Introduction: C2 laminar screw fixation is becoming a popular alternative for posterior upper cervical spine fixation. We radiologically assessed several parameters of the dorsal arch of C2 as it relates to C2 laminar screw placement. To our knowledge, barely any previous study has focussed on an afrocentric population.
Methods: CT scans of the cervical spine done at the University Hospital of the West Indies, Jamaica from January 2017 to July 2017 were evaluated. Various morphometric parameters were assessed including both internal and external diameters of the lamina, length of lamina and the spinolaminar angle. Statistical analysis was done using SPSS.
Results: The CT scans of 70 adult patients (55.7% male) were reviewed. The mean internal diameter of the right lamina was 3.0mm (±1.2); 3.4mm in males and 2.8mm in females (p < 0.05). The mean internal diameter of the left lamina was 3.2mm (±1.2); 3.6mm in males and 2.9mm in females (p < 0.05).
The mean external diameter of the right lamina was 5.8mm (±1.37); 5.9mm in males and 5.7mm in females (p = 0.54). The mean external diameter of the left lamina was 5.9mm (±1.27); 6mm in males and 5.7mm in females (p = 0.19).
The mean length of the right lamina was 32.6mm in males and 30.9mm in females (p < 0.05) and the mean length of the left lamina was 27.3mm in males and 25.2mm in females (p < 0.05).
Mean spinolaminar angle was 48.9°on the right and 48.7° on the left.
Conclusions: The suitability of using a 3.5mm screw for translaminar fixation was assessed. Using external lamina diameters, 25.7% of patients had at least 1 lamina deemed unsuitable. The number of patients with at least 1 unsuitable lamina increased to 62.8% when the internal diameters were analysed.
Patient Care: C2 laminar screw fixation is considered an excellent alternative to the Magerl’s transfacetal approach or Harms construct for atlantoaxial stabilization. This project will help us determine the feasibility of translaminar screw fixation in our population and offer this procedure when indicated to the appropriate subset of patients.
Additionally, the data is scarce when focusing on afrocentric populations. This data attempts to address this literature gap.
Learning Objectives: Dorsal arch of C2 anatomy in afrocentric population
To relate this anatomy to the feasibility to C2 translaminar screw fixation in this population