Overview
Morton's neuroma is an enlarged nerve that usually occurs in the third interspace, which is between the third and fourth toes. To understand Morton's neuroma further, it may be helpful to look at the anatomy of the foot. Problems often develop in the third interspace because part of the lateral plantar nerve combines with part of the medial plantar nerve here. When the two nerves combine, they are typically larger in diameter than those going to the other toes. Also, the nerve lies in subcutaneous tissue, just above the fat pad of the foot, close to an artery and vein. Above the nerve is a structure called the deep transverse metatarsal ligament. This ligament is very strong, holds the metatarsal bones together, and creates the ceiling of the nerve compartment. With each step, the ground pushes up on the enlarged nerve and the deep transverse metatarsal ligament pushes down. This causes compression in a confined space.
Causes
Poorly fitted footwear can be a cause. Shoes that have a tight and narrow toe box can cause the never to become entrapped causing the pain. High heeled shoes abnormally place the metatarsals under extreme pressure which can cause Morton?s Neuroma. In cases of abnormal pronation, there can be significant motion between the 3rd and 4th metatarsals which can cause an irritation to the nerve that runs between them. This inflammation causes the pain.
Symptoms
If you have a Morton's neuroma, you will probably have one or more of these symptoms. Tingling, burning, or numbness. A feeling that something is inside the ball of the foot, or your sock is bunched up. Pain that is relieved by removing your shoes. A Morton's Neuroma often develops gradually. At first the symptoms may occur only occasionally, when wearing narrower shoes or performing certain activities. The symptoms may go away temporarily by massaging the foot or by avoiding aggravating shoes or activities. Over time the symptoms progressively worsen and may persist for several days or weeks. The symptoms become more intense as the neuroma enlarges and the temporary changes in the nerve become permanent.
Diagnosis
Your podiatric physician will begin by taking a history of your problem. Assist him or her by describing your condition as well as you can. Keep track of when the symptoms started and how, any changes you?ve noted (whether the pain has gotten worse, or whether other symptoms have appeared as well, etc.). If you?ve noticed that certain activities or footwear make things worse or bring about additional symptoms, be sure to mention that. If you work in specific footwear, or if you participate in any certain sports, bring the shoes you use. Your doctor may be able to learn quite a lot about your condition that way!
Non Surgical Treatment
Sclerosing alcohol injections are an increasingly available treatment alternative if the above management approaches fail. Dilute alcohol (4%) is injected directly into the area of the neuroma, causing toxicity to the fibrous nerve tissue. Frequently, treatment must be performed 2-4 times, with 1-3 weeks between interventions. An 60-80% success rate has been achieved in clinical studies, equal to or exceeding the success rate for surgical neurectomy with fewer risks and less significant recovery. If done with more concentrated alcohol under ultrasound guidance, the success rate is considerably higher and fewer repeat procedures are needed. Radio Frequency Ablation is also used in the treatment of Morton's Neuroma The outcomes appear to be equally or more reliable than alcohol injections especially if the procedure is done under ultrasound guidance.
Surgical Treatment
Recently, an increasing number of procedures are being performed at specialist centers under radiological or ultrasound guidance. Recent studies have shown excellent results for the treatment of Morton's neuroma with ultrasound guided steroid injections, ultrasound guided sclerosing alcohol injections, ultrasound guided radiofrequency ablation and ultrasound guided cryo-ablation.
Prevention
Ensuring that shoes are well fitted, low-heeled and with a wide toe area may help to prevent Morton's neuroma.
Morton's neuroma is an enlarged nerve that usually occurs in the third interspace, which is between the third and fourth toes. To understand Morton's neuroma further, it may be helpful to look at the anatomy of the foot. Problems often develop in the third interspace because part of the lateral plantar nerve combines with part of the medial plantar nerve here. When the two nerves combine, they are typically larger in diameter than those going to the other toes. Also, the nerve lies in subcutaneous tissue, just above the fat pad of the foot, close to an artery and vein. Above the nerve is a structure called the deep transverse metatarsal ligament. This ligament is very strong, holds the metatarsal bones together, and creates the ceiling of the nerve compartment. With each step, the ground pushes up on the enlarged nerve and the deep transverse metatarsal ligament pushes down. This causes compression in a confined space.
Causes
Poorly fitted footwear can be a cause. Shoes that have a tight and narrow toe box can cause the never to become entrapped causing the pain. High heeled shoes abnormally place the metatarsals under extreme pressure which can cause Morton?s Neuroma. In cases of abnormal pronation, there can be significant motion between the 3rd and 4th metatarsals which can cause an irritation to the nerve that runs between them. This inflammation causes the pain.
Symptoms
If you have a Morton's neuroma, you will probably have one or more of these symptoms. Tingling, burning, or numbness. A feeling that something is inside the ball of the foot, or your sock is bunched up. Pain that is relieved by removing your shoes. A Morton's Neuroma often develops gradually. At first the symptoms may occur only occasionally, when wearing narrower shoes or performing certain activities. The symptoms may go away temporarily by massaging the foot or by avoiding aggravating shoes or activities. Over time the symptoms progressively worsen and may persist for several days or weeks. The symptoms become more intense as the neuroma enlarges and the temporary changes in the nerve become permanent.
Diagnosis
Your podiatric physician will begin by taking a history of your problem. Assist him or her by describing your condition as well as you can. Keep track of when the symptoms started and how, any changes you?ve noted (whether the pain has gotten worse, or whether other symptoms have appeared as well, etc.). If you?ve noticed that certain activities or footwear make things worse or bring about additional symptoms, be sure to mention that. If you work in specific footwear, or if you participate in any certain sports, bring the shoes you use. Your doctor may be able to learn quite a lot about your condition that way!
Non Surgical Treatment
Sclerosing alcohol injections are an increasingly available treatment alternative if the above management approaches fail. Dilute alcohol (4%) is injected directly into the area of the neuroma, causing toxicity to the fibrous nerve tissue. Frequently, treatment must be performed 2-4 times, with 1-3 weeks between interventions. An 60-80% success rate has been achieved in clinical studies, equal to or exceeding the success rate for surgical neurectomy with fewer risks and less significant recovery. If done with more concentrated alcohol under ultrasound guidance, the success rate is considerably higher and fewer repeat procedures are needed. Radio Frequency Ablation is also used in the treatment of Morton's Neuroma The outcomes appear to be equally or more reliable than alcohol injections especially if the procedure is done under ultrasound guidance.
Surgical Treatment
Recently, an increasing number of procedures are being performed at specialist centers under radiological or ultrasound guidance. Recent studies have shown excellent results for the treatment of Morton's neuroma with ultrasound guided steroid injections, ultrasound guided sclerosing alcohol injections, ultrasound guided radiofrequency ablation and ultrasound guided cryo-ablation.
Prevention
Ensuring that shoes are well fitted, low-heeled and with a wide toe area may help to prevent Morton's neuroma.