Overview
Morton neuroma (interdigital neuroma), first described in 1876, is a perineural fibrosis and nerve degeneration of the common digital nerve. Morton neuroma, or Morton's neuroma, is not a true neuroma, although it results in neuropathic pain in the distribution of the interdigital nerve secondary to repetitive irritation of the nerve. The most frequent location is between the third and fourth metatarsals (third webspace). Other, less common locations are between the second and third metatarsals (second webspace) and, rarely, between the first and second (first webspace) or fourth and fifth (fourth webspace) metatarsals.
Causes
Morton's neuroma is an inflammation caused by a buildup of fibrous tissue on the outer coating of nerves. This fibrous buildup is a reaction to the irritation resulting from nearby bones and ligaments rubbing against the nerves. Irritation can be caused by Wearing shoes that are too tight. Wearing shoes that place the foot in an awkward position, such as high heels. A foot that is mechanically unstable. Repetitive trauma to the foot such as from sports activities like tennis, basketball, and running. Trauma to the foot caused by an injury such as a sprain or fracture. It is unusual for more than one Morton's neuroma to occur on one foot at the same time. It is rare for Morton's neuroma to occur on both feet at the same time.
Symptoms
If you have a Morton?s neuroma, you may have one or more of these symptoms where the nerve damage is occurring, Tingling, burning, or numbness, pain, a feeling that something is inside the ball of the foot or a feeling that there?s something in the shoe or a sock is bunched up. The progression of a Morton?s neuroma often follows the following pattern. The symptoms begin gradually. At first they occur only occasionally, when wearing narrow-toed shoes or performing certain aggravating activities. The symptoms may go away temporarily by removing the shoe, 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
Negative signs include no obvious deformities, erythema, signs of inflammation, or limitation of movement. Direct pressure between the metatarsal heads will replicate the symptoms, as will compression of the forefoot between the finger and thumb so as to compress the transverse arch of the foot. This is referred to as Mulder?s Sign. There are other causes of pain in the forefoot. Too often all forefoot pain is categorized as neuroma. Other conditions to consider are capsulitis, which is an inflammation of ligaments that surrounds two bones, at the level of the joint. In this case, it would be the ligaments that attach the phalanx (bone of the toe) to the metatarsal bone. Inflammation from this condition will put pressure on an otherwise healthy nerve and give neuroma-type symptoms. Additionally, an intermetatarsal bursitis between the third and fourth metatarsal bones will also give neuroma-type symptoms because it too puts pressure on the nerve. Freiberg's disease, which is an osteochondritis of the metatarsal head, causes pain on weight bearing or compression.
Non Surgical Treatment
In developing a treatment plan, your foot and ankle surgeon will first determine how long you?ve had the neuroma and evaluate its stage of development. Treatment approaches vary according to the severity of the problem. For mild to moderate neuromas, treatment options may include Padding techniques provide support for the metatarsal arch, thereby lessening the pressure on the nerve and decreasing the compression when walking. Placing an icepack on the affected area helps reduce swelling. Custom orthotic devices provided by your foot and ankle surgeon provide the support needed to reduce pressure and compression on the nerve. Activities that put repetitive pressure on the neuroma should be avoided until the condition improves. Wear shoes with a wide toe box and avoid narrow-toed shoes or shoes with high heels. Oral nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may be recommended to reduce pain and inflammation. Treatment may include injections of cortisone, local anesthetics or other agents.
Surgical Treatment
If symptoms do not respond to any of the above measures then surgery may be suggested. This involves a short 30 minute operation to either remove tissue to take pressure off the nerve or to remove the nerve causing the pain. The surgery can be done as a day case but it will be two or three weeks before you can be fully active on your feet. There may be some lingering numbness afterwards if the nerve is removed. But surgery is successful in around 80% of cases. There is a small risk of complications such as infection and thickening of the skin on the soles of the feet.
Morton neuroma (interdigital neuroma), first described in 1876, is a perineural fibrosis and nerve degeneration of the common digital nerve. Morton neuroma, or Morton's neuroma, is not a true neuroma, although it results in neuropathic pain in the distribution of the interdigital nerve secondary to repetitive irritation of the nerve. The most frequent location is between the third and fourth metatarsals (third webspace). Other, less common locations are between the second and third metatarsals (second webspace) and, rarely, between the first and second (first webspace) or fourth and fifth (fourth webspace) metatarsals.
Causes
Morton's neuroma is an inflammation caused by a buildup of fibrous tissue on the outer coating of nerves. This fibrous buildup is a reaction to the irritation resulting from nearby bones and ligaments rubbing against the nerves. Irritation can be caused by Wearing shoes that are too tight. Wearing shoes that place the foot in an awkward position, such as high heels. A foot that is mechanically unstable. Repetitive trauma to the foot such as from sports activities like tennis, basketball, and running. Trauma to the foot caused by an injury such as a sprain or fracture. It is unusual for more than one Morton's neuroma to occur on one foot at the same time. It is rare for Morton's neuroma to occur on both feet at the same time.
Symptoms
If you have a Morton?s neuroma, you may have one or more of these symptoms where the nerve damage is occurring, Tingling, burning, or numbness, pain, a feeling that something is inside the ball of the foot or a feeling that there?s something in the shoe or a sock is bunched up. The progression of a Morton?s neuroma often follows the following pattern. The symptoms begin gradually. At first they occur only occasionally, when wearing narrow-toed shoes or performing certain aggravating activities. The symptoms may go away temporarily by removing the shoe, 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
Negative signs include no obvious deformities, erythema, signs of inflammation, or limitation of movement. Direct pressure between the metatarsal heads will replicate the symptoms, as will compression of the forefoot between the finger and thumb so as to compress the transverse arch of the foot. This is referred to as Mulder?s Sign. There are other causes of pain in the forefoot. Too often all forefoot pain is categorized as neuroma. Other conditions to consider are capsulitis, which is an inflammation of ligaments that surrounds two bones, at the level of the joint. In this case, it would be the ligaments that attach the phalanx (bone of the toe) to the metatarsal bone. Inflammation from this condition will put pressure on an otherwise healthy nerve and give neuroma-type symptoms. Additionally, an intermetatarsal bursitis between the third and fourth metatarsal bones will also give neuroma-type symptoms because it too puts pressure on the nerve. Freiberg's disease, which is an osteochondritis of the metatarsal head, causes pain on weight bearing or compression.
Non Surgical Treatment
In developing a treatment plan, your foot and ankle surgeon will first determine how long you?ve had the neuroma and evaluate its stage of development. Treatment approaches vary according to the severity of the problem. For mild to moderate neuromas, treatment options may include Padding techniques provide support for the metatarsal arch, thereby lessening the pressure on the nerve and decreasing the compression when walking. Placing an icepack on the affected area helps reduce swelling. Custom orthotic devices provided by your foot and ankle surgeon provide the support needed to reduce pressure and compression on the nerve. Activities that put repetitive pressure on the neuroma should be avoided until the condition improves. Wear shoes with a wide toe box and avoid narrow-toed shoes or shoes with high heels. Oral nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may be recommended to reduce pain and inflammation. Treatment may include injections of cortisone, local anesthetics or other agents.
Surgical Treatment
If symptoms do not respond to any of the above measures then surgery may be suggested. This involves a short 30 minute operation to either remove tissue to take pressure off the nerve or to remove the nerve causing the pain. The surgery can be done as a day case but it will be two or three weeks before you can be fully active on your feet. There may be some lingering numbness afterwards if the nerve is removed. But surgery is successful in around 80% of cases. There is a small risk of complications such as infection and thickening of the skin on the soles of the feet.