Evaluation of hematology, general serum biochemistry, bone turnover markers and bone marrow cytology in a glucocorticoid treated ovariectomized sheep model for osteoporosis research.

Osteoporosis is a metabolic disorder characterized by a loss of bone mass and structure and increasing the risk of fragility fractures, mostly among postmenopausal women. Sheep is a recognized large animal model for osteoporosis research. An experimental group of ewes (3-4 years old) was subjected to ovariectomy (OVX) and weekly glucocorticoid (GC) application for 24 weeks and compared with a sham control group. Blood and bone marrow parameters were analyzed before and 24 weeks after OVX and GC administration. Osteopenia was confirmed through micro-computed tomography and histomorphometric analysis of L4 vertebra in the study end. A statistically significant increase was observed in mean corpuscular volume, mean cell hemoglobin and monocytes and a decrease in red blood count and eosinophils (p<0.05). Alkaline phosphatase (ALP), gamma-glutamyl transpeptidase, magnesium and α1-globulin increased, and creatinine, albumin, sodium and estradiol decreased (p<0.05). A slight decrease of bone formation markers (bone ALP and osteocalcin) and an increase of bone resorption markers (C-terminal telopeptides of collagen type 1 and tartrate-resistant acid phosphatase) were observed, but without statistical significance. This study aims to contribute to better knowledge of sheep as a model for osteoporosis research and the consequences that a performed induction protocol may impose on organic metabolism.

Técnica de TightRope modificada no tratamento da doença do ligamento cruzado cranial em cães: resultados a longo prazo / Modified TightRope technique for treatment of the cranial cruciate ligament disease in dogs: long term outcomes

O objetivo deste estudo foi descrever os resultados a longo prazo do uso da técnica extracapsular TightRope (TR) modificada no tratamento da doença do ligamento cruzado cranial (LCCr) em oito cães (10 articulações) com peso corporal variando entre 4kg e 28kg. Todos os animais selecionados foram submetidos aos exames ortopédicos específicos, sendo diagnosticada ruptura completa do LCCr pelos testes de gaveta e de compressão tibial. Realizaram-se exames radiográficos convencionais e em posição de estresse das articulações. A técnica TR foi modificada utilizando-se o fio de náilon substituindo o fio de fibra empregado na técnica original, facilitando a disponibilidade de obtenção do material. Houve também modificação na origem da perfuração do túnel tibial, sendo realizada imediatamente cranial ao sulco do tendão extensor digital longo. Todos os cães foram submetidos ao exame radiográfico tanto no pós-operatório imediato como no tardio. Aos 30 dias após a intervenção cirúrgica, os pacientes apresentavam claudicação nos membros pélvicos operados de grau discreto a moderado. Foi observado discreto movimento de gaveta cranial em 60% das articulações acometidas. Aos três meses após o procedimento cirúrgico, os animais apresentaram ausência de dor e discreta redução na amplitude dos movimentos articulares. Em duas articulações (20%) observou-se discreto deslocamento cranial da tíbia no teste de gaveta. Nesta fase, 80% dos membros avaliados apresentavam apoio normal. Um ano após a intervenção cirúrgica, observou-se ao exame radiográfico discreta progressão da doença articular degenerativa em 50% das articulações operadas. Das oito articulações avaliadas a longo prazo, em apenas um membro operado observou-se discreta claudicação com reduzida transferência de peso para o membro contralateral. Os demais membros pélvicos avaliados (87,5%) demonstraram ausência de claudicação e adequada recuperação da função articular. Concluiu-se que a técnica cirúrgica extracapsular TR modificada mostrou-se efetiva como opção de tratamento para doença do LCCr em cães de porte pequeno e médio, não apresentando complicações. As modificações do fio cirúrgico e da perfuração da tíbia na técnica TR parecem ter efeitos positivos na estabilização da articulação do joelho.(AU)

The aim of the study was to describe the long term outcomes of the modified extracapsular TightRope (TR) technique in the treatment of the cranial cruciate ligament (CCL) disease in eight dogs (10 joints) with a body weight ranging from 4kg to 28kg. The animals were submitted to specific orthopedic examinations and were diagnosed with total CCL rupture by drawer and tibial compression tests. Conventional and stress positional radiographic examinations of the affected joints were performed. The TR technique was modified using the nylon suture thread replacing the fiber suture used in the original technique, which facilitated the availability of obtaining the material. There was also modification in the origin of the tibial tunnel perforation that was performed immediately cranial to the groove of the long digital extensor tendon. The dogs underwent radiographic examination in the immediate postoperative and in later periods. At one month after surgical procedure, the animals showed mild or moderate lameness in the affected pelvic limbs. Mild cranial tibial drawer was observed in 60% of the operated joints. At three months after the procedure, the animals have mild decrease in the range of joint motion, but without signs of pain. Two stifle joints (20%) showed a slight cranial displacement of the tibia in the drawer test. In this period, 80% of the affected joints showed normal limb support. At one year after the procedure, radiographic examination showed a discrete progression of the degenerative joint disease in 50% of the operated joints. The long term outcomes were obtained from eight joints and in only one pelvic limb was observed mild lameness with slight weight transfer to the normal contralateral limb. All other evaluated pelvic limbs (87.5%) showed no lameness and proper recovery of joint function. In conclusion, the modified TR extracapsular surgical technique proved to be effective as a treatment option for CCL disease in small and medium dogs, with no complications. Modifications of the surgical suture thread and the tibial site perforation of the TR technique seem to have positive effects on stabilization of the stifle joint.(AU)

Preclinical and Translational Studies in Small Ruminants (Sheep and Goat) as Models for Osteoporosis Research.

PURPOSE OF THE REVIEW: This review summarizes research on the use of sheep and goats as large animal models of human osteoporosis for preclinical and translational studies. RECENT FINDINGS: The most frequent osteoporotic sheep model used is the ovariectomized sheep with 12 months post-operatively or more and the combined treatment of ovariectomized sheep associated to calcium/vitamin D-deficient diet and glucocorticoid applications for 6 months, but other methods are also described, like pinealectomy or hypothalamic-pituitary disconnection in ovariectomized sheep. The goat model for osteoporosis research has been used in a very limited number of studies in osteoporosis research relative to sheep. These osteoporotic small ruminant models are applied for biomaterial research, bone augmentation, efficacy of implant fixation, fragility fracture-healing process improvement, or bone-defect repair studies in the osteopenic or osteoporotic bone. Sheep are a recognized large animal model for preclinical and translational studies in osteoporosis research and the goat to a lesser extent. Recently, the pathophysiological mechanism underlying induction of osteoporosis in glucocorticoid-treated ovariectomized aged sheep was clarified, being similar to what occurs in postmenopausal women with glucocorticoid-induced osteoporosis. It was also concluded that the receptor activator of NF-κB ligand was stimulated in the late progressive phase of the osteoporosis induced by steroids in sheep. The knowledge of the pathophysiological mechanisms at the cellular and molecular levels of the induction of osteoporosis in small ruminants, if identical to humans, will allow in the future, the use of these animal models with greater confidence in the preclinical and translational studies for osteoporosis research.

Tartrate-resistant acid phosphate as biomarker of bone turnover over the lifespan and different physiologic stages in sheep.

BACKGROUND: Currently, the best resources for assessment of bone tissue using imaging techniques are expensive and available in few medical facilities, thus serum or urinary bone turnover biomarkers could be useful as early indicators of prognosis. However, there is a wide range of variability in bone turnover markers due to several factors, such as different ages and metabolic stages, thus it is important to have as much data published on the subject as possible. The aim of this study was therefore to generate a reference range for alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) and validate the already published data. RESULTS: Serum alkaline phosphatase decreased with age, with statistical difference between the 1 month old and the other groups and between the over 8 years and the 6 months old groups. There was also a statistical difference in the ALP levels between the 3 to 5 years old gestation and lactation groups. For serum tartrate-resistant acid phosphatase, there was a statistical difference mainly between the 1 month old and the 6 months old, 6-8 years old, and above 8 years old groups. CONCLUSIONS: The results obtained could represent a useful tool for future studies using sheep as an animal model for orthopedic research. The different groups presented a wide variation of serum ALP and TRAP levels, however, these variations are entirely explained by known physiology. Therefore, this detailed study confirms the prediction that unexplained changes in these bone turnover markers do not occur during the lifespan of sheep.

Ressonância magnética na avaliação de enxerto osteocondral autógeno na cartilagem articular de coelhos / Magnetic resonance in the evaluation of autogenous osteochondral graft in articular cartilage of rabbits

Este trabalho teve o objetivo de determinar as características e a aplicabilidade do exame de ressonância magnética na avaliação de enxerto ostecondral autógeno, em formato íntegro ou macerado, associado ou não ao fator de crescimento semelhante à insulina tipo 1 (IGF-1), utilizado no reparo de lesões induzidas na cartilagem articular de coelhos. Foram utilizados 9 coelhos da linhagem Nova Zelândia, em que as 18 articulações fêmoro-tíbio-patelares foram submetidas à enxertia osteocondral autógena no sulco troclear femoral. Estas foram divididas em quatro grupos, denominados como enxerto osteocondral íntegro + IGF-1 (n=5), enxerto osteocondral íntegro + solução fisiológica (n=4), enxerto osteocondral macerado + IGF-1 (n=5) e enxerto osteocondral macerado + solução fisiológica (n=4). Os animais foram eutanasiados em 12 semanas após a cirurgia e as articulações foram submetidas ao exame de ressonância magnética utilizando um aparelho scanner de 1,5 Tesla de alto campo magnético. Além disso, amostras dos locais de enxertia foram submetidas aos exames anatomopatológicos. O exame de ressonância magnética mostrou-se eficaz como um método não invasivo para avaliação do tecido de reparação em enxertos osteocondrais na cartilagem articular do fêmur de coelhos, fornecendo dados complementares aos exames macroscópicos e histológicos. Por meio destas imagens e dos exames anatomopatológicos, foram observados resultados satisfatórios em relação ao processo de reparação dos enxertos osteocondrais autógenos na cartilagem de coelhos, independentemente de seu formato ou da adição de IGF-1.(AU)

This study aimed to determine the characteristics and applicability of magnetic resonance imaging (MRI) in the evaluation of autogenous osteochondral graft in intact or macerated format, with or without insulin-like growth factor type 1 (IGF-1) used in repair of cartilage lesions induced in rabbits. Nine New Zealand rabbits were used, in which 18 stifle joints underwent grafting procedure in the femoral trochlear groove. These were divided into four groups, referred as intact osteochondral graft + IGF-1 (n=5), intact osteochondral graft + saline solution (n=4), macerated osteochondral graft + IGF-1 (n=5) and macerated osteochondral graft + saline solution (n=4). Animals were euthanized 12 weeks after surgery and the joints were subjected to MRI using a high magnetic field scanner of 1.5 Tesla. In addition, samples of grafting sites were subjected to anatomopathological examination. The MRI was effective as a noninvasive method to evaluate the repair tissue in osteochondral grafts in articular cartilage of the femur of rabbits by providing complementary data to macroscopic and histological examinations. Through these images and anatomopathological examinations satisfactory results were observed in relation to the repair process of autogenous osteochondral grafts in cartilage of rabbits, regardless of its format or the addition of IGF-1.(AU)

Bone turnover markers in sheep and goat: A review of the scientific literature.

Bone turnover markers (BTMs) are product of bone cell activity and are generally divided in bone formation and bone resorption markers. The purpose of this review was to structure the available information on the use of BTMs in studies on small ruminants, especially for monitoring their variations related to diet, exercise, gestation and metabolic lactation state, circadian and seasonal variations, and also during skeletal growth. Pre-clinical and translational studies using BTMs with sheep and goats as animal models in orthopaedic research studies to help in the evaluation of the fracture healing process and osteoporosis research are also described in this review. The available information from the reviewed studies was systematically organized in order to highlight the most promising BTMs in small ruminant research, as well as provide a wide view of the use of sheep and goat as animal models in orthopaedic research, type of markers and commercial assay kits with cross-reactivity in sheep and goat, method of sample and storage of serum and urine for bone turnover markers determination and the usefulness and limitations of bone turnover markers in the different studies, therefore an effective tool for researchers that seek answers to different questions while using BTMs in small ruminants.

Bone turnover markers in sheep and goat: A review of the scientific literature

ABSTRACT Bone turnover markers (BTMs) are product of bone cell activity and are generally divided in bone formation and bone resorption markers. The purpose of this review was to structure the available information on the use of BTMs in studies on small ruminants, especially for monitoring their variations related to diet, exercise, gestation and metabolic lactation state, circadian and seasonal variations, and also during skeletal growth. Pre-clinical and translational studies using BTMs with sheep and goats as animal models in orthopaedic research studies to help in the evaluation of the fracture healing process and osteoporosis research are also described in this review. The available information from the reviewed studies was systematically organized in order to highlight the most promising BTMs in small ruminant research, as well as provide a wide view of the use of sheep and goat as animal models in orthopaedic research, type of markers and commercial assay kits with cross-reactivity in sheep and goat, method of sample and storage of serum and urine for bone turnover markers determination and the usefulness and limitations of bone turnover markers in the different studies, therefore an effective tool for researchers that seek answers to different questions while using BTMs in small ruminants.

Bone turnover markers for early detection of fracture healing disturbances: A review of the scientific literature.

Imaging techniques are the standard method for assessment of fracture healing processes. However, these methods are perhaps not entirely reliable for early detection of complications, the most frequent of these being delayed union and non-union. A prompt diagnosis of such disorders could prevent prolonged patient distress and disability. Efforts should be directed towards the development of new technologies for improving accuracy in diagnosing complications following bone fractures. The variation in the levels of bone turnover markers (BTMs) have been assessed with regard to there ability to predict impaired fracture healing at an early stage, nevertheless the conclusions of some studies are not consensual. In this article the authors have revised the potential of BTMs as early predictors of prognosis in adult patients presenting traumatic bone fractures but who did not suffer from osteopenia or postmenopausal osteoporosis. The available information from the different studies performed in this field was systematized in order to highlight the most promising BTMs for the assessment of fracture healing outcome.