Meta-analysis of surgical outcome in adolescent idiopathic scoliosis. A 35-year English literature review of 11,000 patients.

STUDY
DESIGN: Meta-analysis of the English literature on the surgical treatment of adolescent idiopathic scoliosis.
OBJECTIVE: To gather comparable data from a number of different sources and combine the data to create a larger, more statistically significant pool of information for the analysis of surgical outcome. SUMMARY OF BACKGROUND DATA: Meta-analysis is a technique of scientific literature review used in outcome evaluation of medical treatment. This technique has been applied to the surgical outcome of adolescent idiopathic scoliosis.
METHODS: A structured literature review was performed that cross-referenced English literature articles pertaining to the surgical treatment of adolescent idiopathic scoliosis with a focus on patient-based outcomes. Measures of patient satisfaction were compared with process measures of care.
RESULTS: A number of patients (10,989) were reviewed in 139 patient populations. Unspecified curve types (9424) and King curve types (1565) were reviewed over a 35-year period from 1958 to 1993. Of the patients, 87.32% were studied retrospectively and 12.70% prospectively. Effect-weighted follow-up was 6.8 years. Only studies with complete process and patient data for unspecified or King curve types were included for satisfaction correlation calculations. Pearson product moment correlation for n = 33 studies, n' = 2926 patients revealed a positive r' = 0.628 correlation between degree of curve correction and percent satisfaction per study. To determine the degree of curvature correction resulting in patient satisfaction, a stepwise multiple linear regression analysis was performed with level of confidence (P < or = 0.05). Of significance was that the degree of curvature corrected accounted for all the satisfaction variance predicted. A significant correction exists between degree of curve correction and percent of patients satisfied. The percent of correction and the Group type (either unspecified or King classified), did not significantly alter this prediction. The best predictor of satisfaction appears to be degree of curve correction according to these data.
CONCLUSION: Patients appear to be more satisfied by the magnitude of curve correction rather than the percent of curve correction. The degree of curvature before surgery did not predict patient satisfaction. Pearsons r' = 0.045. Satisfaction appears to be best predicted by the degree of correction only and not by the percent curve correction, the curve magnitude before surgery, nor the Group type (King, unspecified). Patient satisfaction is subjective. It does not reflect the benefits of surgery with respect to the future preservation of pulmonary function in thoracic curves nor the prevention of osteoarthritis in lumbar curves.