The MICA technique: An innovative, keyhole approach to bunion corrective surgery

Innovation in minimally invasive techniques for foot and ankle surgery has brought better-than-ever outcomes for patients, particularly those suffering from painful bunions. In this expert guide to corrective surgery for bunions, revered consultant orthopaedic surgeon Mr David Redfern, co-inventor of the MICA technique, sheds light on the causes of the condition and the benefits of minimally invasive techniques.

What are bunions?

A bunion, also referred to as hallux valgus, is a bony lump or protrusion found on the outer side of the big toe joint. A bunion can also cause the big toe itself to become angled towards the other toes.

Bunions usually run in families and most people who experience this problem have a relative with the condition. Around a third of the population will suffer from bunions at some time in their life and women are more commonly affected than men.

What causes bunions?

Bunions form when the bones which support the big toes move out of place. In most cases, a tendency towards bunions is genetic and some people inherit a higher risk of developing them. This risk relates to the structure of the bones and joint in this part of the foot.

Bunions are not caused by wearing high heeled shoes but for a person with a genetic tendency, this type of footwear can exacerbate bunion problems, as can tight or pointed shoes. In other cases, injury, arthritis or muscle imbalance can cause bunions.

When is surgery required to treat bunions?

Although many people with bunions experience pain, rubbing and inflammation from wearing shoes, not all bunions are painful, even if large in size. The leaning angle of the big toe can also put pressure on the second toe and cause it to become misshapen, also known as a hammer toe. In some cases, the two toes may cross over which typically leads to pain from footwear.

If patients are experiencing pain and are not able to wear footwear comfortably, surgery can help to alleviate this. However, it’s vital to be assessed by a qualified and experienced orthopaedic specialist in foot surgery, as any operation in this area must be performed with detailed precision and care to ensure the best outcome.

Although surgery may be necessary in more severe cases, approximately fifty per cent of people with bunions do not require surgical treatment. There are a number of conservative approaches which help to alleviate pressure on the bunion and aim to prevent pressure sores or ulcers from developing in the area, although are not able to correct the bunion itself.

Non-surgical treatment options for bunions include:

• wearing comfortable, well-fitting shoes
• getting specialist advice from a podiatrist or a specially made insole
• using splints, pads and cushions to make footwear more comfortable

What does surgery to correct bunions involve?

When conservative methods cannot provide relief from the pain and limitations caused by bunions, corrective surgery is the definitive approach to treatment. The key aim of bunion correction surgery is to realign the bones in this area of the foot, creating a straight big toe and removing the protruding bump on the side of the foot. To do this, it is necessary to cut and reposition the bones in perfect alignment.

How does minimally invasive surgery differ from open bunion correction surgery?

Traditionally, open surgical techniques have been used in bunion correction surgery, where a large oscillating saw is used to make cuts through the bone so the necessary realignment can be achieved. This involves making a large incision and stripping the soft tissue from the bone and has meant that bunion surgery has developed a reputation for being very painful.

More recently, however, minimally invasive (keyhole) techniques have been developed to achieve better outcomes for patients. In 2008, with my colleague Dr Joel Vernois, I invented significantly less invasive surgical method for performing bunion correction surgery known as MICA (Minimally Invasive Chevron Akin). For over ten years, we have personally trained hundreds of fellow specialists around the world how to perform this innovative technique to achieve the best outcomes for patients and to date, over fifty-thousand MICA procedures have been performed worldwide.

The principal difference between open bunion correction surgery and the MICA procedure is the type of instruments used to cut and reposition the bones into perfect alignment. While a large oscillating bone saw which makes a big incision is used in traditional surgery, our minimally invasive procedure uses a very small drill (just 2mm) to cut the bones.

Once they have been realigned, the bones are held in their new position with specially made screws, which are not able to be felt by the patient after surgery, and help to ensure the bones stay in place during the healing process.

The small size of the instruments used in MICA surgery means only tiny incisions need be made and using X-ray imaging, the surgeon is guided precisely through the procedure. These smaller incisions leave the blood supply in this part of the foot intact and mean less soft tissue damage is sustained during surgery, ensuring a quicker and less painful recovery compared to open surgery.

If you are seeking surgical treatment for bunions and wish to discuss your options with Mr Redfern, you can schedule a consultation with him by visiting his Top Doctors profile.