Variations in the Number of Thoracic and Lumbar Vertebrae in Patients With Adolescent Idiopathic Scoliosis: A Retrospective, Observational Study

Abstract

Background: Abnormal anatomy is a contributory factor to wrong-level surgery. Variations in the number of vertebrae in populations from different races and geographical regions have been described. A~10% prevalence of variations in number of thoracic and lumbar vertebrae in adolescent idiopathic scoliosis (AIS) patients has been previously reported. The objectives of present study were (i) to find out the prevalence of variations in the number of thoracic and lumbar vertebrae and the presence of lumbosacral transitional vertebrae (LSTV) in Indian AIS patients and (ii) to correlate these variations with gender and type of curve.Methods: Hospital records and imaging of 198 AIS patients were reviewed retrospectively. A standardized numbering strategy was used to identify the number of thoracic vertebrae, number of lumbar vertebrae, and presence of LSTV. Patients' gender and curve type were correlated with the presence of an abnormal number of thoracic or lumbar vertebrae. Radiology reports and operation notes were reviewed to find out instances when the radiologist or surgeon had identified an abnormal number of vertebrae.Results: Forty patients (20.2%) with abnormally numbered thoracic or lumbar vertebrae were identified. Twenty patients (10.1%) had abnormally numbered thoracic vertebrae, and 33 patients (16.7%) had abnormally numbered lumbar vertebrae. The prevalence of LSTV was 18.2%. Presence of variations did not correlate with gender or curve type. Radiology reports identified 2/40 patients with variations, whereas operation notes showed 4/40 patients had been correctly identified to have abnormally numbered vertebrae.Conclusions: There is high prevalence of variation in the number of thoracic or lumbar vertebrae in AIS patients, with most of those missed being identified by radiologists or surgeons. The patient's preoperative imaging must be scrutinized to identify these patients and take the variation into account to avoid wrong selection of fusion levels.Level of Evidence: 3. Clinical Relevance: Text. The study raises awareness about possibility of wrong selection in fusion levels due to anatomical variations in surgery for AIS.

Transitional lumbosacral vertebrae

“…Пациенты, страдающие сколиотическими деформациями, в среднем в 12-18% клинических наблюдений имеют лучевые симптомы люмбализации и сакрализации, что усугубляет клиническую картину искривлений позвоночника и требует особо тщательного планирования схем оперативного лечения [28][29][30].…”

“…Важная проблема, характеризующая актуальность изучаемой проблемы, -ошибки, допускаемые при постановке клинического диагноза, и связаны они преимущественно Ряд авторов в качестве ориентиров используют копчик, крыло подвздошной кости, подвздошно-поясничную связку, правую почечную артерию, верхнюю брыжеечную артерию, бифуркацию аорты, мозговой конус [37,68]. Однако большинство из перечисленных анатомических образований имеет анатомо-физиологические особенности развития, подвержено индивидуальной изменчивости, что может приводить к частым диагностическим, а затем и лечебным ошибкам [29]. В клинической практике встречаются такие ошибки с частотой от 33% [45] до 54% [69].…”

The Adolescent Spine

“…An abnormal count is found in up to 10% of patients with AIS. 45 Radiographs should also be assessed preliminarily to exclude findings suggestive of congenital or neuromuscular scoliosis. These include soft tissue abnormalities, wedged vertebrae, or hemivertebrae suggestive of congenital scoliosis, vertebral bone abnormalities suggestive of a bone tumor, increased distance between pedicles suggestive of a spinal cord tumor, syringomyelia, diastematomyelia or spinal dysraphism, or an increased thoracic kyphosis.…”

Variations in the Number of Vertebrae, Prevalence of Lumbosacral Transitional Vertebra and Prevalence of Cervical Rib among Surgical Patients with Adolescent Idiopathic Scoliosis

“…[2][3][4][5][6][7] The number of vertebrae also varies across different races and geographical regions. 8 Furthermore, the presence of anomalies such as lumbosacral transitional vertebra (LSTV) [9][10][11] cervical rib, 12,13 extra thoracic vertebra or L1 lumbar rib 14 could contribute to error in level determination. DOI: 10.1097/BRS.0000000000004711…”