What is Spondylolithesis?
A slipped spine or unstable spine are other names for spondylolisthesis, the slipping forward of one vertebral body over another vertebral body. This may result from birth abnormality (congenital), repetitive physical stress injury (isthmic), accident (traumatic), infection or tumor (pathologic) or arthritis (degenerative). The spine may also weaken and slip after back surgery (iatrogenic). The most common causes of spondylolithesis are isthmic and degenerative.
Isthmic spondylolithesis usually presents in early adulthood. It may be caused by repeated injuries from walking, gymnastics or football. The facet joints act as a hook to hold the spine together. If part of this hook breaks (usually small bone called the pars) then the spine may weaken and slip apart. Scar tissue may form at the break compressing the foramen (foraminal stenosis) pinching the nerve. Isthmic spondylolithesis may cause back and leg pain.
Degenerative spondylolithesis presents in late adult hood. It is often associated with spinal stenosis and presents with severe back and leg pain. The disc and facet joints become loose allowing the spine to slip apart. Scar tissue, bone spurs and thickened ligaments are produced to strengthen the spine, but may pinch nerves causing more pain.
Minimally Invasive Treatment for Spondylolithesis
Patients who are not helped by more conservative treatment may benefit from surgical treatment. Usually the patients require fusion surgery. This used to be a large destructive surgery with significant recovery. Fusion surgery now can be done using minimally invasive techniques. A tube is placed in between the back muscles to decrease muscle damage and weakness caused by muscle retraction. A microscope is commonly used to visualize the nerves and remove disc. Today the disc removal and endplate preparation can be done through a spinal endoscope.
High-risk patients or people who simply want to avoid fusion surgery may be still a candidate for endoscopic spine surgery. Endoscopic spine surgery is state-of–the-art minimally invasive spine surgery. A micro video camera is inserted through a very small incision to the damaged facet joints and/or pinched nerves. The camera projects the images onto a video screen so the surgeon can easily find the pathology. Tiny instruments are inserted through the camera to fix the spine under direct visualization.
Back and leg pain usually rapidly improve. Long-term results are unknown because these procedures are new. Patients may still need a spinal fusion in the future if the slip progresses or pain returns.