“This is a very exciting advance in treatment for spinal stenosis because it restores motion, balance and stability to the lower spine.” Dr. Regan

The spine’s mobility and stability are dependent on small facet joints, which link the vertebrae. Over time, these joints can become inflamed and arthritic. As they wear down, bone spurs may develop, narrowing the space around the spinal cord and pinching spinal nerves. When this occurs in the lower spine, it can create a condition called lower spinal stenosis. 

Symptoms may include pain, weakness and numbness in the lower back and legs, which progressively worsen. Traditionally, the treatment for lumbar spinal stenosis has been the removal of bone, including the facet joints, pressing on the nerves. Then, because the spine lacks stability without the facet joints, adjacent vertebrae are fused together to help stabilize the spine. “The problem with fusion is that it eliminates the natural motion between vertebrae,” said John Regan, MD, a board-certified orthopedic spine surgeon at Saint John’s Health Center. “It also increases stress on adjacent areas of the spine.” Because of fusion’s drawbacks, Dr. Regan and Saint John’s are participating in the CADIA™ Facet Replacement Study to investigate the use of a metal implant that is designed to restore the range of motion provided by the facet joints. Saint John’s.

It is one of 20 centers across the nation participating in the trial, which will compare facet replacement to fusion.  “After decompressing the affected area of the spine by removing the excess bone and facet joints, we insert an implant that is anatomically similar to the body’s own facet joints,” explained Dr. Regan. “This is a very exciting advance in treatment for spinal stenosis because it restores motion, balance and stability to the lower spine.”

The facet replacement trial at Saint  John’s was initiated in October 2008 and is still open for enrollment. “To date, we are pleased with the results of the procedure and have had no problems related to the implant,” Dr. Regan said.   To qualify for enrollment, patients must be 21 to 85 years of age; have symptoms of leg pain, numbness or tingling; have undergone six months of conservative treatment; and must be available to complete five follow-up visits over a two-year period.