Abstract
Objective: It is frequently said that the natural history of adolescent idiopathic scoliosis (AIS) is not understood. This study examines clinical data collected over some years and shows that the information is available and needs only to be generalised and applied.
Design: Retrospective analysis of data, relating basic clinical information (age, Cobb angle, pubertal status, growth) to outcome in the practical terms that are relevant to clinical practice and patient management, Subjects: Two groups of female patients identified from the database: Group 1, girls diagnosed at least one year before the onset of menses and last reviewed at least one year afterwards; Group 2, girls diagnosed at least one day after menarche, followed for at least one year and not having surgery as a first option i.e. within six months.
Outcome measures: Within and between group comparisons as regards age, height and Cobb angle at presentation and at last review and age at menarche. Change in height and Cobb angle of 10°, and the incidence of non-operative treatment and corrective surgery were considered. Statistical analysis was by student’s t test and Fisher’s exact.
Results: Group 1 (N=58) presented at a mean age of 11.6 years SD 1.02, range 10 – 13.9 and reached menarche a mean of 2.1 years later, SD 0.86, range 1.0 – 4.5. Mean Cobb angle was 16.79 SD 8.58. Progression of more than 10° was observed in 24 girls, 11 of whom underwent surgery. Those who progressed had a higher initial Cobb angle (p=0.01) and were taller at discharge (p=0.041), but all other parameters were the same. Group 2 (N=92) presented at a mean age of 13.7 years SD 0.92 with a mean Cobb angle of 23.77° SD 14.52. Progression of 10° or more was observed, one of whom had surgery, her Cobb angle having increased from 48° to 64°. 6 had surgery for cosmetic reasons without further increase in Cobb angle. There was no statistically significant difference between the stable and progressive groups on any parameter other than final Cobb angle.
Comparing Groups 1 & 2, girls in Group 1 were younger and smaller at diagnosis with lower Cobb angles. They were older at menarche, but this was inevitable from the selection criteria, and more likely to progress (p< 0.001), to receive a brace (p=0.047) and to undergo surgery (p=0.043). Age, final Cobb angle and height at discharge were not significantly different.
Conclusions: 1.Girls diagnosed with AIS before puberty are at increased risk of progression but this is not usually clinically significant and does not usually lead to corrective surgery. 2.Girls diagnosed after menarche progress rarely and less. In practice, their deformity can be taken as stable at presentation. 3. In most cases, the course is benign and non-operative treatment had no discernible effect on outcome. As the percentage progressing significantly or requiring treatment at any stage is small, a less interventionist approach is indicated.
The abstracts were prepared by Mr Peter Millner. Correspondence should be addressed to Peter Millner, Consultant Spinal Surgeon, Orthopaedic Surgery, Chancellor Wing, Ward 28 Office Suite, St James’ University Hospital, Beckett Street, Leeds LS9 7TF.
