Abstract
Introduction: Historically, the spinal curvature of adolescent idiopathic scoliosis was considered a life-threatening occurrence, which would result in early death from cardio-respiratory compromise. Consequently, corrective surgery had the primary intention of preventing this unacceptable outcome: cosmetic improvement was considered to be certainly important, but not the prime objective of the treatment. More recent work (e.g. Branthwaite MA. (1986) Br.J.Dis.Chest. 80:360–369) has shown that, while significant deformity presenting in early childhood does carry this outlook, those with an adolescent onset should not be significantly affected in this way. Consequently, any surgery recommended is primarily cosmetic, to improve the deformity when it is unacceptable to the patient and her parents. This, of necessity, changes the criteria by which treatment outcome should be assessed. Scoliosis surgery has generally been judged by the correction in Cobb angle and, more recently, the derotation of vertebrae. However, it is well known that neither factor accurately expresses cosmesis, the criterion by which the patient will judge the operation. Surface topography attempts to quantify the external appearance of a patient and so the cosmetic effect of surgery. Since 1995, when a surface topographic system (Quantec) was acquired by this department, 61 patients were operated for adolescent idiopathic scoliosis, of whom 35 underwent anterior release and posterior fusion for rigid thoracic curves.
Methods and Results: Pre- and post-operative radiographs were compared with topographic results from the same periods and with the latest scan at last review. The mean pre-operative Cobb angle was 74.5° and, postoperatively was 40.7°, a mean correction of 45.4% and was statistically significant (p< .001). This was accompanied by statistically significant reductions in upper and middle topographic spinal angles (p=0.001), an increase in thoracic kyphosis (p< 0.05), a decrease in lumbar lordosis (p=0.001), lower rib hump (p< 0.05), Suzuki hump sum (a measure of back asymmetry, p=0.001) and posterior trunk asymmetry score (POTSI, a measure of trunk balance, p=0.003). At final follow-up a mean of 2.2 years later, topographic spinal angles and POTSI maintained their improvement, still being statistically significantly less than their pre-operative values. Thoracic kyphosis, lumbar lordosis, rib hump and Suzuki hump sum had returned towards pre-operative levels and no longer showed statistically significant differences.
Conclusions:This confirms previous reports of the recurrence of the rib-hump. In conclusion, after two-stage spinal fusion for adolescent idiopathic scoliosis, significant improvement in cosmetic appearance can be achieved. However, over time certain aspects of the original deformity, particularly distortion of the back surface (rib hump or asymmetry) recurs.
Abstracts prepared by Mr J. Dorgan. Correspondence should be addressed to him at the Royal Liverpool Children’s Hospital, Alder Hey, Eaton Road, Liverpool L12 2AP, UK
President’s Lecture: Natural history and management of Congenital Kyphosis and Kyphoscoliosis M.J. McMaster, Edinburgh, Scotland, UK
Greg Houghton Lecture: Idiopathic Scoliosis – Alternatives to traditional surgery R.R. Betz, Philadelphia, USA
Instructional Lecture:New thoughts on the treatment of paralytic scoliosis R.R. Betz, Philadelphia, USA
Keynote Lectures: Idiopathic Scoliosis – How to manage the patient R.A. Dickson, Leeds, UK
Concave or convex approach for Kyphoscoliosis J. Dubousset, Paris, France Surgery or bracing for moderate AIS. How long term follow-up studies change your perspective A. Nachemson, Göteborg, Sweden
