Assessment of the residual spine growth potential in idiopathic scoliosis by risser sign and histological grading

Abstract

To investigate the correlation between histological grade (HG) of vertebral growth plates and Risser grade in the female idiopathic scoliosis (IS) patients; and to identify whether Risser grading is a reliable indicator for accurate evaluation of the spinal residual growth potential. Thirty-nine samples of vertebral growth plates obtained during operation from 15 females IS patients, all female, aged 15.1 (12.4 - 18.0), underwent HE staining and light microscopy to determine the values of HG. Xray photography of pelvis was conducted before operation to identify the Risser sign. The correlation of Risser grade with pubertal status was analyzed. All the vertebral growth plates of the IS patients with the Risser grade of 0 showed growth activity. The vertebral growth plates showed HG II activity in 6 of the 16 IS patients with the Risser grade of 4. All the vertebral growth plates showed no growth activity in the 3 IS patients with the Risser grade of 5. There was a negative correlation between the HG and Risser grade in all 39 patients (r = -0.645, P =0.000). The HG of the patients with the Risser grade of 4 was negatively correlated with the menarchal status (time between menarche and operation) (r = -0.710, P = 0.002). The residual growth potential of spinal growth plates of the patients with the Risser grades of 2 - 5 was significantly lower than of the patients with the Risser grades of 0 - 1 (P = 0.020). Risser sign may be a reliable indicator for predicting the spinal residual growth potential in IS patients, but it should be correlated with menarchal status and chronological ages.