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

Clinical validity of the smallest oblique sagittal area of the neural foramen in patients with suspected cervical spondylotic radiculopathy

OBJECTIVE

To evaluate the smallest oblique sagittal area of the neural foramen in detecting cervical spondylotic radiculopathy (CSR) and to determine its potential significance for treatment decisions.

METHODS

The subjects of the study were patients with CSR who visited the spine surgery from 2016 to 2019. All patients were compared according to the minimum oblique sagittal area and the cut-off point value, and they were divided into positive and negative parameters. The changes in neck disability index (NDI), Japanese Orthopaedic Association score (JOA), and visual analog scale (VAS) during the two treatment groups from baseline to at least 24 months of follow-up were compared.

RESULTS

In the surgery group, there was no significant difference in symptom improvement between patients with positive and negative parameters. In the non-surgical group, for patients with positive parameters, NDI decreased by 2.35, JOA increased by 0.88, and neck VAS score improved by 0.42. For patients with negative parameters, NDI decreased by 10.32, JOA increased by 2.86 on average, and neck VAS score improved by 2.46 points on average (both p<0.01 on t test).

CONCLUSIONS

Patients with both positive and negative parameters showed significant improvement in their symptoms after surgery, and the smallest oblique sagittal area of the neural foramen seems to be unable to predict the outcome of the surgery. However, in non-surgical patients, symptomatic improvement was more limited in patients with positive parameters than in those with negative parameters. This suggests that patients with positive parameters may be more suitable for surgery and those with negative parameters are more suitable for conservative treatment.