Overview
Some sources claim that entrapment of the plantar nerve because of compression between the metatarsal heads, as originally proposed by Morton, is highly unlikely, because the plantar nerve is on the plantar side of the transverse metatarsal ligament and thus does not come in contact with the metatarsal heads. It is more likely that the transverse metatarsal ligament is the cause of the entrapment. Despite the name, the condition was first correctly described by a chiropodist named Durlacher, and although it is labeled a "neuroma", many sources do not consider it a true tumor, but rather a perineural fibroma (fibrous tissue formation around nerve tissue).
Causes
There are many reasons to develop a neuroma. Improper shoe gear is probably the most likely cause. Repetitive activity and excessive pressure on the ball of the foot are common. Heredity and genetic factors may also be involved. In many cases the structure of the foot may predispose the condition. Associated conditions that may cause neuroma include: bunion, hammer toes, ligament laxity, and/or a tight calf muscle. Some patients may have thinning of the fat pad on the ball of the foot, which may result in increased pressure of the nerves. Tight pointy shoes (and high heels) without padding may induce pain in the ball of the foot. Neuroma may occur suddenly, or develop over time.
Symptoms
Morton's neuroma can cause a very painful burning or sharp pain in your foot that feels worse when you walk. It may feel like a small lump inside the ball of your foot. It is usually between the third and fourth toes, but it can also be between other toes.
Diagnosis
Plain x-rays of the foot may demonstrate that one or more of the metatarsals are long (Figure #5). Not uncommonly, the second and/or third metatarsal may be long relative to the third or fourth. This can create a situation where excessive load is occurring in and around the vicinity of the interdigital nerve.
Non Surgical Treatment
The first line of treatment is to try modifying footwear. Often simply wearing broader fitting shoes can reduce pressure on the neuroma and so reduce pain. Orthotic inserts can also help as they can again help reduce pressure on certain parts of the foot. Padding and taping the toe area is another option. In some cases a steroid injection into the foot may be suggested. This can be done as a day case without the need for anaesthesia and helps reduce inflation of the nerve. It can halt the pain in round 70 % of cases. Sometimes a combination of alcohol and local anaesthesia may be injected as this helps reduce pain.
Surgical Treatment
The ultimate success of a Morton?s neuroma treated surgically can be variable. In cases where the underlying problem is only an irritated nerve (a true Morton?s neuroma), then surgery will probably be curative (although it may take a few months for the foot to fully heal). But in many cases, forefoot pain is more complex. There may be an irritated nerve or two causing pain, but the real problem is often excessive loading of the lesser metatarsals. The generic term for this condition is metatarsalgia. When considering surgery, identifying and addressing these problems may lead to a better end result.
Some sources claim that entrapment of the plantar nerve because of compression between the metatarsal heads, as originally proposed by Morton, is highly unlikely, because the plantar nerve is on the plantar side of the transverse metatarsal ligament and thus does not come in contact with the metatarsal heads. It is more likely that the transverse metatarsal ligament is the cause of the entrapment. Despite the name, the condition was first correctly described by a chiropodist named Durlacher, and although it is labeled a "neuroma", many sources do not consider it a true tumor, but rather a perineural fibroma (fibrous tissue formation around nerve tissue).Causes
There are many reasons to develop a neuroma. Improper shoe gear is probably the most likely cause. Repetitive activity and excessive pressure on the ball of the foot are common. Heredity and genetic factors may also be involved. In many cases the structure of the foot may predispose the condition. Associated conditions that may cause neuroma include: bunion, hammer toes, ligament laxity, and/or a tight calf muscle. Some patients may have thinning of the fat pad on the ball of the foot, which may result in increased pressure of the nerves. Tight pointy shoes (and high heels) without padding may induce pain in the ball of the foot. Neuroma may occur suddenly, or develop over time.
Symptoms
Morton's neuroma can cause a very painful burning or sharp pain in your foot that feels worse when you walk. It may feel like a small lump inside the ball of your foot. It is usually between the third and fourth toes, but it can also be between other toes.
Diagnosis
Plain x-rays of the foot may demonstrate that one or more of the metatarsals are long (Figure #5). Not uncommonly, the second and/or third metatarsal may be long relative to the third or fourth. This can create a situation where excessive load is occurring in and around the vicinity of the interdigital nerve.
Non Surgical Treatment
The first line of treatment is to try modifying footwear. Often simply wearing broader fitting shoes can reduce pressure on the neuroma and so reduce pain. Orthotic inserts can also help as they can again help reduce pressure on certain parts of the foot. Padding and taping the toe area is another option. In some cases a steroid injection into the foot may be suggested. This can be done as a day case without the need for anaesthesia and helps reduce inflation of the nerve. It can halt the pain in round 70 % of cases. Sometimes a combination of alcohol and local anaesthesia may be injected as this helps reduce pain.
Surgical Treatment
The ultimate success of a Morton?s neuroma treated surgically can be variable. In cases where the underlying problem is only an irritated nerve (a true Morton?s neuroma), then surgery will probably be curative (although it may take a few months for the foot to fully heal). But in many cases, forefoot pain is more complex. There may be an irritated nerve or two causing pain, but the real problem is often excessive loading of the lesser metatarsals. The generic term for this condition is metatarsalgia. When considering surgery, identifying and addressing these problems may lead to a better end result.
