A plantar calcaneal spur is an outgrowth from the bone at the back of the foot known as the calcaneus. This outgrowth is the cause of severe discomfort on the sole of the foot (plantar surface) and pain and is commonly known as heel spur pain. These spurs may develop over a long period of time and are initially unidentifiable, even upon x-ray, although the symptoms are present. Calcaneal spurs may be mistaken for plantar fasciitis, which is the inflammation of the thin fibrous layer between the skin on the sole of the foot and the bones of the foot.

The exact cause for the formation of a heel spur is unknown since certain conditions may result in the development of these outgrowths in some individuals, yet not in others. It is believed that the plantar fascia may cause excessive pulling of the periosteum (outer bone layer) of the calcaneus, friction with neighboring bones or pressure on prone parts of the calcaneus when walking or standing which ultimately results in the development of a spur. The prolonged pressure and inflammation of the periosteum of the bone may cause outgrowths known as the heel spur. Alternatively, constant inflammation of the parts of the plantar fascia near the calcaneus may result in calcification at these sites, which eventually attaches to the calcaneus bone

Some factors that may contribute to the development of a heel spur include :

• Excessive impact and pressure on the heel and sole, due to strenuous physical activity like in road runners.
• Overweight or obese individuals who are very active.
• Sportspersons who do not stretch prior to strenuous activity, leading to ‘pulling’ of the plantar fascia
• Unusual gait due to joint disorders, lower limb conditions and/or bone diseases or fractures. Persons with a ‘duck walk’ (toes pointing to the sides away from the other foot) or ‘bandy walk’  (toes pointing towards each other when walking) may be more at risk.

Signs and Symptoms of a Calcaneal Heel Spur

• Pain, particularly towards the back of the heel, is most often reported although some patients with a calcaneal spur may not report any symptoms. The heel pain aggravates during walking or standing and may completely subside once lying down or raising the legs off the ground.
• A tender protrusion may be at the back of the sole upon firm pressure.
• Sharp pains when walking on hard surfaces, especially when barefoot.
• Pain upon carrying a heavy object that may distort the pressure applied on the foot.
• Swelling of the foot without the heel spur may occur due to additional weight place on the opposite foot when walking to prevent the heel pain caused by the spur.

Treatment

A calcaneal spur is not easily treated and the patient needs to learn to live with the condition by managing it conservatively. Special footwear, resting regularly when walking or running over long distances and professional care by a podiatrist may assist. In severe cases, an anesthetic injection may be considered although this should only be done when the patient cannot tolerate the pain that is persisting even when resting the feet. Usually anti-inflammatory drugs and corticosteroid injections during acute aggravations are the main method to treat the inflammation caused by the heel spur.