Morton's neuroma

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[2]Faizan Sheraz, M.D. [3]

Morton’s neuroma is a benign neuroma of the interdigital plantar nerve. Although it is labeled a “neuroma“, many sources do not consider it a true tumor, but rather a thickening of existing tissue or a swollen, inflamed nerve located between the bones at the ball of the foot. The most common location of a Morton’s neuroma is in either the second or the third spacing from the base of the big toe. It is characterised by numbness & pain, and relieved by removing footwear.

The term neuroma originates from two Greek words, neuro– from the Greek word for nerve (νεῦρον), and -oma (-ωμα) from the Greek word for swelling. In 1876, neuroma was first described by Thomas Morton and Morton’s neuroma was first correctly described by a chiropodist named Durlacher. In 2000, a small studyreviewed the medical records of 85 people who had their feet imaged with MRI, and it was found out that 33% of the patients had morton’s neuroma without any pain.

Morton’s neuroma is associated with symptomatic collapse of the transverse arch by perineural fibrosis around a plantar digital nerve of the foot due to chronictraction and increased pressure/compression on the interdigital nerve. It is located at the third intermetatarsal space most commonly (between third and fourth metatarsals), and sometimes second or fourth interspaces or bifurcation of the fourth plantar digital nerve. Gross pathological features of morton’s neuroma include adherent fibrofatty tissue, small, firm, oval, yellowish–white, slowly growing, palpable nodule on skin (no discoloration of skin on the top of nodule) and </=2cm in size. Histopathological analysis is characterized by extensive fibrosis around and within the nerve, digital artery, thrombosis, epineural and endoneural arterialthickening/vascular hyalinization, and degenerated/demyelinated axons. Possible tissue pathologies associated with interdigital pain of morton’s neuroma include perineural fibrosis, endoneural edema, neurofibromata, angioneurofibromata, local demyelination, and local vascular degeneration.

The exact cause is unknown. However, morton’s neuroma is believed to be associated with wearing tight shoes with tapered toe box or high heels, overpronation, abnormal positioning of toes, flat feet, forefoot problems such as bunions and hammer toes, and high foot arches.

Morton’s neuroma must be differentiated from other causes of pain in the forefoot such as metatarsophalangeal joint capsulitis, intermetatarsal bursitis, calluses, stress fractures, Freiberg’s disease, osteomyelitis, localized vasculitis, ischemia of plantar digital artery, tarsal tunnel syndrome, rheumatoid arthritis, peripheral neuritis, synovitis, tendonitis, and avascular necrosis.

Morton’s neuroma is more common in women than men.

Risk factors for morton’s neuroma include improper footwear/tight shoes with tapered toe box, abnormal positioning of toes, flat feet, forefoot problems such as bunions and hammer toes, high foot arches, high heels, overpronation, gait abnormalities, and high-impact sports such as rock-climbing, ballet dancing, jogging, running, snow skiing, racquet and court sports.

Symptoms of morton’s neuroma begin gradually and initially occur only occasionally while wearing the narrow-toed shoes and performing certain aggravating activities. Symptoms may go away temporarily by removing the shoe, massaging the foot and avoiding the aggravating shoes/activities. Symptoms become even more intense & start to worsen progressively with time and may persist for several days or weeks. Ultimately, the temporary changes in the nerve become permanent if left untreated for prolonged periods of time. Common complications of morton’s neuroma include difficult walking, trouble performing activities that putpressure on the foot (pressing the gas pedal of an automobile), and feet hurt with wearing certain types of shoes especially high-heels. Postoperative complicationsinclude permanent non-painful numbness, small risk of infection around toes after surgery, incisional soreness, scarring, & recurring stump neuromas. Non-surgicaltreatment is successful in 80% of the cases but does not always improve symptoms and surgery to remove the thickened tissue is successful in about 85% of cases.

Morton’s neuroma is most commonly located at the third intermetatarsal space, with other sites being involved including second or fourth interspaces, at the bifurcation of the fourth plantar digital nerve and fifth interspace rarely. Patient complaints of feeling like ”walking on a marble”. Most common symptom of morton’s neuroma includes persistent pain on weight bearing affecting the contiguous halves of two toes, with the nature of pain being shooting, burning, stabbing, raw, gnawing or sickening sensations. Other symptoms may include numbness, parasthesia, dysesthesia, functional impairment and psychological distress associatedwith severe decrease in the quality of life.

Patients may have antalgic posture. Physical examination may be remarkable for tenderness to palpation, limitation of range of motion, dysesthetic pain and Mulder’s sign which includes replication of symptoms or clicking sensations upon direct pressure between the metatarsal heads or compression of transverse arch in forefoot between the finger and thumb. Negative signs include no obvious deformities, erythema or signs of inflammation.

Blood tests are done to check for inflammation–related conditions, including certain forms of arthritis.

A foot x-ray may be done to rule out bone pathologies such as arthritis or any stress fractures.

MRI can successfully diagnose and assess the location, size, and soft tissue abnormalities associated with Morton’s neuroma. As there’s a 26% chance of morton’s neuroma recurrence after surgery, hence, post-operative MR imaging can help rule out any recurrence. Morton’s neuroma-like abnormalities are seen in asymptomatic and symptomatic intermetatarsal spaces on MRI after the resection of morton’s neuroma. There’s a significant difference in the appearance of morton’s neuroma on MRI done in different positions such as prone, supine, or weight-bearing, with the morton’s neuroma being best visible in the prone position.

Imaging findings on high–resolution ultrasound may help to find out or differentiate any soft tissue abnormalities from morton’s neuroma. In 2000, a study was conducted in which ultrasound done on patients with morton’s neuroma demonstrated to have 100% sensitivity, 83.3% specificity and 96.7% accuracy in detectingthe location of morton’s neuroma. Symptomatic morton’s neuroma is at least 5 mm in diameter on sonogram. A presumed plantar digital nerve identified in continuity with the mass on ultrasound leads to an improved diagnostic confidence of morton’s neuroma.

Nerve testing such as electromyography cannot definitely diagnose Morton’s neuroma, but may be used to rule out conditions that cause similar symptoms.

Non-surgical treatment is instituted first for the treatment of morton’s neuroma. Firstly, the conservative measures are used for the pain relief such as decreasing the pressure on metatarsal heads by using metatarsal support, bars, padded shoe insert just proximal to the metatarsal head, tapping the toe area, orthotics, specialized orthopedic shoes, shoes with wider toe boxes allowing spread of metatarsal heads, low heels, good arch support & stiff soles, determining proper shoewidth, physical therapy, massaging ball of the foot, strength exercises for intrinsic foot muscles, stretching exercises for foot tendons & ligaments, resting the foot, applying ice packs to the sore foot areas and weight loss in overweight patients. When conservative measures fail, medical therapy is used which includes tricyclic antidepressants, anticonvulsants, serotonin-norepinephrine reuptake inhibitors, prolotherapy via Hackett-Hemwall technique which includes ultrasound–guidedinterdigital injection of nerve blocking agents such as steroids, local anaesthetics, dextrose, anti-inflammatory drugs or 4% alcohol sclerosing injections via dorsalapproach into the site of tenderness, oral or injectable anti-inflammatory drugs and painkillers.

Surgery is the last resort in the treatment of morton’s neuroma. In some cases, surgery may be needed to remove the thickened tissue/affected nerve in order to help release the pressure on the affected nerve, relieve the pain and improve foot function. Few complications after surgery are possible and include permanent nonpainful numbness if a portion of the affected nerve is removed, risk of postoperative infection around the toes, incisional soreness, scarring, and recurring stump neuromas. Morton’s neuroma can be removed surgically either via dorsal or plantar approach, with each approach having its own merits and demerits. Dependingupon each individual case, different surgical procedures that can be used for the treatment of morton’s neuroma include neurectomy, cryogenicsurgery/neuroablation, and decompression surgery.

Primary preventive measures for morton’s neuroma include avoiding ill–fitting shoes, high heels, narrow-toed shoes, overpronation, high-impact sports such as rock-climbing, ballet dancing, jogging, running, snow skiing, wearing comfortable shoes with wide toe box, low heels & good arch support and wearing athletic shoes (with enough padding in the soles) while running or playing sports.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[2]

The term neuroma originates from two Greek words, neuro– from the Greek word for nerve (νεῦρον), and -oma (-ωμα) from the Greek word for swelling. In 1876, neuroma was first described by Thomas Morton and Morton’s neuroma was first correctly described by a chiropodist named Durlacher. In 2000, a small study reviewed the medical records of 85 people who had their feet imaged with MRI, and it was found out that 33% of the patients had morton’s neuroma without any pain. In 2000, another study was conducted in which ultrasound done on patients with morton’s neuroma demonstrated to have 100% sensitivity, 83.3% specificity and 96.7% accuracy in detecting the location of morton’s neuroma.

• The term neuroma originates from the following two Greek words:
  • neuro– from the Greek word for nerve (νεῦρον)
  • -oma (-ωμα) from the Greek word for swelling
• In 1876, neuroma was first described by Thomas Morton
• Morton’s neuroma was first correctly described by a chiropodist named Durlacher
• In 2000, a small study reviewed the medical records of 85 people who had their feet imaged with MRI, and it was found out that 33% of the patients had morton’s neuroma without any pain^[1]
• In 2000, another study was conducted in which ultrasound done on patients with morton’s neuroma demonstrated to have 100% sensitivity, 83.3% specificity and 96.7% accuracy in detecting the location of morton’s neuroma ^[2]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [8]; Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[9]

Morton’s neuroma is associated with symptomatic collapse of the transverse arch by perineural fibrosis around a plantar digital nerve of the foot due to chronic traction and increased pressure/compression on the interdigital nerve. It is located at the third intermetatarsal space most commonly (between third and fourth metatarsals), and sometimes second or fourth interspaces or bifurcation of the fourth plantar digital nerve. Gross pathological features of morton’s neuroma include adherent fibrofatty tissue, small, firm, oval, yellowish–white, slowly growing, palpable nodule on skin (no discoloration of skin on the top of nodule) and </=2cm in size. Histopathological analysis is characterized by extensive fibrosis around and within the nerve, digital artery, thrombosis, epineural and endoneural arterial thickening/vascular hyalinization, and degenerated/demyelinated axons. Possible tissue pathologies associated with interdigital pain of morton’s neuroma include perineural fibrosis, endoneural edema, neurofibromata, angioneurofibromata, local demyelination, and local vascular degeneration.

• Morton’s neuroma is associated with symptomatic collapse of the transverse arch by perineural fibrosis around a plantar digital nerve of the foot due to chronic traction and increased pressure/compression on the interdigital nerve^{[1][2][3][4][5][6]}

• Morton’s neuroma is characterized by being located at the:
  • Third intermetatarsal space most commonly (between third and fourth metatarsals)^[7]
  • Second or fourth interspaces
  • Bifurcation of the fourth plantar digital nerve

• On gross pathology, characteristic findings of morton’s neuroma, include:^[8][9]
  • Adherent fibrofatty tissue
  • Small, firm, oval, yellowish–white, slowly growing, palpable nodule on skin (no discoloration of skin on the top of nodule)
  • </=2cm in size

• On microscopic histopathological analysis, characteristic findings of morton’s neuroma include:^{[10][8][9][2]}
  • Extensive fibrosis around and within the nerve
  • Digital artery
  • Thrombosis
  • Epineural and endoneural arterial thickening/vascular hyalinization
  • Degenerated/demyelinated axons

Possible tissue pathologies associated with interdigital pain of morton’s neuroma include:^[11]

• Perineural fibrosis
• Endoneural edema
• Neurofibromata
• Angioneurofibromata
• Local demyelination
• Local vascular degeneration

Template:WH Template:WS

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[2]Faizan Sheraz, M.D. [3]

The exact cause is unknown. However, morton’s neuroma is believed to be associated with wearing tight shoes with tapered toe box or high heels, overpronation, abnormal positioning of toes, flat feet, forefoot problems such as bunions and hammer toes, and high foot arches.

The exact cause is unknown. It is believed that the following may play a role in the development of this condition:

• Wearing tight shoes with:
  • Tapered toe box
  • High heels
• Overpronation

• Abnormal positioning of toes

• Flat feet
• High foot arches

• Forefoot problems such as:
  • Bunions
  • Hammer toes

Template:WH Template:WS

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[2]

Morton’s neuroma must be differentiated from other causes of pain in the forefoot such as metatarsophalangeal joint capsulitis, intermetatarsal bursitis, calluses, stress fractures, Freiberg’s disease, osteomyelitis, localized vasculitis, ischemia of plantar digital artery, tarsal tunnel syndrome, rheumatoid arthritis, peripheral neuritis, synovitis, tendonitis, and avascular necrosis.

• Morton’s neuroma must be differentiated from other causes of pain in the forefoot because too often all forefoot pain is categorized as neuroma
• Since a neuroma is a soft tissue condition, an MRI should be helpful in diagnosis, however, often an MRI will be inconclusive for neuroma even though a neuroma exists
• Other conditions to consider are:^[1]
  • Metatarsophalangeal joint capsulitis/metatarsalgia
  • Intermetatarsal bursitis between the third and fourth metatarsal bones will also give neuroma type symptoms because it too puts pressure on the nerve
  • Calluses
  • Metatarsal stress fracture
  • Freiberg’s disease
  • Osteomyelitis
  • Localized vasculitis
  • Ischemia or lack of blood flow through plantar digital artery, it precedes the fibrous thickening around the nerve known as perineural fibrosis
  • Tarsal tunnel syndrome
  • Rheumatoid arthritis
  • Peripheral neuritis
  • Synovitis
  • Tendonitis
  • Avascular necrosis

Template:WikiDoc Sources

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[2]

Morton’s neuroma is more common in women than men.

• Morton’s neuroma is more common in women than men.

Template:WH Template:WS

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[2]

Risk factors for morton’s neuroma include improper footwear/tight shoes with tapered toe box, abnormal positioning of toes, flat feet, forefoot problems such as bunions and hammer toes, high foot arches, high heels, overpronation, gait abnormalities, and high-impact sports such as rock-climbing, ballet dancing, jogging, running, snow skiing, racquet and court sports.

Risk factors for Morton’s neuroma include:^[1]

• Improper footwear or tight shoes with tapered toe box
• Abnormal positioning of toes
• Flat feet
• Overpronation
• High foot arches
• High heels
• Gait abnormalities
• Forefoot problems such as:
  • Bunions
  • Hammer toes
• High-impact sports such as:
  • Rock-climbing
  • Ballet dancing
  • Jogging
  • Running
  • Snow skiing
  • Racquet sports
  • Court sports

Template:WH Template:WS

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[2]

Symptoms of morton’s neuroma begin gradually and initially occur only occasionally while wearing the narrow-toed shoes and performing certain aggravating activities. Symptoms may go away temporarily by removing the shoe, massaging the foot and avoiding the aggravating shoes/activities. Symptoms become even more intense & start to worsen progressively with time and may persist for several days or weeks. Ultimately, the temporary changes in the nerve become permanent if left untreated for prolonged periods of time. Common complications of morton’s neuroma include difficult walking, trouble performing activities that put pressure on the foot (pressing the gas pedal of an automobile), and feet hurt with wearing certain types of shoes especially high-heels. Postoperative complications include permanent non-painful numbness, small risk of infection around toes after surgery, incisional soreness, scarring, & recurring stump neuromas. Non-surgical treatment is successful in 80% of the cases but does not always improve symptoms and surgery to remove the thickened tissue is successful in about 85% of cases.

• Symptoms of morton’s neuroma begin gradually
• Initially, the symptoms occur only occasionally while:
  • Wearing the narrow-toed shoes
  • Performing certain aggravating activities
• Symptoms may go away temporarily by:
  • Removing the shoe
  • Massaging the foot
  • Avoiding the aggravating shoes/activities
• With the passage of time, symptoms start to worsen progressively and may persist for several days or even weeks
• Symptoms become even more intense as the neuroma enlarges
• Ultimately, the temporary changes in the nerve become permanent if left untreated for prolonged periods of time

• Morton’s neuroma can make walking difficult
• Persons with this foot condition may also have trouble performing activities that put pressure on the foot, such as pressing the gas pedal of an automobile
• It may hurt to wear certain types of shoes, such as high-heels
• Few of the post surgical complications include:
  • If a portion of the affected nerve is removed during the surgery, permanent numbness occurs between the toes, but it’s not painful
  • There is a small risk of infection around the toes after surgery
  • Incisional soreness
  • Scarring
  • Recurring stump neuromas

• Non-surgical treatment is successful in 80% of the cases but does not always improve symptoms
• Surgery to remove the thickened tissue is successful in about 85% of cases^[1]

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