NATURAL-HISTORY IN SPONDYLOLYSIS AND SPON DYLOLISTHESIS

The incidence of spondylolysis is approximately 5-6% in the white popu lation. Males and females are equally affected. In about one third of the cases spondylolysis is associated with spondylolisthesis. For the etiology mechanical and genetic factors are important. At the L4 level mechanical factors play the dominant role, while at the L5 level gene tic factors are equally important (size and orientation of the facet j oints, dysplasia of the vertebral arch). Increased risk for low back p ain is found in the presence of the following factors: spondylolisthes is exceeding 10 mm, a low lumbar index, increased lumbar lordosis, spo ndylolysis at the L4 level and early beginning of symptoms. In the abs ence of one of these factors the risk for low back pain in adulthood i s not greater than in the normal population. This statement is support ed by the fact that in a low back clinic with more than 2000 patients with low back pain, the incidence of patients with spondylolysis was n ot higher than in the normal population. In our own study we followed up 31 patients. The majority of them were symptomatic during adolescen ce. After a follow-up time of 28 years on average 20 of them stated th at they had no pain since adolescence, 8 had only occasional pain and only 2 had undergone operative treatment because of significant low ba ck pain.