Long-term outcomes of atrophic/oligotrophic non-unions in dogs and cats treated with autologous iliac corticocancellous bone graft and circular external skeletal fixation: 19 cases (2014-2021).

OBJECTIVES: To determine the short- and long-term outcomes and complications in dogs and cats undergoing surgical treatment for viable oligotrophic and nonviable atrophic non-unions using circular external skeletal fixation and autologous corticocancellous bone graft. MATERIALS AND METHODS: In this case series, the medical records and radiographs of all dogs and cats with radius/ulna and tibia/fibula viable oligotrophic and nonviable atrophic non-unions treated with corticocancellous bone graft and circular external skeletal fixation at two referral veterinary hospitals between 2014 and 2021 were retrospectively reviewed. The long-term follow-up was 1 year or greater. RESULTS: Thirteen dogs and six cats with 19 non-union fractures met the inclusion criteria for the study. Eighteen non-union fractures (94.7%) healed and one did not. Five patients (26%) had minor perioperative period complications (<3 months). The patient that did not achieve bone union underwent revision surgery with internal fixation (plate and screws) and autologous cancellous bone graft. Fifteen (78.9%) cases returned to full function and three (15.8%) cases returned to acceptable function in the long-term follow-up period. CLINICAL SIGNIFICANCE: The use of circular external skeletal fixation associated with autologous corticocancellous bone graft for the treatment of radius/ulna and tibia/fibula atrophic/oligotrophic non-union fractures in dogs and cats was considered successful in the majority of patients and was free of major or catastrophic complications.

Osteochondral allograft transplantation for treating medial femoral condyle subchondral bone cyst in a 14-year-old standardbred horse: a case report.

Allograft arthroplasty is a promising cartilage-resurfacing technique. A 14-year-old horse was diagnosed with a medial femoral condyle subchondral bone cyst. Allografts were harvested from a young donor animal and implanted to fill the cyst cavity. A visual assessment of the surgical site was possible during follow-up arthroscopy. In addition to a desirable gliding surface and a good adaptation of the grafts, fibrillation of the cranial ligament of the medial meniscus was noted and debrided. The recipient horse became sound four months after follow-up surgery with a high level of owner satisfaction. In conclusion allograft transplantation is a promising technique for treating subchondral bone cysts.

Maternal allogeneic cancellous bone graft for the treatment of osteitis along the physeal scar of the proximal metatarsus in a foal.

OBJECTIVE: To describe the treatment and outcome of a foal with a fresh allogenic cancellous bone graft after surgical debridement of a traumatic septic osteitis. ANIMAL: A neonatal Quarter Horse foal. STUDY DESIGN: Case report. METHODS: The foal sustained a traumatic laceration exposing the proximal third metatarsal bone. One week after surgical debridement and closure, radiographic signs of septic osteitis were noted along the physeal scar. The lesion was debrided, and antimicrobial therapy was implemented. The infection resolved but left a large defect in the metaphysis and epiphysis. Grafting was indicated to avoid pathologic fractures of the plantar and proximal cortices. Due to a discrepancy between defect size and the bone stock of the foal, an allogeneic cancellous bone graft was harvested from the dam's tuber coxae and used to fill the foal's defect. RESULTS: No adverse reactions to the graft were noted. After 1 month, the wound had healed. Radiographic examination was consistent with graft incorporation in the bone structure. The foal was sound at a walk and trot when examined at 6, 12, and 21 months. The bone's contour was even and its structure homogeneously radio dense. The surgical site of the mare healed without complications. CONCLUSION: Fresh allogenic cancellous bone grafting resulted in the healing of a large traumatic-septic bone defect in a foal, with an excellent functional and cosmetic outcome. For future use, compatibility testing should be considered prior to allogeneic bone grafting.

Treatment of an aneurysmal bone cyst in a young dog: A case report.

BACKGROUND: An aneurysmal bone cyst (ABC) is a rare benign lytic lesion affecting the medullary canal of long bones. It has been widely reported in human medicine, but rarely described in domestic animals. OBJECTIVE: To report the surgical treatment and long term follow-up of a dog affected by ABC. METHODS: An 8-month-old, intact female Weimaraner was presented with lameness affecting the left front limb and progressive swelling of the mid-distal radius. Survey radiographs revealed a mid-distal diaphyseal radial lesion. Fine needle aspirates, biopsy, CT scan and histopathology results supported the diagnosis of ABC. Treatment consisted of partial corticotomy of the affected radius, filling of the cystic cavity with demineralised bone matrix and autologous bone graft and stabilisation using lag screws and a neutralisation plate. RESULTS: The long-term follow-up, at 36 post-operative months, showed no recurrence of the cyst and bone modelling. Comparing preoperative radiographs with those at 36 months, bone modelling reduced the radial area by 23.3% in the craniocaudal radiographic view and 30% in the mediolateral projection. CONCLUSIONS: This treatment was sucessful in the case here described, with a 3 years follow-up.

Valuation of angiogenesis in bovine xenografts implanted in intracorporal sites of rabbits as models of in-vivo bioreactors / Avaliação da angiogênese em xenoenxertos bovinos implantados em sítios intracorpóreos de coelhos como modelos de biorreatores in vivo

The aim of this study was to evaluate neovascularization of bovine xenografts implanted in intracorporeal sites of rabbits (bioreactors). 30 rabbits were used, divided into 6 groups, according to the evaluation time (7, 15, 30, 45, and 60 days); each animal received xenogenic implants in 3 different intracorporeal sites (A1 - omentum bag; A2 - intermuscular space of quadriceps femoris; A3 - subperiosteal of ilium bone). Histological assessments graded the presence of angiogenesis, the number of inflammatory cells, newly formed bone tissue, and the presence of giant cells. Histological analyses showed intense angiogenesis in all implanted xenografts. Presence of inflammatory infiltrate and giant cells at the A1 implant site and presence of bone neoformation at the A3 implant site were noted. Degeneration of implants and formation of a fibrous capsule were noted. When comparing the interaction of the site with the days of evaluation, statistical analysis showed a significant difference (p≤0.05) in any time of neovascularization analysis. The vascular endothelial growth factor (VEGF) and inflammatory cells of the omentum in its structure, may have contributed to the greater presence of neovessels and inflammatory cells, a fact that may indicate functionality as a possible bone substitute.(AU)

O objetivo deste estudo foi avaliar a neovascularização de xenoenxertos bovinos implantados em sítios intracorpóreos de coelhos (biorreatores). Foram utilizados 30 coelhos, os quais foram divididos em seis grupos, de acordo com o tempo de avaliação (sete, 15, 30, 45 e 60 dias); cada animal recebeu implantes xenogênicos em três diferentes sítios intracorpóreos (A1 - bolsa de omento; A2 - espaço intermuscular do quadríceps femoral; A3 - subperiosteal do osso ílio). Avaliações histológicas classificaram a presença de angiogênese, o número de células inflamatórias, de tecido ósseo neoformado e a presença de células gigantes. As análises histológicas mostraram intensa angiogênese em todos os xenoenxertos implantados. Observou-se presença de infiltrado inflamatório e células gigantes no local do implante A1 e presença de neoformação óssea no local do implante A3. Ao mesmo tempo, a degeneração dos implantes e a formação de uma cápsula fibrosa foram observadas. Ao comparar a interação do local com os dias de avaliação, a análise estatística mostrou diferença significativa (P≤0,05) em qualquer momento da análise de neovascularização. O fator de crescimento endotelial vascular (VEGF) e as células inflamatórias do omento em sua estrutura podem ter contribuído para a maior presença de neovasos e células inflamatórias, fato que pode indicar funcionalidade como possível substituto ósseo.(AU)

Masquelet-Induced Membrane Characteristics in Chicken Radii Bone Defects.

This study evaluated the formation of a Masquelet-induced membrane created through the formation of segmental bone defects in the radii of 15 healthy domestic chickens. When the chickens were in a surgical plane of anesthesia, a 1.5-cm segmental bone defect was produced in the left radius, which was subsequently filled with a bone cement spacer during its pasty polymerization phase. The bone defects were evaluated through radiographic imaging immediately after surgery and at 7, 15, 21, and 30 days after the creation of the bone defect. Five birds were euthanatized at 15, 21, and 30 days postoperatively for histological evaluation of the bone defect site. Immediate postoperative radiographic examination of the radii showed the presence of bone cement, which occupied the segmental bone defect. Thirty days after the surgical procedure, the presence of new bone formation at the fractured extremities was evident in the 5 remaining chickens. Histologically, the induced-membrane had 3 distinct zones at 15 days postoperatively, including 1 cell layer in contact with the bone cement spacer, 1 layer with collagen fibers, and 1 layer in contact with muscle, which was composed of disorganized connective tissue, active fibroblasts, and blood vessels. Twenty-one days after surgery, the zones were less defined, and there were metaplastic areas comprising cartilage and bone. Postoperative, diffuse mineralization of the membrane was observed 30 days after the surgical procedure. Formation of the induced membrane was observed during all periods of evaluation. The best histological characteristics for the Masquelet-induced membrane were detected 15 days after the formation of the bone defect, suggesting this would be the optimal time for second-stage surgery for bone reconstruction.

Use of three-dimensionally printed ß-tricalcium phosphate synthetic bone graft combined with recombinant human bone morphogenic protein-2 to treat a severe radial atrophic nonunion in a Yorkshire terrier.

OBJECTIVE: To describe a novel surgical approach to treat a critical-sized bone defect due to severe, radial atrophic nonunion in a miniature dog. STUDY DESIGN: Case report ANIMAL: A 1-year-old Yorkshire terrier with a critical-sized left radial defect after failed internal fixation of a transverse radial fracture. METHODS: Computed tomographic (CT) images of the radius were imported for three-dimensional (3D) printing of a custom-designed synthetic 3D-printed ß-tricalcium phosphate (ß-TCP) scaffold. The radius was exposed, and the ß-TCP scaffold was press-fitted in the bone gap underneath the plate. Recombinant human bone morphogenic protein-2 (RhBMP-2) collagen sponges were squeezed to soak the scaffold with growth factor and then placed on both sides of the synthetic graft. Two additional cortical screws were also placed prior to routine closure of the surgical site. RESULTS: Radiographic examination was consistent with complete healing of the radius defect 4 months after surgery. The bone plate was removed 10 months after surgery. According to CT examination 18 months after surgery, there was no evidence of the synthetic graft; instead, complete corticalization of the affected area was noted. Complete functional recovery was observed until the last clinical follow-up 36 months postoperatively. CONCLUSION: Screw fixation and use of a 3D-printed ceramic scaffold augmented with rhBMP-2 resulted in excellent bone regeneration of the nonunion and full recovery of a miniature breed dog. CLINICAL SIGNIFICANCE: The therapeutic approach used in this dog could be considered as an option for treatment of large-bone defects in veterinary orthopedics, especially for defects affecting the distal radius of miniature dogs.

Região metafisária da tíbia de coelhos: uma opção para estudos dos substitutos ósseos / Metaphyseal region of the tibia of rabbits: an option for bone substitutes studies

Apresenta-se um modelo experimental de ostectomia de tíbia em coelhos para estudo de biomateriais em processos de reparação óssea. Foi realizada falha segmentar de 6mm de diâmetro na região metafisária medial proximal de tíbia de 72 coelhos as quais foram preenchidas com substituto ósseo e avaliadas clinicamente, por exame radiográfico e por meio de tomografia computadorizada feixe cônico, em diferentes tempos. Conclui-se que a metáfise medial proximal de tíbia de coelhos é adequada como modelo para estudos que avaliem o comportamento de enxertos e/ou biomateriais em falhas ósseas.

Is presented an experimental model of tibial ostectomy in rabbits to study biomaterials during bone repair process. Segmental failure of 6 mm diameter was performed in the medial proximal tibial metaphyseal region of 72 rabbits, which were filled with bone substitute and evaluated by clinical exam, X-ray, and cone beam computed tomography at different times. It is concluded that the medial proximal tibial metaphysis region of rabbits is suitable as a model for studies that evaluate the behavior of grafts and/or biomaterials on bone defects.

Use of a morcellized fragment of bone as a bone graft in a femoral fracture repair / Uso de fragmento ósseo morcelizado como enxerto ósseo no reparo de fratura femoral

As one of the most frequent reasons for presentation at the orthopedic services in veterinary practice, long bone fractures need bone continuity for consolidation to take place. This case report has demonstrates the use of a morcellized fragment of bone as a bone graft in a femoral fracture with major bone loss. A mixed-breed adult cat with a segmental femoral fracture with a large longitudinal fissure in the central bone fragment was submitted to an interlocking nail osteosynthesis. During the procedure a fracture occurred along the fissure resulting in two bone fragments with significant bone loss. Fragments were morcellized and applied over the defect to act as a bone graft. By the 15th day after the surgery, the cat had a normal gait and showed no pain response, and bone consolidation occurred after 7 months. Once harvesting of humeral, femoral and tibial bone grafts can be frustrating in cats, resulting in just small amounts of bone, the morcellation of the central fragments was vital to provide sufficient graft to cover the big defect in the femoral shaft. The authors suggest that autologous fresh morcellized cortical bone fragments can be an adjunct to the treatment of comminuted fractures in cats, as an alternative to more traditional repairs of comminuted fracture.

Fraturas de ossos longos necessitam de continuidade óssea para que a consolidação ocorra. Este relato de caso tem como objetivo demonstrar o uso de um fragmento ósseo morcelizado com a função de enxerto ósseo em uma fratura de fêmur com presença de uma grande falha óssea entre os fragmentos. Um gato adulto, sem raça definida, com uma fratura múltipla em fêmur com presença de uma fissura longitudinal no fragmento central foi submetido à osteossíntese com uso de haste bloqueada. Durante o processo, ocorreu uma fragmentação a partir da fissura, o que resultou na presença de dois fragmentos ósseos com uma grande porção de perda óssea entre os dois. Os fragmentos ósseos restantes do fragmento central foram morcelizados e aplicados no defeito para atuar com enxerto ósseo. Quinze dias após a cirurgia o paciente apresentou apoio normal e ausência de dor, e consolidação óssea ocorreu em 7 meses pós operatórios. Uma vez que a coleta de enxerto nos gatos resulta em pouca quantidade de osso, a morcelização do fragmento central foi vital para promover enxerto suficiente para cobrir o defeito ósseo. Os autores sugerem que o uso de enxerto cortical autólogo fresco morcelizado pode ser um adjuvante no tratamento de fraturas cominutivas em gatos, como um tratamento alternativo à terapia convencional.

Aloenxertos ósseos e enxerto sintético de hidroxiapatita em falha óssea ulnar em galinhas (Gallus gallus domesticus), aspectos radiográficos e histológicos / Bone allografts and synthetic grafts hydroxyapatite on ulnar bone defect in fowl (Gallus gallus domesticus), radiographic and histological aspects

Dos atendimentos ortopédicos realizados em aves no HCV-UFRGS, 86% são fraturas, sendo aproximadamente 30% delas cominutivas com perda óssea expressiva, justificando a importância da utilização de enxertos em fraturas de aves. O objetivo deste trabalho foi avaliar dois aloenxertos e enxerto sintético de hidroxiapatita em defeito ósseo de galinhas. Utilizaram-se 30 galinhas separadas em três grupos: aloenxerto congelado em ultra-freezer (GUF), aloenxerto congelado em nitrogênio líquido (GNL) e enxerto sintético de hidroxiapatita deficiente em cálcio (GHA). Nos três grupos, os enxertos foram aplicados com placas e parafusos bloqueados de 2mm na ulna direita das aves, avaliando-se a evolução por meio de exames radiográficos até serem completados 90 dias de pós-operatório e o resultado final mediante exame histológico. A média e desvio-padrão relacionando o tempo de consolidação óssea radiográfica foi: GNL 61,67±21,79 dias (90% de consolidação), GUF 47,14±13,50 dias (70% de consolidação) e GHA 70±18,17 dias (60% de consolidação). Houve diferença significativa no tempo de consolidação óssea entre o GUF e o GHA. Histologicamente, os enxertos do GUF foram os que estavam em consolidação mais avançada. Os aloenxertos do GNL foram superiores no preenchimento de falha óssea ulnar de galinhas.(AU)

Of the orthopedic visits performed on birds at HCV-UFRGS, 86% are fractures, and approximately 30% of them are comminuted with expressive bone loss, justifying the importance of the use of grafts in bird fractures. The objective of this work was to test two allografts and a synthetic HADC graft on finishing in Gallus gallus domesticus. 30 laying hens were used, divided in three groups: frozen allograft in ultrafreezer (UFG); frozen allograft in liquid nitrogen (LNG); calcium deficient synthetic hydroxyapatite graft (HAG). The three graft groups were exposed to serial radiographs until the 90 postoperative days, as well as the histological examination at the end of the experiment were: LNG 61.67±21.79 days (90% consolidation), UFG 47.14±13.50 days (70% consolidation) and HAG 70±18.17 days (60% consolidation). There was a significant difference in bone healing time between GUF and GHA. Histologically, GUF grafts were the ones that were in the most advanced consolidation. LNG allografts were superior in filling ulnar bone failure of fowl.(AU)

Use of a morcellized fragment of bone as a bone graft in a femoral fracture repair / Uso de fragmento ósseo morcelizado como enxerto ósseo no reparo de fratura femoral

As one of the most frequent reasons for presentation at the orthopedic services in veterinary practice, long bone fractures need bone continuity for consolidation to take place. This case report has demonstrates the use of a morcellized fragment of bone as a bone graft in a femoral fracture with major bone loss. A mixed-breed adult cat with a segmental femoral fracture with a large longitudinal fissure in the central bone fragment was submitted to an interlocking nail osteosynthesis. During the procedure a fracture occurred along the fissure resulting in two bone fragments with significant bone loss. Fragments were morcellized and applied over the defect to act as a bone graft. By the 15th day after the surgery, the cat had a normal gait and showed no pain response, and bone consolidation occurred after 7 months. Once harvesting of humeral, femoral and tibial bone grafts can be frustrating in cats, resulting in just small amounts of bone, the morcellation of the central fragments was vital to provide sufficient graft to cover the big defect in the femoral shaft. The authors suggest that autologous fresh morcellized cortical bone fragments can be an adjunct to the treatment of comminuted fractures in cats, as an alternative to more traditional repairs of comminuted fracture.

Fraturas de ossos longos necessitam de continuidade óssea para que a consolidação ocorra. Este relato de caso tem como objetivo demonstrar o uso de um fragmento ósseo morcelizado com a função de enxerto ósseo em uma fratura de fêmur com presença de uma grande falha óssea entre os fragmentos. Um gato adulto, sem raça definida, com uma fratura múltipla em fêmur com presença de uma fissura longitudinal no fragmento central foi submetido à osteossíntese com uso de haste bloqueada. Durante o processo, ocorreu uma fragmentação a partir da fissura, o que resultou na presença de dois fragmentos ósseos com uma grande porção de perda óssea entre os dois. Os fragmentos ósseos restantes do fragmento central foram morcelizados e aplicados no defeito para atuar com enxerto ósseo. Quinze dias após a cirurgia o paciente apresentou apoio normal e ausência de dor, e consolidação óssea ocorreu em 7 meses pós operatórios. Uma vez que a coleta de enxerto nos gatos resulta em pouca quantidade de osso, a morcelização do fragmento central foi vital para promover enxerto suficiente para cobrir o defeito ósseo. Os autores sugerem que o uso de enxerto cortical autólogo fresco morcelizado pode ser um adjuvante no tratamento de fraturas cominutivas em gatos, como um tratamento alternativo à terapia convencional.

Sinocutaneous fistula repair with a masseter muscle transposition flap combined with wound matrix and cancellous bone graft in a horse: A new technique.

OBJECTIVE: To describe a new technique to repair a sinocutaneous fistula with a masseter muscle transposition flap. STUDY DESIGN: Case report. ANIMAL: One 13-year-old thoroughbred stallion. METHODS: One 13-year-old stallion with a 3.5 × 6-cm sinocutaneous fistula over the right caudal maxillary sinus was treated with a transpositional masseter muscle flap. This repair consisted of a commercial wound matrix dressing placed directly over the hole in the maxilla and secured with suture material; a cancellous bone graft collected from the right tuber coxa placed on the dressing; and a portion of the superficial layer of the masseter muscle, with its pedicle at the facial crest, transposed dorsally over the bone graft, followed by a rotational skin flap with skin rostral to the fistula to close the defect. RESULTS: Seroma formation and dehiscence of the skin flap occurred, but the transposed muscle flap survived, and the technique resulted in successful closure of the sinocutaneous fistula with excellent cosmetic and functional outcome. CONCLUSION: A chronic maxillary sinocutaneous fistula was successfully treated by using a transposition flap of the masseter muscle and a rotational skin flap with minor complications. CLINICAL IMPACT: Transposition of the superficial layer of the masseter muscle should be considered for a repair of large maxillary sinocutaneous fistulas in horses.

Advances in Exotic Animal Osteosynthesis.

Exotic animal orthopedics has not incorporated the most recent progress made in small animal surgery or human medicine. Although minimally invasive osteosynthesis has been incorporated as a routinely used alternative in small animals, its use in exotic animals is still in its infancy. This article compliments the reviews of orthopedics in small mammals, birds, and reptiles in the previous issue. It reviews relevant recent studies performed in laboratory animals about new orthopedic materials and techniques showing potential to become incorporated into the routine orthopedic treatment of exotic animals in the coming years.

Guided Tissue Regeneration Therapy With Bone Augmentation in a Lingual, Infrabony Osseous Defect of a Mandibular Canine.

This case report describes the use of canine demineralized freeze-dried membrane allograft and cancellous bone graft material to treat an infrabony osseous defect along the lingual aspect of a left mandibular canine in a 10-year-old miniature dachshund. Postoperative examination 6 and 12 months postoperatively showed osseous integration at the infrabony defect and improvement in periodontal probing measurements.

Lateral manus translation for limb-sparing surgery in 18 dogs with distal radial osteosarcoma in dogs.

OBJECTIVE: To describe and report outcomes after lateral translation of the manus for limb-sparing management of distal radial osteosarcoma in dogs. STUDY DESIGN: Retrospective case series. STUDY POPULATION: Eighteen client-owned dogs. METHODS: The distal aspect of the affected radius and associated neoplastic tissues were excised. The distal aspect of the ulna was preserved except for its medial cortex, which was removed en bloc with the radial segment. The manus was translated laterally to place the radial carpal bone in contact with the distal aspect of the ulna. A limb-sparing or locking compression plate was placed on the remaining proximal radius and the 3rd metacarpal bone. A 3.5-mm SOP (string of pearls) plate was placed on the lateral aspect of the proximal ulna and the 4th metacarpal bone. Dogs were administered chemotherapy. Data were collected to assess surgical and oncologic outcomes. Limb function was subjectively assessed. RESULTS: The percentage of radius removed ranged from 43% to 94% (median 54%). Complications developed in 12 limbs, with infection in 10, biomechanical complications in 6, and local recurrence in 4. Limb function was subjectively assessed as acceptable. Median disease-free interval was 219 days, and median survival time was 370 days. CONCLUSION: Outcomes after lateral translation of the manus compared favorably to other limb-sparing techniques for dogs with distal radial osteosarcoma, particularly in dogs requiring excision of a large segment of the radius. CLINICAL SIGNIFICANCE: The lateral manus translation provides an alternative limb-sparing technique that does not require an allograft, endoprosthesis, or autograft.

Use of cancellous bone grafting to promote granulation tissue in a distal limb wound in a dog.

A 5-year-old female spayed Shetland sheepdog presented for evaluation of bandage sores on the left pelvic limb after a splint was placed to stabilise a digit fracture incurred approximately 2 weeks previously. Multiple areas of necrosis were identified upon bandage removal. After debridement of devitalised tissue, a 4 cm wound on the plantar surface of the metatarsal bones (with exposed bone and tendons) remained. The Papineau technique (which involves removal of infected or necrotic tissue, placement of autogenous cancellous bone graft within a wound, and delayed skin closure) was used to treat this wound. Use of bone graft in this manner aims to promote early granulation tissue formation and reduce the time until wound reconstruction can be performed. Autogenous cancellous bone graft was harvested from the proximal humerus and placed within the metatarsal wound. Once a healthy granulation tissue bed was noted to cover the bone graft, a meshed full thickness skin graft was placed. To our knowledge, this is the first report of the Papineau technique being used for this purpose in a dog.

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)

A large animal model for standardized testing of bone regeneration strategies.

BACKGROUND: The need for bone graft substitutes including those being developed to be applied together with new strategies of bone regeneration such as tissue engineering and cell-based approaches is growing. No large animal model of bone regeneration has been accepted as a standard testing model. Standardization may be the key to moving systematically towards better bone regeneration. This study aimed to establish a model of bone regeneration in the sheep that lends itself to strict standardization and in which a number of substances can be tested within the same animal. To this end the caudal border of the ovine scapula was used as a consistent bed of mineralized tissue that provided sufficient room for a serial alignment of multiple experimental drill holes. RESULTS: The findings show that for the sake of standardization, surgery should be restricted to the middle part of the caudal margin, an area at least 80 mm proximal from the Glenoid cavity, but not more than 140 mm away from it, in the adult female Land Merino sheep. A distance of 5 mm from the caudal margin should also be observed. CONCLUSIONS: This standardized model with defined uniform defects and defect sites results in predictable and reproducible bone regeneration processes. Defects are placed unilaterally in only one limb of the animal, avoiding morbidity in multiple limbs. The fact that five defects per animal can be evaluated is conducive to intra-animal comparisons and reduces the number of animals that have to be subject to experimentation.

Sheep embryonic stem-like cells engrafted into sheep femoral condyle osteochondral defects: 4-year follow-up.

BACKGROUND: Articular cartilage lacks a regenerative response. Embryonic stem cells (ESCs) are a source of pluripotent cells for cartilage regeneration. Their use, however, is associated with a risk of teratoma development, which depends on multiple factors including the number of engrafted cells and their degree of histocompatibility with recipients, the immunosuppression of the host and the site of transplantation. Colonies of sheep embryonic stem-like (ES-like) cells from in vitro-produced embryos, positive for stage-specific embryonic antigens (SSEAs), alkaline phosphatase (ALP), Oct 4, Nanog, Sox 2 and Stat 3 gene expression, and forming embryoid bodies, were pooled in groups of two-three, embedded in fibrin glue and engrafted into osteochondral defects in the left medial femoral condyles of 3 allogeneic ewes (ES). Empty defects (ED) and defects filled with cell-free glue (G) in the condyles of the controlateral stifle joint served as controls. After euthanasia at 4 years post-engraftment, the regenerated tissue was evaluated by macroscopic, histological and immunohistochemical (collagen type II) examinations and fluorescent in situ hybridization (FISH) assay to prove the ES-like cells origin of the regenerated tissue. RESULTS: No teratoma occurred in any of the ES samples. No statistically significant macroscopic or histological differences were observed among the 3 treatment groups. FISH was positive in all the 3 ES samples. CONCLUSIONS: This in vivo preclinical study allowed a long-term evaluation of the occurrence of teratoma in non-immunosuppressed allogeneic adult sheep engrafted with allogeneic ES-like cells, supporting the safe and reliable application of ES cells in the clinic.

Surgical management of long bone fractures in cats using cortical bone allografts preserved in honey.

This report describes comminuted fractures in 2 cats repaired by stabilization with cortical bone allografts that had been preserved in honey. Both cats exhibited appropriate post-operative weight-bearing. Preservation of bone in honey is a simple and widely available alternative for bone banking. This is the first report of a bone defect in cats repaired with bone preserved in honey.

Gestion chirurgicale de fractures osseuses longues chez les chats à l'aide d'une allogreffe de la corticale préservée dans du miel. Ce rapport décrit deux fractures comminutives réparées par la stabilisation à l'aide de l'allogreffe de la corticale qui avait été préservée dans du miel. Les deux chats ont manifesté une mise en charge postopératoire appropriée. La préservation de l'os dans du miel est une méthode de remplacement simple et facilement disponible comme ostéothèque. Il s'agit du premier rapport d'un défaut osseux chez des chats qui a été réparé à l'aide d'un os préservé dans du miel.(Traduit par Isabelle Vallières).