A flat or low arched foot is not considered abnormal, the height of the arch does not have any bearing on how well a foot can function. A foot that rolls in excessively with most of the weight passing over the inside border is a cause for concern. Treatment is required in the severe cases were the degree of mal alignment is such that the patient experiences pain or fatigue or is likely to do so. These patients are considered to have a pathological flat foot. The majority of these cases respond to stretching exercises, orthoses (shoe inserts) and supportive footwear. If the patient doesn’t respond to conservative treatment or only in a limited fashion, then surgery might be considered.
Causes of a Pathological Flat Foot
- Congenital mal alignment
- Tendon injuries, typically Tibialis posterior
- Neurological and muscular diseases
- Joint hypermobility
- Abnormal joining of two bones (coalition) resulting in a rigid flat foot
Types of Flat Foot
Here the foot is poorly aligned when standing but when sitting with the weight off the foot the deformity corrects itself.
Here the foot remains in a poor position irrespective of whether it is weight bearing or not.
The diagnosis is made by the examining the foot in combination with investigations, such as X-ray, Ultra sound scanning and MRI.
- Stretching exercises for the calf and hamstring muscles
- Physiotherapy to strengthen muscles and improve coordination
- Orthoses (Insoles), ankle braces
- Anti inflammatories and analgesics
- Local steroid injections
- Supportive shoes
This involves a combination of techniques to restore alignment of the foot to the lower leg and includes osteotomies (cutting bones to re-align them), fusing joints, tendon lengthening and transfers as well as implanted devices to help maintain correction. The combinations required for you will be determined by Professor Tagoe and will be discussed with you prior to your operation.
The operation will probably incorporate several different procedures in order to get a well positioned and functional foot. Listed below are the common ones. Professor Tagoe will indicate which ones are applicable to you. The operation normally lasts for about 90 minutes with a cast put on the leg in theatre whilst you are asleep. The cast will run from just below your knee to your toes allowing us to maintain correction whilst the your body is healing reducing the likelihood of damage. Dissolving sutures will be used to close the skin.
Lengthening of the Calf Tendon
A tight calf muscle will cause your foot to roll in. This can be rectified by lengthening the tendon just below the calf muscle (gastrocnemius). An incision of approximately 6cm is made in centre of the back of your leg and the tendon lengthened. Lengthening of the tendon allows normal foot function but the calf is often weaker than the other side. Rarely the sural nerve is irritated leaving numbness or hypersensitivity to the lower leg.
Tibialis Posterior tendon shortening
The Tibialis posterior muscle is a powerful antagonist to the foot rolling in. In some cases the attachment of the tendon is affected by an extra bone (Os Naviculare) or the tendon is too long both affecting its function. The surgery here shortens the tendon and if present removes the accessory bone. The incision runs from around the ankle to the midfoot.
In cases where the tibialis posterior tendon has torn the foot will collapse inwards. In most cases the tendon is beyond repair. The torn tendon would consequently be replaced by a nearby tendon (flexor digitorum longus tendon). This tendon can be used without greatly affecting lesser toe function, as there is another tendon, which performs almost the same job within the foot. Flexor digitorum longus tendon would be cut and attached under tension onto the navicular
Calcaneal (Heel Bone) Osteotomy
This procedure is used to place the heel back in line with the lower leg. In cases where the foot excessively rolls in, the heel bone can also tilt out of alignment. If this is the case then the heel bone is cut and the alignment restored. This helps provide greater stability and improve the leverage of muscles tasked in controlling the position of the foot.
Sinus Tarsi Implants
Placing an implant into the gap between the calcaneus and the talus called the sinus tarsi controls excessive rolling in of the foot. When the foot rolls in this gap reduces in size and expands when the foot rolls out. By placing the right size implant in the sinus tarsi we can limit the amount of rolling in (pronation) of the foot. This implant is normally well tolerated by the patient, but in certain cases it can cause irritation and as a consequence would have to be removed. Whilst this is not common, we have noticed that when the implant is removed not all the correction is lost.
Evans Calcaneal Osteotomies
This procedure lengthens the outside of the foot in cases where the foot has become severely mal-aligned. The procedure is normally reserved for the younger patient who has a mobile flat foot. The heel bone is cut and a bone graft is inserted lengthening the lateral border and increasing the arch height and stabilising the foot. This procedure is commonly performed on children.
The diagram shows the forefoot rotated outwards on the hind foot. The X-ray below shows a bone graft placed in the heel to lengthen the outside of the foot. The position of the graft and heel bone is maintained with a plate.
Fusion of the Foot
In cases where the foot is rigid either as a result of arthritis or the abnormal formation of bones (coalition) then a fusion of part or all of the major (large) joints in the foot might be considered. The ankle is not included allowing the foot to move up and down, but the rolling in and of the foot would be restricted. The foot would be repositioned to restore alignment and stability.
Before you leave the hospital the physiotherapists will show you how to maneuver around on crutches non-weight bearing as the operated leg will be in a cast and you will not be able to put the foot to the ground. Patients have found the IWalk very helpful enabling them to ambulate without crutches
- A combination of anti-inflammatories and analgesics will be prescribed for you to take away.
- Being in a below knee cast increases the risk of developing a deep vein thrombosis. As a consequence daily injections of low molecular weight heparin will be necessary to reduce this risk. You will be given these drugs to take away as well as being shown how to perform this simple procedure.
You should arrange to go home via car or taxi with an escort. You are advised to have someone with you for the first twenty-four hours in case you feel unwell.
You must rest with the leg elevated for the first 48hrs (essential ambulation only). It is important that you keep the cast clean and dry. Professor Tagoe will see you for a dressing change 3-4 days post surgery, here the cast will be removed and the wound inspected. An X-ray will be taken to ensure good position and stable internal fixation.
A Typical post-operative regime is 8 weeks in a below knee cast with a further 4 weeks partial weight bearing. The length of time you are in a cast for depends on the procedure and how well you are healing.
Once the cast has been removed exercises will be prescribed along with physiotherapy. Returning back to activity and regular footwear is gradual and very much depends on the type of operation, your body’s healing response and the individual’s level of motivation. Once the cast is removed and you are advised to return to a supportive shoe e.g. trainers with driving as soon as you feel you feel safe.
Approximately 900 patients undergo foot surgery annually within the Department of Podiatric Surgery at West Middlesex University Hospital. Most patients have an uneventful recovery.
Outlined below are the common problems or those rare complications with serious outcomes. In cases where we don’t have accurate audit we have used published results from the podiatric literature. These are accompanied by an asterisk *.
- Prolonged swelling taking more than 6 months to resolve occurs 1 in every 500 *
- Haematoma – a painful accumulation of blood within the operation
- Thick and or sensitive scar.
- Adverse reaction to the post-operative painkillers. 1 in every 50 patients report that the codeine preparations can make them feel *
- Infection of soft The incidence is 1 in every 83 operations. *
- Delayed healing of soft
- Circulatory impairment with tissue loss occurred in 3 out of 9000 patients over a 10-year
- Deep vein thrombosis, a complication of which would be a clot that dislodges and settles in the This is potentially a life threatening condition. Within the published literature, deep vein thrombosis requiring treatment after surgery is 0.3%. *
- Chronic pain syndrome: this is where the nervous system dealing with pain over reacts in a prolonged manner often to a minor This normally requires management by specialist in this condition and doesn’t always resolve. This is a rare complication with no audit data available.
The risk of having a complication can be minimised when the patient and all those concerned with the operation and aftercare work together. This starts with the pre-operative screening and continues through to the rehabilitation exercises.
Pre-operative screening of your health allows us to determine whether you are fit for surgery. It is important that you disclose your full medical history. If there is a query regarding your health, then further investigations or the advice of other surgical and medical specialties will be sought. Professor Tagoe and the theatre team will ensure that the operation is performed effectively and with the minimum of trauma.
You can improve the healing process and reduce the risks of complications by:
- Adhering to the post-operative instructions, which include resting and elevating the operated Keeping the wound clean and dry until advised otherwise is essential. Please ask the nurse or Professor Tagoe if you are not sure what to do.
- Having a healthy diet is This provides the nutrition required for healing.
- Smoking is associated with a 20% increased risk of delayed or non-healing of
- Alcohol can interact with the drugs that we will prescribe and in excess can impair wound
- Post-operative mobilisation will be This helps improve the flexibility, strength and stability of your foot.