Equine Referral Hospital, The Royal Veterinary College, Hertfordshire, UK.
Newmarket Equine Hospital, Newmarket, UK.
Vet Radiol Ultrasound. 2023 Jul;64(4):661-668. doi: 10.1111/vru.13255. Epub 2023 Jun 8.
Slab fractures of the third carpal bone (C3) are a common cause of lameness in Thoroughbred racehorses. Information on fracture morphology is commonly obtained from radiographs or CT. This retrospective, methods comparison aimed to explore the agreement between radiography and CT for imaging C3 slab fractures and discuss the contribution of the latter to clinical case management. Thoroughbred racehorses with a slab or incomplete slab fracture of C3 identified on radiographs that subsequently underwent CT examination were included. Fracture characteristics (location, plane, classification, displacement, comminution) and fracture length as a percentage of the proximodistal length of the bone, termed the proximodistal fracture percentage (PFP) were recorded independently from both modalities and then compared. Across all fractures (n = 82) radiographs and CT showed slight agreement on the presence of comminution (Cohen's Kappa (κ) 0.108, P 0.031) and moderate agreement on fracture displacement (K 0.683, P < 0.001). Computed tomography identified comminution in 49 (59.8%) and displacement in nine (11.0%) fractures that were not detected by radiographs. Half of the fractures were only seen on flexed dorsoproximal-dorsodistal oblique (DPr-DDiO) radiographs and therefore were of unknown length without additional CT imaging. Incomplete fractures that could be measured on radiographs (n = 12) had a median (IQR) PFP of 40% (30%-52%) on radiographs and 53% (38%-59%) on CT, a statistically significant difference (P = 0.026). Radiography and CT showed the poorest agreement when determining the presence of comminution. Additionally, radiography often underestimated the incidence of displacement, and fracture length, and resulted in more fractures being classified as incomplete when compared to CT.
第三掌骨（C3）的板状骨折是赛马常见的跛行原因。通常通过 X 射线或 CT 获得骨折形态的信息。本回顾性、方法比较旨在探讨 X 射线摄影和 CT 成像 C3 板状骨折的一致性，并讨论后者对临床病例管理的贡献。纳入在 X 射线摄影上发现 C3 板状或不完全板状骨折且随后接受 CT 检查的纯种赛马。记录骨折特征（位置、平面、分类、移位、粉碎）和骨折长度占骨的近-远长度的百分比，称为近-远骨折百分比（PFP），分别独立于两种方式进行记录，然后进行比较。在所有骨折（n=82）中，X 射线摄影和 CT 在粉碎的存在上显示出轻微的一致性（Cohen's Kappa (κ) 0.108，P 0.031），在骨折移位上显示出中度的一致性（K 0.683，P < 0.001）。CT 检测到 X 射线摄影未发现的 49 处（59.8%）粉碎和 9 处（11.0%）移位骨折。一半的骨折仅在屈曲背侧-跖侧斜位（DPr-DDiO）X 射线摄影上可见，因此如果没有额外的 CT 成像，则长度未知。在 X 射线摄影上可测量的不完全骨折（n=12）在 X 射线摄影上的中位数（IQR）PFP 为 40%（30%-52%），在 CT 上为 53%（38%-59%），差异具有统计学意义（P=0.026）。当确定粉碎的存在时，X 射线摄影和 CT 的一致性最差。此外，与 CT 相比，X 射线摄影通常低估了移位和骨折长度的发生率，导致更多的骨折被分类为不完全。
