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

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

These expert panelists examine the role of orthoses in the management of common clinical presentations such as bunions, hammertoes and Morton’s neuromas.

Q:

Do you think orthotics can be helpful in the treatment of bunion deformities?

A:

James Clough, DPM, FACFAS, notes most people have some limited motion of the first metatarsophalangeal joint (MPJ), which causes compression of the joint when the toe attempts to move. As he explains, patients may wind up partially mitigating this compression force by pushing the first metatarsal medially, which may cause a bunion in some people. Dr. Clough estimates that about 50 percent of his patients with a bunion respond positively with functional control of the foot, noting that orthotics help as one restores motion to the joint during gait.

   Therefore, Dr. Clough notes his main goal with the orthotic is improving motion of the first MPJ so he reduces the compression forces associated with a failure of the joint to move. Maximally plantarflexing the first metatarsal with minimal fill in the medial arch is necessary, according to Dr. Clough.

   When it comes to orthoses for bunion deformities, Doug Richie Jr., DPM, FACFAS, says he has only had success with this in active athletes. A certain percentage of patients with bunion deformities have pain due to abnormal mechanics of the first MPJ but he says this is not “bump pain.” The increased dorsiflexion-inversion of the first ray with rearfoot pronation causes a reciprocal valgus torque on the hallux across the first MPJ, creating a painful ligamentous strain and joint compression across this joint, according to Dr. Richie. He notes that foot orthoses may have the ability to decrease overload of the first ray and perhaps increase stiffness of the first ray.

   Additionally, limiting dorsiflexion of the first ray and facilitating the dynamic forces that plantarflex the first ray can decrease the pain associated with hallux valgus, according to Dr. Richie. He notes this treatment requires the use of suitable footwear such as athletic shoes. Dr. Richie says this orthotic therapy is most effective during more vigorous sporting activities.

   He uses standard functional foot orthotic therapy intervention for the treatment of hallux valgus. Dr. Richie also notes the importance of having appropriate footwear to fit a full-length orthosis with a deep heel cup and normal width. He posts the rearfoot with 4 degrees of inversion and 4 degrees of motion. His patients wear a neutral suspension cast to capture forefoot to rearfoot deformities and notes the fabrication lab must intrinsically balance the deformity with minimal arch fill at the medial arch and transverse metatarsal arch.

   “I make sure the lab does not make the orthosis too wide as I want the first metatarsal to have freedom to plantarflex during terminal stance,” says Dr. Richie.

   Similarly, Bruce Williams, DPM, acknowledges that the difficult part is explaining to patients that orthoses can help with function of the first ray but may take up more room in the shoe. Therefore, he says orthoses may cancel some or all of the improvement in function that patients could gain in relieving their bunion pain. Dr. Williams asks patients to upsize their shoes one-half or one full size for their orthoses. He uses a digital wedge or a Cluffy type wedge at the hallux or for all the digits to engage and plantarflex the first metatarsal head.

   Dr. Williams also uses a first ray cutout with a kinetic wedge modification to allow the first ray to plantarflex. Using a lateral wedge to dorsiflex the lateral column will often help to drive the forefoot toward the first MPJ as well, points out Dr. Williams.

   In contrast, Dr. Clough believes a first ray cutout or reverse Morton’s extension is contraindicated. He says they would destabilize the foot by reducing the support of the medial arm of the tripod of the foot. As Dr. Clough notes, the ground reactive force will push the first metatarsal upward. Additionally, he says an orthotic cutout or accommodations always limit rather than improve weightbearing under a structure so first ray cutouts or reverse Morton’s extensions tend to encourage pronation late in stance as the medial leg of the supportive tripod is weaker. If weightbearing improves at this time, Dr. Clough believes this is due to late stance pronation when the foot should be resupinating at this time.

   He uses the P4 Wedge (Cluffy Institute) in all of these cases and has found it to be very effective at reducing symptoms and enhancing first MPJ motion. In a subgroup of people with bunions, Dr. Clough has noted a reduction in the intermetatarsal angle as the patient achieves maximal dorsiflexion of the joint. Neil Horsley, DPM, FACFAS, will employ the P4 Wedge for sagittal plane deformities at the first MPJ.

   If the chief complaint of the bunion patient is a pain level greater than 8/10 and there is a change in daily activities, Dr. Horsley considers surgical options. If the bunion patient’s pain is less than 7/10 and there has been no change in the activities of daily living, Dr. Horsley considers the patient a candidate for orthoses if the history includes use of over-the-counter inserts and “better” shoes.

   For such patients, he applies a proper low Dye strapping with appropriate accommodative apertures or padding. On the next office visit, if patients report a difference in pain using the strapping, he schedules a complete biomechanical evaluation for orthoses.

   In conjunction with a complete lower extremity biomechanical examination, visual gait analysis, computerized force plate analysis and neutral cast impression, Dr. Horsley orders custom devices based upon the patient’s biomechanical findings. He also considers posting for forefoot or rearfoot deformities, and makes necessary adjustments for any limb length discrepancy. Depending upon the etiology of the bunion deformity, his additions to the orthoses may include a first metatarsal head or first ray cutout, or a metatarsal raise while making every attempt to keep the device low profile for the best shoe fit.

Q:

Are orthotics helpful for flexible hammertoe deformities?

A:

When Dr. Horsley decides to use an orthosis for flexible hammertoe deformities, he tests the flexibility of the digits by loading the forefoot. If the digits become rectus during loading of the forefoot and do not remain plantarflexed through the maneuver, he will include a metatarsal pad on the orthoses in order to achieve rectus digits during stance.

   If the digits are flexible and continue to plantarflex during the maneuver, Dr. Horsley incorporates a toe crest into the extension of the orthotic device.

   Dr. Clough believes orthotics can help with flexible hammertoe deformities. He says this condition is all about first ray insufficiency. If the first metatarsal does not bear enough weight, Dr. Clough notes that pressure transfers to the lesser metatarsals, causing swelling of the MPJs.

   The small intrinsic muscles, primarily the dorsal and plantar interossei and the lumbricals, are dysfunctional as they pull on a swollen joint, according to Dr. Clough. In addition, he says if the windlass mechanism is not working, the plantar fascial slips inserting into the toes are not functional and wind up destabilizing the toe. A hammertoe is the result. When one can reverse these factors, Dr. Clough commonly sees the flexible hammertoes relax as normal stability improves and eventually the hammertoes straighten to a degree that they are often asymptomatic. He advises that corrections to the orthotic involve casting with the first, fourth and fifth metatarsals plantarflexed, and cites the use of the P4 Wedge.

   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.

   Dr. Horsley has found orthoses to be very effective for Morton’s neuroma. As he notes, when one designs orthotics with an accommodation to pocket the neuroma, it will dorsiflex the metatarsal heads directly adjacent to the neuroma. This will indirectly relieve the force from the deep transverse metatarsal ligament, according to Dr. Horsley. He notes the importance of accurately placing the accommodation for the neuroma.

   However, Dr. Horsley notes varying degrees of neural involvement that will respond to appropriate conservative therapies. Low Dye strapping can provide improved function of the first ray and when there is an accompanying neuroma pad, he says this combination provides evidence that the orthoses will offer a similar level of pain relief along with improved function.

   Are the symptoms directly related to the malfunction or instability of the first ray in combination with an equinus deformity? Is this condition referred pain from a tarsal tunnel syndrome? Dr. Horsley suggests a thorough physical evaluation and appropriate testing can assist in differentiation. If Morton’s neuroma is the final diagnosis, in this instance, he suggests control of the first ray, accommodation for the neuroma and intervention for the equinus with stretching and appropriate heel lifts.

   Dr. Clough is in private practice in Great Falls, Mt. He is a Fellow of the American College of Foot and Ankle Surgeons, and a Diplomate of the American Board of Podiatric Surgery. He is the inventor of the Cluffy Wedge (P4 Wedge) and the President of the Cluffy Institute.

   Dr. Horsley is an Assistant Professor and the Department Chair of Podiatric Surgery and Applied Biomechanics at the Dr. William M. Scholl College of Podiatric Medicine at the Rosalind Franklin University of Medicine and Science in Chicago. He is a Fellow of the American College of Foot and Ankle Surgeons.

   Dr. Richie is an Adjunct Associate Professor in the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt University. He is a Past President of the American Academy of Podiatric Sports Medicine, and a Fellow of the American College of Foot and Ankle Surgeons. Dr. Richie is in private practice in Seal Beach, Calif. He also writes a monthly blog for Podiatry Today at www.podiatrytoday.com/blogs/doug-richie-jr-dpm/feed .

   Dr. Williams is in private practice in Merrillville, Ind. He is a Diplomate of the American Board of Podiatric Surgery. Dr. Williams is also a Past President and Fellow of the American Academy of Podiatric Sports Medicine.

   For further reading, see “Inside Insights On Common Orthotic Dilemmas” in the April 2010 issue of Podiatry Today, “Current And Emerging Insights On Hammertoe Correction” in the February 2012 issue or “Keys To Prescribing Orthotics For Sports, Neuromas And High Heels” in the October 2012 issue.

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