Dyson S, Blunden T, Murray R
Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK.
Equine Vet J. 2008 Sep;40(6):538-44. doi: 10.2746/042516408X313661.
Magnetic resonance imaging (MRI) is used with increasing frequency to diagnose injuries of the collateral ligaments (CLs) of the distal interphalangeal (DIP) joint, but the results have not been verified by histology and the mechanism of injury is poorly understood.
Abnormal signal intensity and tissue contour represents change in tissue structure detected on histology.
To compare results in horses free from and those with chronic lameness and to describe possible progression of lesions.
One or both feet of horses free from lameness (Group N: n = 12) and with foot-related lameness (Group L: n = 25) were examined using MRI and by gross post mortem examination. The magnetic resonance (MR) images were graded. Sagittal sections from the proximal and distal aspect of each CL were examined histologically and each ligament assigned a score. Scintigraphic images from lame horses were also evaluated.
In Group N, 25 CLs were graded normal on both MR images and histology, 2 CLs were grade 1 on MR images, but were histologically normal, and 2 CLs had MR abnormalities verified histologically. However, 2 CLs appeared normal on MR images but were histologically abnormal. In Group L, 18 CLs were deemed normal on both MR images and histology, and 54 CLs had MR abnormalities verified histologically. However, 13 CLs appeared normal on MR images but were graded abnormal histologically. Lesions appeared to be degenerative, characterised by extensive fibrocartilaginous metaplasia and development of multiple, intercommunicating fissures within the degenerate collagen in severe lesions. There was an association between increased radiopharmaceutical uptake and a higher histological score.
High-field MRI is reasonably reliable for detection of lesions of the CLs of the DIP joint, but may underestimate their prevalence.
Collateral ligament injury appears to be a primary degenerative process, which may explain the poor response to conservative treatment and a need for promotion of regeneration.
磁共振成像（MRI）在诊断远节指间关节（DIP）侧副韧带（CL）损伤中的应用频率日益增加，但结果尚未经组织学验证，损伤机制也了解甚少。
异常信号强度和组织结构代表了组织学上检测到的组织结构变化。
比较无跛行马和慢性跛行马的检查结果，并描述病变可能的进展情况。
对无跛行马（N组：n = 12）和足部相关跛行马（L组：n = 25）的一只或两只蹄进行MRI检查及大体尸检。对磁共振（MR）图像进行分级。对每个CL近端和远端的矢状面切片进行组织学检查，并给每条韧带评分。还对跛行马的闪烁扫描图像进行了评估。
在N组中，25条CL在MR图像和组织学检查中均分级正常，2条CL在MR图像上为1级，但组织学检查正常，2条CL的MR异常经组织学证实。然而，2条CL在MR图像上看似正常，但组织学检查异常。在L组中，18条CL在MR图像和组织学检查中均被认为正常，54条CL的MR异常经组织学证实。然而，13条CL在MR图像上看似正常，但组织学分级异常。病变似乎为退行性，其特征为广泛的纤维软骨化生，严重病变中退变胶原内出现多个相互连通的裂隙。放射性药物摄取增加与更高的组织学评分之间存在关联。
高场强MRI在检测DIP关节CL损伤方面具有一定可靠性，但可能低估其发生率。
侧副韧带损伤似乎是一种原发性退行性过程，这可能解释了保守治疗效果不佳以及促进再生的必要性。
