Dear Doctor: My wife is 77 and has spinal stenosis. She’s often in pain. We read about a new procedure called “minimally invasive lumbar decompression,” which we are hoping might help. She really wants to avoid surgery. What can you tell us about it?
Dear Reader: To understand spinal stenosis and its treatment, we should start with the structure of the spinal column, or backbone. It’s a collection of 33 bones, known as vertebrae, which enclose and protect the spinal cord, along with the fluid that surrounds it. It also includes the muscles, tendons and other tissues that provide support and allow movement. The spinal column rises from the coccyx, or tailbone, and runs the length of the back to the base of the skull. The spinal cord, which serves as the master communications pathway between the brain and the body, houses 31 pairs of spinal nerves. These connect to the spinal cord and enter and exit the spinal column at various points, depending on their function. In between the vertebrae are discs, rubbery pads that provide additional space and cushioning.
In people who develop spinal stenosis, the spaces within the spine become constricted. (The word "stenosis" refers to the abnormal narrowing of a passage within the body.) This is often due to osteoarthritis, which damages the joints and discs in the neck and lower back, and may cause the growth of bone spurs. This results in pressure on the nerves in the region of the narrowing, which can cause symptoms such as a tingling sensation or numbness, muscle weakness and cramping, and pain in the lower back, buttocks and legs that can become severe. If nerve compression lasts long enough, numbness, weakness and, in more serious cases, even paralysis can become permanent.
Spinal stenosis usually occurs in the lumbar region, which is the lower portion of the spine. It’s typically treated with nonsurgical pain management, or with surgery such as laminectomy or discectomy. These are procedures that, in different ways, surgically excavate additional space within the spinal column. As with all surgeries, they carry a certain degree of risk.
However, as you mention in your letter, there is now a new approach to correcting spinal stenosis. Known as minimally invasive lumbar decompression, it uses a small implanted device that acts as a lift to create additional space within the spinal column. The device, which doesn’t use connecting hardware, is implanted via a small incision. The bone and tissue removal associated with traditional back surgery is usually not necessary. The procedure takes from 45 to 90 minutes and is often performed under local anesthesia. Patients may be asked to participate in physical therapy following the procedure and will have follow-up visits to assess progress. Many return to normal activities two to six weeks after receiving the implant.
Factors such as bone density and the degree of spinal stability play a role in whether this approach is appropriate. Complications can include fracture or tissue tears at the site of the implant. Unfortunately, studies regarding success rates aren’t yet available.
(Send your questions to email@example.com, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)