Purpose: the study of the correction of scoliotic deformity in young adults 18–21 years of age, compared to that of older adults with adult idiopathic scoliosis.

Materials and methods: in this retrospective study, 65 patients (7 male, 58 female), with a mean age of 25,3 years (range, 18–68) suffering from adult idiopathic scoliosis, who underwent posterior instrumentation with fixation systems utilizing transpedicular screws and hooks between January 1999 and May 2003, were included. Patients with scoliosis of another etiology were not included. Patients were divided in two age groups: the first group included patients 18–21 years old and the second group included patients over 21 years old. The preoperative and postoperative Cobb angle was measured and the percentage of correction of the deformity was compared between the two groups.

Results: The first group (18–21y) included 41 patients (5 male, 36 female). The mean Cobb angle was 44° pre-operatively and 15,9° postoperatively, with a mean correction of deformity of 64%. The second group (over 21y) included 24 patients (2 male, 22 female). The mean Cobb angle was 49° preoperatively and 26,1° postoperatively, with a mean correction of deformity of 47%. Comparing the correction of deformity between the two age groups resulted in statistically significant difference (p< 0,05).

Conclusion: The percentage of correction of the scoliotic deformity after posterior instrumentation with fixation systems utilizing transpedicular screws and hooks is significantly greater in young adults between 18 and 21 years of age, compared to older adult patients over 21 years of age, although a significant percentage of correction can also be achieved in the latter group of patients.