Practice Essentials
Metatarsalgia is a common overuse injury described as pain in the forefoot that is associated with increased stress over the metatarsal head region. [1] Metatarsalgia is often referred to as a symptom, rather than as a specific disease. Common causes of metatarsalgia include interdigital neuroma (also known as Morton neuroma), metatarsophalangeal synovitis, avascular necrosis, sesamoiditis, and inflammatory arthritis; however, these causes are often diagnosed separately. (See also the Medscape Reference articles Physical Medicine and Rehabilitation for Morton Neuroma, Surgery for Morton Neuroma, and Avascular Necrosis.)
Signs and symptoms
The primary symptom of metatarsalgia is pain at one or more of the metatarsal heads. Diffuse forefoot pain and midfoot pain are often present in athletes with combinations of high-impact inflammatory conditions.
See Presentation for more detail.
Diagnosis
Laboratory studies
Measurement of uric acid levels, the erythrocyte sedimentation rate, and C-reactive protein level may be helpful in excluding gouty arthritis and other rheumatologic conditions in subtle cases.
Imaging studies
A radiographic foot survey is indicated as an initial imaging test and may be helpful in excluding other etiologies of forefoot pain.
See Workup for more detail.
Management
The initial treatment includes regular icing and application of a pressure bandage. Semi-rigid orthoses worn in supportive shoes have been shown to be effective treatment for metatarsalgia.
Nonsteroidal anti-inflammatory drugs, such as ibuprofen, are useful for the symptomatic relief of the pain of metatarsalgia; however, these agents rarely provide a long-term solution.
See Treatment and Medication for more detail.
Etiology
The foot is frequently injured during sports activities that typically involve repetitive high-pressure loading on the forefoot. [2, 3]
As in many other overuse syndromes, the condition may be the result of an alteration in normal biomechanics that has caused an abnormal weight distribution among the metatarsal heads.
Persistent stress can lead to chronic irritation and inflammation of the periosteum and adjacent tissues.
The following factors can contribute to excessive localized pressure over the forefoot:
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High level of activity
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Prominent metatarsal heads
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Tight toe extensors
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Weak toe flexors
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Hammertoe deformity (See also the Medscape Reference article Hammertoe Deformity.)
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Hypermobile first ray
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Tight Achilles tendon
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Excessive pronation
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Equinus deformity (See also the Medscape Reference articles Clubfoot and Clubfoot Imaging.)
Some anatomic conditions may predispose individuals to forefoot problems, such as the following.
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A high arch with stress to the forefoot, as seen with pes cavus foot type, often causes pain in the metatarsal region. (See also the Medscape Reference article Pes Cavus.)
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Individuals with a Morton toe have a short first metatarsal bone. The normal forefoot balance is disturbed, which results in abnormal subtalar joint pronation. This pronation results in the shift of an increased amount of weight to the second metatarsal.
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Iatrogenic changes from surgeries such as osteotomies can change the anatomy of the foot, resulting in unequal force distribution and metatarsalgia. [4]
Hammertoe deformity causes metatarsalgia because the top of the shoe pushes the toe down, depressing the metatarsal head. The toes also share some weight bearing. Hallux valgus may create abnormal foot biomechanics. (See also the Medscape Reference article Hallux Valgus.) These musculoskeletal problems may contribute to forefoot trauma in athletes. Calluses are formed as a skin reaction to prolonged pressure, with the skin becoming thickened and hyperkeratotic.
Epidemiology
United States statistics
Athletes who participate in high-impact sports that involve the lower extremities commonly present with forefoot injuries, including metatarsalgia. [2, 3]
Athletes, especially those who are middle-aged women, may experience a gradual onset of pain that is associated with improper footwear, a change in running terrain, or a rapid increase in training intensity. [5]
Functional Anatomy
Body weight is transferred to the foot by gravity. This transfer of force is increased to the forefoot during the mid-stance and push-off phases of walking and running. [3, 6] In the forefoot region, the first and second metatarsal heads receive the greatest amount of this energy transfer. Peak vertical forces reach 275% of body weight during running, and a runner may absorb 110 tons per foot while running 1 mile. [3] Pressure studies have shown that runners spend most of the time weighted over the forefoot while running.
Sport-Specific Biomechanics
Athletes who take part in high-impact sports that involve running or jumping are at high risk of forefoot injuries. [2, 3] Although track-and-field runners are exposed to the highest level of traumatic forces to the forefoot, many other athletes, including tennis, football, baseball, and soccer players, often present with forefoot injuries.
Prognosis
Generally, with the treatment described in the Treatment section, the prognosis for metatarsalgia is good.
Complications
Freiberg avascular necrosis can occur from a congenital, traumatic, or vascular etiology. An athletic injury is unlikely to be the sole cause of avascular necrosis; however, mechanical stress to the forefoot from high-impact sports may precipitate a previous predisposition to this condition. Progression of attritional ligamentous injury may result in a crossover deformity, joint instability, and toe dislocation. Loss of flexibility can lead to chronic stiffness and loss in ROM. (See also the Medscape Reference article Freiberg Infraction.)
Patient Education
Athletes who suddenly and dramatically increase training activity are at risk of forefoot injury. Whether the increase is in time or intensity, athletes should increase their levels of activity gradually, and they should never exercise through the pain.
Long-distance runners, women, and athletes who diet to qualify for certain weight divisions may experience bone loss from nutritional deficiency, predisposing them to foot injury. A well-rounded diet is necessary for healthy tissues.
The selection of footwear and orthotic devices is an important part of foot care and injury prevention. Warm-up and passive stretching increase vascular supply and flexibility.
