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A bunion is a bony bump on the side of the big toe. It is also called hallux valgus as it usually occurs when the big toe (Latin name hallux) points away from the mid-line of the body towards the other toes (valgus). Sometimes the bony bump can be noticeable but the degree of toe angulation is mild.

The bump can also be visible in some people with big toe arthritis. This is called hallux rigidus or stiff big toe and there can be bony arthritic spurs (called osteophytes). 

The cause of a bunion is unknown in the majority of cases. Many patients find that their foot shape and bunion runs in their family. Tight shoe wear can contribute to the symptoms of a bunion by pinching the front part of the foot, although they are not usually the cause. Some factors such as a flat foot, tight Achilles tendon and increased joint flexibility can also contribute.

A bunion can cause a number of problems such as direct pressure pain due to rubbing from shoe wear. A swelling (bursa) can develop over the bony bump of the bunion, which can become inflamed and very rarely form an ulcer.

A bunion also changes the way the joint and foot work mechanically and can increase the pressure on the 2nd toe next to the big toe. This pressure transfer across the foot can also lead to painful hard skin on the sole of the foot and the formation of a 2nd hammer toe (a deformed toe with a painful and swollen knuckle joint).

The aims of bunion surgery are to reduce pain due to pressure on the bump of the big toe and ease difficulty wearing comfortable shoes.

Correcting a bunion can also help reduce the transfer problems further across the foot or to reduce the pressure on the next toes. Correcting a bunion deformity associated with big toe arthritis will not resolve all the symptoms of pain and needs to be part of the discussion with the surgeon.

Correcting a bunion or foot problem to make it look nicer for cosmetic reasons is not a reason for surgery. In addition to this, surgery should not be performed to try and fit feet into narrow or tight shoes.

The joint is opened and some tendons may need to be released or lengthened to see the bone and joint properly. Most bunion surgery requires the bones of the big toe to be cut and realigned with an osteotomy (a surgical bone cut). The big toe first metatarsal is often cut in a Z shape called a scarf osteotomy, however other techniques use a V or other-shaped bone cut.

The split bone is then moved and fixed with wires, small screws or plates. There may also be the need to cut the big toe first toe bone proximal phalanx to add to the correction (called an Akin osteotomy) and the bone may be fixed with wires, sutures, staples or screws. The joint sac (called the capsule) is also repaired.

This sort of surgery requires surgical skin cut incisions to see the bones and joint and is not a keyhole operation. Minimally Invasive Surgery (MIS) is not performed to correct bunions at UCLH. Sometimes the bump of the big toe can be prominent, but the toe remains quite straight and, in these cases, the bump can be shaved with a bunionectomy. The surgeon will discuss with you whether you are able to have this procedure.

There are some general risks from having any orthopaedic foot operation and some which are specific to a bunion correction with an osteotomy.

Post operation pain: This can be expected for the first six weeks. You will be discharged with simple painkillers and should take these regularly for the first few days and then as required. Non-Steroidal Anti-Inflammatory Drugs (NSAIDS) such as Ibuprofen, Naproxen and Diclofenac, may contribute to delays in bone healing and are avoided after an osteotomy.

Infection: The risk of a deep joint infection that needs repeated operations and long courses of antibiotics is rare. At UCLH this is less than one per cent or 1 in every 100 cases. To minimise the risk of infection, routine antibiotics are given at the time of surgery. Sometimes after the operation, a wound can look inflamed. This can be caused by the stitch material dissolving or be because of a skin surface infection requiring a short course of antibiotics.

Bleeding: Severe bleeding is uncommon from the big toe but there can be bruising for the first few weeks.

Nerve damage: The skin nerves can be stretched or rarely cut, which can cause a patch of numbness over the side of the big toe or a sensitive scar. This usually improves with time (although may not return to normal). A sensitive scar can benefit from scar massage. The surgeon will advise you how to perform this if needed.

Swelling: Swelling is common after foot surgery. During the first couple of weeks your foot should be elevated to the level of the hip for most of the time. Swelling can continue for several months and varies between patients. The more you elevate your foot in the early post-operation period, the less the swelling will continue.

Stiffness: Any operation on the big toe can lead to stiffness. This can be more common when there is pre-existing joint stiffness or arthritis. Physiotherapy exercises that you do yourself can help although sometimes a joint injection and manipulation may be required.

Incomplete pain relief: Not all your big toe or foot pain may be made better after a bunion operation. There can be wear and tear arthritis inside the joint which can give some pain. Joint arthritis pain can get worse after any operation although this may be helped with an injection.

Transfer metatarsalgia: A big toe which does not function normally can force you to walk further across the foot producing increased pressure on the little toes. The little toes can deform, producing hammer toes or pain can be felt under the ball of the front foot due to loss of padding. This can be improved with an insole.

Fracture: This is where the toe bone becomes cracked or broken beyond where the osteotomy is performed. This is rare in the operation. Fracture of the bone after surgery and during walking, may mean you will need a specific cast or boot to support the foot until it heals. If a significant fracture occurred, an operation to re-fix the fracture and osteotomy might be required.

Loss of fixation: The small screws can lose hold on the bone and rarely the position of the osteotomy can change and need to be fixed again.

Under-correction / recurrence of deformity: If your big toe is stiff and cannot be straightened fully before the operation, then the operation may not be able to straighten your toe fully. There is also a risk of some recurrence over time after any bunion correction meaning that the toe moves back to the position where it started.

Over correction of deformity: This is called a hallux varus deformity and causes your big toe to move away from the second toe widening your first web space and forefoot. If this does occur and gives you any problems, further surgery may be needed to try and straighten the toe.

Delayed / non-healed bone: The bone is cut using a saw during an osteotomy and takes time to heal similar to a bone fracture. The bone should be secure with enough healing to return to a normal shoe from six to eight weeks but may take several months to gain full strength. Sometimes the bone healing is slow (called a delayed union) and occasionally does not heal at all (called a non-union). Regular anti-inflammatory medication usage and smoking contribute to delays in bone healing. It is advisable to reduce and stop smoking in preparation for any operation on bone to reduce the chance of complications.

Prominent metal: Occasionally the metal screws, staples of plates can be felt and may need to be removed although this is not performed routinely.

Chronic Regional Pain Syndrome (CRPS): This is a form of chronic severe pain, where you can also experience tingling, hypersensitivity, abnormal sweating, colour and temperature changes in your foot. This can appear in a mild form when the foot is swollen, painful and not used for the first few weeks but mostly recovers quickly. A true CRPS is rare, less than one per cent or 1 in 100 cases for UCLH foot surgery. This requires help from anaesthetists with a special interest in chronic pain who use nerve blocks, medication and physiotherapy, although it can sometimes take many months or years.

Deep vein thrombosis/pulmonary embolism: Thrombosis (leg blood clot) and embolism (lung blood clot) are rare after big toe surgery. A day case operation rarely requires chemical injections to reduce the risk of thrombosis unless you have other risk factors (previous thrombosis, strong family history, and contraceptive pill for example). The risk would be assessed using the UCLH Venous Thromboembolism (VTE) prevention guidelines.

Anaesthesia: There are risks according to the type of anaesthesia used. General anaesthesia may cause a sore throat or sickness which the anaesthetist will discuss with you. Specific medical risk factors sometimes require an anaesthetic review at the time of the pre-assessment clinic a few weeks before surgery. The operation can also be performed using local anaesthetic injections around the ankle with sedation if required.

General medical complications: The risks of a stroke, chest infection, heart attack or abnormal heart rhythm are rare after big toe surgery, unless you have significant health problems. Having the operation under an ankle injection can reduce the strain an anaesthetic has on the body.

Wearing spacious, wide fitting flat shoes can avoid pressure on the painful bunion. Simple painkillers and anti-inflammatory medication can give relief of symptoms.

A steroid injection and gentle manipulation (stretching movements) of the joint may help any pain or stiffness if the joint has arthritis. An insole can help support the foot arch position especially you have a flat foot.

Over the counter silicon or felt bunion pads or splints to reduce pressure can be helpful but will not correct the deformity.

After your first surgical clinic review

The patient pathway coordinator will contact you to offer you a date for surgery and for a pre-assessment clinic. Please keep all letters sent to you regarding the dates and appointments.

Pre-assessment clinic

The pre-assessment clinic is an outpatient clinic, which you must attend before you are admitted to hospital for your operation. This clinic normally takes place four weeks before you come into hospital. It can take up to two hours so please allow time. You will meet a nurse who will ask you questions about your general health and you might have medical checks, such as X-rays and blood tests. It is important that you bring your medication list with you and inform us of any known allergies. Depending on your medical history, you might meet an anaesthetist who will assess you regarding your anaesthetic. You do not meet the surgeon at this visit. If you have further questions for the surgeon you would like answering before the day of surgery, please contact the patient pathway coordinator.

Before your admission

It is important to look after your foot before the operation. Keep your feet clean and avoid letting the skin get dry and cracked. Dry between your toes and use some talcum powder to avoid any Athlete’s fungal foot infection. Do not wear tight shoes which risk rubbing and giving you blisters or sores. Do not have chiropody / podiatry care involving cutting of hard skin for two weeks before the operation. If you have any local inflammation or infection in your foot, it is important to let us know. This can increase the likelihood of complications and we may have to re-schedule your operation to a later date. Avoiding smoking and alcohol before the admission as these can slow down the healing process.

The day of surgery

You will be given instructions by the pre-assessment clinic and patient pathway coordinator about when to fast, where to come to on the day of surgery and about your regular medications. The surgical team will see you at the start of the day, put a mark on the correct foot and confirm the consent form details. The operation can be performed as a day case if you are well enough and have someone to take you home. This will be discussed before the day of surgery. Very occasionally, you might need an overnight stay if you found the operation more painful than expected, and you require stronger painkiller injections.

Certain medical problems may mean you need to stay in hospital overnight. You should bring toiletries and clothes that you would need for an overnight stay. Do not bring in items of value, as there is limited secure storage. On discharge, you are allowed to walk taking full weight using a flat post operation sandal, which you will be given. Crutches may be required for balance. The physiotherapist will assess your walking either before or after the operation. If required, they may provide you with crutches for balance.

If you decide to go ahead with the surgery, the operating surgeon and their team will ask you to sign a consent form with the operation name. This confirms that you agree to the procedure and understand what it involves. The surgeon will explain again all the risks and benefits before you sign the consent form.

If you are unsure about any part of your proposed treatment, please speak to a senior member of staff.

You may be asked to complete foot surgery outcome questionnaires before and at different times several time points after the surgery so that we can assess the outcome of the operation. The use of these questionnaires is part of routine governance of our foot surgery practice and they are used for other foot and ankle operations.

If you are invited to be part of a dedicated research project, this will have separate information and details beyond the normal practice.

The operation can be performed under either general anaesthesia (fully asleep on a breathing machine) or using local anaesthetic ankle injections (called a block) with sedation. You will see an anaesthetist on the day of surgery who can talk to you about the options. You will be given a dose of antibiotics to help reduce the risk of infection.

During the operation, a tight band called a tourniquet (like a blood pressure cuff) is placed around your ankle to reduce any bleeding. Your foot is cleaned with an alcoholic disinfectant. The operation is performed through a small cut over the top of the joint and a longer one over the inside of the toe, both of which will give you a scar. The bones and joint are exposed, the osteotomies performed and fixed. An X-ray may be taken during the operation to check the position of the bones and hardware.

The wound is closed with stitches. These are often buried under the skin and will dissolve but sometimes it is necessary to use external stitches which need to be removed at the first post-operative visit. A bulky dressing is placed on the foot which is left in place for up to two weeks. You will be given a wedge-shaped Velcro-strap sandal for walking for six weeks after surgery. You will be able to walk with the shoe which keeps your weight on the heel.

During the first two weeks at home, you should elevate your foot at the level of your hip for as much time as possible and keep the wound dry. Most pain after foot surgery is related to swelling which is common, minimising walking and keeping the foot elevated is the best treatment for swelling.

A few days after your surgery you may see some bruising in the big and little toes which can be normal. If your dressing becomes soaked with blood, you should let the hospital team know as soon as possible.

Call the patient pathway coordinator on 020 3447 9216 or the orthopaedic discharge nurse on 07508 178273 (Monday to Friday 0800-1600) and they will contact the surgical team urgently. If there is an emergency out of hours, you should return to your closest A&E department to be seen.

Two weeks after your operation, the surgical team will see you in the outpatient clinic to check the wound, trim the sutures and apply an elastic toe splint to hold the toe position. You can start bathing the wound for short periods thereafter and apply some simple moisturising cream to your foot, as the skin can be quite dry. If there are some scabs on the scar, these should be protected with a light dressing and should be allowed to come off in time.

You will be seen again in a further outpatient clinic at the six-week mark to assess your progress after the operation and perform an X-ray. If all is well aligned and the bone fixation secure, you will be allowed to walk with a flat Velcro-strap sandal. Following this you will be advised about returning to your own shoes.

Frequently asked questions

You can only drive when you are back wearing your own shoes and able to perform an emergency stop safely. As a bare minimum, this will not be for six weeks. Realistically you are unlikely to achieve this until approximately eight weeks post operation.

Wearing high heels can be difficult and painful as they pinch the big toe and front foot, increase pressure over the bunion and increase the risk of recurrence.

Running may be possible but not for the first three to four months after your operation. It is better to mix up running with other sports activities such as swimming, cycling and cross-training machines. The repeated impact on your foot during running can lead to a stress fracture.

On discharge, you will be given the ward contact details for the nursing team and instructions, with numbers to call if you have any questions regarding your post-operative recovery.

To enquire about your consultant follow up appointment please call the patient pathway coordinator on 020 3447 9216.

Orthopaedic discharge nurse: 07508 178273 (Monday to Friday 0800-1600)

UCLH switchboard: 020 3456 7890

Page last updated: 03 May 2024

Review due: 31 December 2024