Classification system for cervical spine deformity morphology: a validation study

J Neurosurg Spine 37:865–873, 2022

OBJECTIVE The objective of this study was to initially validate a recent morphological classification of cervical spine deformity pathology.

METHODS The records of 10 patients for each of the 3 classification subgroups (flat neck, focal deformity, and cervicothoracic), as well as for 8 patients with coronal deformity only, were extracted from a prospective multicenter database of patients with cervical deformity (CD). A panel of 15 physicians of various training and professional levels (i.e., residents, fellows, and surgeons) categorized each patient into one of the 4 groups. The Fleiss kappa coefficient was utilized to evaluate intra- and interrater reliability. Accuracy, defined as properly selecting the main driver of deformity, was reported overall, by morphotype, and by reviewer experience.

RESULTS The overall classification demonstrated a moderate to substantial agreement (round 1: interrater Fleiss kappa = 0.563, 95% CI 0.559–0.568; round 2: interrater Fleiss kappa = 0.612, 95% CI 0.606–0.619). Stratification by level of training demonstrated similar mean interrater coefficients (residents 0.547, fellows 0.600, surgeons 0.524). The mean intrarater score was 0.686 (range 0.531–0.823). A substantial agreement between rounds 1 and 2 was demonstrated in 81.8% of the raters, with a kappa score > 0.61. Stratification by level of training demonstrated similar mean intrarater coefficients (residents 0.715, fellows 0.640, surgeons 0.682). Of 570 possible questions, reviewers provided 419 correct answers (73.5%). When considering the true answer as being selected by at least one of the two main drivers of deformity, the overall accuracy increased to 86.0%.

CONCLUSIONS This initial validation of a CD morphological classification system reiterates the importance of dynamic plain radiographs for the evaluation of patients with CD. The overall reliability of this CD morphological classification has been demonstrated. The overall accuracy of the classification system was not impacted by rater experience, demonstrating its simplicity.

Clinical Presentation, Diagnosis, and Surgical Treatment of Spontaneous Cervical Intradural Disc Herniations

World Neurosurg. (2018) 109:275-284

Spontaneous cervical intradural disc herniation (IDH) is a rare occurrence with limited and disparate information available regarding its presentation, diagnosis, and treatment. However, its accurate detection is vital for planning surgical treatment. In this review of the literature, we collected data from all cervical IDHs described to date. Particular attention was paid to diagnostic findings, surgical approach, and causation for cervical IDH, especially at the cervicothoracic junction.

METHODS: A review for cases of cervical IDH was performed via the following search criteria: (“neck”[MeSH Terms] OR “neck”[All Fields] OR “cervical”[All Fields]) AND intradural[All Fields] AND disc[All Fields]. Thirtyseven cases of cervical disc herniation were identified. Demographic variables identified included age, sex, cervical level of herniation, history of associated cervical trauma, presence of Brown-Séquard syndrome, Horner syndrome, and other neurologic findings, radiographic findings, direction of surgical approach, and postoperative outcomes.

RESULTS: A total of 37 cases of cervical IDH were identified. Most of the cases occurred at the lower levels of the cervical spine, with 35.1% at the C5e C6 level, followed by 24.3% at C6eC7, and lower still at other levels. Of the patients reviewed, 44.4% had a previous history of trauma before manifestation of symptom, with the majority being spontaneous IDH with no previous history of trauma or spine surgery. Brown-Séquard syndrome was present in 43.2% of the patients, whereas 10.8% of patients experienced Horner syndrome. The most common presentations of IDH included quadriplegia, finger/gait ataxia, radiculopathy, and nuchal pain. The degree of neurologic recovery was not associated with patient age. Most of the cervical IDHs in the literature were treated surgically via an anterior approach, but a larger portion of patients who underwent a posterior approach had improved recovery.

CONCLUSIONS: Cervical IDH is a rare event, with this review of the literature outlining the clinical and radiographic parameters of its presentation as well as comparing common surgical strategies for treatment. We outline theories underlying the development of cervical IDH and argue for a posterior surgical approach in which the disc herniation is sequestrated with migration