Morton’s Neuroma Surgery

Introduction

Morton’s neuroma is a common condition of the foot. It involves nerve compression of the common digital nerve between the metatarsal heads, usually between the 3rd and 4th metatarsal heads but can occur also occur between the 2nd and 3rd metatarsals. It is entirely a biomechanical phenomenon.

Patients with neuroma may develop pain on the bottom of the forefoot, commonly between the 3rd and 4th toes. The pain may be dull and mild or sharp and severe and is aggravated by wearing shoes. A classic complaint is that the patients feel as if they are “walking on a stone or a pebble” and/or feels as if a sock is rolled up in the shoe. Pain can also occur when walking barefoot.

Dr Lane usually establishes the diagnosis of Morton’s (interdigital) neuroma on clinical history and examination. MRI scan may be useful to confirm the diagnosis. However other contributing factors such as bursa, fat, capsular thickening and bony growth can all contribute to the impingement process and may need to be surgically removed.

Depending on the severity, Dr Lane may offer conservative (non-surgical) or surgical treatment.

Non-operative treatments aim at reducing the inflammation and impingement causes. The inflammation can be addressed with rest, elevation, ice and non-steroidal anti-inflammatory agents- either massaged with gel or by taking tablets. Wearing broad based shoes, protective foot pads, custom-made orthotics may be considered. Cortisone injections may give temporary relief.

Indications for surgery

Surgery is indicated if symptoms are severe despite modifications in activity and conservative treatments taken.

Surgical excision of the neuroma is regarded as the gold standard treatment. The surgical success rate varies between 79 to 93%- failure usually due to inadequate excision of the neuroma.

Neuroma surgery is usually performed under a general anaesthetic (when the patient is asleep) as a day procedure. 

Pre-operative Instructions

At the time of consultation, Dr Lane will give a full explanation of the proposed surgery. Educational leaflets, supplied by the Australian Orthopaedic Association, which covers your procedure are also given for your information. If there are any other concerns, the staff are happy to take calls and if needed, further consultation with Dr Lane is encouraged.

Anti-inflammatory drugs such as Feldene, Naprosyn, Indocid, Voltaren, Mobic and Celebrex should be stopped 5 days before surgery. These drugs increase the risk of bleeding. Aspirin or other blood thinning drug use prior surgery should be discussed with Dr Lane as this would depend on the patients underlying medical condition. The foot to be operated on should be free of cuts, abrasions or sores as this would increase the risk of infection following surgery. If you have damaged skin, your surgery will be postponed until healed.

Our reception staff will provide clear instructions when to attend the day hospital, depending on your surgery time. You are advised to take your Medicare, DVA or private health care cards. Do not to eat or drink anything 6 hours prior to your surgery. 

Once your details are taken at the admissions desk:

  • You will be admitted by the duty nurse and baseline observations taken.
  • Theatre gown given to wear.
  • The foot will be inspected by the nursing staff and an antiseptic lotion applied to the skin. The foot is then covered with a sterile drape.
  • The other leg will have a TED stocking applied to reduce the risk of thrombosis after surgery.

You will be taken from the day hospital to the theatre complex by the nursing staff and then to the anaesthetic bay, which is situated next to the operating room. It is expected to have some numbness in the area of toes that the excised nerve supplied.

Procedure

When you are asleep in theatre a tourniquet is applied above the ankle to give the surgeon a bloodless field for surgery. The foot is then washed with an antiseptic solutions and sterile drapes covers the patient leaving a window for the operative site. The surgery usually takes 30 minutes. A 3cm excision is made on the dorsal aspect (on top) of the foot and the nerve is carefully removed. The end of the transected nerve is buried in soft tissue such as muscle. Dr Lane generally sends the specimen to the laboratory to confirm the histological appearances of a neuroma. The incision is closed with sutures, skin infiltrated with local anaesthetic to aid post- operative pain relief and a sterile dressing applied.

After surgery, you will be taken to the recovery area. Once adequately awake, observations normal and able to eat and drink, you will be discharged from hospital. It is important that someone takes you home. You will be given a script for pain relief.

Post-operative Instructions

The patient will be given a ‘surgical shoe” to wear when walking and so usually able to walk immediately after the operation. Foot dressings should be kept dry and intact until review by Dr Lane 10 to 14 days after surgery – please book an appointment. In the immediate post-operative phase, you are advised to rest and elevate the foot as much as possible to reduce swelling. The surgical shoe should be worn when walking. Sutures are generally removed at this first post-operative visit.

It is very common and acceptable to have some numbness in the area the nerve supplied. This never causes any discomfort and gets better in a few years.

Risks 

General risks associated with Anaesthetic (rare)

  • Death.
  • Myocardial Infarction (heart attack).
  • Short term confusion.
  • Stroke.
  • Deep venous thrombosis (blood clot).

Local risks (uncommon)

  • Infection.
  • Swelling.
  • Bleeding +/- haematoma formation.
  • Poor wound healing and incision breakdown.
  • Metatarsalgia.
  • Complex Regional Pain Syndrome.
  • Recurrence.

Factors which prolong healing and increase risk of complications are smoking, age, poor nutritional status, diabetes and other medical conditions.