Adult cavovarus foot surgery

Summary

This operation is performed for symptoms caused by a cavovarus (high arch) foot deformity.  The inner arch of the foot can develop into a high arch causing patients to walk on the outside of their foot.  There are a number of causes of this but the deformity usually arises from a muscle imbalance.

A high arch foot can cause pain and limit function.  It also puts the foot at risk of recurrent ankle sprains.  Patients can usually be treated in the early stages with physiotherapy, orthotics and footwear modification.  The aim of surgery is to restore the position of the heel , lower the arch and rebalance the tendons around the foot that have contributed to the deformity.

Factors to Consider

You have been diagnosed with an adult cavovarus foot.  This is a condition with varying degrees of severity.  In the early stages the deformity may be managed with simple non-surgical treatments such as orthotics and physiotherapy.  

As the condition worsens the deformity becomes less correctable and so surgery should be considered if your symptoms dictate.  The surgery for cavovarus foot varies between each patient and your surgeon will discuss this with you in more detail.  The main factor causing a cavovarus foot is the overactivity of the peroneus longus tendon that sits on the outer side of the ankle, passes under the foot and attaches to the base of the big toe.  The principles of surgery are to correct these deforming forces to the foot by rebalancing the tendons, through releases and transfers.  Surgery may also involve bony procedures including cutting the calcaneum (heel bone) and/or other bones (osteotomy) and realigning them.

Surgery should help your foot to look and function more normally but it will not make it completely normal.  It is likely that you will still have some weakness and stiffness in your foot even with surgery.  It is therefore important to reflect on how much your symptoms bother you before embarking on what is considered major surgery.

Description of Surgery

The operation can involve a number of different stages.  Tendon transfers , particularly the peroneus longus and tibialis posterior tendons, are commonly required to rebalance the foot.  This involves releasing the insertion of the tendon and reattaching that to a site on the foot which will help the foot maintain more normal function.  Other muscles or tendons may also require releases.  The Achilles tendon may need to be lengthened to allow the heel to strike the ground first when walking.

The heel bone (calcaneum) is surgically cut (osteotomy) and the 2 bone fragments then realigned and fixed in their new position using screws to bring the heel back under the foot.  A further ostoeotomy may be needed to the 1st metatarsal bone to flatten the arch.  

A cavovarus foot can cause other problems around the foot and ankle including recurrent ankle sprains or clawing of the toes.  Your surgeon will discuss with you if you need surgery for these as well.  Recurrent ankle sprains may need to be treated with ankle arthroscopy and/or a Broström repair.  These operations can be performed at the same time as your surgery.

Your surgeon will discuss with you which aspects of the surgery your foot requires as this will depend on a number of factors.     

The operation takes about 2-3 hours.

Anaesthetic

The operation is usually performed under a general or spinal anaesthetic and so you will be given instructions as to when you need to stop eating and drinking (normally the night before) before you come into hospital.  

Your pain can be well controlled with local anaesthetic given during the operation.

What are the risks?

All operations involve an element of risk.  The risks for this particular operation are small but it is important that you are aware of them.

The main risk for this operation is a failure of the reconstruction.  The osteotomy needs to heal and, while the surgery provides the stability for this to occur, you provide the “biology”.  Smoking affects this and so you should stop before surgery if you do smoke.  

The risk of infection is small and is thought to be about 1%.  Most infections will settle simply with antibiotics.  Damage to nerves and blood vessels around the foot can also occur.  

Any major surgery to the foot increases the risk of developing a clot in your leg (DVT).  Your surgeon will assess your risk of this prior to surgery and may offer you blood thinning medication if your risk is considered high.

After Surgery

Pain

Local anaesthetic will be used during the operation and so you will feel comfortable when you first wake up.  This can last 12-18 hours but the foot may be sore after it wears off. You will usually stay in hospital overnight on the day of surgery. You will be given a combination of pain killers to go home with.  

Dressings

You will wake up with your foot in a plaster.  Your foot will remain in plaster for the first 6 weeks and you will not be allowed to weight bear during this time.  The surgeon will give you instructions as to when you can start weight bearing as this will depend on the appearances on the Xray.  It is likely that you will need to be placed in a walking boot until 12 weeks following surgery.   

Physiotherapy

The physiotherapist should see you before the operation to explain some simple exercises you can do after the operation.  They will also ensure a physiotherapy appointment is made for you once the plaster has been removed.  Physiotherapy can be arranged local to you.  

Driving

You can drive when you feel you are safe to drive.  This means that you feel confident that you have full control of your car and are able perform an emergency stop.  This will vary between patients but normally takes atleast 12 weeks, unless the surgery is on your left foot and you drive an automatic car.  

Return to work

This depends on what your job is.  You should be able to return to a “desk job” within 6 weeks of your surgery.  If you have a more manual job it can take 12 weeks before you feel ready to return to work.  Please discuss this further with your surgeon or physiotherapist if you feel unsure.  A sick note can be given to you at the time of your surgery if required.  Please ask the nurses on the ward if you need one.

What to expect

Recovery following surgery can be quite variable but the expectation is that “it takes 3 months to be fair, 6 months to be good and 12 months to be right”.