Comparação de ângulos anatómicos femorais em cães com e sem luxação patelar
Data
2019-01-28
Autores
Título da revista
ISSN da revista
Título do Volume
Editora
Resumo
O varus e valgus femoral distal são definidos como uma angulação, medial ou lateral, do fémur distal em relação à linha média do corpo do mesmo, estando estas deformações intimamente associadas com a luxação patelar, tanto medial como lateral. A luxação patelar é uma das condições ortopédicas mais comummente diagnosticadas em cães, que pode causar osteoartrite, dor e claudicação. Pode ocorrer em qualquer raça, mas incide maioritariamente em raças de pequeno porte. A maioria dos casos são diagnosticados enquanto jovens, ou em fases precoces da doença, no entanto os sinais clínicos podem surgir em qualquer idade. Estão descritas múltiplas técnicas cirúrgicas para a correção desta condição, estando muitas delas centradas no realinhamento do mecanismo de flexão do membro. Para isso são requeridas técnicas de osteotomia e ostectomia do fémur. No entanto, qual o valor angular a partir do qual se devem realizar e o valor final a obter são ainda tema de debate na literatura. Os objetivos deste trabalho foram tentar padronizar a caracterização das deformidades acima referidas, pretendeu-se comparar os valores do ângulo anatómico lateral distal do fémur (aLDFA) e do ângulo mecânico lateral distal do fémur (mLDFA) em cães de diferentes conformações, assim como comparar esses mesmos ângulos entre animais com e sem luxação de patela. Para isso, inicialmente, foram utilizadas 238 radiografias de fémures de cães que não apresentavam luxação de patela, divididos em três grupos (Grupos I, II e III), dependendo da sua conformação, segundo a Federação Cinológica Internacional (FCI). O Grupo I foi constituído por animais de raças suscetíveis à luxação patelar, o Grupo II por cães de parar e poodles de médio porte e o Grupo III por cães molossoides de grande porte. Estes grupos foram comparados entre si. De seguida, foram utilizadas 33 radiografias de fémures de cães que apresentavam luxação patelar, formando um outro grupo (Grupo IV), que foi comparado com o Grupo I. Finalmente, o Grupo IV foi dividido em dois, segundo o grau de luxação (Grupo IVa , graus I e II e Grupo IVb , graus III e IV), que foram comparados entre si. Em relação aos resultados, foram encontradas diferenças significativas (P0,05). Os valores foram também significativamente maiores no Grupo IV (100,8±5,3; 104,1±4,3) quando comparados com os do Grupo I. Não foi possível validar estatisticamente a diferença de valores médios entre o Grupo IVa e IVb, apesar dos valores dos membros com luxação patelar de grau III e IV serem bastante maiores, devido ao número reduzido de animais deste grupo. Nesta população foi possível verificar que varus ou valgus femoral está associado ao surgimento de luxação patelar e que raças predispostas ao surgimento desta patologia apresentam valores médios significativamente mais elevados em relação aos demais grupos. Os nossos resultados podem ser úteis para que os cirurgiões possam determinar com maior exatidão o grau de deformação presente em determinado caso clínico e ajudar na decisão para os ângulos de correção necessários para restabelecer o alinhamento do membro.
Distal femoral varus and valgus are defined as a medial or lateral angulation of the distal femur in relation to the midline of its body, and these deformations are closely associated with patellar luxation, both medial and lateral. Patellar luxation is one of the most commonly diagnosed orthopedic conditions in dogs, which can cause osteoarthritis, pain and lameness. It can occur in any breed, but mainly affects small breeds. Most cases are diagnosed as young or in early stages of the disease, however, clinical signs can arise at any age. Multiple surgical techniques are described for the correction of this condition, many of them focused on the realignment of the limb flexion mechanism. For this, osteotomy and ostectomy techniques of the femur are required. The objectives of this study were to try to standardize the characterization of the aforementioned deformities, describing a method for the measurement of the distal femoral angles. In addition, it was intended to compare the anatomical lateral distal femoral angle (aLDFA) and the mechanical lateral distal femoral angle (mLDFA) in dogs of different conformations as well as compare these same angles between animals with and without patellar luxation. In order to do this, we initially used 238 radiographs of femurs of dogs that did not present patellar luxation, which were divided into three groups (Groups I, II and III), depending on their conformation, according to the International Cynological Federation (FCI). Group I was composed of susceptible animal breeds to patellar luxation, Group II by pointing dogs and medium poodles, and Group III by large molossoid dogs. These groups were compared to each other. Then, 33 radiographs of femurs of dogs with patellar luxation were used, forming another group (Group IV), which was compared with Group I. Finally, Group IV was divided into two, according to the grade of dislocation (Groups IVa, grade 1 and 2 and IVb, grade 3 and 4), which were compared to each other. According to the results, significant differences (P0,05). The values were also significantly higher in Group IV (100,8 ± 5,3, 104,1 ± 4,3) when compared with those in Group I. It was not possible to statistically validate the difference of average values between Group IVa and IVb, although the values of the limbs with patellar luxation of grade III and IV are much larger, due to the reduced number of animals of this group. In this population it was possible to verify that femoral varus or valgus is associated with the appearance of patellar dislocation and that breeds predisposed to the onset of this pathology have significantly higher mean values in relation to the other groups. Our results may be useful in determining if any femoral deformity is present and assist in determining the correction angles required to restore limb alignment.
Distal femoral varus and valgus are defined as a medial or lateral angulation of the distal femur in relation to the midline of its body, and these deformations are closely associated with patellar luxation, both medial and lateral. Patellar luxation is one of the most commonly diagnosed orthopedic conditions in dogs, which can cause osteoarthritis, pain and lameness. It can occur in any breed, but mainly affects small breeds. Most cases are diagnosed as young or in early stages of the disease, however, clinical signs can arise at any age. Multiple surgical techniques are described for the correction of this condition, many of them focused on the realignment of the limb flexion mechanism. For this, osteotomy and ostectomy techniques of the femur are required. The objectives of this study were to try to standardize the characterization of the aforementioned deformities, describing a method for the measurement of the distal femoral angles. In addition, it was intended to compare the anatomical lateral distal femoral angle (aLDFA) and the mechanical lateral distal femoral angle (mLDFA) in dogs of different conformations as well as compare these same angles between animals with and without patellar luxation. In order to do this, we initially used 238 radiographs of femurs of dogs that did not present patellar luxation, which were divided into three groups (Groups I, II and III), depending on their conformation, according to the International Cynological Federation (FCI). Group I was composed of susceptible animal breeds to patellar luxation, Group II by pointing dogs and medium poodles, and Group III by large molossoid dogs. These groups were compared to each other. Then, 33 radiographs of femurs of dogs with patellar luxation were used, forming another group (Group IV), which was compared with Group I. Finally, Group IV was divided into two, according to the grade of dislocation (Groups IVa, grade 1 and 2 and IVb, grade 3 and 4), which were compared to each other. According to the results, significant differences (P0,05). The values were also significantly higher in Group IV (100,8 ± 5,3, 104,1 ± 4,3) when compared with those in Group I. It was not possible to statistically validate the difference of average values between Group IVa and IVb, although the values of the limbs with patellar luxation of grade III and IV are much larger, due to the reduced number of animals of this group. In this population it was possible to verify that femoral varus or valgus is associated with the appearance of patellar dislocation and that breeds predisposed to the onset of this pathology have significantly higher mean values in relation to the other groups. Our results may be useful in determining if any femoral deformity is present and assist in determining the correction angles required to restore limb alignment.
Descrição
Dissertação de Mestrado em Medicina Veterinária