A New Parameter, the Smallest Oblique Sagittal Area of the Neural Foramen, as an Index to Diagnose Cervical Neural Foramen Stenosis.

Abstract

The objective was to reconstruct the cervical neural foramen and accurately measure the minimum oblique sagittal area of the neural foramen. Then, a quantitative diagnostic standard for cervical neural foramen stenosis was proposed and its value as an indication for surgery was evaluated. (1) CT data were used to reconstruct the neural foramen using Mimics software, and the minimum area was measured. (2) The optimal cut-off value was determined using a receiver operating characteristic (ROC) curve. (3) Patients who underwent single-segment surgery were divided into 2 groups according to the cut-off value. Then the postoperative neurological function improvement rate was analyzed to identify any significant difference between the 2 groups. A total of 1056 neural foramens were measured in 132 patients, of which 495 (46.88%) were diagnosed as radiculopathy by clinical neurological examination. The optimal cut-off value determined by the ROC curve was 25.95 mm2 (sensitivity 74.1%, specificity 80.9%) and the area under the curve (AUC) was 0.827 (95%CI: 0.803-0.849). There was a significant difference in the neurological function improvement rate between the 2 groups after surgery (P < 0.05). The intraclass correlation coefficient (ICC) was 0.969. Three-dimensional digital simulation reconstruction of CT data is a good measurement method. The optimal cut-off value determined here not only has a certain reference value for the diagnosis of cervical neural foramen bony stenosis, but also helps to select patients suitable for neural foramen decompression and can be used as a reference for surgical indication.