Legg Calvé Perthes disease in the dog.

Legg Calvé Perthes disease (LCPD) is a developmental abnormality that usually affects young small breed dogs. Although the etiology is still uncertain, the pathogenesis is very similar to that described in humans. Diagnosis with physical examination and medical imaging is relatively easy. Treatments offered in dogs, mainly surgical, are also presented. Legg Calvé Perthes disease has many similarities between children and puppies. Dog is therefore an interesting spontaneous model of aseptic osteonecrosis.

Generation and characterization of mesenchymal stem cells from the affected femoral heads of dogs with Legg Calvé Perthes disease.

Background: Canine Legg Calvé Perthes disease (LCPD) occurs during the growth period, and the cause of ischemic necrosis of the femoral head during growth remains unclear. If LCPD-affected femoral head-derived mesenchymal stem cells (LCPD-MSCs) can be generated, they can be used as a new tool for the pathophysiological analysis of canine LCPD. Aim: To generate affected femoral head-derived mesenchymal stem cells (MSCs) from dogs with LCPD and investigate the mRNA expression levels of angiogenesis-related factors and osteogenic differentiation potency of LCPD-MSCs. Methods: This study was performed using affected femoral heads from dogs diagnosed with LCPD and underwent femoral head and neck ostectomy. The necrotic tissue was harvested from the LCPD-affected femoral head and cultured statically (LCPD group, n = 6). Canine bone marrow-derived MSCs (BM-MSCs) were used as controls (control group, n = 6). First, the morphology of the cultured cells was observed, and the expression of CD29, CD34, CD44, CD45, CD90, and major histocompatibility complex class II was analyzed using flow cytometry. Additionally, the trilineage differentiation potency of the LCPD-affected head-derived adherent cells was examined. Furthermore, the expression levels of HIF1A, VEGFA, VEGFB, and PDGFB mRNAs and the bone differentiation potency of LCPD-affected head-derived adherent cells were investigated. Results: LCPD-affected femoral head-derived adherent cells showed a fibroblast-like morphology, and the expression of cell surface antigens was similar to that of BM-MSCs. In addition, LCPD-affected femoral head-derived adherent cells showed the same trilineage differentiation potency as BM-MSCs and were consistent with MSC characteristics. Furthermore, the mRNA expression levels of angiogenesis-related factors could be objectively measured in LCPD-MSCs and those MSCs had bone differentiation potency. Conclusion: In the present study, canine LCPD-MSCs were successfully generated, suggesting their usefulness as a tool for pathological analysis of LCPD in dogs.

A Case of Animal and Domestic Abuse Initially Diagnosed as Legg-Calve-Perthes Disease.

A 1 yr old castrated male shih tzu was evaluated for an acute right rear limb lameness and hyphema in the anterior chamber of the right eye. On initial examination, the dog was non-weight bearing on his right rear limb. Ophthalmic examination revealed a centrally located, superficial corneal ulcer in the right eye and blood in the anterior chamber. Radiographic findings of the pelvis and right rear were suggestive of avascular necrosis of the right femoral neck with resultant fracture and possible avascular necrosis of the left femoral neck. The dog presented 20 days later for evaluation of an acute left rear limb lameness. A left distal femur Salter-Harris type II fracture; a nondisplaced, healing right pubic fracture; and a healing right zygomatic arch transverse fracture were seen on radiographs. The dog's initial injuries were attributed to a routine fall at home, and radiographic interpretation suggested that this was plausible. Subsequent patient visits, evaluation of additional injuries, and interviews with the owner indicated that both animal and domestic abuse had occurred. Veterinarians must be alert to recognize signs of animal abuse and must be aware of the connection between animal and domestic abuse.

Legg-Calvé-Perthes disease in a rhesus macaque (Macaca mulatta).

A juvenile rhesus macaque presented with atrophy of the musculature of its left leg. Physical examination localized the problem to the coxofemoral joint. Radiography revealed changes consistent with Legg-Calvé-Perthes (LCP) disease. Femoral head ostectomy was performed, and the femoral head was submitted for histologic examination, results of which confirmed a diagnosis of LCP.

Analysis of blood clotting factor activities in canine Legg-Calvé-Perthes' disease.

Legg-Calve-Perthes' (LCP) disease is a noninflammatory aseptic necrosis of the femoral head and neck in small-breed dogs. The etiology of the disease is not known, but ischemia resulting from vascular compression or occlusion has been proposed. A latent ischemic phase during development of the femoral epiphysis seems to be responsible for the onset of the typical clinical features of LCP disease. Ischemia might result from insufficient oxygen supply either caused by a reduced number of afferent arterial vessels or an occlusion of the efferent venous vessels by thrombosis. In humans, LCP disease has been linked to hypercoagulability and hypofibrinolysis caused by deficiencies of protein C, protein S, or resistance to activated protein C. To determine whether canine LCP disease is caused by similar deficiencies, we determined protein C, protein S, activated protein C, factor II, factor V, factor VIII:C, and AT III activities in plasma samples of 18 dogs with clinically and histopathologically verified LCP disease. All dogs had normal plasma activities of these factors, indicating that in these dogs LCP disease was not caused by deficiencies of the analyzed blood clotting factors.

Long term results of excision arthroplasty of the canine hip.

An analysis has been made of the long term results of excision of the canine femoral head and neck. The most frequent postoperative findings include shortening of the operated limb and restricted movement of the hip pseudarthrosis. Although few dogs show lameness or pain in the operated hip, muscle atrophy is a frequent finding even after eight years. Difficulty in jumping and in climbing stairs are more commonly found postoperatively in the larger breeds of dog. Despite these noted abnormalities almost all owners expressed their satisfaction with the outcome of excision arthroplasty.

Comparative vascular anatomy of the hip of the miniature dog and of the normal-size mongrel.

In order to investigate the aetiology of Perthes' disease in the dog the author has conducted a comparative anatomical study of the vascular system of the femoral heads in miniature dogs and in normal-size mongrels. The study was made in five three-months old miniature dogs and five age-matched normal-size mongrels, in which the epiphyseal plate of the femoral head was still open. The most distinct difference between the two species was in the channel of the superior retinacular vessels. In miniature dogs, these vessels go through the shallow neck and appear as a "suspended bridge". In normal-size mongrels they go through the deep fossa of the femoral neck and appear to be very rigidly stable. Although foveolar vessels in the round ligament were present in both species, no vessels were found in either species reaching the epiphysis by penetrating the articular cartilage at this stage of development.

Avascular necrosis of the femoral heads in a red panda (Ailurus fulgens fulgens): possible Legg-Calve-Perthes disease.

A 17-mo-old captive-born female red panda (Ailurus fulgens fulgens) presented with a sudden onset of lameness in its left hind leg was diagnosed radiographically as having possible severe, bilateral Legg-Calve-Perthes disease with fracture of the great trochanter of the left femur. Surgical repair of the fracture was performed using pins and a tension band wire through a lateral approach to the hip. This is the first case reported at Madrid Zoo-Aquarium, where 63 individuals have been bred over 15 yr.

Comparative structural analysis of the canine femoral head in Legg-Calvé-Perthes disease.

The goal of this study was to examine the microarchitecture of the trabecular bone of the canine femoral head using microcomputed tomography (micro-CT) technology. Specifically, we assessed changes seen in the femoral head in dogs with Legg-Calvé-Perthes disease and compared this with changes seen in dogs with hip dysplasia and coxofemoral luxation. Femoral heads from healthy animals were examined as a control. In total, 38 femoral heads were studied. Rules for defining spherical volumes (region of interest) for determination of the structural parameters within the trabecular structure were established using micro-CT images. The following parameters were determined directly in three dimensions: bone volume fraction, surface volume fraction, trabecula thickness, trabecular count, trabecular spacing, and connectivity. Characteristic femoral head changes were found for each condition. An unexpected result was found that contradicts the prevailing understanding of Legg-Calvé-Perthes disease. Instead of observing a thickening of the bone trabeculae caused by layering of new bone matrix on top of necrotic trabeculae, we observed an increase in trabecular count and a smaller trabecular thickness. From this it may be concluded that trabecular regeneration is more prominent or prevails over the characteristically described layering processes in the revascularization and repair processes occurring in this illness.

Dual-energy X-ray absorptiometry in canine legg-Calvé-Perthes disease.

Radiographic examination and subsequent dual-energy X-ray absorptiometry scans of the hips were performed in seven dogs with monolateral Legg-Perthes-Calvé disease to quantify bone changes produced by osteonecrosis in the proximal femur on the affected and unaffected side. All dogs were found to be affected with grade 2 and 3 of the radiographic classification proposed by Ljunggren. Bone mineral density (g/cm(2)) of the femoral neck and proximal femoral metaphysis were evaluated on the affected and unaffected side; we detected no differences in bone mineral density for both regions of interest within the population studied in relation to gender, body weight and side analysed nor between the affected and the unaffected limb. We therefore assume that radiographic areas of decreased density in the proximal femoral epiphysis during chronic stages of Legg-Calvé-Perthes disease do not alter the global mineral content of the scanned region.

Perthes' disease in rabbits and puppies.

An effusion was simulated in the hip joints of rabbits and puppies known to be susceptible to Perthes' disease. The effusion was produced by the injection of glycol wax. The object of producing the effusion was to show that a transitory interruption of the venous flow was capable of producing changes that would subsequently manifest the pathologic changes and establish a Perthes-like disease.

Legg-Calvé-Perthes disease in dogs: a comparison to human Legg-Culvé-Perthes disease.

The femoral heads of 12 dogs with naturally occurring Legg-Calvé-Perthes disease were studied by light and electron microscopic techniques. In the early stages of the disease, the bony capital femoral epiphysis was necrotic, but the articular cartilage and growth plate cartilage were not affected. By the early stages of repair, the femoral head had collapsed. the articular cartilage was thickened and furrowed at the sites of collapse, and the chondrocytes appeared more metabolically active. Sites of bone resorption were associated with osteoclasts and macrophages. In some specimens there were areas of necrosis in the metaphysis which interrupted normal enchondral ossification in the growth plate. By the final stages of repair, the epiphysis was almost completely revascularized with the exception of the central proximal segment. In some areas, repair tissue had penetrated into the deeper layers of the articular cartilage. The flattening of the femoral head in Legg-Calvé-Perthes disease appears to be the result of several processes: mechanical collapse, asymmetric growth, and disturbed enchondral ossification at the growth plate.

Mode of inheritance of Perthes' disease in Manchester terriers.

A test mating between two Manchester Terriers affected by Perthes' disease (PD) resulted in the birth of three affected males and two unaffected females. In the three puppies with PD, roentgenographically detectable changes in the affected femurs were observed two to three weeks before the onset of lameness and muscle atrophy in the corresponding limb. Analysis of the related pedigrees and of the results of the test mating indicated that PD is an inherited condition with high heritability.