Plantar neuroma or more commonly called as Morton’s neuroma is a benign neuroma on the plantar nerve located in the metatarsals. The term neuroma means tumor, but contrary to the name, plantar neuroma is not a true tumor, but a perineural fibroma or the formation of a fibrous tissue around a nerve tissue. It was first correctly described by Durlacher indicating that plantar neuroma is indeed not a tumor formation.
Plantar neuroma is characterized by the presence of numbness and pain on the ball of the feet where the plantar nerve passes through (specifically between the 2nd and 3rd or 3rd and 4th heads of the metatarsals).
Symptoms of Plantar Neuroma
Plantar neuroma commonly produces pain on the foot while walking or during weight bearing activities because of the pressure on the fibrous tissue around the plantar nerve. The pain can occur frequently; however, the discomfort is only short-lived.
The characteristic of pain usually vary among individuals. Some report a shooting pain on the ball of the foot until the 2nd and 3rd toes. Other people characterize the pain as being incising similar to walking on a razor blade. Others only describe the discomfort similar to the presence of pebbles in the shoe.
Aside from the classical symptom of pain, plantar neuroma may also result in numbness, burning and other abnormal sensations on the foot as a result of the affectation of the nerve that supplies the area. Despite the term neuroma, there is usually no visible or palpable lump on the ball of the foot.
Causes of Plantar Neuroma
The condition involves the thickening of the tissue around the nerves leading to the toes and it is commonly a result of irritation, pressure or injury to the area. Nevertheless the exact cause or explanation why plantar neuroma develops is still unclear to experts.
Although the exact cause is still unknown, risk factors have been identified in its development. Risk factors for plantar neuroma include:
- Wearing high heels. Wearing high heels will usually place your feet in a slanted position putting pressure on the ball of the feet and toes.
- Presence of foot deformities. The presence of hammertoes, bunions, low arches or flat feet and over pronation are also identified as risk factors for plantar neuroma.
- Sports. Running, jogging, rock climbing, and snow skiing are also risk factors for the condition because of the pressure on the toes.
Managements for Plantar Neuroma
The main aim of the treatment involves reduction of the symptoms. The type of treatment will usually depend on the severity of the condition. Both conservative and surgical approaches can be employed depending on the case.
Conservative managements often involve:
- Use of orthotics
The use of foot pads and arch supports are commonly employed to reduce pressure on the nerve on the toes.
- Anti0inflamtory medications
Medications such as ibuprofen are used to reduce inflammation and pain.
- Rest and Icing
Rest is also employed to relieve pressure on the toes. During rest, ice packs can be placed over the area to relieve swelling and pain.
For more severe cases, surgery may be involved. Surgical procedures may include:
- Decompression. Nearby structures around the plantar neuroma can be removed to relive pressure on the affected nerve.
- Cryogenic neuroablation. This procedure involves the exposure of the affected nerve to very cold temperatures to help interfere with the transmission of pain signals. Since the transmission of pain signals is the only focus, this treatment is not permanent.
- Dissection or removal of the neuroma. When symptoms do not disappear with the above treatments, the removal of the neuroma along with the nerve may be the last option. Since the nerve will also be removed, patients can suffer from permanent numbness on the toes.
Finally, plantar neuroma may also require change in footwear to provide adequate support to the feet and prevent pressure from being placed on the sensitive nerves.
Since plantar neuroma has no definite cause, employing proper ergonomics during exercise and sports, using the right type of shoes, and limiting the use of high heels may help prevent the condition.