[Feasible study for evaluating upper cervical reduction by the clivo-axial angle]

Area of Science:

• Neurosurgery
• Orthopedic Surgery
• Radiology

Background:

• Upper cervical deformities pose challenges in surgical correction.
• Accurate measurement of spinal alignment is critical for successful outcomes.
• The clivo-axial angle (CAA) and cervicomedullary angle (CMA) are key radiographic parameters.

Purpose of the Study:

• To measure the clivo-axial angle (CAA) and cervicomedullary angle (CMA) in patients with upper cervical deformity.
• To analyze the correlation between CAA and CMA before and after computer-assisted posterior upper cervical reduction and fixation surgery.
• To assess the utility of intraoperative CAA measurements in predicting intraoperative CMA.

Main Methods:

• 25 patients with symptomatic upper cervical deformity underwent posterior upper cervical reduction and fixation.
• Preoperative and postoperative CAA and CMA were measured using MRI and intraoperative C-arm.
• CAA and CMA measurements were performed by two experienced spinal surgeons and averaged.

Main Results:

• A significant positive correlation was found between preoperative CAA and CMA (r=0.902, P<0.001).
• Postoperative CAA and CMA also showed a significant positive correlation (r=0.921, P<0.001).
• Postoperative CAA and CMA values were significantly increased compared to preoperative values (P<0.001).

Conclusions:

• CAA and CMA are significantly correlated in upper cervical deformity patients, both preoperatively and postoperatively.
• Intraoperative CAA measurement, feasible with navigation systems, may predict CMA.
• Predicting CMA is vital for assessing spinal cord decompression and reduction during surgery.