Calluses

Areas of skin that grow thick in response to pressure.

Calluses are areas of skin that grow thick in response to repeated pressure and friction. They are the body's way of protecting its skin, or the structures beneath it, from injury. Calluseswill form on the skin of any part of the body that is exposed to excessive pressure or friction. Sometimes calluses are useful.
Labourers and people who work hard with their hands typically develop thick calluses that protect their fingers and palms from nicks, scratches and cuts, and anyone who has ever tried to play a stringed musical instrument will tell you it's a painful process until you develop strong calluses on your fingertips.

Calluses typically occur on the sole of the foot, either on the heel or under one or more of the five Metatarsal heads, the area where the long inner bones of the toes extend into the foot. These two areas typically bear most of the pressure and friction from standing and walking, and respond by growing callusesto protect the skin there. Unfortunately, there is only so much room inside a shoe, and as these callusesgrow thicker, they cause more pressure against the skin. This makes the callus grow ever thicker and, ultimately, they can become painful secondary to pushing on the underlying nerve structures/bone.

Unlike the hand, where calluses reflect normal wear and tear, calluses of the feet normally indicate something is biomechanically wrong in the foot, resulting in excessive pressure between the skin and the underlying bone.

The biomechanical abnormality, (abnormal bone position), causes the bone to take more load with the foot, more than it should.

The excessive pressure causes the fibro fatty padding, a specilised layer of cushioning soft tissue that only occurs on the bottom of the feet and the palms of the hands, then starts to displace away from the pressure point exposing the bone and overlying skin tissue to increase compression or shear stress.

This increase in mechaical stress irritates the deepest layer of the Epitheliem, the Epidermal Junction. The cells at this level, the Basal cells, start to produce more skin cells. They migrate to the most superficial surface of the skin and start to stack up with other extra cells. The normal 14 day to surface and 14 day to exfoliate skin cells cycle is prolonged and the cells continue to be made in excessive numbers.  A Callus, that is simply stacked up dead, excessive skin cells, is then  made.

Typically, callusesdevelop under the Metatarsal heads for two reasons. In many cases, one or more of the Metatarsal heads, usually the first or fifth, is too low, causing it to bear more pressure than the others.  In other cases these callusesindicate one of the Metatarsals is unstable and shifts weight to those adjacent to it. This is commonly seen in people with flat feet (Pes Planus).  Because the plantar arch is too low, the foot is not as stable as it should be. This makes the first Metatarsal, the one connected to the big toe, unstable also. When weight is applied to this area, the first Metatarsal drifts upward, causing the second Metatarsal to accept the extra weight. The second Metatarsal isn't capable of supporting this extra force, and a callus forms where the skin tries to protect the bone.

This process can also happen with the other Metatarsals, and often more than one callus will form on the foot at the same time. In many cases, a single large callus will develop across the entire Metatarsal pad, often on both feet.  If your foot’s callusescause you pain even when you wear proper, “human foot shaped”, shoes that are shaped to fit your feet, the use of a simple orthotic within your foot wear may be enough to maintain good arch and foot alignment and reduce the excessive load at these areas.

If this is not successful, Metatarsal surgery may be considered.

Although the Callus formation may be easily visualised, it is essential that Mr Edwards fully evaluates your condition.

A physical examination of your foot, full medical history taken and an X-ray investigation may be utilised to determine the degree and nature of your deformity.   A plan and appropriate treatment recommendation will then be given.

Identifying and understanding the cause of your Callus formation is vital if we are to treat it successfully and prevent it from re-occurring. They are a product of an underlying structural abnormality, they don’t go away, and will usually get worse over time. Early treatment is recommended as it also helps avoid other associated foot disorders.

While there are many variants of Metatarsal surgery, in principle it is aimed a re-aligning the affected Metatarsal enabling its adjacent Metatarsal to take more load during weight bearing.

This surgery is performed as a day stay procedure, here in our own theatre. This means that you arrive one hour before the scheduled surgery time and go home the same day. The procedure itself can involve cutting the affected Metatarsal and removing a small section of the bone. Screws (and sometimes a plate) are used to hold the Metatarsal in the shortened position until it heals.

Specific Techniques
The patient receives numbing medication for the foot.  An incision is then made on top of the foot in line with the effected Metatarsal. The bone is visualized and a saw is used to make a cut in the bone. The bone is shortened and often lifted to the desired position. It is typically held in place with one or two screws. Sometimes a plate with screws is used. The incision is closed with sutures and  a dressing is applied. A boot or hard-soled shoe is used.

What happens after surgery
Mr Edwards will determine if you are allowed to walk or put any weight on your foot. For some patients, weight bearing is allowed the same day, but for others it may not be allowed for six to eight weeks. The goal is to transition back to supportive shoes at four weeks based on bone healing. It can take up to 12 weeks to get back to regular shoes, and recovery time is largely determined by other procedures performed at the same time as the shortening osteotomy. The overall goal is to be 75 percent recovered at three months, 90 percent recovered at six months, and 99 percent recovered one year after surgery. 

The long-term outcome, prognosis for this type of procedure is good with a complete resolution of the callus and no ongoing requirement for palliative care.

As with many conditions of the foot, the onset of Callus can be largely attributed to the shape of your foot. This is genetically pre-determined so difficult to avoid however appropriate foot wear can help reduce the effects of abnormal Callus formation.

For further advice or to make an appointment, please contact one of our professional team, our numbers and contact details are listed on the Contact page.