Q My husband is suffering from a 'calcium claw' on the heel of his foot. It's painful and makes it difficult to walk. Both his sister and mother have the same problem, so it would seem to be genetic. What exactly is a calcium claw and, apart from steroid injections, is there any alternative treatment? - Shirley Robinson, Cumbria
A Another name for 'calcium claw' is a 'heel spur'. Contrary to popular belief, this abnormal, hook-like bony growth is not the main cause of the pain. Heel spurs form as a consequence of several medical conditions, the most common of which is plantar fasciitis.
This term refers to an inflammation of the plantar fascia, the thick, taut band of fibrous tissue that runs from the heel to the ball of the foot, and forms the arch. Each time the foot hits the ground, the tension causes the fascia to pull at the heel. With time - and repetitive trauma - the fascia starts developing small tears around the heel, causing the area to become inflamed and painful. In attempting to keep the fascia attached to the heel, the body lays down more fibrous tissue and calcium, resulting in the spiky heel spur. As the spur grows, it digs into the fibres of the fascia, thereby exacerbating the inflammation and increasing the pain.
Several factors increase the chances of developing this condition, including - as you've already guessed - genetics. It seems likely that certain biomechanical foot defects - such as 'flat feet', high arches or short-leg syndrome - run in your husband's family, making them more prone to developing plantar fasciitis.
Other predisposing factors include being on your feet for excessively long periods of times, and doing activities that put excessive strain on your fascia. Athletes are particularly vulnerable. Going barefoot a lot can also put stress on the plantar fascia.
As for treatment, corticosteroids - as you mentioned - are often used to relieve the pain and swelling. They are closely related to cortisol (a stress hormone produced in the adrenal gland), and work by blocking the production of inflammatory triggers such as prostaglandins.
Your husband may wish to avoid these steroid injections altogether. One side-effect of these drugs is weakening of the tendons. Patients receiving corticosteroid injections for plantar fasciitis have been found to be more prone to rupture of the fascia (Foot Ankle Int, 1998; 19: 91-7; Foot Ankle Int, 1994; 15: 376-81). While such a rupture may help to relieve the heel pain in some patients, the torn fascia can lead to a whole new set of foot problems such as pain and swelling in other parts of the foot, stress fractures and 'hammertoe' deformity, to name just a few.
Also, as an injection punctures the skin, it can also introduce infection into the body. One case report describes a man who, treated with steroid injections for plantar fasciitis, went on to develop a bacterial infection of the heel bone that eventually led to amputation of the affected area (Foot Ankle, 1985; 6: 44-6).
Furthermore, although injections are designed to deliver the medication directly to the site, some of the drug invariably leaches into the body, where it can potentially wreak the same havoc as when the drug is taken orally.
The list of side-effects with oral steroids is impressive, to say the least. They include increased appetite and weight gain, increased fat absorption, water and salt retention, high blood pressure, diabetes, osteoporosis, cataracts, acne, stomach ulcers and depression.
The key to treating heel spurs/plantar fasciitis is to pinpoint the reason behind the excessive stretching of the plantar fascia. In your husband's case, it's most likely to be an inherited abnormality of the foot. If it happens to be 'flat feet', the best solution would probably be to get a pair of specially designed shoes, with an arch support to correct the foot.
Make sure that the shoes have good motion control and cushioned heels to absorb shock. Adding heel cups or cradles to the shoe will provide extra cushioning as well as raise the heel and take some weight off that area.
When the heel becomes painful and swollen, apply ice packs. This is not only effective in reducing the pain, but it also constricts the blood vessels, thus, easing the inflammation.
If your husband is overweight, he should lose the excess pounds. Increased weight means increased pressure on the soles of the feet.
There is evidence to support the use of nutrition to aid musculoskeletal disorders and chronic inflammatory diseases such as rheumatoid arthritis (see WDDTY vol 14 no 6). The same advice may also help in plantar fasciitis.
* Avoid meat, which is high in arachidonic acid, a type of fatty acid believed to promote inflammation in the body.
* Supplement your diet with good fats to keep joints lubricated. These include polyunsaturated and omega-3 fats such as those found in oily fish, and certain nuts and seeds. The essential fatty acid gamma-linolenic acid (GLA) is an anti-inflammatory that is found in borage, evening primrose and blackcurrant seed oils.
* Go Mediterranean. The classic Mediterranean diet consists mainly of fish, fruit, vegetables, cereals, beans and olive oil, and is believed to be high in anti-inflammatory compounds. It has been found to reduce joint-swelling, tenderness and pain by more than half (Ann Rheum Dis, 2003: 62: 208-14).
* Supplement with glucosamine. This sugar is produced in the body for maintaining the cartilage that cushions joints. Its ability to relieve pain, stiffness and swelling in musculoskeletal disorders is supported by a raft of studies. There are several forms in which it can be taken, with glucosamine sulphate being the one most easily absorbed by the body and the form most commonly used to treat osteoarthritis.