Footmed Foot and Ankle Clinic is Adelaide, Elizabeth Vale and Murray Bridge’s experienced team of podiatrists. The first step is to determine the diagnosis and cause of your foot pain. This will allow our specialists to provide the most effective and lasting treatment.
Morton’s neuroma is a pathological condition of the common digital nerve, most frequently between the third and fourth metatarsals (third intermetatarsal space). The nerve sheath becomes abnormally thickened with fibrous (scar) tissue. A diagnostic ultrasound may be ordered to confirm this.
- Pain most commonly in the ball of the foot and affecting one or two of the lesser toes (usually the third and fourth).
- Pain can sometimes radiate to the top of the foot
- The pain may can be intermittent in nature – it may disappear as quickly as it came
- Pain is often sharp, burning, or cramping in nature
- Pain may radiate into the tips of the toes or up the foot/ leg
- Aggravated by tight shoes and prolonged weight-bearing
- Removing the shoe often relieved the pain
Morton’s neuroma causes
The exact cause is not fully understood, but theories propose entrapment of the nerve from adjacent anatomical structures such as the bursae and ligaments. Faulty foot mechanics is thought to play a role and increasing compression of the entrapped nerve. A neuroma most often affects women over 50 years of age and aggravated by tight or high-heeled shoes.
The condition seems to occur in response to continued long term irritation, pressure or injury to one of the nerves that lead to your toes. The excessive thickening of the nerve (neuroma) is your body’s response to this irritation or injury. In some cases, Morton’s neuroma may result from abnormal movement of your foot, caused by bunions, hammertoes, flatfeet or excessive flexibility.
Metatarsal dome pads, rest, ice, anti-inflammatory medication can help improve comfort. Wide shoes with foot orthoses and cortisone injections may resolve the pain in some people. If the neuroma is small in size a course of injections of local anaesthetic and/or cortisone around the neuroma can be helpful. This idea is to release the nerve from within the scar tissue and/or ‘shrink’ the thickening. No long-term studies are available. However, surgery is recommended if treatment is ineffective and problems interfere with quality of life.
At Footmed the operation of choice involves removing the enlarged nerve by a cut made on the top of the foot. The deep transverse metatarsal ligament suspected of causing some of the constriction above the nerve is released. The thickened nerve is then isolated from the surrounding tissue and cut where the nerve trunk appears normal again. An inflamed intermetatarsal bursa is often present and this is also removed. The specimen is sent for a pathology examination.
This operation (neurectomy) by a dorsal approach has shown good to excellent patient satisfaction in several uncontrolled trials. These trials indicate good to excellent results ranging from 80% to 96% patients being satisfied with their surgery. The Coughlin and Pinsonneault study is the longest term follow up after 11 years.
- Infection (smoking increases by 16X)
- Stump neuroma can occur when little sproutlets of nerve from the cut end of the nerve starts to grow again. These sproutlets can grow into a ball that hurts like (or more than) the original neuroma and this requires further surgery to rectify.
- Wound problems (slow to heal)
- Scar sensitivity
- Nerve Injury (nerves can be bruised which resolves but you can be left with permanent numbness)
- CRPS = Complex Regional Pain Syndrome (Rare <1%)
- Deep vein thrombosis (clot in deep vein in the legs)
The underneath of the foot can remain tender for about 3-4 months after surgery. This is likely to resolve on its own without treatment. An orthotic will also help.