Radiologic Findings and Curve Progression 22 Years After Treatment for Adolescent Idiopathic Scoliosis

STUDY DESIGN: This study is a follow-up investigation for a consecutive series of patients with adolescent idiopathic scoliosis treated between 1968 and 1977. In this series, 156 patients underwent surgery with distraction and fusion using Harrington rods, and 127 were treated with brace. OBJECTIVES: To determine the long-term outcome in terms of radiologic findings and curve progression at least 20 years after completion of the treatment. SUMMARY OF BACKGROUND DATA: Radiologic appearance is important in comparing the outcome of different treatment options and in evaluating clinical results. Earlier studies have shown a slight increase of the Cobb angle in brace-treated patients with time, but not in fused patients. METHODS: Of 283 patients, 252 attended a clinical and radiologic follow-up assessment by an unbiased observer (91% of the surgically treated and 87% of the brace-treated patients). This evaluation included chart reviews, validated questionnaires, clinical examination, and full-length standing frontal and lateral roentgenographs. Curve size was measured by the Cobb method on anteroposterior roentgenograms as well as by sagittal contour and balance on lateral films. The occurrence of any degenerative changes or other complications was noted. An age- and gender-matched control group of 100 individuals was randomly selected and subjected to the same examinations. RESULTS: The mean follow-up times were 23 years for surgically treated group and 22 years for brace-treated group. The deterioration of the curves was 3.5 degrees for all the surgically treated curves and 7.9 degrees for all the brace-treated curves (P < 0.001). Five patients, all brace-treated, had a curve increase of 20 degrees or more. The overall complication rate after surgery was low: Pseudarthrosis occurred in three patients, and flat back syndrome developed in four patients. Eight of the patients treated with fusion (5.1%) had undergone some additional curve-related surgical procedure. The lumbar lordosis was less in the surgically treated than in the brace-treated patients or the control group (mean, 33 degrees vs 45 degrees and 44 degrees, respectively). Both surgically treated and brace-treated patients had more degenerative disc changes than the control participants (P < 0.001), but no significant differences were found between the scoliosis groups. No statistically significant difference in terms of radiographically detectable degenerative changes in the unfused lumbar discs was found between patients fused below L3 or those fused to L3 and above (P = 0.22). A study on intra- and interobserver measurements of kyphosis, lordosis, and sagittal vertical axis on two films for each patient demonstrated that the repeatability of measuring sagittal plumbline on two different lateral radiographs, with patients moving between radiograms, was unreliable for comparison. CONCLUSIONS: Although more than 20 years had passed since completion of the treatment, most of the curves did not increase. The surgical complication rate was low. Degenerative disc changes were more common in both patient groups than in the control group.