Rijkenhuizen A B, Németh F, Dik K J, Goedegebuure S A
Department of General and Large Animal Surgery, Veterinary Faculty, University of Utrecht, The Netherlands.
Equine Vet J. 1989 Nov;21(6):405-12. doi: 10.1111/j.2042-3306.1989.tb02185.x.
A macroscopic, arteriographic and histological study of the development and the arterial anatomy of the navicular bone of 33 foetuses and 55 young horses is described. After 125 days of gestation the blood supply consists of two routes: one situated in the superficial layer of the fibrocartilage and the other similar to the blood supply of the navicular bone of the normal mature horse. After 270 days gestation, the blood vessels in the fibrocartilage gradually regressed and retracted until they have disappeared at six months after birth. At two months after birth the first macroscopic thinning of the fibrocartilage was noticed. From seven months to one year about 45 per cent of the navicular bones showed a slight thinning of the fibrocartilage. A positive correlation was found between radiographic abnormalities (ie enlargement of the nutrient foramina) and the frequency of thinning of the fibrocartilage. Radiographic abnormalities were first recognised 14 days after birth, whereas the arteriogram showed the first changes such as fewer or no arteries entering distally at the distal extremities at 10 weeks after birth. At four weeks after birth the first arterial wall changes were found, ie intimal thickening with or without splitting of the internal elastic membrane. From that age onward, the number of navicular bones with arterial wall changes gradually increased. Starting at five months after birth only 6 to 20 per cent of the arteries in the navicular bones without radiographic abnormalities showed arterial wall changes. However, the navicular bones with radiographic abnormalities showed arterial wall changes in 25 to 80 per cent of the arteries.
本文描述了对33例胎儿和55匹幼马舟骨发育及动脉解剖的大体、血管造影和组织学研究。妊娠125天后，血液供应有两条途径：一条位于纤维软骨表层，另一条与正常成年马舟骨的血液供应相似。妊娠270天后，纤维软骨中的血管逐渐退化和回缩，直至出生后6个月消失。出生后2个月，首次发现纤维软骨出现大体变薄。出生7个月至1岁时，约45%的舟骨显示纤维软骨轻度变薄。影像学异常（即滋养孔扩大）与纤维软骨变薄频率之间存在正相关。出生后14天首次发现影像学异常，而血管造影显示出生后10周首次出现变化，如远端进入远端的动脉减少或无动脉。出生后4周首次发现动脉壁变化，即内膜增厚，伴或不伴有内弹性膜分裂。从那个年龄起，出现动脉壁变化的舟骨数量逐渐增加。出生后5个月起，无影像学异常的舟骨中只有6%至20%的动脉出现动脉壁变化。然而，有影像学异常的舟骨中，25%至80%的动脉出现动脉壁变化。
