Bone spurs

Bony spurs (enthesophytes) can occur at the attachments of a wide variety of tendons and ligaments, although they most often develop at the top of the back part of the pelvic bone (iliac crest), the bottom of the knee cap (patella), spine, fingers, and at the undersurface and at the back of the heel bone (calcaneus). Although they can be extremely painful, most do not cause pain.

Although most spurs occur in otherwise healthy individuals, and so are not an indication of disease, they can develop as part of an inflammatory or metabolic disease process (e.g., ankylosing spondylitis, psoriatic arthritis,  Reiter’s syndrome, and acromegaly), and are widespread in diffuse idiopathic skeletal hyperostosis (DISH).

They are irregular outgrowths of varying size that extend from the bone into the tendon or ligament. They often develop in parallel with bone growths (osteophytes) at the outer part of joints, a feature of osteoarthritis. Large spurs can easily be detected by x-rays.  

They develop over a period of many months or years as a result of a repeated excessive tension and/or compression on the ligament or tendon. Spurs may be an adaptive response to heel bone stress fractures or to excessive tension and/or compression by giving the bone a greater surface area. Small spurs can also develop as part of normal bone development.

The pain associated with spurs can be gradual, intermittent and chronic or it can be of sudden onset, very sharp (knife-like), severe and ‘out of the blue’.