{'fraction_non_alphanumeric': 0.019632678910702975, 'fraction_numerical': 0.013299556681443952, 'mean_word_length': 5.124031007751938, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The Ste‐Justine Adolescent Idiopathic Scoliosis Cohort Study: Part IV Surgical Correction and Back Pain

Objectives. This study determined whether the prevalence, nature, and consequences of back pain in adulthood among persons who underwent Harrington rod instrumentation was related to the number of vertebrae fused, distal level of hook insertion, and degree of correction. Study Design. This study was designed as a comparative retrospective cohort study. Subjects referred for AIS between 1960 and 1979 to a large pediatric hospital in Montreal, Quebec, were entered into the cohort. A population based control group was selected from the general population of Quebec using a telephone survey. Methods. Back pain was assessed by postal questionnaire administered in 1990. Data was analyzed using two multivariate regression models: relative risk regression for dicholomous outcomes and ordinal regression for outcomes measured on an ordinal scale. Results. Among the 723 AIS subjects who had surgery at Ste. Justine's Hospital, 555 completed the questionnaire on back pain. Overall, 73% of patients treated surgically reported back pain in the past year. Proportions varied little by presurgery characteristics or by degree of surgical correction. The distal level of fusion did not influence, in any consistent way, the occurrence of back pain in later life nor the degree of disability associated with back pain. This study does not provide even any evidence that extending the level of fusion down even as far as L4 will increase the prevalence of back pain in adulthood.