Morphometric Analysis of the Neural Arch of C2 Vertebra in Indian Population.

BACKGROUND AND OBJECTIVE: The most common injuries to upper cervical spine are fractures of the second cervical vertebrae. The study aims to evaluate the morphometry of the neural arch of the second cervical vertebrae in the South Indian population. MATERIALS AND METHODS: Sixty-three second cervical vertebrae of undetermined gender and age without any gross defect were used for the study. The dimensions of neural arch, including superior articular facet, inferior articular facet, pediculoisthmic component, lamina, spinous process, foramen transversarium, and vertebral foramen, were measured by two independent observers using digital vernier caliper accurate to 0.1 mm and the data was analyzed. Descriptive statistics were obtained for the variables. Paired t-test was done to compare the measurements between right and left sides. RESULTS: There was no statistical difference between the right and left sides of the dimensions of superior articular facets, foramen transversarium, and the transverse diameter of inferior articular facet. The anteroposterior diameter of the inferior articular facets was more on the right side (P = 0.009). The width of the pediculoisthmic component in both the superior and inferior aspects was found to be less on the right side than that of the left (P = 0.006 and P = 0.031, respectively). The thickness in the middle one-third of laminae was optimum for bilateral safe screw insertion (≥4.0 mm) in 77% specimens. CONCLUSION: In summary, measurements of the transverse diameter of superior articular facet and thickness of lamina differed significantly from those reported in literature. This should be kept in mind while doing neurosurgery procedures in the Indian population.

Morphometric analysis and clinical application of the working dimensions of cricothyroid membrane in south Indian adults: with special relevance to surgical cricothyroidotomy.

OBJECTIVE: To measure the working dimensions of the cricothyroid membrane in the adult south Indian population and to establish the association between the working dimensions and the appropriate endotracheal tube size for the purpose of cricothyroidotomy. METHODS: Cross-sectional evaluation of 50 fresh adult autopsy cases (35 men, 15 women) in a medical university teaching hospital in South India. RESULTS: Age ranged from 17.0 to 83.0 years. Working dimensions of the membrane in neutral position of neck, in men: width = 8.41 +/- 2.11 mm, height = 6.57 +/- 1.87 mm; in women: width = 6.30 +/- 1.29 mm, height = 5.80 +/- 1.56 mm. Depth of the subglottic larynx at the level of cricoid cartilage: men = 20.73 +/- 1.97 mm, women = 15.62 +/- 1.71 mm. Distance of the lower border of cricothyroid membrane from suprasternal notch in neutral position of neck, in men = 5.18 +/- 1.76 cm, women = 4.72 +/- 1.55 cm; in passively extended neck, men = 7.86 +/- 1.25 cm, women = 8.05 +/- 1.28 cm. Regression equations have been derived to determine endotracheal tube size for cricothyroidotomy, based on distance between sternal notch and chin, and height of the individual (P < 0.05). CONCLUSIONS: Working dimensions are smaller in the Indian group compared with western publications. Endotracheal tubes ranging from size 3.0 to 6.0 might be used for cricothyroidotomy in the adult south Indian population.