American College of Foot and Ankle Surgeons Issues Forefoot Disorders Practice Guideline

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March 4, 2009 — The American College of Foot and Ankle Surgeons (ACFAS) has issued new treatment guidelines on management of common forefoot conditions, including broken bones and other traumatic conditions, bunionettes (bunions of the smallest toes), nerve compressions, toe deformities, and pain in the ball of the foot and the 4 small toes.

The new recommendations, developed by the Clinical Practice Guideline Forefoot Disorders Panel of ACFAS, are published in the March/April issue of the Journal of Foot & Ankle Surgery. A separate, previously published ACFAS guideline describes management of similar conditions affecting the great toe.

"These new guidelines help your foot and ankle surgeon, or even your family doctor or another physician, figure out the best way to diagnose and treat problems in your forefoot," James L. Thomas, DPM, FACFAS, guidelines coauthor and a past president of ACFAS, said in a news release.

An expert panel convened by ACFAS reviewed hundreds of pertinent studies and used them as an evidence base to formulate the guidelines. The 5 main clinical practice areas addressed by the guidelines are as follows:

• Digital deformities. These include hammertoe and crossover toe. In addition to being painful in their own right, they may also contribute to additional painful conditions such as corns and calluses.

• Central metatarsalgia (pain in the ball of the foot). The guidelines discuss differential diagnosis of the range of conditions that can cause pain in the forefoot. These include second metatarsophalangeal joint (MPJ) instability, avascular necrosis of the metatarsal head, tumor, foreign body, or infection.

• Morton's neuroma. This frequently encountered form of nerve compression is often described by patients as a "lump" on the bottom of the foot or as the sensation of walking on a rolled-up or wrinkled sock.

• Bunionettes. Although most bunions (hallux valgus) affect the big toe, a similar joint deformity may affect the fifth toe. The bunionette is also known as a tailor's bunion.

• Traumatic injury to the forefoot. Examples include bone fracture, lawnmower injuries, or puncture wound from stepping on a rusty nail.

Deformities of the 4 lesser toes include hammertoe, clawtoe, and mallet toe. Hammertoe consists of an extension contracture at the MPJ, flexion contracture at the proximal interphalangeal joint (PIPJ), and hyperextension at the distal interphalangeal joint (DIPJ), whereas clawtoe consists of an extension contracture at the MPJ and a flexion contracture at both the PIPJ and DIPJ. Mallet toe refers to an isolated flexion contracture at the DIPJ.

Other distinct deformities involve the second toe and fifth toe. A "crossover" second toe deformity consists of an extension contracture combined with medial deviation (subluxation) at the level of the second MPJ. Deformities of the fifth toe, which may be congenital, may include deformity in multiple planes (adductovarus deformity) or significant overlap of the fifth toe over the fourth toe. Other congenital deformities include polydactyly, syndactyly, clinodactyly, and macrodactyly.

For symptomatic digital deformity, nonsurgical treatment is often the first treatment choice, with use of padding techniques, orthotics, taping, shoe insole modifications, or footwear changes. Debridement of associated hyperkeratotic lesions may help reduce symptoms. Corticosteroid injection may be helpful for local inflammation or bursitis.

Depending on the degree and flexibility of toe deformity, along with any associated pathologic condition, surgery may be needed. Options include tenotomy or tendon lengthening at the level of the MPJ, PIPJ, or DIPJ, alone or combined with capsular and/or ligamentous release; partial or complete phalangeal head resection and/or flexor tendon transfer; or a combination of both osseous and soft tissue procedures. Exostectomy may help correct hyperkeratotic lesions along the medial or lateral aspects of the toe, especially in conditions involving the fifth toe, partial amputation of the toe may be indicated in some cases.

Differential diagnosis of conditions underlying central metatarsalgia includes capsulitis, which may be mechanical, arthritic, or secondary to second MPJ instability. Metatarsal abnormalities causing forefoot pain include dorsiflexed, elongated, plantarflexed, shortened, or hypertrophic plantar condyles, and first ray hypermobility. Other causes of metatarsalgia are metatarsal stress fracture, second MPJ instability, avascular necrosis, tumor, foreign body, or infection.

Depending on the cause of forefoot pan, conservative and/or specific nonsurgical treatment may be helpful. Surgery may be needed for those patients who are not candidates for nonsurgical treatment or who have not responded to nonsurgical care.

Morton's intermetatarsal neuroma is a compression neuropathy of the common digital nerve, most often, but not always or exclusively, occurring in the third intermetatarsal space. Diagnostic workup may include plain radiography, ultrasound, and magnetic resonance imaging to rule out other possible causes of symptoms, but the diagnosis is primarily clinical.

Nonsurgical care of Morton's neuroma aims to relieve pressure on the nerve. Measures include wearing shoes with a wide toe box, avoiding high-heel shoes, and using metatarsal pads. Other nonsurgical options include injection therapy with corticosteroids, dilute alcohol or vitamin B₁₂, and local anesthetic block. When surgery is necessary, the usual approach is excision of the affected portion of the nerve. In recent years, endoscopic and minimally invasive techniques have been used to decompress the intermetatarsal nerve.

Examination of the patient with tailor's bunion shows a lateral or plantar-lateral prominence of the fifth metatarsal head, sometimes with tenderness on palpation of the lateral and/or plantar-lateral fifth metatarsal head and/or adduction or adductovarus deformity of the fifth toe. The diagnosis may be confirmed by standard weightbearing foot radiographs.

Measures that reduce pressure and irritation over the fifth metatarsal head include proper footwear, padding, and injections, as well as anti-inflammatory medication. Surgical treatment, which aims to decrease the prominence of the fifth metatarsal laterally, is indicated for patients who are not candidates for nonsurgical care or for those in whom nonsurgical care has failed.

Forefoot trauma may range from simple, nondisplaced fractures to limb-threatening injuries, and most injuries also involve the soft tissue. Radiographic evaluation is usually indicated. Surgical decompression is indicated if compartment syndrome is suspected from clinical findings and/or compartment pressures of the foot above 30 mm Hg to 35 mm Hg.

"The attention and care given to the soft tissue envelope is an integral part of the evaluation and management of any forefoot injury," the study authors write. "High-energy and crush injuries should raise the level of suspicion for compartment syndrome. Clinical signs include digital weakness or paralysis, gross edema, tense compartments, parasthesias, mottled skin, and unrelieved pain."

J Foot Ankle Surg. 2009;48:230-272.

Medscape Medical News © 2009  Medscape

Cite this: Laurie Barclay. American College of Foot and Ankle Surgeons Issues Forefoot Disorders Practice Guideline - Medscape - Mar 04, 2009.