Midfoot Fusion

Mid Fusion Xray weight bearing

Arthritis or an injury to the middle of your foot can cause pain and swelling making walking very difficult. In some cases fusion of the bones in your midfoot may ease your pain and aid your mobility. This operation removes any degenerate joints and fixes the joints together, with the aim that bone will grow across and 'fuse' the joints. The joints will then be rigid and no longer painful. These joints have very little movement normally and the fusion will cause no noticeable change in the function of the foot, in fact it should be significantly better with the loss of pain. Normal walking and activity will not be altered.

The surgery is performed through 1-3 incisions over the top of the foot. The arthritic joint surfaces are excised (cut out) and the joint fixed together with screws. The operation takes approximately 2 hours.

Risks of surgery

Swelling

Initially the foot will be very swollen and needs elevating. The swelling will disperse over the following weeks & months but will still be apparent at 6-9 months.

Infection

This is the biggest risk with this type of surgery. You will be given intravenous antibiotics to prevent against it. The best way to reduce the chance of acquiring an infection is to keep the foot elevated for 14 days. If there is a mild infection, it often resolves with oral antibiotics. If the infection is severe, it may warrant admission to hospital and intravenous antibiotics. A severe infection often results in failure of the fusion, and extremely rarely may result in an amputation at a later date.

Malposition

Ideally, the foot is fused in a position that allows optimum function and gives the best appearance. I take great efforts to judge the best position for the fusion at surgery, but as you are asleep and lying down, it is not always possible to achieve this 'best' position. If the position is not optimal following surgery, most deformities can be accommodated by insoles and shoe ware. Rarely is further surgery required.

Non Union

This is when the joint fails to fuse and bone has not grown across the joint. We won't know whether this is the case for 6-12 months. The risk of this is approximately 5-10%. Smoking increases this risk 16 times.

If a non union does occur and is painful, then further surgery is usually needed.

Nerve Damage

The top of the foot has 3 nerves – the superficial peroneal, deep peroneal and saphenous nerves. They supply sensation to the side and the top of the foot and toes. They may become damaged during the surgery and this will leave a patch of numbness, either at the side of the foot or over the top of the foot and toes. This numbness may be temporary or permanent. There is approximately a 10-15% of this happening.

Recovery from surgery

After surgery, your leg will be immobilised in a backslab (half plaster) for 2 weeks. Elevation of the foot (above the pelvis) for the first 10 days is vitally important to prevent infection. Naturally, small periods of walking and standing are necessary, but no weight must be taken through this leg for 6 weeks.

After 2 weeks the backslab will be removed and the stitches taken out, here in clinic. Another non-weight bearing plaster is applied for a further 4 weeks. At this stage you will be reviewed in clinic with x-rays and changed to a weight bearing plaster for a further 6 weeks.

You will be reviewed again at 3 months following surgery, with x-rays. If all is well, no more plaster casts are needed and you can walk freely. Usually no physiotherapy is required. If the fusion has not completely healed, then a further 6 weeks in a weight bearing cast will be necessary.

 

Mid Fusion Xray

 

Activity and time off work

In general, 4 weeks off work is required for sedentary posts. 12 weeks for standing or walking posts. 16 weeks for manual / labour intensive posts.

It can take several months (9-12) for swelling to settle. Continue to elevate your foot as needed.

Once your fusion is achieved you should be able to return to wearing normal shoes and resume exercise.

Follow up

  • 2 weeks for removal of sutures & Change of Plaster
  • 6 weeks in Mr Rosenfeld's clinic: COP to WB cast / X-ray Foot AP, Obq & Lateral
  • 3 Months: Removal of POP / X-ray Foot AP, Obq & Lateral WB / Mobilise FWB out of POP
  • 6 months for final assessment if no complications