Bone spurs, also known as Osteophytes, are bony projections that usually form along joints.
Bone spurs form due to increased damage in the joint's surface area. This occurs, most commonly, with the onset of arthritis. Bone spurs usually limit joint movement and typically cause pain.
As a person ages, bone spurs grow naturally on the back of the spine and are a sign of degeneration in the spine. In this case, the spurs are not the source of back pain. The pain is usually a symptom of a deeper problem. However, bone spurs on the spine can impinge on nerves exiting the foramen of the spine. The foramen is the bony open archway between vertebrae through which spinal nerve roots exit. The impingement can cause pain in both upper and lower limbs and a numbness or tingling sensations in the hands and feet due to the nerves supplying sensation to their dermatomes. A dermatome is the area of sensory nerves near the skin that are connected to a specific spinal nerve root.
Spurs can also appear on the feet, either along toes or the heel, as well as on the hands. In extreme cases bone spurs have grown along a person's entire skeletal structure, i.e. along the knees, hips, shoulders, ribs, arms, and ankles.
Osteophytes on the fingers or toes are known as Heberden's nodes (if on the DIP joint). Osteophytes on the nodes closet to the palm are known as Bouchard's nodes (if on the PIP joints)
Bone spurs may also be the end result of certain disease processes, such as osteomyelitis, charcot foot and some others.