Morton's Neuroma is the most common neuroma in the foot. It occurs in the forefoot area (the ball of the foot) at the base of the third and fourth toes. It is sometimes referred to as an intermetatarsal neuroma. "Intermetatarsal" describes its location in the ball of the foot between the metatarsal bones (the bones extending from the toes to the midfoot). A neuroma is a thickening, or enlargement, of the nerve as a result of compression or irritation of the nerve. Compression and irritation creates swelling of the nerve, which can eventually lead to permanent nerve damage.
Morton's neuroma develops for several reasons. The primary reason is wearing narrow toe-box shoes, which compress the metatarsal heads. Certain anatomical factors also make nerve compression more likely with the narrow toe box shoes. In some people fibers, the medial and lateral plantar nerves converge close to the heads of the third and fourth metatarsals. This junction creates a larger nerve structure between the metatarsal heads making it more vulnerable to compression.
Morton's neuroma may cause Burning, pain, tingling, and numbness often shooting into the toes. Discomfort that is worse while walking. Feeling of a lump between the toes. Symptoms are usually temporarily relieved when taking off shoes, flexing toes or rubbing feet.
The most common condition misdiagnosed as Morton's neuroma is metatarsophalangeal (MTP) joint synovitis. When pain occurs in the third interspace, the clinician may misdiagnose the condition as Morton's neuroma instead of MTP synovitis, which may manifest very much like Morton's neuroma. MTP synovitis is distinguished from Morton's neuroma by subtle swelling around the joint, pain localized mainly within the joint, and pain with forced toe flexion. Palpation of the MTP joint is performed best with a pinching maneuver from the dorsal and plantar aspects of the joint to elicit tenderness of the joint. Other conditions often misdiagnosed as Morton's neuroma include the following. Stress fracture of the neck of the metatarsal. Rheumatoid arthritis and other systemic arthritic conditions. Hammertoe. Metatarsalgia (ie, plantar tenderness over the metatarsal head) Less common conditions that have overlapping symptoms with Morton's neuroma include the following. Neoplasms. Metatarsal head osteonecrosis. Freiburg. steochondrosis. Ganglion cysts. Intermetatarsal bursal fluid collections. True neuromas.
Non Surgical Treatment
Common treatments involve wearing different shoes or using arch supports. Resting the foot, massaging the toes and using an ice pack may work for some people. A GP or a podiatrist (foot specialist) may also recommend anti-inflammatory painkillers or a course of steroid injections. Numbing injections, in which alcohol and a local anaesthetic are injected into the affected area of the foot, may also be effective. In extreme cases, when the condition does not respond to treatment, day case surgery may be needed.
Patients are commonly offered surgery known as neurectomy, which involves removing the affected piece of nerve tissue. Postoperative scar tissue formation (known as stump neuroma) can occur in approximately 20%-30% of cases, causing a return of neuroma symptoms. Neurectomy can be performed using one of two general methods. Making the incision from the dorsal side (the top of the foot) is the more common method but requires cutting the deep transverse metatarsal ligament that connects the 3rd and 4th metatarsals in order to access the nerve beneath it. This results in exaggerated postoperative splaying of the 3rd and 4th digits (toes) due to the loss of the supporting ligamentous structure. This has aesthetic concerns for some patients and possible though unquantified long-term implications for foot structure and health. Alternatively, making the incision from the ventral side (the sole of the foot) allows more direct access to the affected nerve without cutting other structures. However, this approach requires a greater post-operative recovery time where the patient must avoid weight bearing on the affected foot because the ventral aspect of the foot is more highly enervated and impacted by pressure when standing. It also has an increased risk that scar tissue will form in a location that causes ongoing pain.