Morgan line and its relationship with distraction index, angle of inclination and degenerative joint disease in the diagnosis of canine hip dysplasia / Linha Morgan e sua relação com índice de distração, ângulo de inclinação e doença articular degenerativa no diagnóstico da displasia coxofemoral canina

We evaluated 160 hip joint radiographs of 40 dogs of different large breeds (25 females and 15 males) from the metropolitan area of Belo Horizonte, Minas Gerais, Brazil. The radiographs of each dog were obtained at two different stages: stage 1 (mean 7.23 months) and stage 2 (mean 14.25). The conventional radiographic method (CRM) and the radiographic distraction method (RDM) were used, carried out in both stages. CRM measured the Norberg angle (NA), the angle of inclination (AI) and evaluated the presence of degenerative joint disease (DJD). The MRD was performed to establish the distraction index (DI). The aims were to evaluate the presence of the Morgan line and other signs of DJD and correlate them with the degree of canine hip dysplasia (CHD) and also check if the DI greater than 0.3 (first stage) was associated with the presence of ML (second stage). It was found that DI, AI and changes of femoral neck and the formation of osteophytes were associated with the presence of ML. It was observed that if the DI is greater than 0.3 at the first stage, the chance of a positive outcome of ML in the second stage increases by 7.2 times. Thus, 49 joints showed DI > 0.3 at the first stage, in which 31 (63.3 %) presented ML at the second stage. Of the 31 animals that showed DI ≤ 0.3 at first, six (19.4%) had LM at the second stage. There has been a significant association between the presence of ML and the degree of CHD. The more severe the CHD, the higher the percentage of positive ML results. Thus, among the 24 (60 %) animals that showed ML, 11 (45.83 %) were classified as severe dysplastics, 5 (20.83%) as moderate and 8 (33.33 %) as mild. None of the animals classified as normal or borderline presented ML. Among the 8 animals classified as mild dysplastics, 5 showed only ML as DJD.(AU)

Avaliaram-se 160 radiografias das articulações coxofemorais de 40 cães de diferentes raças de grande porte, provenientes de Belo Horizonte, Brasil. As radiografias de cada animal foram obtidas em dois momentos: um (média de 7,23 meses de idade) e dois (média de 14,25 meses). Utilizaram-se o método radiográfico convencional (MRC) e o método radiográfico em distração (MRD), ambos realizados nos dois momentos. No MRC, mensurou-se o ângulo de Norberg (AN), o ângulo de inclinação (AI) e avaliou-se a presença de doença articular degenerativa (DAD). O MRD foi realizado para se estabelecer o índice de distração (ID). Os objetivos foram avaliar a presença da linha Morgan (LM) e de outros sinais de DAD, correlacionando-os com o grau de displasia coxofemoral (DCF); além de se verificar se o ID maior que 0,3 (primeiro momento) possui associação com a presença de LM (segundo momento). Verificou-se que ID, AI e encurtamento e/ou espessamento do colo femoral e formação de osteófitos foram associados à presença da LM. Observou-se que, quando o ID era maior que 0,3 no primeiro momento, a chance de um resultado positivo da LM no segundo momento aumentava em 7,2 vezes. No primeiro momento, 49 articulações apresentaram ID > 0,3. Destas, 31 (63,3%) apresentaram LM no segundo momento. Dos 31 animais que apresentaram ID ≤ 0,3 no primeiro momento, seis (19,4%) desenvolveram LM no segundo momento. Houve associação significativa entre presença de LM com o grau de DCF, e quanto mais grave a DCF, maior foi o percentual de resultados positivos da LM. Dos 24 (60%) animais que apresentaram LM, 11 (45,83%) foram classificados como displásicos graves, cinco (20,83%) como médios e oito (33,33%) como leves. Nenhum dos animais considerados suspeitos ou normais apresentou LM. Dos oito animais classificados como displásicos leves, cinco apresentaram apenas LM como sinal de DAD.(AU)

The relationship between the size of caudolateral curvilinear osteophyte of the canine femoral neck and the radiographic view

Caudolateral curvilinear osteophyte (CCO), an osteophyte at the site of joint capsule attachment on the caudal aspect of the femoral neck, has been advocated as a radiographic criterion for coxofemoral subluxation. The correlation between the presence of CCO on radiographs (radiographic-CCO), the size of the CCO (CCO index) on three-dimensional computed tomographic (CT) images, and hip evaluation using transverse CT images was assessed in 22 Border Collies. CCOs were detected on the radiographs and CT images of 32% and 100% femurs, respectively. The CCO index correlated significantly with radiographic-CCO, but a large CCO index did not necessarily imply that the CCO was visible on radiographs. Hence, radiographic-CCO findings should be used cautiously in hip evaluation of Border Collies.

Presença de "Linha Morgan" como indicador de displasia coxofemoral em cães da raça Pastor-Alemão

The aim of this study was to determine the relationship between the presence of Morgan line and hip dysplasia. From June, 1986 to October, 1993, 190 X-ray plates of German Shepherd dogs, from both sexes were collected and analyzed. The results showed that out of the 190 dogs evaluated, 136 (71.6%) had hip dysplasia, 43 (22.6%) presented Morgan line and 41 (21.5%) showed both of them. Just two (1.1%) dogs presented Morgan line without hip dysplasia. No statistically significant difference was found between males (21.8%) and females (23.3%). From this study it can be concluded that the presence of the Morgan line can be considered indicative to hip dysplasia diagnosis, even though the absence of the line does not exclude the possibility of hip dysplasia.