Peterson and Smith Equine Hospital, Ocala, Florida, USA.
Royal Veterinary College Equine Referral Hospital, London, UK.
Equine Vet J. 2020 Mar;52(2):205-212. doi: 10.1111/evj.13166. Epub 2019 Sep 23.
Pathology of the digital flexor tendon sheath is a significant cause of lameness in the horse. Imaging is important to identify lesions and inform on prognosis prior to tenoscopic surgery.
To use a large population to evaluate 1) the sensitivity and specificity of digital flexor tendon sheath (DFTS) contrast radiographs in diagnosing manica flexoria (MF) tears, deep digital flexor tendon (DDFT) tears and constriction of the palmar/plantar annular ligament (PAL) using novel criteria; 2) predisposition to pathology in signalment and limb affected.
Multicentre retrospective cohort study.
The medical records of 206 horses with lameness localised to the DFTS, contrast radiographs and subsequent tenoscopic surgery were reviewed. Breed and limb predispositions were evaluated for pathology of the DDFT, MF and PAL constriction. Contrast radiographs of the DFTS were reviewed by four masked operators and for each pathology the sensitivity, specificity and interobserver variability were calculated.
Contrast tenography was a sensitive test for MF tears (92% confidence interval [CI] 88.4-94.4%; specificity 56%, CI 51.1-61.1%) and specific for diagnosing DDFT tears (73%, CI 68.6-76.8%; sensitivity 54%, CI 47.8-60.2%) but had a lower sensitivity (71%, CI 65.1-75.9% ) and specificity (45%, CI 39.1-52.0%) for PAL constriction. It had good to substantial interobserver agreement for MF and DDFT tears (Krippendorff's alpha 0.68 and 0.46 respectively). Ponies (57%) and cobs (58%) were significantly more likely to be affected with MF tears (other breeds 20-39%, P = 0.003) and Thoroughbreds (50%), warmbloods (45%) and draught breeds (48%) were more likely to have DDFT tears (other breeds 22-34%, P = 0.01). MF tears and PAL constriction were overrepresented in the hindlimbs compared to DDFT tears in forelimbs.
No standardisation of contrast radiographs was possible. The subjectivity of diagnosis of PAL constriction may also have led to bias. Radiographs were read as JPEGS reducing ability to manipulate images.
Contrast radiography of the DFTS is accurate in the pre-operative diagnosis of DFTS pathologies. Different pathologies are overrepresented in certain breeds and limbs.
马的屈肌腱鞘病理学是跛行的一个重要原因。影像学检查对于确定病变并在进行关节镜手术前预测预后非常重要。
使用大量病例评估 1）使用新的标准，数字屈肌腱鞘（DFTS）对比放射摄影术诊断屈肌滑膜（MF）撕裂、深屈肌腱（DDFT）撕裂和掌/跖环形韧带（PAL）狭窄的敏感性和特异性；2）在信号和受影响的肢体方面的病理学易感性。
多中心回顾性队列研究。
回顾了 206 例以屈肌腱鞘为局部病变的跛行马的病历、对比放射照片和随后的关节镜手术。评估了 DDFT、MF 和 PAL 狭窄的病理学的品种和肢体易感性。由四位盲法操作人员对 DFTS 的对比放射照片进行了评估，并为每种病理学计算了敏感性、特异性和观察者间变异性。
对比造影术对 MF 撕裂（92%置信区间[CI]88.4-94.4%；特异性 56%，CI 51.1-61.1%）是一种敏感的检查方法，对 DDFT 撕裂具有特异性（73%，CI 68.6-76.8%；敏感性 54%，CI 47.8-60.2%），但对 PAL 狭窄的敏感性（71%，CI 65.1-75.9%）和特异性（45%，CI 39.1-52.0%）较低。它对 MF 和 DDFT 撕裂具有良好到实质性的观察者间一致性（Krippendorff 的 alpha 分别为 0.68 和 0.46）。小马（57%）和柯柏（58%）发生 MF 撕裂的可能性明显更高（其他品种 20-39%，P=0.003），而纯种马（50%）、温血马（45%）和重型马（48%）更有可能发生 DDFT 撕裂（其他品种 22-34%，P=0.01）。与前肢的 DDFT 撕裂相比，后肢中 MF 撕裂和 PAL 狭窄更为常见。
无法对对比放射照片进行标准化。PAL 狭窄的诊断主观性也可能导致偏倚。由于只能以 JPEG 格式读取放射照片，因此减少了对图像进行操作的能力。
DFTS 的对比放射摄影术在术前诊断 DFTS 病变方面是准确的。不同的病理学在某些品种和肢体中更为常见。
