In-Depth Analysis on Influencing Factors of Adjacent Segment Degeneration After Cervical Fusion

Abstract

BackgroundTo explore the related influencing factors of adjacent segment degeneration (ASD) after cervical discectomy and fusion (ACDF).Material/MethodsA retrospective analysis of 263 patients who underwent ACDF was carried out. Cervical x-ray and magnetic resonance imaging (MRI) were required before operation, after operation, and at the last follow-up. General information and some radiographic parameters of all patients were measured and recorded. According to the imaging data, patients were put into one of two groups: non-ASD group and ASD group. The differences between the two groups were compared by t-test and χ2-test, and the related influencing factors of ASD were analyzed by logistic regression.ResultsIn all, 138 patients had imaging ASD. Comparing the age, the postoperative cervical arc chord distance (po-CACD), and the plate to disc distance (PDD) of the two groups, differences were statistically significant (p<0.05). The gender, the fusion segment number, the pre-CACD, the pre-and-po CACD, the preoperative cervical spinal canal ratio, and the upper and lower disc height (DH) showed no statistical difference between the two groups (p>0.05). The results of logistic regression analysis showed that there were significant correlations in the following characteristics: age, postoperative po-CACD, and the PDD (p<0.05). Of all these characteristics, the correlation of age was the highest (R=1.820).ConclusionsAge, po-CACD, and PDD were risk factors for ASD after ACDF. The older the operation age, the worse the recovery was of postoperative physiological curvature of cervical spine, and a PDD < 5 mm was more likely to lead to ASD.

Association between sagittal balance and adjacent segment degeneration in anterior cervical surgery: a systematic review and meta-analysis

“…Nunley et al [29] reported that osteopenia (OD = 9.35) and documented lumbar degenerative disc disorder (OD = 5.13) were two independent risk factors for ASD in patients undergoing total disc replacement. Yu et al [30] found that older age, poor restoration of postoperative cervical lordosis, and a plate to disc distance less than 5 mm may result in ASD after cervical fusion. Lee et al [31] revealed that patients with one- or two- level anterior arthrodesis and those who smoked were more likely to receive an adjacent segment surgery within 10 years.…”

Radiological exploration on adjacent segments after total cervical disc replacement with Prodisc-C prosthesis

“…Yu et al [19] considered that non-operated segments increased ROM in order to maintain physiological activities after ACDF, where ROM gradually decreased cranially and caudally with a center of the operated segments. In this condition, ASD was incidental with adjacent segments overloaded.…”

Biomechanical Effect of Plate-to-Disc Distance on Surgical and Adjacent Segment in C5/C6 Anterior Cervical Discectomy and Fusion - A Finite Element Analysis

“…So they considered that to prevent adjacent segment degeneration, the PDD should be 5 mm or more if possible. In addition, Yu et al 25 agreed that PDD < 5 mm is a risk factor for ASD by the logistic regression analysis based on 138 patients. However, Yang et al 26 retrospectively reviewed 218 patients who underwent anterior cervical arthrodesis with plating and considered that there is no correlation between PDD and the incidence of ASD, but PDD > 5 mm could avoid the development of adjacent segment ossi cation.…”

“…However, it has been reported that the use of short PDD plate will accelerate the degeneration of adjacent segments, eventually result in symptomatic ASD 25 .…”