S3 Dataset -

Site selection for cervical stabilization surgery in horses with spinal ataxia frequently relies on measurements derived from radiographic myelography. A variety of measurement criteria exist and can provide conflicting results. The main objectives of this study were to assess the correlation between two commonly used myelographic measures, dorsal contrast column reduction (DCCR) and dural diameter reduction (DDR), and their association with previously selected operative sites in a population of horses operated at a tertiary clinic. Secondary objectives were to determine if articular process joint (APJ) atrophy occurred in a subset of operated horses with radiographic follow-up, and to describe complications of cervical stabilization surgery and long term outcomes. The study was primarily cross-sectional using previously recorded medical information and images from horses operated between 2008 and 2022: three masked raters assessed previously acquired pre-operative myelograms obtained in neutral, flexed and extended neck positions from horses that had subsequently undergone stabilization surgery consisting of cervical interbody fusion via a Kerf-cut cylinder technique at one or two sites. A veterinary radiologist evaluated changes in APJ in radiographs obtained in a subset of horses re-evaluated >18 months after surgery. DCCR was unremarkable at nearly all articulations in all horses, while DDR met reduction criteria at over 50% of articulations in flexed position. Neither DCCR nor DDR distinguished operated from non-operated sites at most intervertebral junctions, except at the C6-7 articulation in neutral and extended position. The two measures were also poorly correlated at most sites and in most positions. Surgical complications included a high incidence of laryngeal hemiplegia. Comparison of operated to non-operated sites within individuals radiographed years later showed consistent, mildly reduced APJ opacity at most operated sites without a consistent decrease in APJ height or area ratios. Our results suggest that DCCR and DDR measures did not reliably predict surgical site selection in this surgical cohort except at C6-7, and that the two measures yielded conflicting diagnostic classification at many sites and positions. Complication rates from stabilization surgery were high; and predictable reduction in APJ height or area after surgery was not demonstrated by radiography in this study.患有脊髓共济失调的马匹，其颈椎固定手术的术区选择通常依赖于放射脊髓造影（radiographic myelography）所得的测量数据。目前存在多种测量标准，其结果可能存在冲突。本研究的主要目的为评估两种常用的脊髓造影测量指标——背侧造影柱缩小（DCCR）与硬脊膜直径缩小（DDR）之间的相关性，以及二者与某三级诊疗中心收治的手术马匹群体中已选定术区的关联。次要目的为：在接受放射影像学随访的手术马匹亚组中，确认是否存在关节突关节（APJ）萎缩；同时描述颈椎固定手术的并发症与长期预后情况。本研究为回顾性横断面研究，采用2008年至2022年间接受手术的马匹的既往医疗记录与影像学资料：由3名盲法评估者，对后续接受单节段或双节段切缝圆柱体技术颈椎椎体间融合固定术的马匹，在颈部中立、屈曲及伸展位下获取的术前脊髓造影片进行评估。一名兽医放射科医师对术后18个月以上接受再次影像学评估的马匹亚组的X线片进行关节突关节（APJ）变化评估。所有马匹的几乎所有关节节段的背侧造影柱缩小（DCCR）结果均无异常，而在颈部屈曲位下，超过50%的关节节段的硬脊膜直径缩小（DDR）符合缩小判定标准。在大多数椎间连接处，背侧造影柱缩小（DCCR）与硬脊膜直径缩小（DDR）均无法区分手术节段与非手术节段，仅在颈部中立及伸展位下的C6-7关节节段除外。两种测量指标在大多数节段与体位下的相关性也较差。手术并发症包括较高发生率的喉偏瘫。对多年后接受影像学检查的个体，对比其手术节段与非手术节段的结果显示：大多数手术节段的关节突关节（APJ）密度呈一致性轻度降低，但未出现关节突关节高度或面积比值的一致性下降。本研究结果表明：除C6-7节段外，背侧造影柱缩小（DCCR）与硬脊膜直径缩小（DDR）无法可靠预测本次手术队列的术区选择；且两种测量指标在众多节段与体位下的诊断分类结果存在冲突。颈椎固定手术的并发症发生率较高；本研究的影像学结果未证实术后关节突关节高度或面积可出现可预测性降低。