Although foot surgery is fairly common in people with CMT, it should usually be carried out only when less invasive measures, such as orthoses, have failed. The foot is a complicated part of the anatomy: even minor surgery has some risks, whether it is from the surgery itself, the anaesthesia or the recovery period.
The aim of surgery is to:
Operations range from straightening the toes, particularly the big toe, to fairly major surgery on the ankle joint.
Terms you may hear include:
Tendon transfers – moving a working tendon and muscle group and attaching the end of the tendon to a new place so that it works in a different manner. Often the tendon/muscle causing the deformity is moved to work in the opposite direction to prevent the chance of deformity occurring again.
This kind of surgery can be extremely successful – giving a much better long term outcome than bony surgery – and needs less revision in the future. However, ideally it must be done before deformities become fixed – in other words, whilst the foot can still be put into the correct position manually.
Osteotomy – cutting the bone and repositioning it. Usually the bone is fixed in its new position with plates, screws and other devices. Sometimes in cases with drop foot, the drop foot can be improved or overcome by tendon transfers or osteotomy.
Triple arthrodesis – stabilising the hind foot joint by stiffening (welding) three joints together (arthrodesis is another term for ‘fusion’), preventing movement in two directions (left-right and ankle tilt). A triple arthrodesis is only carried out once the foot has stopped growing – usually no earlier than 12 in girls and 14 in boys – and sometimes later. This surgery is rarely carried out, unless there really is no choice, due to the risk of developing arthritis in other ankle joints later in life.
Plantalar fusion – triple fusion combined with ankle fusion, for the most severe cases of inturned ankle and feet, fuses the ankle as well as the triple joints. It leads to a very stiff ankle region, with loss of drop-lift of the ankle as well as the left-right and ankle tilt of the triple fusion. On the plus side, it gives a straighter and more stable ankle in cases where recurrence is otherwise likely.
Foot problems most commonly considered for surgery include:
If clawing of the toes is the only problem being addressed by surgery, then tendons may need to be transferred to release the pressure causing the clawing, as well as fusing the joint in the middle of the toes to prevent recurrence. Operations on claw toes are often done at the same time as other procedures such as osteotomy and arch correction.
Turned-in heel (heel varus)
If turning in of the heel is not adequately corrected by orthotics, some cutting of the bone may be needed. A wedge of bone will be removed from the heel bone so that the heel can be straightened.
High arched foot (cavus foot/pes cavus)
If there are no bone deformities, the goal of surgery is to release the tightened muscles and ligaments, relaxing the bottom of the foot so that it flattens, as well as releasing pressure on the toes so they do not become clawed. Tendon transfers may also be necessary.
If there are bony deformities, some removal or cutting of the bone (osteotomy) will be needed, as well as muscle and tendon transfers, removing the pressure that leads to a high arched foot.
Operations to correct the position of your foot include:
Operations to rebalance the pull of the muscles in order to prevent the deformity returning include:
Surgery may also include one or more of the following: soft tissue releases; other tendon transfers; other bone procedures; and joint fusions.
These procedures should result in:
Full recovery may take up to twelve months
The recovery time from surgery is often very long. Doctors tend to refer to recovery time from surgery as being the time in plaster – around eight weeks. In fact, it can take much longer to achieve decreased pain and return of function – a year or two for complete recovery from aching and swelling in some cases.
You may well need help with everyday tasks following the operation. It is very important to rest and keep your foot elevated.
People having major surgery requiring casts or splints will normally be prescribed some kind of blood thinning drugs, as recommended by NICE (National Institute for Health and Care Excellence). People with reduced mobility – such as that caused by CMT – may be at particular risk of developing blood clots in the leg or lung, which are potentially very serious complications. Before you leave hospital, make sure you know how long you need to be on the prescribed drugs and that you are fully trained in administering them: some of them have to be injected by you or a relative.
The physiotherapists in the hospital may expect you to be able to ambulate with crutches or a Zimmer in the ‘normal’ fashion, by hopping – possibly before they sanction your discharge. You may well not be able to do this, due to the weakness in your arms and wrists, so do not be afraid of standing up for yourself, and explaining clearly why this is unsafe or difficult for you to do. You will need to have made a plan as to how you will manage in your home if you cannot get around using crutches. Do you have a wheelchair or can you borrow one in the short term? Can you get in and out of a wheelchair safely, or will you need a transfer board? Is there room to get around your home in a wheelchair? Can you get in the front door? How will you get to the toilet or upstairs to bed? It is far better to plan all these things well in advance of the surgery, so that you can inform the staff that all is organised. Your community occupational therapist can help you get any equipment you require before the surgery takes place. Otherwise, it is unlikely that any equipment could be put in place quickly enough before you are discharged.