Morton neuroma

Morton's neuromas mainly occur in splayfeet and become symptomatic when wearing (narrow) shoes. A foot does not have to be extremely wide, the decisive factor is the relationship between the space required for the nerve and the space between the metatarsals. In principle, Morton's neuromas can occur between all toes. However, they occur most frequently between toes 3 and 4, followed by those between toes 2 and 3, often simultaneously. They are much less common between the fourth and fifth toes and practically never between the first and second toes. Pregnancy is a special case: the rapidly increasing weight of the mother and the loose connective tissue associated with pregnancy can cause the feet to flatten. This can also lead to typical Morton's neuroma symptoms. However, these can be treated with insoles that support the transverse arch and thus create space. After the birth, all conditions normalise again and in most cases the symptoms disappear - no further treatment is necessary.

Other causes

In addition to obvious sources of pain associated with a deformity or infection, such as hammer toes, corns or ingrown toenails, there are also pain symptoms on the forefoot that can simulate Morton's neuroma, especially as there are usually no visible external manifestations. Also frequently associated with splayfeet is forefoot pain, which often appears similar to Morton's neuroma, but has a completely different origin: metatarsalgia, which can occur either isolated on individual toes or under the entire transverse arch. Differentiation from Morton's neuroma is not always easy, but is practically always successful if the history and symptoms are carefully recorded and the affected foot is examined.

Metatarsalgia

If the metatarsal bones drift apart, the ligaments are overstretched and can even tear. As a result, the metatarsal bones can also shift in height in relation to each other, which can cause individual metatarsal heads to drop. These are then constantly overloaded, especially when walking, and begin to hurt more and more. Although the pain often occurs in practically the same place as with Morton's neuroma, there are fundamental differences: the pain occurs mainly when walking barefoot, because the pressure then acts unsprung on the corresponding area. The pain is much less pronounced in shoes. The pain does not radiate into the toes, but is localised below the affected metatarsal head. Inspection of the sole of the foot usually reveals a more or less thick callus in the area of the painful spot, which forms as a kind of defence reaction of the body to increased pressure. Often the neighbouring metatarsophalangeal joint is also inflamed, so that movement is also painful; this is not the case with Morton's neuroma.

Initially, the swelling and therefore the pain disappear again, and long periods without pain can occur. Cortisone infiltration can be used during this phase to help the swelling to subside and partially prevent recurrence, especially in the early stages of an acute flare-up. However, it is not possible to predict how long the effect will last in each case. The nerve is damaged by the constant irritation and repeated inflammation in the same place, and scars form. These do not disappear even with cortisone injections. Therefore, in these cases, the only effective treatment to date is surgical removal of the neuroma.

The operation

The nerve between the toes is exposed under regional or general anaesthetic. Depending on the space available, this can reach impressive sizes. As a new neuroma is always created when a nerve is injured, it is important to cut it as far back as possible so that this "new" (stump) neuroma cannot become trapped again. Postoperative treatment simply consists of giving the operated foot a rest period of around two weeks. During this time, it is advisable to wear a relief shoe, after which the bandage can be removed and the foot can be put under increasing weight according to symptoms. Complications are rare with this minor procedure. A hammer toe may form, which must then also be treated. A new neuroma can also form, which can be surgically corrected if it is disturbing. Nerve damage can also occur, but this is not due to the operation but to the previous condition.