Spondylolisthesis is a type of spine injury that most frequently affects the lower (lumbar) region of the spine. In spondylolisthesis, one of the lumbar vertebrae, usually the fifth one but sometimes the fourth, slips out of its proper position. The displaced lumbar vertebra may press on the vertebra below it, and in some cases it is possible for a pinched nerve may occur as a complication of the condition.
There are several potential causes of spondylolisthesis. Some individuals are born with a birth defect of the vertebrae of the lower spine that makes it much more likely for vertebral shifting to occur. Another major cause of spondylolisthesis is an acute or chronic sports injury or instance of acute trauma. Spondylolisthesis is common in some young athletes, such as gymnasts. High-impact exercises can cause stress fractures in the vertebrae in the lumbar spine; this condition is also called spondylolysis. Vertebrae that have sustained stress fractures are more likely to slip out of place, so spondylolysis frequently leads to spondylolisthesis. Spondylolisthesis can also be caused by arthritis of the spine in older adults.
Symptoms of spondylolisthesis may vary depending on how far the vertebra slips out of place and whether there is spinal nerve involvement. The most common symptoms are lower back pain, back stiffness, tenderness in the affected area of the spine, and muscle tightness. If a nerve is pinched, pain, numbness and tingling may radiate away from the back and down the leg, and muscle weakness may also occur in the legs. Spondylolisthesis may also produce abnormal curvatures of the spine over time.
Spondylolisthesis is usually easily diagnosed with an X-ray of the spine. Other types of medical imaging, such as a CT scan or MRI, may be used to determine nerve involvement. If the case of spondylolisthesis is mild, conservative treatments are usually successful. Conservative treatments for spondylolisthesis include the use of a back brace, anti-inflammatory medications to control pain and inflammation, and physical therapy exercises to strengthen the spine. In more severe cases in which conservative measures are not enough, surgery to stabilize and fuse the affected vertebrae can usually solve the problem and relieve symptoms. Individuals with vertebral stress fractures due to sports injuries should avoid exercises and activities that will make their condition worse and potentially lead to spondylolisthesis.