Classification of cervical disc herniation myelopathy or radiculopathy: a magnetic resonance imaging-based analysis

Preoperative magnetic resonance imaging (MRI) can clearly show the location and level of disc herniation. When the symptoms are consistent with the Prominent segments, surgical treatment can be indicated. However, the varied extents of the protruding masses in cervical disc herniation (CDH) have been rarely reported. This study aimed to characterize the severity of CDH and to develop a reproducible grading and zoning system for cervical disc degeneration.

A total of 200 patients who presented with single CDH and underwent MRI/computed tomography (CT) scans were enrolled in this prospective study between 2018 and 2021. A total of 170 cervical discs were graded according to MRI by 3 spine surgeons in a blinded fashion. CDHs were graded 1-3, with regions A-C. All patients with grade 1 and mild C symptoms were excluded. The foramen facet spinal (FFS) classification based on MRI Japanese Orthopedic Association (JOA) scores and the incidence of complications were evaluated and analyzed, and follow-up outcomes were assessed.

Areas 2-A, 2-B, and 1-C had high motor function scores, areas 2-A, 3-A, and 2-AB had high sensory scores, but areas 3-AB and 3-A had low bladder function scores. Areas 3-AB had the most severe symptoms and the lowest scores. Area 1-C showed neurogenic abnormal sensation and higher visual analog scale (VAS) scores. A good/excellent outcome as indicated by the JOA score was 94.70% at 3 months and 92.35% at 1 year in 170 patients. The complication rate was 9.41%. The diagnostic coefficient of the FFS classification was 0.888, P<0.001.

The FFS classification is an objective scoring system that can be applied similarly by multiple examiners and is correlated with clinical symptoms.