Though hard, bone tissue is constantly renewing—a bit like fingernails and hair. Sometimes new bone cells form small protrusions on a bone, called bone spurs. Bone spurs are usually painless, but occasionally they irritate surrounding tissues and cause symptoms.

2 Types of Bone Spurs

Bone spurs are sometimes called by their medical names, osteophytes and enthesophytes. Experts suggest both types of bone spurs are a reaction to skeletal stress.1

  • Osteophytes are typically found at the edge of a bone at a joint. They are considered to be the result of friction and stress on the bone, and are often associated with osteoarthritis.
  • Enthesophytes are bone spurs that develop where ligament or tendon insert into a bone. (The site of attachment of soft tissue into bone is called an enthesis.) Enthesophytes may develop because of tight ligaments and tendons rubbing against bone, a soft tissue injury, or an inflammatory disease.

People do not always make the distinction between osteophytes and enthesophytes; Enthesophytes may sometimes be called osteophytes.

Below are a few differentiating points about the two types of bone spurs.

Article continues below

Osteophytes

Osteophytes can develop for a number of reasons, including chronic stress, friction, or pressure. Mini-traumas prompt the body to build more bone in an effort to repair itself.

  • Osteophytes can be found throughout the body, including the spine, neck, shoulder, knee, heel, fingers, back, or hip. Osteophytes are usually asymptomatic, so person can have a bone spur(s) for years and not know it.
  • Symptoms depend on the location of the spur. A bone spur on the knee may elicit pain when the knee is bent; whereas a spur on the spinal cord may affect nerves, producing numbness in extremities.
  • If the osteophyte causes pain, nonsurgical treatment is typically recommended first. Treatment can include:
    • Anti-inflammatory medications
    • Physical therapy
    • Corticosteroid injection
  • Developing an osteophyte is a typical sign of osteoarthritis. In fact, osteoarthritis is the leading cause of osteophytes.2

The incidence of developing an osteophyte increases with age, and becomes common among people over 60 years old.2

Enthesophytes

These bone spurs form where soft tissues—tendons, fascia, ligaments, or articular capsules—inserts into bones.

  • Enthesophytes can occur throughout the body, from the spine to the upper and lower extremities. In otherwise healthy patients, they are common in the heel.
  • Symptoms can include pain and swelling in the joint, or redness.
  • The development of enthesophytes is often associated with:
    • Local trauma
    • High levels of physical activity

Occasionally, enthesophytes are a symptom of a systemic condition, such as seronegative spondyloarthritides; an endocrine disorder, such as diabetes mellitus; and calcium pyrophosphate deposition disease.

References:

  1. Benjamin M, Toumi H, Ralphs JR, Bydder G, Best TM, Milz S. Where tendons and ligaments meet bone: attachment sites ('entheses') in relation to exercise and/or mechanical load. J Anat. 2006;208(4):471-90.
  2. Bone Spur. ReedGroup MD Guidelines website. http://www.mdguidelines.com/bone-spur Accessed July 6, 2016.