RESUMO

The aim of this study was to present a novel surgical method for correction of medial patellar luxation in small-breed dogs with trochlear dysplasia and marked hypoplasia of the medial femoral condyle. The "Watermelon" approach was applied together with trochlear wedge recession or trochlear block recession and consisted in increasing the height of the medial condyle with an osteochondral autograft resembling a watermelon slice, placed into an additional slot in the medial femoral condyle to prevent the postoperative reluxation of the patella. The study cohort included 19 dogs (25 joints) from small breeds (Pinscher, Pomeranian, and Chihuahua) with second-grade medial patellar luxation. Fourteen joints were submitted to wedge recession surgery combined with "Watermelon" grafting, and 11 joints: to block recession surgery with "Watermelon" grafting. The sulcus-deepening trochleoplasty combined with "Watermelon" grafting was clinically successful and with low percentage of minor postoperative complications. The mean duration of anesthesia was significantly longer for block recession combined with "Watermelon" (P<0.001), but the recovery period was shorter (P<0.05).

O objetivo deste estudo foi apresentar um novo método cirúrgico para correção da luxação patelar medial em cães de raça pequena com displasia troquelar e hipoplasia marcada do côndilo femoral medial. A abordagem "Melancia" foi aplicada juntamente com a recessão da cunha trocolear ou recessão do bloco trocolear e consistiu em aumentar a altura do côndilo medial com um auto-enxerto osteocondral parecido com uma fatia de melancia, colocado em uma fenda adicional no côndilo femoral medial para evitar o relaxamento pós-operatório da patela. A coorte do estudo incluiu 19 cães (25 juntas) de raças pequenas (Pinscher, Pomeranian, e Chihuahua) com luxação patelar medial de segundo grau. Catorze juntas foram submetidas à cirurgia de recessão em cunha combinada com enxerto de "melancia", e 11 juntas: para bloquear a cirurgia de recessão com enxerto de "melancia". A trocleoplastia de "melancia" combinada com o enxerto de "melancia" foi clinicamente bem sucedida e com baixo percentual de pequenas complicações pós-operatórias. A duração média da anestesia foi significativamente maior para a recessão em bloco combinada com "Melancia" (P<0,001), mas o período de recuperação foi mais curto (P<0,05).

Assuntos

RESUMO

Medial patellar luxation (MPL) is one of the commonest orthopaedic diseases in small dog breeds. Although the bone deformities associated with canine medial patellar luxation are described in numerous studies, the pathogenesis of the condition is still disputable. What is more, there is no categorical evidence that luxation of the patella is associated to a shallow trochlear groove as no objective method for determination of trochlear depth and shape has been proposed. The aim of the present study was to evaluate the depth and shape of femoral trochlear groove on radiographs obtained from healthy dogs and dogs affected with grade II and grade III MPL. A total of 45 dogs (33 with MPL and 12 healthy) from 4 small breeds (Mini-Pinscher, Pomeranian, Chihuahua and Yorkshire terrier) were included in the study. After deep sedation, stifle radiographs were obtained in tangential projection (skyline view). The dogs were positioned in ventral recumbency, the examined stifle bent as much as possible, and the central beam focused on the patella between femoral condyles. Six morphometric parameters associated with the onset of trochlear dysplasia similar to those used in human medicine were measured: trochlear sulcus angle (SA), lateral and medial trochlear inclination angles (LTI; MTI), trochlear groove depth (TD), patellar thickness (PaT) and the ratio between trochlear depth and patellar thickness (PaT/TD). The non-parametric Mann-Whitney test was used for evaluation of differences between healthy joints and those affected with grade II and III MPL. The association between measured variables was evaluated via the Spearman's rank-order correlation. TD was greater in healthy joints as compared to those affected with MPL grade II and III (P < 0.001). In healthy stifles, PaT value exceeded significantly (P < 0.01) that in joints with grade III MPL. The TD/PaT ratio was significantly greater in healthy joints vs both those with grade II (P < 0.01) and grade III MPL (P < 0.001). In healthy joints, there was a significant negative relationship (rho­0.508; P = 0.0113) between SA and TD: smaller sulcus angles corresponded to deeper trochleas. This correlation was even stronger in joints with patellar luxation (rho ­0.723; P < 0.0001). The LTI and MTI showed a very strong positive correlation in healthy joints (rho 0.854; P < 0.0001) and at the same time, lack of significant association in joints affected with MPL (rho -0.163; P = 0.327 for grade II MPL and rho 0.175; P = 0.448 for grade III MPL) was demonstrated. The altered trochlear shape and depth were more pronounced in joints with grade III MPL. As MPL grade increased, the SA became statistically significantly greater. In grade III MPL it was accompanied with considerably reduced trochlear depth, medial trochlear inclination angle and trochlear depth/patellar thickness ratio. Five of the measured morphometric parameters for radiographic detection of trochlear dysplasia in dogs were found to be important in the evaluation of trochlear morphology in dogs. The obtained results indicated the presence of trochlear dysplasia in dogs with MPL. A 3-stage classification system for assessment of abnormal trochlear development in small dog breeds: mild; moderate and severe trochlear dysplasia, was proposed. The occurrence of shallow trochlear groove and medial femoral condyle's hypoplasia could be accepted as signs of mild and moderate trochlear dysplasia. The pre-operative measurements of these parameters could improve surgical planning and decisions-making.

Assuntos

RESUMO

A luxação patelar é o deslocamento medial ou lateral da patela a partir de sua posição anatômica normal no sulco troclear. Ela normalmente é causada por uma má formação congênita ou por trauma e pode ser classificada em 4 graus, sendo uma condição rara o grau IV de causa traumática em felinos. Diagnosticamos a luxação patelar a partir do exame físico, o tratamento pode ser cirúrgico ou conservativo, dependendo do grau da luxação. Foi atendido um felino, macho, de 5 meses, com histórico de trauma e após apresentou claudicação que persistia há 20 dias. Ao exame físico, foi observada presença de luxação patelar medial grau IV, do membro pélvico esquerdo. O raio X evidenciou luxação patelar medial esquerda e ausência de deformidade angular. O tratamento preconizado foi a correção cirúrgica e o paciente apresentou uma ótima recuperação. O objetivo deste relato é evidenciar esse tipo de afecção pouco diagnosticada e investigada nos felinos.

The patellar luxation is a medial or lateral patella displacement from your normal anatomical position in the trochlear groove. It is usually caused by poor congenital formation or by trauma and can be classified in 4 degrees, being a rare condition the 4th degree of traumatic cause in felines. We diagnose the patellar luxation from the physical examination. The treatment can be surgical or conservative, depending on the degree of the luxation. It was attended a feline, male, 5 months old, with a history of trauma and after showing lameness that persisted for 20 days. At physical examination, the presence of medial patellar luxation grade IV, of the left pelvic limb was observed. The x-ray showed left medial patellar dislocation and absence of angular deformity. The recommended treatment was surgical correction and the patient presented an excellent recovery. The purpose of this report is to high light this type of condition that is little diagnosed and investigated in felines.

La luxación patelar es el desplazamiento medial o lateral de la patela a partir de suposición anatómica normal en el surco troclear. Por lo general es causada por una mala formación congénita o por trauma y puede ser clasificada en 4 grados, siendo una condición rara el grado IV de causa traumática en felinos. Diagnosticamos la luxación patelar a partir del examen físico, el tratamiento puede ser quirúrgico o conservador, dependiendo del grado de la luxación. Fue atendido un felino, macho, de 5 meses, con historial de trauma y después, presentó claudicación que persistió hace 20 días. En el examen físico, se observó presencia de luxación patelar medial grado IV, del miembro pélvico izquierdo. El rayo x evidenció luxación patelar medial izquierda y ausencia de deformidad angular. El tratamiento preconizado fue la corrección quirúrgica y el paciente presentó una óptima recuperación. El objetivo de este relato es evidenciar este tipo de afección poco diagnosticada e investigada en los felinos.

Assuntos

RESUMO

A luxação patelar é o deslocamento medial ou lateral da patela a partir de sua posição anatômica normal no sulco troclear. Ela normalmente é causada por uma má formação congênita ou por trauma e pode ser classificada em 4 graus, sendo uma condição rara o grau IV de causa traumática em felinos. Diagnosticamos a luxação patelar a partir do exame físico, o tratamento pode ser cirúrgico ou conservativo, dependendo do grau da luxação. Foi atendido um felino, macho, de 5 meses, com histórico de trauma e após apresentou claudicação que persistia há 20 dias. Ao exame físico, foi observada presença de luxação patelar medial grau IV, do membro pélvico esquerdo. O raio X evidenciou luxação patelar medial esquerda e ausência de deformidade angular. O tratamento preconizado foi a correção cirúrgica e o paciente apresentou uma ótima recuperação. O objetivo deste relato é evidenciar esse tipo de afecção pouco diagnosticada e investigada nos felinos.(AU)

The patellar luxation is a medial or lateral patella displacement from your normal anatomical position in the trochlear groove. It is usually caused by poor congenital formation or by trauma and can be classified in 4 degrees, being a rare condition the 4th degree of traumatic cause in felines. We diagnose the patellar luxation from the physical examination. The treatment can be surgical or conservative, depending on the degree of the luxation. It was attended a feline, male, 5 months old, with a history of trauma and after showing lameness that persisted for 20 days. At physical examination, the presence of medial patellar luxation grade IV, of the left pelvic limb was observed. The x-ray showed left medial patellar dislocation and absence of angular deformity. The recommended treatment was surgical correction and the patient presented an excellent recovery. The purpose of this report is to high light this type of condition that is little diagnosed and investigated in felines.(AU)

La luxación patelar es el desplazamiento medial o lateral de la patela a partir de suposición anatómica normal en el surco troclear. Por lo general es causada por una mala formación congénita o por trauma y puede ser clasificada en 4 grados, siendo una condición rara el grado IV de causa traumática en felinos. Diagnosticamos la luxación patelar a partir del examen físico, el tratamiento puede ser quirúrgico o conservador, dependiendo del grado de la luxación. Fue atendido un felino, macho, de 5 meses, con historial de trauma y después, presentó claudicación que persistió hace 20 días. En el examen físico, se observó presencia de luxación patelar medial grado IV, del miembro pélvico izquierdo. El rayo x evidenció luxación patelar medial izquierda y ausencia de deformidad angular. El tratamiento preconizado fue la corrección quirúrgica y el paciente presentó una óptima recuperación. El objetivo de este relato es evidenciar este tipo de afección poco diagnosticada e investigada en los felinos.(AU)

Assuntos