Definition
Metatarsalgia literally means pain felt under the lesser (second to fifth) metatarsal heads, that is the ball of the foot. It describes a symptom, not a specific disease. The most common causes of metatarsalgia are mechanical capsulitis or transfer pain, but it can be due to a stress fracture or inlammatory joint disease such as rheumatoid athritis.
Symptoms
The pain is felt under one or more of the lesser metatarsal heads and is usually worse with weight bearing, barefoot or wearing high heels. It is often more comfortable in padded shoes such as trainers. Sometimes it can feel as though there is a stone in your shoe when there is none. There may be hard skin (callus) under the affected area and there may be associated hammer or claw toes.
Causes
A number of conditions can cause this problem, but the mostly they result in too much load being put through one or more of the metatarsal heads producing local inflammation, pain and calluses. If the problem is present for a long time the ligaments of the metatarsophalangeal (MTP) joints at the base of the toes may fail leading to deformities of the toes. In cases of extreme overload a stress fracture of the metatarsal may result.
Factors which commonly contribute to this are metatsals that are too long or out of alignment with one another, excessive tightness of the calf muscles or achilles tendon and poor function of the great toe due a bunion, arthritis or shortening of the first metatarsal in surgery.
Diagnosis
It is usually possible to make the diagnosis from your symptoms and examining your foot. Standing x-rays to assess the alignment of the bones may be helpful and your doctor may request an MRI scan or ultrasound for additional information and to exclude other problems such as Morton neuroma.
Medical treatment
Many cases of metatarsalgia respond to treatment with insoles (orthotics) and exercises to stretch the calf muscles and achilles tendon.
Injections of steroid and local anaesthtic under x-ray or ultrasound guidence can be used to bring rapid relief and also confirm the diagnosis. Often these are combined with the use of iorthotics and calf stretches.
Chiropody or podiatry to scrape away the hard, callused skin can bring temporary relief, but the callus will return unless the underlying cause is dealt with.
Surgical treatment
If medical tratment fails, surgery may be considered. This usually aims to correct the cause of the problem, but should be planned very carefully taking the whole foot and leg into account.
Some common operations include:
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Lengthening of the Achilles tendon, or calf muscles;
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Correction of a great toe problem eg bunion or arthritis
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Transfer of a flexor tendon to the top of a toe;
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Suture of the stabilizing plantar structures;
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Osteotomy: an operation to correct poor alignment of the proiblem metatarsal or metstarsals but cutting and shortening or lifteing them up. A screw is inserted to hold each bone or in position while it heals.
Post-operative care
Operations for metatarsalgia are usually performed as day case procedures, or with an overnight stay.
The recovery period depends on which operation has been performed, but in most cases it if possible to bear weight on the heal with a special heal-bearing shoe. In general, however, the foot will need to be kept up a great deal in the recovery phase to control the swelling.