Spondylolisthesis

Spondylolysis is the one of the most common causes of low back pain in teenagers. It is basically a fracture in

one of the vertebra of the lower back, most often in the 5th vertebra.

Clinically spondylolysis is defined as a defect in the pars interarticularis of a vertebra, the area between two

joints, caused by repeated microtrauma, resulting in a stress fracture. When the fracture is present it allows the

vertebra above to slip forward on the vertebra below. This results in a condition called spondylolisthesis.

Approximately 3-7% of the general population have spondylolysis. In certain athletes, the incidence increases to

22% in weight lifting, 29% in wrestling and 43% in diving. Over 25% of the Olympic Romanian gymnastics

team during the years 1970-1990, among them Nadia Comaneci had problems involved with spondylolysis.

Patients with suspected spondylolysis should be evaluated initially with plain radiography. On lateral

radiographs, the most sensitive projection, spondylolysis appears as a linear lucency in the pars interarticularis.,

This lucensy also can be seen in oblique radiographs and has been termed the “collar on the neck of the Scottie

dog”.

Further imaging may be warranted, MRI, CT and SPECT bone scintigraphy are used to further evaluate these

patients. MRI of the lumbar spine is very sensitive for detecting early acute stress reactions in the pars

interarticularis where there is only marrow edema and microtrabecular fracture. These findings are not visible on

CT.

People with spondylolysis/spondylolisthesis may feel pain and stiffness in the centre of the low back. Bending

fully backward increases pain. Doctors refer to this type of back pain as “mechanical back pain” because it most

likely comes from excess movements between the vertebra. The younger child has a higher chance of further slip

with growth. Girls are more prone to progressive slip than boys. Grade I indicates 25% slip, Grade II up to 50%,

Grade III up to 75% slip and so forth. The higher grade of slip, the more serious the problem, and the higher the

chances of further slip. For grades I and II, conservative treatment is usually instituted.

This will be similar to treatment for spondylolysis, with the use of a rigid brace and physical therapy. X-rays are

done every 3 to 6 months to check the severity of the slip. Keeping the spine from moving can help ease the pain

and inflammation. It can also improve the chances the bone will grow back together. There might be a need to

take some time away from sports activities, especially if it requires repeated back bending. If the pain does not

improve, or there are neurologic symptoms down into the legs and /or follow up X-rays demonstrate further slip,

surgery may be needed.

Surgery consists of decompression of the nerves and fusion of the vertebra to prevent further slipping and to

relieve pain. In young persons the fusion rate is over 90% and the success-rate generally high. A similar illness

in adults is called degenerative spondylolisthesis. It is difficult to detect in its initial phase which might cause

confusion and delayed treatment. We will discuss that in next months issue.