creates a strain on the fourth and fifth metatarsals, which he says actually have quite a bit of motion at the metatarsocuboid joint. Dr. Clough notes that this leads to a relative elevation of these rays and the development of a forefoot valgus. The second and third metatarsocuneiform joints are relatively locked in place and as a result, Dr. Clough notes there is a shearing between the mobile fourth metatarsal and the relatively immobile third metatarsal. He says the cause of this can be an uncompensated rearfoot varus, usually from a high degree of tibial varum.

   However, Dr. Clough finds the most common cause of lateral forefoot overload is limited motion of the first MPJ. If patients cannot roll through the first MPJ, they will roll off the foot laterally to move forward. To correct this problem with plantarflexion of the first metatarsal, he suggests minimal orthotic fill. Additionally, Dr. Clough corrects any forefoot valgus by plantarflexing the fourth and fifth metatarsals, and adds minimal fill in the lateral arch just as he would do medially. For all such cases, he uses a P4 Wedge.

   “Very often, you also need to spend a few moments with your patients to get them to start to roll through the first MPJ and take a longer stride and walk faster without shuffling,” suggests Dr. Clough.

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