The human spine is part of the body’s skeletal system that provides balance and stability, protects the spinal cord, and allows you to turn, stretch and bend.
A normal spine allows you to move about freely and bend with flexibility. Your low back, or lumbar spine, is made up of five bones (vertebrae) which are numbered L1 to L5 and are stacked on top of each other to form a column (see Fig. 1).
Normally the discs between the vertebrae provide the cushioning space that keeps the bones separated. Degenerative Disc Disease (DDD) is a condition that can occur when a disc in your spine no longer functions normally because of aging, wear, or from being injured. The disc may shrink and lose height which can cause pain or make the spinal joint unstable. A worn out disc or spinal joint can also press on the nerves that branch out from the spinal cord which may cause leg or back pain when you move certain ways. DDD can often be treated non-surgically with medications, physical therapy, spinal injections, chiropractic care, braces, exercise programs, or rest. However, in some cases, the symptoms may not improve or may get worse, and then your doctor may suggest surgery.
The traditional surgery for treating DDD has been spinal fusion surgery. In spinal fusion surgery, the unhealthy disc is removed, bone graft or a plastic spacer is placed in the area, and often medical implants (such as rods, screws, or plates) are used to hold the bones in position so that they are stable (see Fig. 1). In some cases, the bone for the graft is obtained from the patient’s hip bone through a separate cut. After surgery, bone is supposed to grow between the two vertebrae, creating one solid piece of bone. The goal is to permanently fuse the vertebrae together so that they cannot move except as a single unit and therefore reduce the movement of that part of your spine. If you have fusion surgery, it may take away your pain, but you may have less motion in your back.
Another option your doctor may consider is surgery with an artificial disc replacement device (see Fig. 2). The activL Artificial Disc is one artificial disc replacement device. The activL Artificial Disc has been developed to provide pain relief while potentially still allowing motion of your lower back (lumbar spine). In an activL Artificial Disc procedure, after the unhealthy disc is removed, it is replaced with the activL Artificial Disc alone (no bone graft or plastic spacer).