written by Dr SW KONG
Last update: Aug 26th 2020
What is Hallux valgus/Bunion ?
Hallux valgus is the medical term for "bunions" (Fig. 1). "Hallux" is the medical term for the big toe and "valgus" refers to the abnormal angulation of the big toe towards the second toe. Usually there is also a bump at the base of the big toe on the inner aspect of the foot, which is called a 'bunion' (Fig. 2).
What causes hallux valgus/Bunions?
The toe gets 'out of balance'. This biomechanical abnormality may be caused by a variety of conditions intrinsic to the structure of the foot - such as flat feet, excessive ligamentous flexibility, abnormal bone structure, and certain neurological conditions. These factors are often considered genetic. Although some experts are convinced that poor fitting footwear is the main cause of bunion formation, others believe that footwear only exacerbates the problem caused by the original genetic deformity. Nevertheless, it is not surprising to learn that women wearing tight fitting fashionable shoes more commonly have hallux valgus.
How does it affect me?
Mild hallux valgus can be no problem except for the prominence of the bunion. Severe hallux valgus can lead to recurrent inflammation and pain over the bunion due to the repeated friction with shoe wear, difficulty in fitting shoes, second toe or other lesser toe deformities due to overcrowding, and calluses on the sole. These may cause pain walking. Hallux valgus often progresses from mild to severe because of the biomechanical imbalance, but progress can be slowed, or sometimes stopped with appropriate shoewear modifications.
How is hallux valgus/Bunion diagnosed?
History: Most patients complain of deformity and pain.
Examination: Reveals the combination of problems described above.
Investigations: Weight-bearing X-rays are usually sufficient to understand the problem (Figs. 3, 4 & 5). Blood tests are sometimes needed if there is a suspicion of rheumatoid arthritis.
Could it be anything else?
The commonest alternative cause of pain and swelling at the base of the big toe is osteoarthritis of the joint at the base of the big toe, known as 'hallux rigidus'. In hallux rigidus the joint at the base of the big toes is usually painful, whereas in hallux valgus the joint is deformed but usually painless. For information on hallux rigidus see the 'Hallux Rigidus FAQs'. Sometimes one can have both problems, and in severe longstanding hallux valgus the joint can develop arthritis.
Pain at the base of the big toe is often assumed to be caused by gout, but this can be a surprisingly difficult diagnosis to confirm. Often patients labelled with 'gout' turn out to have 'hallux rigidus'. Athletes with bunions can develop pain because of stress fractures and other problems  - because one has bunions it does not mean the bunion is automatically the source of any pain in the foot.
What are the treatment options?
Mild cases with minimal symptoms may be OK with minor shoe wear modifications - wider shoes, soft materials, the use of a special shoe-tree to pre-stretch shoes, possibly custom-made shoes, and, as much as possible, avoiding very high heels.
Moderate cases may be helped with the addition of 'orthotics'. One's podiatrist will help. A hallux valgus splint for night-time stretching helps to slow down progress, a spacer between the big toe and the second toe helps to avoid friction during the day, and a medial arch support insole corrects any associated flat feet. Claw toe splints can help to prevent lesser toes rubbing on shoes. Whilst orthotics can be helpful, they are not very convenient and do not 'cure' the problem – they only help while they are worn.
Severe cases with intractable symptoms or failure of orthotic treatment are best treated by an operation. Operation is the only method to 'cure' hallux valgus, by correcting the deformity and rebalancing the toe. Most surgeons would recommend surgery only if a patient had pain, and not simply for cosmetic reasons, though the foot will look much better afterwards.
What kind of operation should I have?
There are more than a hundred hallux valgus operations described in the medical literature, but no one operation has proved itself to be the best. However, most modern operations have the same underlying principle: to 'rebalance' the toe by correcting all the deformities and making the foot as biomechanically normal as possible (Fig. 6).
Fig. 6 The operation has corrected all the deformities: the toe is straight, the metatarsals aligned & the sesamoids (circled) in place.
The exact operation performed depends on an individual's particular combination of problems, and it is usually necessary to perform a number of procedures to deal with each of the deformities:
Bunion: The bone forming the bunion is usually cut off with a saw.
Deviation of the big toe: This is usually caused by a combination of the 1st metatarsal bone in the foot deviating one way and the big toe deviating in the opposite direction. Both deformities are corrected, often by carefully cutting (osteotomising) the 1st metatarsal and fixing it in a new position with small screws buried in the bone, and also by releasing the tight tissues on one side of the big toe and 'taking up the slack' on the other side.
Lesser toe deformities: The toes are straightened so they no longer rub on shoes or jam on the floor.
Flat feet: Flat feet contribute to the problem of bunions, so it is often helpful to correct them – often the best method is to osteotomise the heel bone and fix it with buried screws, usually combined with a procedure to tighten up the loose ligaments.
Bunionettes: If a bunion of the little toe causing problems, this can be corrected with a small osteotomy of the 5th metatarsal at the base of the little toe.
Are there other operative options?
As mentioned above, there are over a hundred operations, but the alternatives which patients most wish to know about are 'minimally invasive' procedures with smaller scars, and/or 'non-osteotomy' procedures, which do not involve cutting the bones.
There are some promising new techniques, some of which I use in less severe deformities. If it is possible to achieve the primary goal of fully correcting the deformity and rebalancing the toe by a minimally invasive or non-osteotomy procedure, I do so, but I do not compromise the operation (and thus the result) for the sake of a slightly shorter scar (Fig. 7).
Fig. 7 The operations require three incisions for the toe, and, if a calcaneal osteotomy is needed, another incision over the heel. They heal well.
What will my feet be like?
Most people are delighted with the result of the operation, as their foot looks normal, they can wear normal shoes, and usually any pain goes away. The big toe resumes its normal job actually helping one to walk, and with better walking biomechanics people look better and can walk further and faster. One can return to sport.
Most people go on to have the second foot operated as they are pleased with the result of the first foot.
What does operation involve?
Hallux valgus operations are performed in the operation room in the hospital. Usually we anaesthetise the foot by injection local anaesthetic around the ankle – this is called an ankle block, and it lasts for quite a few hours after the operation, thus providing excellent post-operative pain control. It is possible to perform the surgery with an ankle block alone, but I also usually use a tight tourniquet around the thigh to prevent bleeding during the operation, and the tourniquet can be uncomfortable, so I recommend additional light anaesthesia – either a light general anaesthetic or a spinal or epidural anaesthetic as-well-as or in-place-of the ankle block, and, with this anaesthetic, one can be awake or asleep during the procedure. The operations take from 45 minutes up to 2 hours depending on what is required. Incisions are made in various places as required, the operation is performed to correct the deformities, the incisions are stitched closed (usually with invisible dissolving sutures) and, usually, a waterproof fibreglass cast is applied to protect the foot. One rests in hospital with one's foot up for at least 24 hours, to allow any bleeding to stop, and then goes home with the aid of crutches.
What happens after the operation?
One walks with the aid of crutches for 2 weeks, keeping the weight off the operated foot. After 2 weeks, one starts walking on one's heel and after another 2 weeks one walks 'flat footed' without flexing the forefoot. This progression occurs almost automatically and one does not have to worry about it – essentially, as one's foot recovers, one's limp improves. Physiotherapy helps to make one feel more comfortable, to walk more easily and to regain strength and flexibility of the foot. Even though one may be able to squeeze one's newly dainty feet into tiny shoes (after the swelling has settled, which takes a few months), I advise avoiding very narrow, very high heeled shoes, as these are likely to increase the rate of recurrence. I recommend saving such shoes for parties!
When can I return to work?
This depends on the type of surgical procedure, one’s occupation and the accessibility of one's place of work. Usually it takes 4 weeks to 4 months, depending on one's job.
One can start walking with crutches without bearing weight on the operated foot for the first 2 weeks, and then gradually increasing weight bearing as comfort allows.
If one can work at a computer with one's foot up, use crutches and take breaks as needed, one can return to work in as little as one week. If one needs to stand for long periods and be physically fit to work, for example, as a police officer or flight attendant, it will more likely be 4 months before one is able to return to normal duties.
Can I have both sides done together?
I do not recommend this, as one will be very disabled for the first few weeks, and some patients lose their surgical correction because of the difficulty protecting two operated feet. For people in a hurry, I recommend staged operations by planning for the second foot to be operated about 4 weeks after the first foot.
If time is really a concern, for instance for people who cannot return to work until they are fully fit, for example, police officers, I do perform simultaneous procedures on both feet, however if one is an office worker, it is much easier to have the procedures staged, and the result is likely to be better. Patients who have both feet operated simultaneously usually concede the first few weeks are 'difficult', even if they are lying on the sofa with their feet up, being looked after by relatives!
What are the risks of operation?
There is a very small risk of complications associated with an anaesthetic, though, on the whole, modern anaesthesia is very safe. Surgical risks are divided into general risks, which can occur in any operation, and specific risks of hallux valgus surgery. General risks include a small risk of infection, a clot (deep vein thrombosis or 'DVT') possibly leading to a serious pulmonary embolus. These are all uncommon in foot and ankle procedures .
Specific risks include:
Under-correction or recurrence: There is no clear guideline for what constitutes a ‘standard’ result, as the results can vary with the severity of the deformity, the extent of soft tissue rebalancing required as well as the site and extent of any bony correction. Recurrences are not common, and depend to a large extent on one's choice of shoes.
Over-correction: There is a small chance of correcting too much and producing 'hallux varus' with the big toe being deviated inward. This is mostly a cosmetic issue, but could require repeat surgery. Documented incidence is 1-3% .
Avascular necrosis: Loss of blood supply to the bone leading to bone death, causing pain and other problems. This is uncommon and has become less common since the modification of soft tissue release procedures .
Pain: It is normal for one's feet to be quite uncomfortable for a few weeks, but very occasionally one may experience unusually severe pain due to nerve 'overreaction' – this is known as "causalgia" or "complex regional pain syndrome" and may require treatment by a pain specialist.
Nerve damage: It is common to get a little numbness or pins & needles near to the incisions due to damage to small nerves in the skin. This does not usually worry people. Tourniquet application for the bloodless surgical field may sometimes causes temporary numbness due to the nerve compression, which usually recovers within 2 – 3 days, however individuals with underlying nerve degeneration, such as in diabetes, could have more severe problems. Very occasionally there is damage to a larger nerve resulting in numbness of a larger area of the foot – this can be unpleasant - annoying or disturbing, but is not usually a serious problem .
Swelling: It is normal for the foot to be quite swollen for about 3 months and for it to take a full year for the foot to return entirely normal. This is not a complication, it is a normal result of gravity.
Stiffness: This may occur due to the initial period of immobilisation. Once the tissues are healed the physiotherapists will supervise stretches.
Implant problems: If an implant, such as a screw, is used for bony fixation, skin impingement, loosening, breakage or infection, may occur. If so, the implant may need to be removed – this is a very minor procedure with a very quick recovery. There is no need for routine implant removal. Most of the implants are buried entirely in the bone and cannot be felt.
Is there anyone who should not have hallux valgus surgery?
People who are really not very healthy, for example with medical problems such as heart disease, are at higher risk of complications, and it would be necessary to carefully weigh the risks and benefits.
People with poor blood supply to the feet are at greater risk, and it would be necessary to carefully weigh the risks and benefits.
Active infection in the foot is an 'absolute contraindication' – it would need to be treated first. Diabetes is not an absolute contraindication for surgery, but it would be necessary to carefully weigh the risks and benefits. Individuals who are unable to cope with the demands of the rehabilitation should not have surgery.
Children. This is not an absolute contraindication, hallux valgus can occur in quite young people, but in general I advise delaying until skeletal maturity, usually around 13 years of age, if possible.
See the American Academy of Orthopaedic Surgeons website http://orthoinfo.aaos.org.
1. Brockwell, J., Y. Yeung, and J.F. Griffith, Stress fractures of the foot and ankle. Sports Med Arthrosc, 2009. 17(3): p. 149-59.
2. Thalava, R. and R. Thalava, Venous thrombosis after hallux valgus surgery.[comment]. Journal of Bone & Joint Surgery - American Volume, 2004. 86-A(4): p. 872; author reply 872.
3. Sammarco, G.J. and O.B. Idusuyi, Complications after surgery of the hallux. Clinical Orthopaedics & Related Research, 2001(391):p. 59-71.
4. Shariff, R., et al., The risk of avascular necrosis following chevron osteotomy: a prospective study using bone scintigraphy. Acta Orthopaedica Belgica, 2009. 75(2): p. 234-8.
5. Tarver, H.A., et al., Techniques to maintain a bloodless field in lower extremity surgery. Orthopaedic Foot & Ankle Surgery, 2000. 19(4): p. 65-73.
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