We reviewed the cases of 727 patients with idiopathic scoliosis in whom the initial curve measured from 5 to 29 degrees. The patients were followed either to the end of skeletal growth or until the curve progressed. One hundred and sixty-nine patients (23.2 per cent) showed progression of the curve. The incidence of curve progression was found to be related to the pattern and magnitude of the curve, the patient's age at presentation, the Risser sign, and the patient's menarchal status. We found no correlation between progression of the curve and the patient's sex, Harrington factor, rotational prominence, family history, or radiographic measurements. A progression factor was calculated using the three strongest correlations available at initial examination: the magnitude of the curve, the Risser sign, and the patient's chronological age. A graph and nomogram are presented that can serve as a guide for advising patients' families and for planning continuing care.

The prediction of curve progression in untreated idiopathic scoliosis during growth.

Adolescent idiopathic scoliosis is a common disease with an overall prevalence of 0.47–5.2 % in the current literature. The female to male ratio ranges from 1.5:1 to 3:1 and increases substantially with increasing age. In particular, the prevalence of curves with higher Cobb angles is substantially higher in girls than in boys: The female to male ratio rises from 1.4:1 in curves from 10° to 20° up to 7.2:1 in curves >40°. Curve pattern and prevalence of scoliosis is not only influenced by gender, but also by genetic factors and age of onset. These data obtained from school screening programs have to be interpreted with caution, since methods and cohorts of the different studies are not comparable as age groups of the cohorts and diagnostic criteria differ substantially. We do need data from studies with clear standards of diagnostic criteria and study protocols that are comparable to each other.

https://online.boneandjoint.org.uk/doi/pdf/10.1007/s11832-012-0457-4

Epidemiology of adolescent idiopathic scoliosis

ContextPrevious 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.ObjectiveTo present the outcomes related to health and function in untreated
patients with LIS.Design, Setting, and PatientsProspective 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).Main Outcome MeasuresMortality, back pain, pulmonary symptoms, general function, depression,
and body image.ResultsThe 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° 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.ConclusionsUntreated 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.

/pdf/health-and-function-of-patients-with-untreated-idiopathic-4scgnvdoyg.pdf

Health and function of patients with untreated idiopathic scoliosis: a 50-year natural history study.

One hundred and thirty-three curves in 102 patients who were followed for an average of 40.5 years were evaluated to quantitate curve progression after skeletal maturity and for prognostic factors leading to curve progression. Sixty-eight per cent of the curves progressed after skeletal maturity. In general, curves that were less than 30 degrees at skeletal maturity tended not to progress regardless of curve pattern. In thoracic curves the Cobb angle, apical vertebral rotation, and the Mehta angle were important prognostic factors. In lumbar curves the degree of apical vertebral rotation, the Cobb angle, the direction of the curve, and the relationship of the fifth lumbar vertebra to the intercrest line were of prognostic value. Translatory shifts played an important role in curve progression. Curves that measured between 50 and 75 degrees at skeletal maturity, particularly thoracic curves, progressed the most.

Curve progression in idiopathic scoliosis.

To quantitate the intrinsic error in measurement, fifty anteroposterior radiographs of patients who had scoliosis were each measured on six separate occasions by four orthopaedic surgeons using the Cobb method For the first two measurements (Set I), each observer selected the end-vertebrae of the curve; for the next two measurements (Set II), the end-vertebrae were pre-selected and constant The last two measurements (Set III) were obtained in the same manner as Set II, except that each examiner used the same protractor rather than the one that he carried with him The pooled results of all four observers suggested that the 95 per cent confidence limit for intraobserver variability was 49 degrees for Set I, 38 degrees for Set II, and 28 degrees for Set III The interobserver variability was 72 degrees for Set I and 63 degrees for Sets II and III The mean angles differed significantly between observers, but the difference was smaller when the observers used the same protractor

Measurement of the Cobb angle on radiographs of patients who have scoliosis. Evaluation of intrinsic error.

A prospective study was carried out of the incidence and natural history of adolescent idiopathic scoliosis in 26,947 students. Data were obtained on 1,122 students with idiopathic scoliosis. The incidence of idiopathic scoliosis was 4.5 per cent. The female-to-male ratio was 1.25:1.0 over-all, but the ratio varied directly with the severity of the curve--that is, 1:1 for curves of 6 to 10 degrees, and 5.4:1 for curves of more than 20 degrees. Progression of the curve was determined by a two-year follow-up of 603 patients. Progression was observed in 6.8 per cent of the students and in 15.4 per cent of the skeletally immature girls with scoliosis of more than 10 degrees at the initial examination. In 20 per cent of the skeletally immature children with curves of 20 degrees at the initial examination, there was no progression. Spontaneous improvement of the curve occurred in 3 per cent and was seen more frequently in curves milder than 11 degrees. Treatment was required in 2.75 students per 1,000 screened.

D S Drummond

Papers

Scoliosis: incidence and natural history. A prospective epidemiological study.