The Problem: Degenerative Disc DiseaseDegenerative disc disease is one type of back pain that is caused by wearing away of the cushion that rests between the vertebrae of our spine. The spinal column is made of stacked bones called vertebrae. These bones are separated by a cushion at each level called a spinal disc. The disc is a tough but pliable tissue that helps maintain the position of the spine, but also allows motion between the vertebrae. With this design we have the stability to stand upright, but also the flexibility to bend and twist. Unfortunately, these discs can cause problems as they wear away.
As the disc ages, it becomes more brittle and less flexible. The disc also becomes more prone to injury and degradation. Exactly what causes pain with lumbar disc degeneration is debatable, but we do know that some patients with worn out discs have typical symptoms of low back pain.
It is important to understand that aging discs is normal! MRIs of patients with no symptoms of back pain often show wearing away of the discs. It should not be considered abnormal to have wearing of the spinal discs. That said, some patients can develop symptoms of back pain, and it is possible that their symptoms come from the spinal disc degneration. It is very important to have this carefully evaluated by your orthopedic surgeon before embarking on any treatment plan.
Current Treatment: Spine Fusion SurgerySpine fusion has long been considered the best treatment for degenerative disc disease of the lumbar spine once conservative treatment measures have failed. The first treatment for degenerative disc disease is always with non surgical options. These include anti-inflammatory medications, physical therapy, and epidural steroid injections. However, if patients try these treatments, and do not find satisfactory relief, then spine fusion surgery may be an option.
Spine fusion surgery is done to remove the damaged disc, and stimulate bone growth in that same area. Fusion of bone means that the space once occupupied by the flexible disc will be occupied by bone that will not allow motion at that spinal level. Once the bone fuses across the disc space, the vertebrae above and below the damaged disc are locked together. By securing the vertebrae together, the spine does not move at this segment, and the pain relief can be excellent.
However, there are several problems with spine fusion surgery. First, the rate of successful fusion is about 80%. While complete fusion of the segments is not always necessary for pain relief, it is concerning that we cannot always find a way for bone to grow across the damaged disc space. Second, fusing a spinal disc space decreases the motion of the back, and may lead to symptoms of stiffness. Finally, because of the stiffness when the fusion is performed, the segments of spine above and below the fusion are subjected to increased stresses. Patients who have a fusion at one level are more likely to develop problems at discs above or below (so-called adjacent levels) down the road.