Cervical Spine Endplate Abnormalities and Association With Pain, Disability, and Adjacent Segment Degeneration After Anterior Cervical Discectomy and Fusion

Abstract

Study Design. A retrospective study with prospectively-collected data. Objective. To determine how type, location, and size of endplate lesions on magnetic resonance imaging (MRI) may be associated with symptoms and clinical outcomes after anterior cervical discectomy and fusion (ACDF). Summary of Background Data. Structural endplate abnormalities are important, yet understudied, phenomena in the cervical spine. ACDF is a common surgical treatment for degenerative disc disease; however, adjacent segment degeneration/disease (ASD) may develop. Methods. Assessed the imaging, symptoms and clinical outcomes of 861 patients who underwent ACDF at a single center. MRI and plain radiographs of the cervical spine were evaluated. Endplate abnormalities on MRI were identified and stratified by type (atypical, typical), location, relation to operative levels, presence at the adjacent level, and size. These strata were assessed for association with presenting symptoms, patient-reported, and postoperative outcomes. Results. Of 861 patients (mean follow-up: 17.4 months), 57.3% had evidence of endplate abnormalities, 39.0% had typical abnormalities, while 18.2% had atypical abnormalities. Patients with any endplate abnormality had greater odds of myelopathy irrespective of location or size, while sensory deficits were associated with atypical lesions (P = 0.016). Typical and atypical abnormalities demonstrated differences in patient-reported outcomes based on location relative to the fused segment. Typical variants were not associated with adverse surgical outcomes, while atypical lesions were associated with ASD (irrespective of size/location; P = 0.004) and reoperations, when a large abnormality was present at the proximal adjacent level (P = 0.025). Conclusion. This is the first study to examine endplate abnormalities on MRI of the cervical spine, demonstrating distinct risk profiles for symptoms, patient-reported, and surgical outcomes after ACDF. Patients with typical lesions reported worsening postoperative pain/disability, while those with atypical abnormalities experienced greater rates of ASD and reoperation. This highlights the relevance of a degenerative spine phenotypic assessment, and suggests endplate abnormalities may prognosticate clinical outcomes after surgery. Level of Evidence: 3

The Modic‐endplate‐complex phenotype in cervical spine patients: Association with symptoms and outcomes

“…Based on their results, the authors proposed that endplate defects were the initiating factor that triggered a cascade of degradation that results in degenerative disc disease, which may precede the development of clinical symptoms. Although several studies have found that MC and endplate abnormalities may be related to axial neck pain, 15,16,20 as well as low back pain, 11,13,45 the present study found no association between any of the imaging groups and preoperative neck pain. These findings should be taken with special consideration as our control group had significant neck pain at baseline, which may have masked associations with pain and imaging phenotypes.…”

“…In a previous study of the same group of patients, both typical and atypical endplate abnormalities were associated with myelopathy and upper extremity sensory deficits. 21,20 There is still not much understood regarding specific phenotypes and their impact on the transition from pure spondylosis to a spondylotic myelopathy. As described above, much of the lumbar research on MC and endplate anatomy has been focused on back pain.…”

“…[32][33][34][35] In addition, other factors implicated in the development of degenerative cervical myelopathy, such as facet joint degeneration, ligamentous hypertrophy, and osteophytes, 36 may also be linked to endplate pathology, contributing to a higher likelihood of cord compression. In fact, recent studies by Baker et al 17 and Harada et al 20 further highlighted the slate of degenerative changes that are associated with MC and endplate abnormalities, respectively, of the cervical spine. In addition, the MEC may be an imaging and structural biomarker for subphenotype developmental etiologies that can affect canal dimensions.…”

“…18,19 Similar to MC, there is a paucity of studies that have addressed endplate abnormalities in the cervical spine. 20 Recent studies by Harada et al 20,21 were the first to extensively describe the endplate phenotype on MRI in cervical spine patients, noting that these are clinically relevant phenotypes associated with pain, disability, degeneration and adverse surgical outcomes (e.g., adjacent segment degeneration/ disease).…”

“…22 Previous work has suggested that degenerative findings, such as MC and endplate abnormalities, may be linked to suboptimal outcomes following ACDF. 16,20 However, the extent to which these imaging phenotypes impact outcomes of ACDF is still largely up for debate. Moreover, studies to date have largely focused on assessing these phenotypes in isolation, and to our knowledge few studies have examined the impact that a combined MC and structural endplate abnormality has on outcomes following ACDF.…”