What Is an Osteophyte (Bone Spur)?

Commonly Found in Joints Showing Signs of Degeneration

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An osteophyte is a smooth bony growth or deposit, also referred to as a bone spur. They are also sometimes called osteochondral nodules, osteochondrophytes, and chondro-osteophytes. Technically-speaking, an osteophyte is a fibrocartilage-capped bony outgrowth originating from precursor cells of the periosteum and growth factors. Osteophytes commonly develop in joints that show signs of degeneration.

They are associated with the most common type of arthritis, osteoarthritis. Their presence can serve to distinguish osteoarthritis from other types of arthritis. In actuality, the characterization of osteoarthritis as the degradation of cartilage is oversimplified. Osteoarthritis also involves subchondral bone remodeling, as well as osteophyte formation.

An osteophyte develops as a reparative response by the remaining cartilage in a damaged joint, correlating with cartilage loss elsewhere in the joint. Osteophyte formation stabilizes the damaged joint. These changes tend to be compartmental, suggestive of a localized event. That said, the pathophysiology of osteophyte formation is not completely understood. While osteophyte formation is associated with cartilage damage, they can also develop in the absence of explicit cartilage damage.

Location of Osteophyte Formation

Marginal osteophytes can develop at the periphery or margin of any joint.

Central osteophytes are most prominent in the hip and knee. Osteophytes also may be found in the spine region, where they are associated with back or neck pain and considered a common sign of degenerative arthritis (osteoarthritis). In the spine, an osteophyte or bone spur can cause nerve impingement (compression of the spinal cord or nerve roots) at the neuroforamen (the empty space to the left and right of each vertebra which allows nerves to pass from the spinal cord to other parts of the body).

Sensory symptoms in this situation include pain, numbness, burning and pins and needles in the extremity served by the affected spinal nerve root. Motor symptoms include muscle spasm, cramping, weakness, or loss of muscular control in an associated part of the body. The osteophyte itself is not painful, but its location and therefore its effect on other structures of the body can cause pain.

Risk Factors for Osteophyte Formation

Certain factors and conditions are considered contributory to osteophyte formation. Those factors or conditions include:

  • Increased age
  • Disc degeneration
  • Joint degeneration
  • Sports injury or other joint injury
  • Poor posture
  • Genetics
  • Congenital skeletal abnormalities

Diagnosing Osteophytes

Osteophyte formation can be diagnosed by a physical exam of the PIP (proximal interphalangeal joint), DIP (distal interphalangeal joint), and first CMC joints (carpometacarpal joint) of the hand. Simply put, in the hand, a bump or lump may be visible during a physical examination.

For other joints, the presence of an osteophyte can be diagnosed using imaging studies, such as x-rays or MRI or CT scan.

If x-rays were performed on everyone over 50 years of age, most would show some evidence of osteophyte formation. Yet, most osteophytes are asymptomatic (i.e., they do not produce symptoms). Only around 40 percent of people with osteophytes develop symptoms that require treatment.

Treatment of Osteophytes

The presence of an osteophyte alone is not clinically significant unless associated symptoms are experienced. Treatment may include:

Typically, conservative treatment is tried first. Surgery is reserved for people who have severe symptoms. Activity tends to increase pain associated with an osteophyte, while rest helps to lessen pain.

Sources:

Goel, Atul. Is it necessary to resect osteophytes in degenerative spondylotic myelopathy?  Journal of Craniovertebral Junction and Spine. 2013 January-June;4(1):1-2.

Moskowitz, Roland W. MD et al. Osteoarthritis. Fourth edition. Chapter 2 and Chapter 4. Wolters Kluwer. Lippincott | Williams & Wilkins.

van der Kraan PM et al. Osteophytes: Relevance and Biology. Osteoarthritis and Cartilage. March 2007.

Bone Spurs (Osteophytes). Cedars-Sinai.

Neuroforamen - An Overview. Laser Spine Institute.
 

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