Development of spondylolytic olisthesis in adolescents

Although it has been well documented that slippage in patients with spondylolysis is most prevalent during the growth period, the exact time when slippage initiates and halts during the growth period is still unknown. Moreover, the contribution of spinal deformities, such as wedging of the vertebral body to the slippage, remains controversial. To clarify when slippage in pediatric spondylolysis initiates and halts. Retrospective study. We radiographically examined 46 athletes under 18 years of age with spondylolysis at the fifth lumbar vertebra (L5). The mean age at the first consultation was 13.3 years. The average follow-up period was 6.0 years. Longitudinal observation of slippage at L5 on radiogram in correlation with the maturity of the lumbar spine. From a lateral radiogram of each patient, percent slippage, lumbar index (LI), and skeletal age of the affected vertebra were measured. Changes in the percent slippage over time were investigated, and the correlation between the percent slippage and LI was analyzed. From the cartilaginous stage to the apophyseal stage, the slippage increased in 80.0% of the patients (16 of 20). From the cartilaginous stage to the epiphyseal stage, slippage increased in 11.1% of the patients (3 of 27). None of the patients (0 of 22) showed an increase after the epiphyseal stage. In 20 patients in whom slippage increased during the follow-up period, the percent slippage at the final consultation and the LI at the first consultation showed no significant correlation; however, the percent slippage and the LI at the final consultation were significantly (p<.01) correlated. In conclusion, slippage was more prevalent in individuals of a younger skeletal age whose lumbar spine was immature, and it halted during the epiphyseal stage when the growth period was over and the vertebra matured. Furthermore, the results suggest that wedge deformity of an affected vertebra might be the result rather than the cause of slippage.


Characteristics of velocity-controlled knee movement in patients with cervical compression myelopathy: what is the optimal rehabilitation exercise for spastic gait?


Double-immunolabeling studies of glucocorticoid receptors in enkephalinergic neurons of the rat spinal cord

Using double-immunolabeling, we attempted to localize the glucocorticoid receptor (GR) and methionine-enkephalin-octapeptide (ENK-8) in the rat spinal cord. The 2nd to 8th cervical segments were analyzed in intact and in colchicine-injected animals. GR immunoreactivity was detected in the nuclei of neurons in all segments, and was most intense in small neurons in the superficial layers (laminae 1-3) of the dorsal horn. Medium-sized neurons in laminae 4-6 and the reticular formation, as well as the large ventral horn neurons, all showed moderate immunoreactivity. Double-immunolabeling revealed that, in all regions examined except the ventral horn, some of the GR-positive neurons were also ENK-8-positive. These findings suggest that enkephalinergic neurons in the spinal cord may be regulated by glucocorticoids, each of which is presumably related to the neuronal antinociceptive mechanism in the dorsal horn.