Janutta V, Distl O
Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Germany.
Dtsch Tierarztl Wochenschr. 2008 May;115(5):172-81.
Elbow dysplasia (ED) is a progressive skeletal disease, which may comprise osteoarthrotic changes, incongruity of the joint, a fragmented medial coronoid process (FCP), osteochondrosis dissecans of the trochlea humeri (OCD), and an ununited anconeal process (UAP). Disturbances of enchondral ossification, as well as asynchronous growth of the antebrachial bones and an increased growth rate may provoke abnormal stresses on specific locations such as the medial coronoid process, the anconeal process of the ulna or the humeral trochlea, which may result in ED. Overnutrition with calcium, vitamin D and energy had important influence on rapidity of growth and proneness to ED. ED manifests most often in young dogs less than 1 1/2 year, causing clinical signs such as (intermittent) lameness, pain on movement and altered posture of the affected limb, and radiographically secondary osteoarthrotic changes such as osteophytes or the aforementioned primary lesions. As radiographic projection of the primary lesions FCP and OCD may be difficult in the commonly used mediolateral flexed and craniocaudal views, additional projections such as mediolateral extended or anteroposterior oblique views and alternative diagnostic means such as computed tomography (CT) may be worth considering. Cases of ED are reported in various breeds, though some breeds are especially predisposed and seem to be prone to specific primary lesions. For the German shepherd dog, a breed-predisposition for UAP may be explained by broad chondral junction in association with an accelerated pattern of skeletal maturation. Heritabilities were estimated in a variety of studies, depending strongly on the type of model used. The mode of inheritance is not yet ascertained, but recently the common assumption of a polygenic mode of inheritance for ED is doubted. Instead, genetic independence was supposed between different primary lesions, and also for ED as well as for FCP major gene influence was discussed. So long, phenotypic mass selection was accomplished in different countries most often resulting in a reduced prevalence of ED. The use of best linear unbiased prediction (BLUP) methods including information on relatives and separate evaluation of genetically independent primary lesions may further improve selection against ED.
肘部发育不良（ED）是一种进行性骨骼疾病，可能包括骨关节炎变化、关节不协调、内侧冠状突碎裂（FCP）、肱骨滑车剥脱性骨软骨炎（OCD）以及未愈合的肘突（UAP）。软骨内骨化紊乱，以及前臂骨生长不同步和生长速度加快，可能会在特定部位如内侧冠状突、尺骨肘突或肱骨滑车产生异常应力，从而导致肘部发育不良。钙、维生素D和能量摄入过多对生长速度和易患肘部发育不良有重要影响。肘部发育不良最常出现在1.5岁以下的幼犬身上，会引起诸如（间歇性）跛行、运动时疼痛以及患肢姿势改变等临床症状，在X线片上表现为继发性骨关节炎变化，如骨赘或上述原发性病变。由于在常用的内外侧屈曲和头尾位视图中，原发性病变FCP和OCD的X线投影可能困难，因此额外的投影，如内外侧伸展或前后斜位视图以及替代诊断方法，如计算机断层扫描（CT），可能值得考虑。虽然各种犬种都有肘部发育不良的病例报告，但有些犬种特别易感，似乎易患特定的原发性病变。对于德国牧羊犬，UAP的品种易感性可能与宽阔的软骨结合处以及骨骼成熟加速模式有关。在各种研究中估计了遗传力，这在很大程度上取决于所使用的模型类型。遗传模式尚未确定，但最近人们对肘部发育不良多基因遗传模式的普遍假设表示怀疑。相反，不同原发性病变之间被认为存在遗传独立性，并且对于肘部发育不良以及FCP，也讨论了主要基因的影响。长期以来，不同国家通过表型质量选择，最常导致肘部发育不良的患病率降低。使用包括亲属信息的最佳线性无偏预测（BLUP）方法以及对遗传独立的原发性病变进行单独评估，可能会进一步改善针对肘部发育不良的选择。
