Bone spurs can restrict the foraminal canal of the spine (the openings where nerves exit) and cause a pinched nerve. Most bone spurs are not symptomatic. However, symptoms of a pinched nerve may include extremity pain, sciatica, numbness, and in severe cases muscle weakness and even partial paralysis.
A bone spur is often a response to an injury or abnormal pressure or stress at a spot on a normal bone that continues over a long period of time. They can also be a natural result of aging, as the cartilage that covers the ends of the bones within joints deteriorates. Certain inflammatory arthritis conditions can also form bone spurs such as rheumatoid arthritis.
Bone spurs can cause problems in the back when they form in and around the facet joints and the intervertebral disc. Facet joints have a rich nerve supply, including tiny nerve endings called nociceptors that are responsible for a specific type of back pain.
The facet joint can develop bone spurs, or osteophytes, as well as synovial cysts that act as cushions to prevent arthritic bone from grinding against other structures.
If an excessive amount of bone spurs form, they can occupy and narrow the foraminal canal that is formed by the facet joint above and below each vertebra. They can also cause narrowing of the spinal canal. This narrowing can cause pinching of the exiting nerve root that is trying to exit the spine on its way to one of extremities. If symptoms of a pinched nerve occur due to this condition, it is called foraminal stenosis.
Bone spurs are not generally treated themselves, but may be removed as part of treatment for a condition they contribute to, such as facet arthritis, foraminal stenosis, or spinal stenosis.
