Three-dimensional computed tomography analysis of the atlanto-dental interval in a healthy Karachi population: a single-center retrospective cross-sectional study

Background: The atlantoaxial joint has a complex anatomical configuration and has a wide range of mobility. Traumatic, inflammatory, and neoplastic joint pathologies frequently affect this joint. The aim of this retrospective cross-sectional study was to evaluate the atlanto-dental intervals (ADI) in patients who underwent computed tomography (CT) scans of the neck and cervical spine in at a Tertiary Care Hospital in Karachi, Pakistan. Methods: This was a retrospective cross-sectional study conducted at a tertiary care hospital in Karachi between 1 January 2021 and 31 December 2021, following approval from the hospital ethical review committee. Patients above the age of 15 who underwent CT scans were included, while individuals with a history of cervical trauma, infection, rheumatoid arthritis, or congenital anomalies, as well as those younger than 15 years old, were excluded. CT scans were performed using a multidetector scanner utilizing a standardized protocol. Sagittal and coronal images were reconstructed. ADI measurements, including anterior ADI (AADI), posterior ADI (PADI), and lateral ADI (LADI) on both sides, were determined using appropriate bone window settings. A radiologist with a minimum of 3 years of experience analyzed the CT scans. Results: The mean age of the patients was 49.3 +/- 17.7 years (age range: 16-85 years). The mean AADI was 1.4 +/- 0.4 mm, with a range of 0.0-2.1 mm. The mean PADI was 19.1 +/- 1.9 mm, with a range of 13.8-24.6 mm. The mean left LADI measurement was 3.3 +/- 1.2 mm with a range of 1.2-10.0 mm, and the mean right LADI measurement was 3.2 +/- 1.1 mm with a range of 1.2-6.3 mm. Conclusion: Our study examined the ADI in patients who underwent CT scans of the neck and cervical spine in Karachi. The findings provide valuable insights into the relationship between ADI measurements, age, and sex. These results contribute to our understanding of the anatomical variations in this region, which may aid in the diagnosis and management of cervical spine disorders.