Topics discussed on this page:

Exostoses
Hyperostoses
Spurs

What exactly is a spur?

The word Spur is usually used to describe an abnormal prominence of bone.  In the foot, the most common area in which people describe having a spur is on the heel bone.

Technically there are two different types of spurs--Exostoses and Hyperostoses.

What's the difference between the two?

An Exostosis (plural "exostoses") is a bony enlargement in an area where there is not supposed to be a bony prominence.

A Hyperostosis (plural "hyperostoses") is an excessive enlargement of a bony prominence that is supposed to be present.  

In practice, these words are sometimes used interchangeably.  

Where do people get spurs?

I'll give you three examples of common areas for spur formation to develop in the foot:

• Heel spurs may develop on the bottom of the foot, a condition called "infracalcaneal exostosis" (meaning a bone spur below the heel bone).  This condition is most often associated with a flatter than normal foot type, and may be associated with pain from pain from a condition known as plantar fasciitis. Various types of arthritis, too, frequently cause these spurs to develop. 

• Another area that frequently develops spurs is behind the back of the heel, a condition called "retrocalcaneal exostosis" (meaning a bone spur behind the heel)".  This condition is commonly associated with various arthritic conditions and with Achilles tendon disorders. 

Both of these types of spurs are called exostoses because they are bony growths in an area that is not supposed to have a bony prominence. 

• A third common location for spurs to develop in the foot is on the toes.  These are probably more correctly termed "hyperostoses", as most develop as an excessive growth of a normal bony prominence.