Dorset Foot & Ankle Clinic

Figure 1 – preoperative x ray, showing a widened 1st / 2nd intermetatarsal angle

Figure 2 – post operative x ray of the patient seen in figure 1. The two screws are for the Scarf osteotomy, and the staple is for the akin osteotomy. You can see how the intermetatarsal angle has been corrected, and the big toe is now straight, with no bunion

Figure 3 – This lady, pictured just before surgery has a severe hallux valgus and bunion requiring a Lapidus Fusion procedure

Figure 4 – These X Rays show the typical sever hallux valgus and the result from a Lapidus Fusion

Bunions (Hallux Valgus)

Bunions, otherwise known as hallux valgus, occur when the big toe deviates towards the lesser toes. This is usually associated with a prominence on the inner side of the foot, which is the bunion itself. A common misconception is that the bump is caused by extra bone growing in this place. This infact is not the case. The bump on the inner side of the foot occurs as a combination of 2 of the bones on the inner part of the foot splaying apart (the 1st and 2nd metatarsals) as well as the big toe deviating laterally (outwards) – see figure 1.

Causes of Bunions

There are many causes of hallux valgus described. When they occur in younger patients, there is often a strong family history, particularly down the female side of the family. They are occasionally associated with poorly fitting shoes and may occur as a result of an imbalance in the muscles of the foot. They can also occur in conjunction with arthritis of the big toe. This is known as hallux rigidus, although bunions often exist in the absence of any significant arthritis.

Symptoms of Hallux Valgus

The most common symptom is pain. This usually occurs in the region of the bunion, although may also occur under the foot across the forefoot. This is known as transfer metatarsalgia and occurs as a result of failure to take weight through the big toe as a result of the hallux valgus deformity. Other symptoms include problems with footwear and corns and callosities due to the misshapen toes.

Treatment

1. Non Operative Treatment

This includes modification of footwear, usually in the form of wider shoes with a high toe box to accommodate any hammer toes. Various forms of splinting and padding can be used to control the symptoms, although there is no evidence that any splints will reverse the process of the hallux valgus once it has begun.

2. Surgery

Over the last 75 to 100 years, more then 100 surgical procedures have been described to treat hallux valgus! Here at the Dorset Foot and Ankle Clinic, we use the latest surgical techniques to ensure the best possible results. The type of hallux valgus that you have, combined with other factors, will determine the nature of the surgery that you undergo and this will be discussed with you by Mr Taylor and Mr Farrar. The most common procedures that we perform are listed below.

(a) Scarf osteotomy
This involves cutting the 1st metatarsal with a fine saw in a controlled manner. It allows an excellent correction of the divergent 1st and 2nd metatarsals. The osteotomy is stabilised with 2 screws. The screws that we use at the Dorset Foot and Ankle Clinic are Barouk screws (De Puy). These are the very latest technique in stabilising this procedure and provide excellent fixation. We may also perform an Akin osteotomy which is a small wedge cut at the base of the big toe to bring the toe to a straighter position. Post-operatively you may not require to be in plaster, although this will be discussed with you by Mr Taylor or Mr Farrar.

(b) Chevron or Mitchell’s osteotomy
This involves a cut in the end part of the 1st metatarsal just below the bunion itself. This is a technique used for more mild to moderate deformities that do not require as extensive an operation as the Scarf osteotomy. Again this is stabilised with a single screw and you may or may not require to be in plaster of Paris post-operatively.

(c) Lapidus fusion
This is a procedure reserved for the most severe hallux valgus deformity. It is also used in patients with hyper-mobile joints. It involves fusing a joint in the middle part of the foot near the instep. Stabilisation of the fusion is achieved usually either with screws or staples. The staples that we use in the Dorset Foot and Ankle Clinic are Memory staples (De Puy). These provide excellent fixation, although you will require to be in plaster for at least 6 weeks post-operatively.

(d) Beware!
A number of procedures for hallux valgus are now considered out of date. In particular these include a simple bunionectomy and a Keller’s procedure. The simple bunionectomy involved simply cutting off the bump on the inner part of the foot. This is a procedure very rarely performed here at the Dorset Foot and Ankle Clinic as the long term results are often disappointing with rapid recurrence of the deformity. The Keller’s procedure again is a rather old fashioned procedure that is used only for the most severe deformity in immobile patients. This is not a procedure that we would recommend for patients who are active as the results are often very disappointing.

Mr Taylor and Mr Farrar will of course discuss the surgery with you in detail when you attend for your outpatient appointment and can answer any questions relating to the above procedures, or any other procedures, that you should have.