[Clinical study of spondylolysis and spondylolisthesis--mainly on the spinal curvature].

The study was performed to aid in the selection of therapeutic methods for spondylolysis and spondylolisthesis. The subjects consisted of 359 cases, whose symptoms were analyzed using various X-ray examinations concerning the spinal curvature, as well as psychological tests. Age at onset of symptoms was most often in the 15-24-year range (34.7%). The symptom rate was 64.9% for spondylolysis and 75.0% for spondylolisthesis, increasing with age. The symptoms were almost all seen in the lumbar region. Abnormal mobility of the pars interarticularis was observed in 66.6% of the symptomatic group. The spinal curvature showed intensified kyphosis from the teens in the symptomatic group. Downward movement of the apex of the kyphosis and instability of the lumbar vertebral column, including abnormal mobility of the pars interarticularis, are assumed to play a major role in the appearance of symptoms. The above results seem to be helpful in deciding indications for operative therapy in cases with these diseases. From the above results, it appears that cases showing downward movement of the apex of the kyphosis and instability of the lumbar vertebral column are indicated for surgical treatment in consideration of the clinical findings, age, occupation, etc.