Short-term outcomes of trochlear recession surgery combined with "Watermelon" autograft for treatment of canine medial patellar luxation: a case series / Resultados a curto prazo da cirurgia de recessão trocolear combinada com o auto-enxerto "Melancia" para tratamento da luxação patelar medial canina: uma série de casos

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).

Radiological measures of patellofemoral alignment in healthy small-breed dogs: reference values and sex variability

Background: The evaluation of vertical kneecap position within the trochlear groove is essential for understanding the anatomical changes that may lead to canine patellar luxation. Unlike other important diagnostic imaging measurements (e.g. measures of pelvic limb alignment), no data on patellofemoral congruence parameters of canine stifles (congruence angle, linear axial patellar displacement, lateral patellofemoral angle, patellar tilt angle) are reported. The aim of this study was to present metric values of these parameters in healthy dogs from small breeds from both sexes in order to use them for identification of animals with increased risk for medial patellar luxation. Materials, Methods & Results: The study was performed on 44 stifle joints from 22 healthy dogs of both sexes from 4 small breeds (Pinscher, Pomeranian, Chihuahua and Yorkshire terrier). Inclusion criteria were negative patellar displacement and dancing patella tests after orthopaedic examination, lack of femoral and gluteal muscles asymmetry after palpation, lack of signs of long-term proprioceptive dysfunction, normal patellar and withdrawal reflexes after neurological examination. The translation of the patella in the axial plane was evaluated by means of congruence angle and axial linear patellar displacement. The rotation of the patella in the axial plane was evaluated through measurement of lateral patellofemoral angle and patellar tilt angle. Reference ranges of parameters were analysed in agreement with the guidelines of the American College of Veterinary Pathologists for the determination of reference intervals in veterinary species for sample sizes of 40-120 with non-Gaussian distribution - robust method, 95% confidence interval (CI) with 90 % CI for upper and lower reference limits. All measured patellofemoral congruence angles were negative. Their reference range was from -8.06o to -0.58o (median value -3o ). The axial patellar displacement was negligible, with values ranging from 0.1 to 0.8 mm. Lateral patellofemoral angles in all dogs were open to the lateral side (positive); the computed reference interval was from 21.61o to 41.80o (median 31.5o ). Patellar tilt angles ranged from 2o to 8o (median 5o ). A statistically significant difference between sexes was demonstrated for angles describing the rotation of the patella in the axial plane: the lateral patellofemoral angle (P = 0.0248) and the patellar tilt angle (P = 0.0004) were greater in stifles of male dogs. Discussion: This is the first study presenting reference values of parameters describing patellofemoral alignment in healthy dogs from small breeds on tangential radiographs. The values of one of most commonly measured parameters on tangential radiographs (the lateral patellofemoral angle) in stifles of small breed dogs were higher than values in humans, supposedly due to the specific joint anatomy. The patellar tilt angle is considered as more objective and not influenced by limb rotation. For the detection of patellar misalignment, the tilt angle was reported to be almost as specific as the congruence angle but more sensitive and more accurate. It is the most specific and sensitive parameter determining the direction of patellar luxation. In male dogs, the median lateral patellofemoral angle was greater than in females (P = 0.0248). Similar tendency was shown for patellar tilt angle that was also greater in male stifles (P = 0.0004). The reported statistically significant between-sex differences in lateral patellofemoral angle and patellar tilt angle with higher values of both angles in stifles of male dogs could be attributed to the better developed femoral muscles, in particular m. vastus medialis and m. sartorius, and to differences in trochlear groove and kneecap morphology. The presented reference intervals may be useful for early detection of subjects with increased risk to medial patellar luxation.

Lateral patellar luxation and Ehlers Danlos Syndrome (EDS) in a dog

Background: Ehlers Danlos Syndrome (EDS) is a rare genetic disease characterized by a deficiency in collagen synthesis,which can result in joint laxity. Patellar luxation is one of the main orthopedic conditions that affect the canine knee joint,with limited descriptions of its association with EDS in dogs. The purpose of this report is to describe the surgical management and postoperative evolution of a 1-year-old Chow Chow dog with grade II patellar luxation, tibial valgus and EDS.Case: A 1-year-old Chow Chow dog was referred to the University Veterinary Hospital due to lameness of the left pelvicfor 3 months. At the orthopedic examination were verified severe lameness and lateral deviation of the left stifle joint during the ambulation of the animal. Additionally, it was verified bilateral hyperextension of the tibiotarsal joint and grade IIpatellar luxation of both pelvic limbs with painful hyperextension of the left stifle joint. Radiographic evaluation showedlateral displacement of the patella from both femoral trochlear groove, and a valgus deviation of the proximal left tibialshaft. In addition, it was verified cutaneous hyperextensibility and an extensibility index suggestive of EDS. The animalwas submitted to trochlear block resection technique and medial imbrication, followed by corrective tibial osteotomy.Furthermore, skin biopsies of the scapular and lumbar folds were performed during the corrective tibial osteotomy. Thesamples were sent for histopathological examination, which revealed fragmented and unorganized collagen fibers in thedermis. Histopathological findings were compatible with EDS. The absence of lameness and correct positioning of thepatella in the trochlear sulcus were verified in the post-surgical follow-up. Complete bone consolidation of the closingwedge osteotomy to correct the tibial...

Lateral patellar luxation and Ehlers Danlos Syndrome (EDS) in a dog

Background: Ehlers Danlos Syndrome (EDS) is a rare genetic disease characterized by a deficiency in collagen synthesis,which can result in joint laxity. Patellar luxation is one of the main orthopedic conditions that affect the canine knee joint,with limited descriptions of its association with EDS in dogs. The purpose of this report is to describe the surgical management and postoperative evolution of a 1-year-old Chow Chow dog with grade II patellar luxation, tibial valgus and EDS.Case: A 1-year-old Chow Chow dog was referred to the University Veterinary Hospital due to lameness of the left pelvicfor 3 months. At the orthopedic examination were verified severe lameness and lateral deviation of the left stifle joint during the ambulation of the animal. Additionally, it was verified bilateral hyperextension of the tibiotarsal joint and grade IIpatellar luxation of both pelvic limbs with painful hyperextension of the left stifle joint. Radiographic evaluation showedlateral displacement of the patella from both femoral trochlear groove, and a valgus deviation of the proximal left tibialshaft. In addition, it was verified cutaneous hyperextensibility and an extensibility index suggestive of EDS. The animalwas submitted to trochlear block resection technique and medial imbrication, followed by corrective tibial osteotomy.Furthermore, skin biopsies of the scapular and lumbar folds were performed during the corrective tibial osteotomy. Thesamples were sent for histopathological examination, which revealed fragmented and unorganized collagen fibers in thedermis. Histopathological findings were compatible with EDS. The absence of lameness and correct positioning of thepatella in the trochlear sulcus were verified in the post-surgical follow-up. Complete bone consolidation of the closingwedge osteotomy to correct the tibial...(AU)

Evaluation of trochlear dysplasia in dogs with medial patellar luxation: comparative studies

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.

Dimensões da patela relacionadas à massa corporal do cão para emprego na confecção de prótese: estudo em cadáver / Patellar dimensions related to canine body mass for use in the manufacture of prosthesis: cadaver study

O objetivo deste trabalho foi mensurar as dimensões da patela de cadáveres caninos e avaliar sua relação com a massa corporal. Para a realização das medidas patelares, foram utilizados 70 cadáveres de cães adultos, com massa corpórea de 1 a 50kg, sem evidência clínica de afecção na articulação femorotibiopatelar. Com auxílio de um paquímetro, foram mensurados os comprimentos externo e interno, a largura externa no terço médio, a largura e a espessura internas nos terços proximal, médio e distal das patelas. Também foram mensuradas a largura nos terços proximal, médio e distal, a profundidade nos terços proximal, médio e distal do sulco troclear; essas medidas foram exclusivamente internas. Observou-se, de forma geral, forte correlação entre as medidas patelares e a massa corporal de cadáveres de cães. Nas condições deste estudo, pode-se concluir que o tamanho da patela varia segundo a massa corporal do cão e que essas medidas devem ser consideradas ao se planejar uma substituição protética.(AU)

The aim of this study was to measure the canine cadaver patellar dimensions and evaluate its relationship with body mass. 70 cadavers of adult dogs were used, with a body mass between 1 and 50kg, without clinical evidence of affection in the stifle joint. The external and internal lengths, external width in the middle third, width and thickness of the proximal, middle and distal thirds were measured using a pachymeter. The width was also measured in the proximal third, middle third and distal third, depth in the proximal third, middle third and distal third of the trochlear groove; these measurements were exclusively internal. A strong correlation was observed between the patellar dimension and body mass of canine cadavers. Under this study conditions, it is possible to conclude that the patellar size varies according to the canine body mass and these measures should be considered when planning a prosthetic replacement.(AU)

Dimensões da patela relacionadas à massa corporal do cão para emprego na confecção de prótese: estudo em cadáver / Patellar dimensions related to canine body mass for use in the manufacture of prosthesis: cadaver study

O objetivo deste trabalho foi mensurar as dimensões da patela de cadáveres caninos e avaliar sua relação com a massa corporal. Para a realização das medidas patelares, foram utilizados 70 cadáveres de cães adultos, com massa corpórea de 1 a 50kg, sem evidência clínica de afecção na articulação femorotibiopatelar. Com auxílio de um paquímetro, foram mensurados os comprimentos externo e interno, a largura externa no terço médio, a largura e a espessura internas nos terços proximal, médio e distal das patelas. Também foram mensuradas a largura nos terços proximal, médio e distal, a profundidade nos terços proximal, médio e distal do sulco troclear; essas medidas foram exclusivamente internas. Observou-se, de forma geral, forte correlação entre as medidas patelares e a massa corporal de cadáveres de cães. Nas condições deste estudo, pode-se concluir que o tamanho da patela varia segundo a massa corporal do cão e que essas medidas devem ser consideradas ao se planejar uma substituição protética.(AU)

The aim of this study was to measure the canine cadaver patellar dimensions and evaluate its relationship with body mass. 70 cadavers of adult dogs were used, with a body mass between 1 and 50kg, without clinical evidence of affection in the stifle joint. The external and internal lengths, external width in the middle third, width and thickness of the proximal, middle and distal thirds were measured using a pachymeter. The width was also measured in the proximal third, middle third and distal third, depth in the proximal third, middle third and distal third of the trochlear groove; these measurements were exclusively internal. A strong correlation was observed between the patellar dimension and body mass of canine cadavers. Under this study conditions, it is possible to conclude that the patellar size varies according to the canine body mass and these measures should be considered when planning a prosthetic replacement.(AU)

Avaliação radiográfica da profundidade do sulco troclear e diâmetro patelar em cães / Radiographic assessment of the depth of the troclear groove and patellar diameter in dogs

Background: Patellar luxation is an alteration of bone development for which the indicated treatment is surgery. Failure to correct it may result in clinical worsening. The most commonly used surgical approach is the transposition of the tibial crest with trochleoplasty, which aims to accommodate 50% of the patella in the trochlea. The femoral groove and trochlea can be evaluated radiographically by tangential projection, tomography, or ultrasonography; however, all these methodologies have limitations. The objective of this study was to evaluate the depth of the trochlear groove in three regions and to compare it with the patellar diameter on simple mediolateral radiographic images. Materials, Methods & Results: Fifty non-paired pelvic limbs of adult dogs of a specific breed, weighing less than 40 kg and without orthopedic changes, were used. In the mediolateral radiographic projection, three evaluators measured the femoral trochlear sulcus at three different points and the patellar diameter. After imaging examinations, all limbs were skeletonized, and the trochlea and patella were measured with a digital caliper in the same regions as that of the radiographic measurements. All post-skeletonization calculations were performed by an evaluator. The highest mean radiographic and ex vivo trochlear depth was 3.4 ± 1.2 mm and 2.7 ± 0.8 mm, respectively. The lowest mean radiographic and ex vivo patellar diameter was 7.7 ± 1.7 mm and 7.9 ± 1.6 mm, respectively. The average relationship between the trochlear depth and patellar diameter was less than 50% in all animals, with the highest radiographically determined ratio being 44.15% and that determined ex vivo as 34.17%. The mean patellar diameter calculated radiographically was similar among the animals. Discussion: Radiographic images made it possible to assess the patella and bone surface regions of the femoral condyles. A wide arthrotomy...

Luxação patelar medial em canino / Canine medial patellar dislocation

A luxação patelar é uma das condições mais comuns da articulação do joelho em cães e pode evoluir para doença articular degenerativa. A luxação pode ocorrer medial ou lateralmente, sendo unilateral ou bilateral, onde a ocorrência medial é mais frequente em animais de raças pequenas e a lateral é mais comum em animais de raças grandes. A classificação da luxação patelar compreende quatro graus, de acordo com a posição patelar, sinais clínicos e gravidade das deformidades ósseas encontradas. O diagnóstico é feito com base na avaliação clínica, associada a uma radiografia. O presente estudo apresenta uma fêmea de 10 meses de idade, na qual o tutor relatou que o animal já havia sido submetido à cirurgia para corrigir o deslocamento medular da patela e ainda apresentava claudicação e dor. Após a radiografia, foi encontrado o diagnóstico de luxação patelar medial do membro em que a cirurgia havia sido realizada.(AU)

Patellar dislocation is one of the most common knee joint conditions in dogs and may progress to degenerative joint disease. The dislocation can run medially or laterally, being unilateral or bilateral, where the medial occurrence is more frequent in small breed animals and the lateral one is more common in large breed animals. The classification of patellar luxation comprises four grades, according to the patellar position, clinical signs and seriousness of the bone deformities found. The diagnosis is made based on the clinical evaluation, associated with a radiograph. The present study presents a 10-month-oldfemale canine in which the tutor reported that the animal had already undergone surgery to correct medial patellar dislocation and still had lameness and pain. After x-ray the diagnosis of medial patellar dislocation of the limb in which surgery had been performed was found.(AU)

Luxação patelar medial em canino / Canine medial patellar dislocation

A luxação patelar é uma das condições mais comuns da articulação do joelho em cães e pode evoluir para doença articular degenerativa. A luxação pode ocorrer medial ou lateralmente, sendo unilateral ou bilateral, onde a ocorrência medial é mais frequente em animais de raças pequenas e a lateral é mais comum em animais de raças grandes. A classificação da luxação patelar compreende quatro graus, de acordo com a posição patelar, sinais clínicos e gravidade das deformidades ósseas encontradas. O diagnóstico é feito com base na avaliação clínica, associada a uma radiografia. O presente estudo apresenta uma fêmea de 10 meses de idade, na qual o tutor relatou que o animal já havia sido submetido à cirurgia para corrigir o deslocamento medular da patela e ainda apresentava claudicação e dor. Após a radiografia, foi encontrado o diagnóstico de luxação patelar medial do membro em que a cirurgia havia sido realizada.

Patellar dislocation is one of the most common knee joint conditions in dogs and may progress to degenerative joint disease. The dislocation can run medially or laterally, being unilateral or bilateral, where the medial occurrence is more frequent in small breed animals and the lateral one is more common in large breed animals. The classification of patellar luxation comprises four grades, according to the patellar position, clinical signs and seriousness of the bone deformities found. The diagnosis is made based on the clinical evaluation, associated with a radiograph. The present study presents a 10-month-old female canine in which the tutor reported that the animal had already undergone surgery to correct medial patellar dislocation and still had lameness and pain. After x-ray the diagnosis of medial patellar dislocation of the limb in which surgery had been performed was found.

Técnica de avanço e transposição da tuberosidade tibial (TTTA) com uso de espaçador único de TTA-Maquet em cão / Technique of tibial tuberosity transposition and advancement (TTTA) with use of TTA-Maquet cage-only in dog

Background: The most common conditions that compromise the stifle joint in dogs are medial patellar luxation (MPL) and cranial cruciate ligament (CCL) rupture. Surgical procedures are usually indicated for the treatment of these diseases. One ordinarytechnique for the treatment of MPL is the tibial tuberosity transposition, and one prominent technique for CCL rupture is the tibialtuberosity advancement. These techniques can be associated in one surgical procedure called tibial tuberosity transposition andadvancement (TTTA) for the simultaneous treatment of both stifle diseases. The aim of this study is to report the surgical treatmentof a dog with MPL and CCL rupture affecting the same joint by the TTTA technique with the use of a TTA-Maquet cage-only.Case: A 3-year-old Pitbull dog weighing 39 kg was attended at Veterinary Hospital with a history of marked lameness in theleft pelvic limb. The orthopedic examination showed positive results for cranial drawer motion and tibial compression tests,and a complete CCL rupture was diagnosed. The presence of patellar luxation was evaluated by manual pressure on the patella, and grade 3 of MPL was diagnosed. Both conditions were affecting the same stifle joint. In addition, survey radiographsof the affected joint were performed. Surgical treatment was indicated by the TTTA technique. Radiographic measurementswere taken to calculate the cranial tibial tuberosity advancement by the tibial plateau and the common tangent methods, and atitanium TTA-Maquet cage-only of 10.5 x 20.0 mm was selected. Linear osteotomy was performed on the tibial tuberosity withthe aid of an oscillating saw, based on the Maquet hole technique. The tibial tuberosity was carefully displaced cranially and thecage was inserted at the site of osteotomy. The cage ears were molded on the tibial surface and fixed with 2.4 mm self-tappingcortical screws...

Técnica de avanço e transposição da tuberosidade tibial (TTTA) com uso de espaçador único de TTA-Maquet em cão / Technique of tibial tuberosity transposition and advancement (TTTA) with use of TTA-Maquet cage-only in dog

Background: The most common conditions that compromise the stifle joint in dogs are medial patellar luxation (MPL) and cranial cruciate ligament (CCL) rupture. Surgical procedures are usually indicated for the treatment of these diseases. One ordinarytechnique for the treatment of MPL is the tibial tuberosity transposition, and one prominent technique for CCL rupture is the tibialtuberosity advancement. These techniques can be associated in one surgical procedure called tibial tuberosity transposition andadvancement (TTTA) for the simultaneous treatment of both stifle diseases. The aim of this study is to report the surgical treatmentof a dog with MPL and CCL rupture affecting the same joint by the TTTA technique with the use of a TTA-Maquet cage-only.Case: A 3-year-old Pitbull dog weighing 39 kg was attended at Veterinary Hospital with a history of marked lameness in theleft pelvic limb. The orthopedic examination showed positive results for cranial drawer motion and tibial compression tests,and a complete CCL rupture was diagnosed. The presence of patellar luxation was evaluated by manual pressure on the patella, and grade 3 of MPL was diagnosed. Both conditions were affecting the same stifle joint. In addition, survey radiographsof the affected joint were performed. Surgical treatment was indicated by the TTTA technique. Radiographic measurementswere taken to calculate the cranial tibial tuberosity advancement by the tibial plateau and the common tangent methods, and atitanium TTA-Maquet cage-only of 10.5 x 20.0 mm was selected. Linear osteotomy was performed on the tibial tuberosity withthe aid of an oscillating saw, based on the Maquet hole technique. The tibial tuberosity was carefully displaced cranially and thecage was inserted at the site of osteotomy. The cage ears were molded on the tibial surface and fixed with 2.4 mm self-tappingcortical screws...(AU)

Patellar luxation and articular lesions in dogs: a retrospective: study research article / Luxação de patela e lesões articulares em cães: estudo retrospectivo

This study describes lesions that occur in the stifle joints of dogs with patellar luxation. These lesions are associated with the animal's age, body weight, and degree of luxation. The rate of redislocation was also evaluated. The patellar lesions found include articular cartilage erosion, subchondral bone exposure, a flattened or concave patellar surface, and enthesophytes. Extra-patellar lesions included synovitis, osteophytes, blunting of the trochlear groove, an absent trochlea, erosion of the condylar margins, capsule thickening, a long digital extensor tendon injury, cranial cruciate ligament rupture, and meniscal prolapse. Such lesions were frequently found in animals with Grade II or III luxation who were aged 24 months or more, and they were more severe in dogs weighing more than 15 kg. Patellar luxation causes changes that favor articular degeneration and should be treated surgically. Conservative treatment relieves pain, but does not address tissue alterations.(AU)

O estudo descreve as lesões articulares em cães com luxação de patela. Elas foram associadas com a idade do animal, massa corporal e grau de luxação. Foi avaliada também a porcentagem de casos com recidiva. As lesões patelares observadas foram erosão da cartilagem articular, exposição óssea subcondral, superfície patelar achatada ou côncava e entesófitos. As lesões extra patelares incluíram sinovite, osteófitos, ausência do sulco troclear, erosão das bordas condilares, espessamento da cápsula, lesão do tendão do músculo extensor digital, ruptura do ligamento cruzado cranial e prolapso de menisco. As lesões foram encontradas com maior frequência em animais com luxação de Grau II ou III e idade de 24 meses ou mais, sendo mais graves em cães com massa corporal superior a 15 kg. A luxação patelar ocasiona alterações que favorecem a degeneração articular e devem ser tratadas cirurgicamente. O tratamento conservativo alivia a dor, mas não corrige as alterações teciduais.(AU)

Patellar luxation and articular lesions in dogs: a retrospective: study research article / Luxação de patela e lesões articulares em cães: estudo retrospectivo

This study describes lesions that occur in the stifle joints of dogs with patellar luxation. These lesions are associated with the animal's age, body weight, and degree of luxation. The rate of redislocation was also evaluated. The patellar lesions found include articular cartilage erosion, subchondral bone exposure, a flattened or concave patellar surface, and enthesophytes. Extra-patellar lesions included synovitis, osteophytes, blunting of the trochlear groove, an absent trochlea, erosion of the condylar margins, capsule thickening, a long digital extensor tendon injury, cranial cruciate ligament rupture, and meniscal prolapse. Such lesions were frequently found in animals with Grade II or III luxation who were aged 24 months or more, and they were more severe in dogs weighing more than 15 kg. Patellar luxation causes changes that favor articular degeneration and should be treated surgically. Conservative treatment relieves pain, but does not address tissue alterations.(AU)

O estudo descreve as lesões articulares em cães com luxação de patela. Elas foram associadas com a idade do animal, massa corporal e grau de luxação. Foi avaliada também a porcentagem de casos com recidiva. As lesões patelares observadas foram erosão da cartilagem articular, exposição óssea subcondral, superfície patelar achatada ou côncava e entesófitos. As lesões extra patelares incluíram sinovite, osteófitos, ausência do sulco troclear, erosão das bordas condilares, espessamento da cápsula, lesão do tendão do músculo extensor digital, ruptura do ligamento cruzado cranial e prolapso de menisco. As lesões foram encontradas com maior frequência em animais com luxação de Grau II ou III e idade de 24 meses ou mais, sendo mais graves em cães com massa corporal superior a 15 kg. A luxação patelar ocasiona alterações que favorecem a degeneração articular e devem ser tratadas cirurgicamente. O tratamento conservativo alivia a dor, mas não corrige as alterações teciduais.(AU)

Using allogeneic cortical graft preserved in glycerin as spacer in the advancement of tibial tuberosity in 34 dogs / Uso de enxerto cortical alogênico preservado em glicerina como espaçador no avanço da tuberosidade tibial em 34 cães

Cranial cruciate ligament is the main responsible for knee stability by preventing cranial tibial displacement regarding the femur. Deficiency in this ligament (CCLD) may cause subluxation of the tibia and dysfunction of the pelvic member due to overloading. Tibial osteotomies are among the more current surgical techniques for treating CCLD in dogs and they proportionate the dynamic stability by means of modifying bone geometry and the distribution of forces acting on the articulation. The objective of this work is to describe the use of the allogeneic cortical bone graft conserved in glycerin as a spacer on the tibial tuberosity advancement (TTA) for treating the CCLD. In order to do that, 34 dogs submitted to TTA surgery correction were evaluated, being 23 males (67.35%) and 11 females (32.35%). Surgical procedures happened from May 2011 to October 2015. Regarding the surgical procedure after osteotomy of the tibial tuberosity, a disk of allogeneic cortical disk, sawn wedge-hapsed, conserved in glycerin, proportions of 2x1mm was applied as spacer, enabling TTA. Advancements from 3 to 12 mm were executed, depending on the need of the patient. For animals with patella dislocation, trochleoplasty and TTA were executed in order to correct the deviation. The mean ± SD age of animals was 6.67±3.58 and weight was 15.16±12.97 kg. Mongrel dogs, Poodles and Yorkshire terriers were the most affected ones. From the 36 evaluated knees, 11 (30.56%) were associated with some traumatic process and in 25 (69.44%) there was no relation with previous trauma. From those wounds, 20 (55.56%) happened in the right limb and 16 (44.44%) in the left limb and two animals had CCLD bilaterally. Animals had continuous support, discreet drawer movement and negative tibial compression 15 days after surgery. At 30 days, 26 cases (72.22%) had firm support (FS); at 45 days, 24 cases (66 test at 7 and 67%) had FS and eight cases (22.22%) without claudication (WC). During subsequent radiographic evaluations the progressive incorporation of the graft and osteotomy union were observed. In this study, most of the diagnosed CCLD occurred in males diverging from results obtained by other authors that found greater frequency in females. Support without claudication it was observed in most of the cases of implants at 60 days. We concluded that the conserved allogeneic cortical bone graft was able to promote bone union in TTA of dogs with CCLD. None of the animals had signs of contamination, infection of the surgical wound or rejection related with the presence of the graft, demonstrated by the complete graft-bone incorporation observed early at 45 days in some animals. The glycerin was a good conservation medium for those fragments intended for grafting because, besides being of low cost, it kept bone fragments free of contamination, reducing antigenicity and preserving the functions of osteoinduction and osteoconduction. The possibility of molding the graft to the animal need is a characteristic favorable to executing the modified technique that could be molded according to the size of the animal, allowing perfect adaptation to the osteotomized local in different breeds. Intercurrences commonly observed in TTA with patellar dislocation, meniscal lesions, tibial crest fracture and displacement were not found in the animals of this study, probably due to the better distribution of forces between the pass screw in TT and the TTA plate confirming that it has good adaptation to the technique conferring to the modified TTA advantages regarding the conventional TTA.(AU)

O ligamento cruzado cranial é o principal responsável pela estabilidade do joelho, impedindo o deslocamento da tíbia cranial em relação ao fêmur. A deficiência neste ligamento (CCLD) pode causar subluxação da tíbia e disfunção do membro pélvico devido à sobrecarga. As osteotomias tibiais estão entre as técnicas cirúrgicas mais atuais para o tratamento de CCLD em cães e proporcionam a estabilidade dinâmica por meio da modificação da geometria óssea da distribuição das forças que atuam sobre a articulação. O objetivo desse estudo é descrever o uso do enxerto ósseo cortical alogênico conservado em glicerina como espaçador no avanço da tuberosidade tibial (TTA) para o tratamento do CCLD. Para isso, 34 cães submetidos à cirurgia de TTA foram avaliados, sendo 23 machos (67,35%) e 11 fêmeas (32,35%). Os procedimentos curúrgicos aconteceram entre maio de 2011 e outubro de 2015. Com relação ao procedimento cirúrgico após a osteotomia da tuberosidade tibial, um disco alogênico cortical, em forma de cunha serrada, conservado em glicerina com proporções de 2 x 1mm foi aplicado como espaçador possibilitando a TTA. Avanços de 3 a 12mm foram executados, dependendo da necessidade do paciente. Para animais com luxação da patela, realizou-se a trocleoplastia e a TTA para a correção do desvio. A idade média dos animais foi de 6,67±3,58 anos e pesos médios de 15,16±12,97kg. Cães sem raça definida, Poodles e Yorkshire Terriers foram os mais afetados. Dos 36 joelhos avaliados, 11 (30,56%) foram associados a algum processo traumático e em 25 (69,44%) não havia nenhuma relação com um trauma prévio. Dos ferimentos, 20 (55,56%) aconteceram no membro direito e 16 (44,44%) no esquerdo, sendo que dois animais apresentavam CCLD bilateralmente. Os animais tiveram suporte contínuo, discreto movimento de gaveta e compressão tibial negativa 15 dias após a cirurgia. Aos 30 dias, 26 casos tinham suporte firme (FS); aos 45 dias, 24 casos tinham FS e oito casos sem claudicação (WC). Durante avaliações radiográficas subsequentes, observou-se a incorporação progressiva da união do enxerto e da osteotomia. Neste estudo, a maior parte do CCLD diagnosticado ocorreu em machos, divergindo dos resultados obtidos por outros autores que encontraram maior frequência em fêmeas. Suporte sem claudicação foi observado na maioria dos casos de implantes aos 60 dias. Foi concluído que o enxerto ósseo cortical alogênico conservado foi capaz de promover a união óssea na TTA de cães com CCLD. Nenhum dos animais apresentou sinais de contaminação, infecção da ferida cirúrgica ou rejeição relacionada à presença do enxerto, demonstrada pela incorporação completa do enxerto ósseo observada precocemente aos 45 dias em alguns animais. A glicerina foi um bom meio de conservação para os fragmentos destinados à enxertia porque, além do menor custo, manteve os fragmentos ósseos livres de contaminação, reduzindo a antigenicidade e preservando as funções de osteoindução e osteocondução. A possibilidade de moldagem do enxerto à necessidade do animal é uma característica favorável à execução da técnica modificada que pode ser moldada de acordo com o tamanho do animal, possibilitando perfeita adaptação ao local osteotomizado em diferentes raças. Intercorrências comumente observadas na TTA com luxação patelar, lesões meniscais, fratura da crista tibial e deslocamento não foram encontradas nos animais deste estudo, provavelmente devido à melhor distribuição de forças entre a passagem do parafuso no TT e a placa do TTA, confirmando que tem boa adaptação à técnica conferindo às vantagens da TTA modificada em relação à TTA convencional.(AU)

Comparação da TTTT® (Tibial Tuberosity Transposition Tool) com a técnica tradicional de transposição e fixação da tuberosidade tibial em cães com luxação patelar: revisão bibliográfica / Comparison of TTTT® (Tibial Tuberosity Transposition Tool) with the traditional technique for tibial tuberosity transposition and fixation in dogs with patellar luxation: literature review

A luxação de patela representa casuística importante entre as afecções ortopédicas que acometem o membro pélvico dos cães. É consenso que a luxação de patela é sinal clínico e não doença, sendo causada por deformidades musculoesqueléticas, como a torção externa ou interna da tíbia proximal. A transposição da tuberosidade tibial (TTT) é técnica frequentemente empregada para correção desses desvios torcionais, consistindo no deslocamento lateral ou medial da tuberosidade tibial (TT), permitindo o reestabelecimento da posição da patela no sulco troclear do fêmur. Esta técnica é considerada indispensável por muitos autores, mesmo nos casos mais graves. A TTTT® (Tibial Tuberosity Transposition Tool) é técnica que permite o deslocamento da TT após osteotomia parcial e que não necessita de fixação da TT deslocada com banda de tensão. O presente trabalho tem por objetivo comparar os aspectos relacionados à execução, condições de aplicabilidade e incidência de complicações pós-operatórias da técnica tradicional de transposição e fixação da tuberosidade tibial, em relação à TTTT®.

The patellar dislocation is a important casuistry among the orthopedic disorders affecting the dog’s hindlimb. There’s a consensus that patellar luxation is a clinical sign and not the disease, caused by underlying musculoskeletal deformities, which we can highlight the external or internal torsion of the proximal tibia. Tibial tuberosity Transposition (TTT) is the technique commonly performed to correct these torsional deviations, consisting on lateral or medial displacement of the tibial tuberosity (TT), allowing the restoration of the patella neutral path in the femoral trochlear groove. This technique is considered indispensable by many authors, even in the most severe cases. The TTTT® (Tibial Tuberosity Transposition Tool) provides a method that allows the displacement of tibial tuberosity, after partial osteotomy, that doesn’t require fixation of the transposed tuberosity with tension band wire. The present paper aims to compare the aspects related to performance, applicability and incidence of postoperative complications of the established technique of transposition and attachment of tibial tuberosity in relation to TTTT®.

Comparação da TTTT® (Tibial Tuberosity Transposition Tool) com a técnica tradicional de transposição e fixação da tuberosidade tibial em cães com luxação patelar: revisão bibliográfica / Comparison of TTTT® (Tibial Tuberosity Transposition Tool) with the traditional technique for tibial tuberosity transposition and fixation in dogs with patellar luxation: literature review

A luxação de patela representa casuística importante entre as afecções ortopédicas que acometem o membro pélvico dos cães. É consenso que a luxação de patela é sinal clínico e não doença, sendo causada por deformidades musculoesqueléticas, como a torção externa ou interna da tíbia proximal. A transposição da tuberosidade tibial (TTT) é técnica frequentemente empregada para correção desses desvios torcionais, consistindo no deslocamento lateral ou medial da tuberosidade tibial (TT), permitindo o reestabelecimento da posição da patela no sulco troclear do fêmur. Esta técnica é considerada indispensável por muitos autores, mesmo nos casos mais graves. A TTTT® (Tibial Tuberosity Transposition Tool) é técnica que permite o deslocamento da TT após osteotomia parcial e que não necessita de fixação da TT deslocada com banda de tensão. O presente trabalho tem por objetivo comparar os aspectos relacionados à execução, condições de aplicabilidade e incidência de complicações pós-operatórias da técnica tradicional de transposição e fixação da tuberosidade tibial, em relação à TTTT®.(AU)

The patellar dislocation is a important casuistry among the orthopedic disorders affecting the dogs hindlimb. Theres a consensus that patellar luxation is a clinical sign and not the disease, caused by underlying musculoskeletal deformities, which we can highlight the external or internal torsion of the proximal tibia. Tibial tuberosity Transposition (TTT) is the technique commonly performed to correct these torsional deviations, consisting on lateral or medial displacement of the tibial tuberosity (TT), allowing the restoration of the patella neutral path in the femoral trochlear groove. This technique is considered indispensable by many authors, even in the most severe cases. The TTTT® (Tibial Tuberosity Transposition Tool) provides a method that allows the displacement of tibial tuberosity, after partial osteotomy, that doesnt require fixation of the transposed tuberosity with tension band wire. The present paper aims to compare the aspects related to performance, applicability and incidence of postoperative complications of the established technique of transposition and attachment of tibial tuberosity in relation to TTTT®.(AU)

FATOR NECROSE TUMORAL ALFA EM LÍQUIDO SINOVIAL EM CÃES COM LUXAÇÃO DE PATELA

A luxação de patela é uma das causas mais comuns de claudicação em cães. Pode ser uni ou bilateral, medial ou lateral, sendo esta última menos comum e é considerada uma das principais causas de doença degenerativa do joelho de cães. Marcadores inflamatórios já são estudados há alguns anos nos casos de doenças inflamatórias crônicas e o aprofundamento de seu estudo é de grande valia, pois permite o conhecimento mais abrangente sobre a patogênese das afecções, e abre horizontes para as estratégias de tratamento. O objetivo do trabalho foi mensurar o Fator de Necrose Tumoral (TNF) no líquido sinovial da articulação fêmoro-tíbio-patelar e relacioná-lo com outros marcadores já consolidados deste tipo de afecção articular: como o escore clínico da luxação patelar, escore de claudicação e grau de osteoartrose articular. Foram selecionados 15 (n=15) animais para o estudo, sendo 10 previamente diagnosticados clinicamente com luxação patelar, agrupados no Grupo Doente (GD), e 5 animais não doentes (sem luxação patelar evidenciada clinicamente), considerados Grupo Controle (GC). Os animais do GD foram clinicamente avaliados em sua luxação patelar de acordo com os seguintes critérios: grau de luxação, grau de claudicação e grau de osteoartrite evidenciado na imagem radiográfica. Para avaliação radiográfica todos os animais foram sedados em neuroleptoanalgesia (midazolam + metadona + acepromazina), quando também foi coletada amostra de líquido sinovial para dosagem do TNF através de ensaio imunoenzimático. Por fim todos os dados foram entrecruzados para avaliação de sua correlação. A correlação foi avaliada de acordo com o fator de correlação de Postos de Spearman (). Como resultado, encontramos uma correlação positiva forte entre o grau de claudicação (GCl) e o grau de osteoartrite (GOA) (=0,8251, p=0,0001) e entre o grau de luxação (GL) e o grau de claudicação (=0,8172, p=0,0002), porém, não se encontrou correlação positiva importante quando correlacionados ao TNF (GCl =-0,0078, p=9780; GL = -0,1354, p=0,6304; GOA = -0,2971, p=0,2822). Sugere-se mais estudos para a conclusão da correlação deste biomarcador sinovial e a luxação patelar em cães.

Patellar luxation is one of the most common causes of dog lameness. It can be unilateral or bilateral, medial or lateral, being this last one the less common, and it is one of the most important causes of articular knee degeneration in dogs. Inflammatory markers have been studied for years in cases of inflammatory diseases, and its study has a main importance in the knowledge of its pathogenesis, and it opens up the possibilities for new treatments. In this study, ten dogs with patellar luxation were analyzed in order to correlate their proved radiographic and clinical luxation grade with inflammatory markers such as Tumoral Necrosis Factor and their clinical lameness score, those results were confronted with the results of 5 dogs considered control. The aim of this study was to measure the Tumor Necrosis Factor (TNF) in the synovial fluid of the knee, and relate with other yet consolidated markers of this type of condition, such as clinical score of patellar luxation, lameness score and radiographic osteoarthritis score. There was selected 15 dogs (n=15) for this study, 10 of them were previously clinically diagnosed with patellar luxation and were considered Disease Group (GD), and the other 5 not affected dogs (those who did not clinically showed patellar luxation) were considered Control Group (GC). The GD animals were then clinically evaluated for their patellar luxation according to the criteria: luxation grade, lameness grade and radiographic osteoarthritis grade. For the radiographic evaluation the dogs were put on sedation with methadone, midazolam and acepromazin, and then the synovial liquid was obtained. In the end, this liquid was sent for TNF dosage by ELISA. The correlation was evaluated by the correlation factor of Pearson. The results found have shown a strong positive correlation between the lameness score (GCl) and the osteoarthritis score (GOA) (=0,8251, p=0,0001) and the lameness score and luxation score (GL) (=0,8172, p=0,0002), however there was no positive or important correlation with TNF (GCl =-0,0078, p=9780; GL = -0,1354, p=0,6304; GOA = -0,2971, p=0,2822). It is suggested that more studies should be developed in order to get a definite conclusion to the relation between this biomarker and patellar luxation in dogs.

AVALIAÇÃO ULTRASSONOGRÁFICA E RADIOGRÁFICA DA PROFUNDIDADE DA TRÓCLEA FEMORAL EM CÃES

A luxação de patela é problema ortopédico frequente em cães. Os sinais clínicos variam conforme a gravidade da luxação. O diagnóstico é clínico, por meio de palpação do joelho e pode ser classificada em graus que variam de I a IV. As técnicas cirúrgicas empregadas na estabilização da luxação de patela podem ser separadas em intervenção nos tecidos moles e osteotomias. Dentre as osteotomias, destaca-se a trocleoplastia como técnica de aprofundamento do sulco troclear do fêmur. A avaliação da profundidade do sulco troclear pode ser realizada através de exame radiográfico, em projeção crânio-caudal tangencial, porém, há necessidade de sedação e é de difícil execução, não sendo realizada na maioria dos casos. A avaliação do sulco é realizada de forma mais frequente no trans cirúrgico, após artrotomia, e neste momento decide-se por realizar ou não trocleoplastia. Este estudo teve como objetivo avaliar a concordância entre as medidas da profundidade da tróclea femoral em exame ultrassonográfico, radiográfico e anatômico. Foram utilizados 67 membros pélvicos de cadáveres caninos. A profundidade da tróclea femoral foi mensurada em exame ultrassonográfico, radiográfico (projeção crânio-caudal tangencial) e após esqueletização com auxílio de paquímetro. Durante o estudo observou-se concordância entre as medidas ultrassonográficas e as anatômicas realizadas com o paquímetro nas avaliações realizadas com o membro em extensão e em flexão de 90 graus (proximal a patela). Em relação as medidas ultrassonográficas comparadas com as medidas radiográficas tangenciais, foram observadas a concordância entre as medidas em flexão a 90 graus (proximal a patela) e flexão 45 graus (proximal a patela). Quando comparada as medidas anatômicas com relação as medidas em projeção tangencial, observou-se concordância entre as medidas realizadas com o membro em flexão de 90 graus (proximal a patela). Conclui-se que o exame ultrassonográfico dos joelhos em flexão de 90 graus, com o transdutor proximal a patela, pode ser útil para avaliar a profundidade da tróclea femoral proximal. Porém, mais estudos se mostram necessários para demonstrar a reprodutibilidade e repetibilidade da técnica, bem como a aplicabilidade na rotina clínica.

Patellar dislocation is a common orthopedic problem in dogs. Clinical signs vary according to the severity of the dislocation. The diagnosis is clinical, through palpation of the knee and can be classified into degrees ranging from I to IV. The surgical techniques used to stabilize the dislocation of the patella can be separated by intervention in soft tissues and osteotomies. Among osteotomies, trocleoplasty stands out as a technique for deepening the femur's trochlear groove. The assessment of the depth of the trochlear groove can be performed through radiographic examination, in a tangential cranio-caudal projection, however, there is a need for sedation and is difficult to perform, not being performed in most cases. The groove evaluation is performed more frequently in the surgical trans, after arthrotomy, and at this moment it is decided to perform or not to perform trocleoplasty. This study aimed to evaluate the agreement between the measures of the depth of the femoral trochlea in ultrasound, radiographic and anatomical examination. 67 pelvic limbs from canine cadavers were used. The depth of the femoral trochlea was measured in ultrasound, radiographic examination (tangential craniocaudal projection) and after skeletonization with the aid of a caliper. During the study, agreement was observed between the ultrasound and anatomical measurements performed with the caliper in the evaluations performed with the limb in extension and in 90 degree flexion (proximal to the patella). Regarding ultrasound measurements compared with tangential radiographic measurements, agreement was observed between measurements in flexion at 90 degrees (proximal to the patella) and flexion at 45 degrees (proximal to the patella). When comparing the anatomical measurements with those in tangential projection, there was agreement between the measurements made with the limb in 90 degree flexion (proximal to the patella). It is concluded that the ultrasound examination of the knees in 90-degree flexion, with the transducer proximal to the patella, may be useful to assess the depth of the proximal femoral trochlea. However, more studies are necessary to demonstrate the reproducibility and repeatability of the technique, as well as its applicability in the clinical routine.

Estudo retrospectivo de cães portadores de ruptura do ligamento cruzado cranial: 32 casos (2006 a 2012) / A retrospective study of dogs with cranial cruciate ligament rupture: 32 cases (2006-2012)

A ruptura do ligamento cruzado cranial (RLCCr) é uma das lesões mais comuns no cão e a maior causa de doença articular degenerativa (DAD) do joelho. Os animais não tratados exibem DAD dentro de poucas semanas e alterações graves dentro de poucos meses. A gravidade da degeneração parece ser diretamente proporcional ao porte e idade. Doenças articulares inflamatórias sistêmicas são associadas com a ruptura deste ligamento. O objetivo deste trabalho foi caracterizar a população de cães acometidos de RLCCr segundo os seguintes fatores: tipo de claudicação, ruptura ligamentar uni ou bilateral, raça, idade, sexo, estado reprodutivo, dieta, peso corporal, presença de DAD e luxação patelar anteriores à RLCCr. A base dos dados foi a análise de prontuários de 32 cães com RLCCr no período de janeiro de 2006 a dezembro de 2012. Os resultados mostram que a maioria (56,25%) apresentava claudicação de apoio no momento da consulta. A RLCCr unilateral foi a mais frequente (90,62%), 13,8% dos casos apresentaram RLCCr no membro contralateral, após um período médio de 2 anos e 4 meses. A raça de maior ocorrência foi o Poodle toy (21,9%) e Pitbull (18,75%); cães sem raça definida foram responsáveis por 12,5% dos casos. As idades com maior frequência foram 2, 3, 4 e 7 anos (média = 5,7 anos). Com relação ao sexo e estado reprodutivo, as fêmeas (68,75%) e animais não castrados (69%) foram mais acometidos. Luxação patelar anterior à RLCCr foi percebida na minoria dos animais, diferentemente da DAD anterior à RLCCr, que foi vista na maioria dos casos.(AU)

Rupture of the cranial cruciate ligament (RLCCr) is one of the most common injuries in the dog and the leading cause of degenerative joint disease (DAD) of the knee. Untreated animals exhibit degenerative joint changes in a few weeks and severe changes within a few months. The severity of degeneration appears to be directly proportional to body size and age. Systemic inflammatory joint diseases are associated with the rupture of this ligament. The aim of this study was to characterize the population of dogs suffering from RLCCr according to the following factors: type of lameness, unilateral or bilateral ligament rupture, breed, age, sex, reproductive status, diet, body weight, presence of DAD and patellar luxation prior to RLCCr. The data base was created from information from medical records of 32 dogs diagnosed with RLCCr in Companion Animals Hospital Uninity, Catholic University of Parana in the period from January 2006 to December 2012. The results showed that most of dogs (56.25%) had weight bearing lameness on initial presentation. The unilateral RLCCr was the most frequent (90.62%), 13.8% of these cases presented RLCCr in the contralateral limb, after an average period of 2 years and 4 months. The most frequent breeds were Toy Poodle (21.9%) and Pitbull (18.75%); mixed breed dogs accounted for 12.5% of cases. The most frequent ages were 2, 3, 4 and 7 years (average = 5.(AU)