Metatarsalgia is the name given to pain in the front part of your foot under the heads of your metatarsal bones (the ball of your foot). Metatarsalgia can be caused by a number of different conditions affecting the foot. You may need some investigations to find the cause of your metatarsalgia. Treatment will depend on the underlying cause. Simple measures such as changes to your footwear, rest and losing weight can sometimes help.

Some anatomy of your foot

Your feet have to bear the weight of your whole body. They enable you to walk, jump, land and run. There are many bones in your foot. They can briefly be divided into the tarsal bones, the metatarsal bones and the phalanges. The tarsal bones are the larger bones that form the back section of your foot, with the calcaneum being the largest. There are five metatarsal bones and these are given names from the first to the fifth. The first metatarsal bone is the largest and is the bone that joins to your big toe. Each toe has three phalanges, except the big toe which only has two. This means that there are three joints in the toes (two joints in the big toe).

There are also many muscles, tendons and ligaments within your foot. The bones, ligaments and tendons within your foot form the foot arches. These arches are called the longitudinal and transverse arches. It is your foot arches that allow your foot to hold up the weight of your body. Nerves also provide sensation to the skin of your foot.

What is metatarsalgia?

Metatarsalgia is a general name given to pain in the front part of your foot under the heads of your metatarsal bones. This is the area on the sole of your foot, just before the toes. It is sometimes called the ball of your foot. Metatarsalgia can be caused by a number of different conditions affecting the foot. It is really a symptom of other problems rather than a specific disease itself.

What causes metatarsalgia?

Metatarsalgia can be caused by a number of different conditions. Common causes can include:

• • Overuse. For example, in runners and athletes, which can cause some mild inflammation in the metatarsal heads and nearby joints.

  • Wearing high-heeled shoes. This can put extra stess on the metatarsal heads.

  • Being overweight. This can put extra stress on your feet in general.

  • Morton's neuroma. This is sometimes called Morton's metatarsalgia. It is a condition that affects one of the nerves that run between the metatarsal bones in the foot (the plantar digital nerves). The exact cause is not certain. Symptoms include pain, burning, numbness and tingling between two of the toes of the foot. See separate leaflet called 'Morton's Neuroma' for more detail.

  • Pes cavus. This is also known as claw foot. In pes cavus, your foot has a very high arch which does not flatten when you put weight on your foot. It happens because of an imbalance in the muscles of the foot. It can run in families. Sometimes pes cavus can happen out of the blue but most people with pes cavus also have a neurological problem such as cerebral palsy, spina bifida, muscular dystrophy or polio. Pes cavus can mean that extra stress is placed on the ball of your foot, which can lead to metatarsalgia.

  • Hammer toe or claw toe deformity. With a claw toe you have an abnormal position of all three of the joints in the toe. The joint with the metatarsal bone is bent upwards, the middle joint in the toe is bent downwards and the end joint in the toe may also be bent downwards. The toe resembles a claw. With a hammer toe, your toe is permanently bent at its middle joint so that it looks like a hammer. There are a number of conditions that can cause these toe deformities. These can include poorly fitted shoes, injury to the toes, bunions and rheumatoid arthritis. Hammer and claw toe can also occur in someone with pes cavus. They can also run in families. These toe deformities can mean that extra stress is placed on the ball of your foot, which can lead to metatarsalgia.

  • Bunion (Hallux valgus). A bunion is a deformity of the base joint of the big toe. Your big toe is angled towards your second toe. This causes a bump on the side at the base of the big toe. There is often thickening of the skin and tissues next to the affected joint. The thickened skin and tissues may become inflamed, swollen and painful. Because of the bunion, extra stress is put on the ball of the foot and this can lead to metatarsalgia. See separate leaflet called 'Bunions (Hallux Valgus)' for more detail.

  • Previous surgery to your foot. For example, previous surgery for bunions.

  • Stress fracture of a metatarsal. A stress fracture is a type of incomplete fracture in a bone. Stress fractures tend to occur as a result of overuse and are known as 'overuse injuries'. A metatarsal stress fracture is a stress fracture in one of the metatarsal bones in the foot. See separate leaflet called 'Metatarsal Fractures' for more detail, including metatarsal stress fractures.

  • Arthritis or gout. This can cause inflammation of the joints in the ball of the foot or of the big toe and can be a cause of metatarsalgia. See separate leaflet called 'Gout' and those on arthritis for more detail.

  • Diabetes. This can cause damage to the nerves in your feet and can be a cause of metatarsalgia. Please refer to the separate leaflets on diabetes for more details.

What are the symptoms of metatarsalgia?

Metatarsalgia causes pain in the ball of your foot that can be made worse by walking or running. Some people describe the pain as 'walking on pebbles', others describe more of a general aching pain. The pain can occur in one or both feet. In some people the pain is felt under one or two metatarsal heads, in others it is felt under all of them. Morton's neuroma has other specific symptoms and is explained further in the separate leaflet.

Do I need any investigations?

The aim of investigations for metatarsalgia is to try to find the cause of the pain. Your doctor may be able to find the cause of your metatarsalgia just by listening to you, asking you questions and examining your foot. However, they may also suggest one or more of the following investigations:

• • Blood tests. These can check for diabetes, arthritis and gout.

  • X-ray of the foot. This can show a problem with the bones or joints in your foot.

  • Bone scan of the foot. Your doctor may suggest this if they suspect a stress fracture of one of your metatarsal bones (see below).

  • Other tests. Occasionally more detailed tests such as an MRI scan of your foot are needed.

What is the treatment for metatarsalgia?

Simple measures can help to relieve the symptoms of metatarsalgia. These include:

• • Resting with your feet elevated where possible.

  • Losing weight if you are overweight.

  • Wearing shoes that are well fitted, low-heeled and with a wide toe area.

  • Metatarsal pads and orthotic inserts for your shoes may help to relieve pain in your foot by reducing the pressure placed on the heads of your metatarsal bones.

  • Physiotherapy may also be helpful.

  • Simple painkillers such as paracetamol and non-steroidal anti-inflammatory drugs may help to relieve pain.

Other treatment will depend on the underlying cause of your metatarsalgia. For example, if diabetes is the cause, you may need better control of your diabetes. If gout or arthritis are the cause, you may need treatment for these conditions. Surgery is sometimes needed to treat metatarsalgia if other treatments have failed. This will depend on the underlying cause, for example, straightening of hammer or claw toes or surgery for Morton's neuroma.

For specific treatments for Morton's neuroma and Hallux valgus, please refer to the separate leaflets.

Can metatarsalgia be prevented?

Some of the causes of metatarsalgia cannot be prevented, for example metatarsalgia due to pes cavus. However, there are some things that may help to prevent some other causes of metatarsalgia. These include:

• • Ensuring that shoes are well fitted, low-heeled and have a wide toe area. This may help to prevent some causes of metatarsalgia, including Morton's neuroma.

  • Ensuring that you wear good, properly fitted footwear when running or doing sports with high impact on the feet.

  • Losing weight if you are overweight.

  • If you have diabetes, good control of your diabetes may reduce your chance of developing foot problems.

Morton's Neuroma

Some anatomy of the foot

There are many bones in the foot. They can briefly be divided into the tarsal bones, the metatarsal bones and the phalanges. The tarsal bones are the larger bones that form the back section of the foot, with the calcaneum being the largest. There are five metatarsal bones and these are given names from the first to the fifth. The first metatarsal bone is the largest and is the bone that joins to the big toe. Each toe has three phalanges, except the big toe which only has two.

There are many nerves, muscles and ligaments within the foot. Of note, the common plantar digital nerves run between the metatarsal bones in the foot. These have branches that supply sensation to the skin of the toes.

What is Morton's neuroma?

Morton's neuroma is named after Dr Morton who first described this condition in 1876. It is sometimes called Morton's metatarsalgia or interdigital neuroma.

It is a condition that affects one of the common plantar digital nerves that run between the metatarsal bones in the foot. It most commonly affects the nerve between the third and fourth metatarsal bones, causing pain and numbness in the third and forth toes. It can also affect the nerve between the second and third metatarsal bones, causing symptoms in the second and third toes.

Morton's neuroma rarely affects the nerve between the first and second, or between the fourth and fifth, metatarsal bones. It tends to affect only one foot. It is rare to get two neuromas at the same time in the same foot.

What causes Morton's neuroma?

Some say that this condition should not be called Morton's neuroma as, in fact, it is not actually a neuroma. A neuroma is a benign (non-cancerous) tumour that grows from the fibrous coverings of a nerve. There is no tumour formation in Morton's neuroma.

The exact cause of Morton's neuroma is not known. However, it is thought to develop as a result of chronic (longstanding) stress and irritation of a plantar digital nerve. There are a number of things that are thought to contribute to this. Some thickening (fibrosis) and swelling may then develop around a part of the nerve. This can look like a neuroma and can lead to compression of the nerve.

The anatomy of the bones of the foot is also thought to contribute to the development of Morton's neuroma. For example, the space between the metatarsals (the long bones of the foot) is narrower between the second and third, and between the third and fourth metatarsals. This means that the nerves that run between these metatarsals are more likely to be compressed and irritated. Wearing narrow shoes can make this compression worse.

Sometimes, other problems can contribute to the compression of the nerve. These include the growth of a fatty lump (called a lipoma) and also the formation of a bursa (a fluid-filled sac that can form around a joint). Also, inflammation in the joints in the foot next to one of the digital nerves can sometimes cause irritation of the nerve and lead to the symptoms of Morton's neuroma.

Who gets Morton's neuroma?

About three-quarters of people with Morton's neuroma are women. It commonly affects people between the ages of 40 and 50 but can affect someone of any age.

Poorly fitting or constricting shoes can contribute to Morton's neuroma. It is more likely in women who wear high-heeled shoes for a number of years or men who are required to wear constrictive shoe gear. It may also be more common in ballet dancers.

What are the symptoms of Morton's neuroma?

People with Morton's neuroma usually complain of pain that can start in the ball of the foot and shoot into the affected toes. However, some people just have toe pain. There may also be burning and tingling of the toes. The symptoms are usually felt up the sides of the space between two toes. For example, if the nerve between the third and fourth metatarsal bones is affected, the symptoms will usually be felt up the right hand side of the forth toe and up the left hand side of the third toe. Some people describe the pain that they feel as being like walking on a stone or a marble.

Symptoms can be worse if you wear high-heeled shoes. The pain is relieved by taking your shoe off, resting your foot and massaging the area. You may also experience some numbness between the affected toes. Your affected toes may also appear to be spread apart, which doctors refer to as the 'V sign'.

The symptoms can vary and may come and go over a number of years. For example, some people may experience two attacks of pain in a week and then nothing for a year. Others may have regular and persistent pain.

How is Morton's neuroma diagnosed?

Morton's neuroma is usually diagnosed by your doctor listening to your symptoms and examining your foot. Sometimes your doctor can feel the 'neuroma', or an area of thickening in your foot, which may be tender.

Sometimes, your doctor may suggest an ultrasound or MRI scan to confirm the diagnosis but this is not always necessary. Some doctors inject a local anaesthetic into the area where you are experiencing pain. If this causes temporary relief of pain, burning and tingling, it can sometimes help to confirm the diagnosis and show the doctor where the problem is.

What is the treatment for Morton's neuroma?

Non-surgical treatments

Simple treatments may be all that are needed for some people with a Morton's neuroma. They include the following:

• • Footwear adjustments including avoidance of high-heeled and narrow shoes and having special orthotic pads and devices fitted into your shoes.

  • Calf-stretching exercises may also be taught to help relieve the pressure on your foot.

  • Steroid or local anaesthetic injections (or a combination of both) into the affected area of the foot may be needed if the simple footwear changes do not fully relieve symptoms. However, the footwear modification measures should still be continued.

  • Sclerosant injections involve the injection of alcohol and local anaesthetic into the affected nerve under the guidance of an ultrasound scan. Some studies have shown this to be as effective as surgery. However, this may not be widely available in the UK yet.

Surgical treatments

If these non-surgical measures do not work, surgery is sometimes needed. Surgery normally involves a small incision (cut) being made on either the top, or the sole, of the foot between the affected toes. Usually, the surgeon will then either create more space around the affected nerve (known as nerve decompression) or will resect (cut out) the affected nerve. If the nerve is resected (cut out), there will be some permanent numbness of the skin between the affected toes. This does not usually cause any problems.

You will usually have to wear a special shoe for a short time after surgery until the wound has healed and normal footwear can be used again.

Surgery is usually successful. However, as with any surgical operation, there is a risk of complications. For example, after this operation a small number of people can develop a wound infection. Another complication may be long-term thickening, or callus formation, of the skin on the sole of the foot (known as plantar keratosis). This may require chiropody.

What is the outlook (prognosis) for Morton's neuroma?

About a quarter of people do not require any surgery for Morton's neuroma and their symptoms can be controlled with footwear modification and steroid/local anaesthetic injections. Of those who choose to have surgery, about three quarters have good results with relief of their symptoms.

Recurrent or persisting symptoms can occur after surgery. Sometimes, decompression of the nerve may have been incomplete or the nerve may just remain 'irritable'. In those who have had resection of the nerve (neurectomy), a recurrent or 'stump' neuroma may develop in any nerve tissue that was left behind. This can sometimes be more painful than the original condition.

Can Morton's neuroma be prevented?

Ensuring that shoes are well fitted, low-heeled and with a wide toe area may help to prevent Morton's neuroma.

References

• • Schaller TM; Morton Neuroma. eMedicine. Last Updated May 2008.

  • Gonzalez P, Bowman II RG; Morton Neuroma. eMedicine. Last Updated June 2006.

  • Prior T; Common Foot Disorders. Arthritis Research Campaign. Reports on the Rheumatic Diseases Series 5: Hands On. October 2006: No 10

  • Hughes RJ, Ali K, Jones H, et al; Treatment of Morton's neuroma with alcohol injection under sonographic guidance: follow-up of 101 cases. AJR Am J Roentgenol. 2007 Jun;188(6):1535-9. [abstract]

  • Wheeless' Textbook of Orthopaedics; Morton's Neuroma: Interdigital Perineural Fibrosis

References

• • Wheeless' Textbook of Orthopaedics; Metatarsalgia

  • Durham BA, Kaplan D; Metatarsalgia. eMedicine. Last Updated Nov 1, 2007.