Computed Tomographic Morphometric Analysis of C1 and C2 for Lamina Cross Screw Placement in Malay Ethnicity

Abstract

The C1 and C2 laminas in the Malaysian Malay population were analyzed for the feasibility of fitting 3.5-mm laminar screws in a cross configuration. Overview of Literature: Morphometric analysis of the C1 and C2 laminas has been performed for various populations but not for the Malaysian Malay population. Methods: A total of 330 CT cervical images were measured to establish the bicortical diameter of the C1 and C2 laminas as well as their height and length. The C1 posterior tubercle bicortical diameter and height were also determined from these images. All parameters were measured up to 0.1 mm, and statistical analysis was performed using IBM SPSS Statistics ver. 24.0 (IBM Corp., Armonk, NY, USA). An independent t-test and the Pearson chi-square test were used to determine the mean difference and screw acceptance. Results: The means of the C1 lamina measurements were 5.79±1.19 mm in diameter, 9.76±1.51 mm in height, and 20.70±1.86 mm in length. The means of the measurements of the posterior tubercle were 7.20±1.88 mm in diameter and 10.51±1.68 mm in height. The means of the C2 lamina measurements were 5.74±1.31 mm in diameter, 11.76±1.69 mm in height, and 24.96±2.56 mm in length. Overall 65.5% of C1 and 80.3% of C2 laminas are able to accept 3.5-mm screws in a cross configuration. Screw acceptability is similar between the right and left sides (p>0.05). However, males have a higher screw acceptability compared with females (p<0.05), except for the C2 left lamina. Conclusions: It is feasible to insert a 3.5-mm screw in a cross configuration in the C1 and C2 laminas of the Malaysian Malay population, especially in males. However, a CT scan should be performed prior to the operation to determine screw acceptability and to estimate screw sizes.

Bioelectrical Impedance Analysis Can Be an Effective Tool for Screening Fatty Liver in Patients with Suspected Liver Disease

“…Fat mass index (FMI) was defined as a value obtained by dividing BIA’s total body fat mass (kg) by the square of the height [ 26 ]. As a subgroup study, patients who had abdominal computed tomography (CT) three months before or after BIA were analyzed for visceral fat and muscle mass using axial images at the L3 spine level [ 27 , 28 ].…”

Characteristics and Comparisons of Morphometric Measurements and Computed Tomography Hounsfield Unit Values of C2 Laminae for Translaminar Screw Placement Between Patients With and Without Basilar Invagination

“…4B). 16 Based on the Chan criterion, 18 for laminae undergoing unilateral placement, the minimum laminar thickness and height should not be less than 4.5 mm if a 3.5-mm screw was inserted with a margin of error of 0.5 mm on each side, and the minimum laminar length must be 20 mm; for patients receiving bilateral placement, the bilateral laminar thickness, bilateral length, and bilateral height should be ≥ 4.5, ≥ 20, and ≥ 9 mm, www.e-neurospine.org 903 respectively. In addition, for patients with laminar assimilation of C2/3, the measurement of laminar height was abandoned, and it was assumed that the height of the lamina was large enough to accommodate the safe unilateral placement of the screw.…”

“…8,[13][14][15][16][17] In addition, the acceptability of TSP is analyzed in some studies. Chan et al 18 performed morphometric analysis of the C1 and C2 laminae and found that 65.5% of C1 and 80.3% of C2 laminae could accept 3.5 mm screws. Ma et al 19 conducted a cadaveric specimen study to assess the applicability of C2 TSP in adult population and indicated that 5% and 9.2% specimens had a laminar thick-ness of ≤ 4.0 mm bilaterally and unilaterally.…”

Translaminar screw of C1 for the reinforcement of subaxial cervical spine reconstruction

“…[ 1 ] However, the available literature reporting C1 translaminar screws are remarkably anecdotal. The C1 translaminar screw was firstly described by Floyd and Grob[ 2 ] in 2000, and until now has not been widely used only having reports of biomechanical[ 3 ] and radiological morphometric[ 4 ] analyses, with scarce clinical applications published. [ 5 6 ]…”