Qualitative and quantitative assessment of degeneration of cervical intervertebral discs and facet joints

Abstract

Degeneration of intervertebral discs and facet joints is one of the most frequently encountered spinal disorders. In order to describe and quantify degeneration and evaluate a possible relationship between degeneration and biomechanical parameters, e.g., the intervertebral range of motion and intradiscal pressure, a scoring system for degeneration is mandatory. However, few scoring systems for the assessment of degeneration of the cervical spine exist. Therefore, two separate objective scoring systems to qualitatively and quantitatively assess the degree of cervical intervertebral disc and facet joint degeneration were developed and validated. The scoring system for cervical disc degeneration consists of three variables which are individually scored on neutral lateral radiographs: "height loss" (0-4 points), "anterior osteophytes" (0-3 points) and "endplate sclerosis" (0-2 points). The scoring system for facet joint degeneration consists of four variables which are individually scored on neutral computed tomography scans: "hypertrophy" (0-2 points), "osteophytes" (0-1 point), "irregularity" on the articular surface (0-1 point) and "joint space narrowing" (0-1 point). Each variable contributes with varying importance to the overall degeneration score (max 9 points for the scoring system of cervical disc degeneration and max 5 points for facet joint degeneration). Degeneration of 20 discs and facet joints of 20 patients was blindly assessed by four raters: two neurosurgeons (one senior and one junior) and two radiologists (one senior and one junior), firstly based on first subjective impression and secondly using the scoring systems. Measurement errors and inter- and intra-rater agreement were determined. The measurement error of the scoring system for cervical disc degeneration was 11.1 versus 17.9% of the subjective impression results. This scoring system showed excellent intra-rater agreement (ICC = 0.86, 0.75-0.93) and excellent inter-rater agreement (ICC = 0.78, 0.64-0.88). Surgeons as well as radiologists and seniors as well as juniors obtained excellent inter- and intra-rater agreement. The measurement error of the scoring system for cervical facet joint degeneration was 20.1 versus 24.2% of the subjective impression results. This scoring system showed good intra-rater agreement (ICC = 0.71, 0.42-0.89) and fair inter-rater agreement (ICC = 0.49, 0.26-0.74). Both scoring systems fulfilled the criteria for recommendation proposed by Kettler and Wilke. Our scoring systems can be reliable and objective tools for assessing cervical disc and facet joint degeneration. Moreover, the scoring system of cervical disc degeneration was shown to be experience- and discipline-independent.

Facet Joint Degeneration of the Cervical Spine

“…Degeneration of 20 discs and facet joints of 20 patients were blindly assessed by 4 raters. 4 The measurement error of the scoring system for cervical facet joint degeneration was 20.1% versus 24.2% with subjective impression results. 4 This scoring system had good intrarater agreement (ICC = 0.71; range, 0.42-0.89) and fair inter-rater agreement (ICC = 0.49; range, 0.26-0.74).…”

“…13 , 14 However, to our knowledge, there is only one CT grading system for cervical facet joints. 4 The purpose of this study is to evaluate a new CT-based grading system for cervical facet joint degeneration and to determine the location and grades of degeneration of cervical facets.…”

“…3 There are few studies in the literature that have evaluated cervical facet joint degeneration using CT. 4 , 5 However, there is only one grading system for cervical facet joints using CT but no grading system using MRI. 4 The purpose of this study is to propose and evaluate a new grading system for cervical facet degeneration using CT. We then use the grading system to determine the severity of degeneration according to age, sex, and cervical level.…”

Factors that may affect outcome in cervical artificial disc replacement: a systematic review

“…The incidence of r-ASD in these three large multicenter trials ranged from 39.1 to 47.5 % evaluated by Kellgren-Lawrence scale or Walraevens scale [20,21], with an overall incidence of 42.4 % (P = 0.46; 95 % CI 38.3-46.6 %) (Fig. 5) [6,18,22].…”

Cervical spine injuries and flexibilities following axial impact with lateral eccentricity

“…Degeneration of the intervertebral disks and facet joints were evaluated by a spine surgeon (JS) using the CT scans and scored as normal (0), mild (1), moderate (2), or severe (3), according to the scoring system of Walraevens et al [36]. Total degeneration scores for each specimen were the sum of the disk and facet scores.…”