Prevalence of adolescent idiopathic scoliosis in Turkey: an epidemiological study

Studies have shown that adolescent idiopathic scoliosis (AIS) prevalence varies between 0.35% and 5.2% and it is generally accepted as an average of 2%-3% in children under age 16. There are a few narrow-scope studies based on school screening performed on the epidemiology of AIS in Turkey. Prevalence rates reported by these studies are lower than reported in neighboring countries. Of note, they were conducted in single cities, generally based on small sample size, and are different from each other in terms of methodology and age groups. The present study was conducted based on a large population in 85 schools of 40 provinces in Turkey.

The aim of this study was to determine the prevalence of AIS in Turkey. Secondary outcomes were to determine age, gender, curve distribution, using standard tests, and radiological verification.

A cross-sectional epidemiological study.

The sample size was calculated to estimate the prevalence of AIS in children aged 10-15 years in Turkey.

Adams' forward bending test, angle of trunk rotation measurement, and posture analysis were used to screen. Students who had an angle of trunk rotation greater than or equal to five (≧5°) with scoliometer measurement or who had a positive forward bending test were referred to the mobile X-ray unit located in the school-yard on screening day. Their diagnosis was confirmed using Cobb angles of greater than or equal to 10 (≧10°).

Medical personnel, mobile radiological tools, and logistical support needed during fieldwork were provided by the Directorate General for Health Research, Ministry of Health Republic of Turkey. Spine and posture were examined in upright standing position. Examiners looked for shoulder asymmetries, scapular prominence, unequal waist, and lower limb length discrepancy. Potential scoliosis diagnosis was verified with onsite radiographic examination. Cases with a Cobb angle of ≧10° detected in any region were accepted as scoliosis. The direction and location of scoliosis were determined according to the Scoliosis Research Society terminology criteria.

A total of 16,045 students were reached whose informed consent forms were signed by their parents. The prevalence of AIS was found to be 2.3% (female, 3.1%; male, 1.5%). Radiological confirmation rate was 98.8%; 256 (69.3%) of 369 adolescents with scoliosis had a single curvature and 108 (29.3%) had a double curvature. The most common single curve type was a lumbar curve. In all, 90.5% of cases with AIS had a mild (range of 10°-19°) Cobb angle.

The prevalence of AIS was 2.3% in Turkey. This prevalence rate was considerably higher than the values in previous regional studies conducted in Turkey; however, it was close to generally accepted averages in the literature. One of the strongest aspects of the study was that radiologic confirmation of each suspected case was made during the screening.