Previous long-term studies of idiopathic scoliosis have included patients with other etiologies, leading to the erroneous conclusion that all types of idiopathic scoliosis inevitably end in disability. Late-onset idiopathic scoliosis (LIS) is a distinct entity with a unique natural history. To present the outcomes related to health and function in untreated patients with LIS. Prospective natural history study performed at a midwestern university with outpatient evaluation of patients who presented between 1932 and 1948. At 50-year follow-up, which began in 1992, 117 untreated patients were compared with 62 age- and sex-matched volunteers. The patients' mean age was 66 years (range, 54-80 years). Mortality, back pain, pulmonary symptoms, general function, depression, and body image. The estimated probability of survival was approximately 0.55 (95% confidence interval [CI], 0.47-0.63) compared with 0.57 expected for the general population. There was no significant difference in the demographic characteristics of the 2 groups. Twenty-two (22%) of 98 patients complained of shortness of breath during everyday activities compared with 8 (15%) of 53 controls. An increased risk of shortness of breath was also associated with the combination of a Cobb angle greater than 80 degrees and a thoracic apex (adjusted odds ratio, 9.75; 95% CI, 1.15-82.98). Sixty-six (61%) of 109 patients reported chronic back pain compared with 22 (35%) of 62 controls (P =.003). However, of those with pain, 48 (68%) of 71 patients and 12 (71%) of 17 controls reported only little or moderate back pain. Untreated adults with LIS are productive and functional at a high level at 50-year follow-up. Untreated LIS causes little physical impairment other than back pain and cosmetic concerns.
