What Is a Bone Spur?

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.¹Benjamin 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.

• 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.

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.²Bone Spur. ReedGroup MD Guidelines website. http://www.mdguidelines.com/bone-spur Accessed July 6, 2016.

The incidence of developing an osteophyte increases with age, and becomes common among people over 60 years old.²Bone Spur. ReedGroup MD Guidelines website. http://www.mdguidelines.com/bone-spur Accessed July 6, 2016.

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.