International Evidence-Based Anatomy Working Group, Krakow, Poland.
Department of Anatomy, Jagiellonian University Medical College, Krakow, Poland.
Folia Morphol (Warsz). 2022;81(2):503-509. doi: 10.5603/FM.a2021.0040. Epub 2021 Apr 26.
Intervertebral disc (IVD) degeneration plays a crucial role in the pathophysiology of low back pain. Several grading systems have been developed for both morphological and radiological assessment. The aim of this study was to assess the morphological and radiological characteristics of IVD degeneration and validate popular radiological Pfirrmann scale against morphological Thompson grading system.
Full spinal columns (vertebrae L1-S1 and IVD between them) were harvested from cadavers through an anterior dissection. Magnetic resonance imaging scans of all samples were conducted. Then, all vertebral columns were cut in the midsagittal plane and assessed morphologically.
A total of 100 lumbar spine columns (446 IVDs) were included in the analysis of the degeneration grade. Morphologic Thompson scale graded the majority of discs as grade 2 and 3 (44.2% and 32.1%, respectively), followed by grade 4 (16.8%), grade 1 (5.8%) and grade 5 (1.1%). The radiologic Pfirrmann grading system classified 44.2% of discs as grade 2, 32.1% as grade 3, 16.8% as grade 4, 5.8% as grade 1, and 1.1% as grade 5. The analysis on the effect of age on degeneration revealed significant, although moderate, positive correlation with both scales. Analysis of the agreement between scales showed weighted Cohen's kappa equal to 0.61 (p < 0.001). Most of the disagreement occurred due to a 1 grade difference (91.5%), whereas only 8.5% due to a 2 grade difference.
With the increase of the prevalence of IVD disease in the population, reliable grading systems of IVD degeneration are crucial for spine surgeons in their clinical assessment. While overall there is agreement between both grading systems, clinicians should remain careful when using Pfirrmann scale as the grades tend to deviate from the morphological assessment.
椎间盘（IVD）退变在腰痛的病理生理学中起着关键作用。已经开发出几种用于形态学和影像学评估的分级系统。本研究旨在评估 IVD 退变的形态学和影像学特征，并验证流行的影像学 Pfirrmann 分级与形态学 Thompson 分级系统的相关性。
通过前路解剖从尸体中取出整个脊柱（L1-S1 椎体及其之间的 IVD）。对所有样本进行磁共振成像扫描。然后，将所有脊柱沿正中矢状面切开并进行形态学评估。
共纳入 100 个腰椎柱（446 个 IVD）进行退变分级分析。形态学 Thompson 分级将大多数椎间盘分为 2 级和 3 级（分别为 44.2%和 32.1%），其次是 4 级（16.8%）、1 级（5.8%）和 5 级（1.1%）。放射学 Pfirrmann 分级系统将 44.2%的椎间盘分为 2 级，32.1%分为 3 级，16.8%分为 4 级，5.8%分为 1 级，1.1%分为 5 级。分析年龄对退变的影响发现，两种分级系统均显示出显著但中等程度的正相关。两种分级系统之间的一致性分析显示，加权 Cohen's kappa 值等于 0.61（p<0.001）。大多数不一致是由于 1 级差异（91.5%），只有 8.5%是由于 2 级差异。
随着 IVD 疾病在人群中的患病率增加，可靠的 IVD 退变分级系统对脊柱外科医生的临床评估至关重要。虽然两种分级系统总体上具有一致性，但临床医生在使用 Pfirrmann 分级时应保持谨慎，因为其分级可能与形态学评估存在偏差。
