Erythropoietin as promoter of engraftment for treatment of radius/ulnar non-union fracture in a dog: Case report.

Background: Fractures with large bone defects and non-unions are a great challenge for veterinary orthopaedists. In small dog breeds, this complication is commonly encountered in fractures of the radius and ulna due to poorer vascularisation of the distal antebrachium region. Case Description: A case of radius/ulnar non-union in a 1.5-year-old Pinscher occurring after trauma and two successive unsuccessful osteosyntheses is described. During the operative revision, after the removal of existing bone implants, the bone defect was filled with cortical autologous bone graft. Autocancellous bone mixed with erythropoietin was applied proximally and distally to the cortical autograft for stimulation of bone healing. The post-operative period was without complications. As early as the 9th post-operative week, the animal was able to bear weight on the limb, without signs of lameness, pain, and swelling. Radiologically, a very good bridging of the graft was observed. Fifteen weeks after the operative revision, the fracture was completely healed with excellent clinical outcome. Conclusion: The application of autogenous cortical bone graft and cancellous autograft mixed with erythropoietin demonstrated an excellent therapeutic effect and resulted in complete regeneration of the large bone defect over a 15-week period.

Successful centralisation technique for treatment of post-traumatic absence of the radial shaft in a dog.

This report describes a centralisation procedure for the treatment of a radial non-union, characterised by extensive bone loss and an intact ulna, in an 18-month-old toy poodle. A lateral approach to the radius/ulna shafts was realised and, after debridement of the non-union site, an ulnar osteotomy was performed proximal to the styloid process of the ulna. Transposition of the distal fragment of the radius to the distal end of the osteotomised proximal segment of the ulna was performed and the stabilisation was obtained using a locking plate with proximal screws in the ulnar shaft and distal screws in the radius epiphysis. The patient achieved bone union in 10 weeks and the last evaluation, performed 112 weeks postoperatively, showed a full return to pre-injury function. Based on the results of this report, the centralisation was effective in the treatment of post-traumatic absence of the radial shaft in a dog.

Elucidation of the radius and ulna fracture mechanisms in toy poodle dogs using finite element analysis.

Fractures occurring in the distal radius and ulna of toy breed dogs pose distinctive challenges for veterinary practitioners, requiring specialized treatment approaches primarily based on anatomical features. Finite Element Analysis (FEA) was applied to conduct numerical experiments to determine stress distribution across the bone. This methodology offers an alternative substitute for directly investigating these phenomena in living dog experiments, which could present ethical obstacles. A three-dimensional bone model of the metacarpal, carpal, radius, ulna, and humerus was reconstructed from Computed Tomography (CT) images of the toy poodle and dachshund forelimb. The model was designed to simulate the jumping and landing conditions from a vertical distance of 40 cm to the ground within a limited timeframe. The investigation revealed considerable variations in stress distribution patterns between the radius and ulna of toy poodles and dachshunds, indicating notably elevated stress levels in toy poodles compared to dachshunds. In static and dynamic stress analysis, toy poodles exhibit peak stress levels at the distal radius and ulna. The Von Mises stresses for toy poodles reach 90.07 MPa (static) and 1,090.75 MPa (dynamic) at the radius and 1,677.97 MPa (static) and 1,047.98 MPa (dynamic) at the ulna. Conversely, dachshunds demonstrate lower stress levels for 5.39 MPa (static) and 231.79 MPa (dynamic) at the radius and 390.56 MPa (static) and 513.28 MPa (dynamic) at the ulna. The findings offer valuable insights for modified treatment approaches in managing fractures in toy breed dogs, optimizing care and outcomes.

Outcomes of 11 dogs with short radius syndrome treated with acute arthroscopically assisted ulnar shortening.

OBJECTIVE: To describe the short-term outcome of acute arthroscopically assisted ulnar shortening (AUS), to treat short radius syndrome in dogs. STUDY DESIGN: Case series. ANIMALS: Eleven client owned dogs. METHODS: Records of dogs that had undergone AUS for treatment of short radius syndrome were reviewed for inclusion. Reporting data included among others pre- and postoperative radioulnar, humeroradial and humeroulnar distances, lameness scores, surgical times, complications and clinical outcome. RESULTS: Following AUS, radiohumeral articulation was improved in all dogs. Median presurgery radioulnar, humeroradial and humeroulnar values were 4.5, 3.2, and 2.2 mm and were improved with surgery by a median of 3.2, 1.8, and 1.2 mm, respectively. Median surgery time was 140 min. Median time to bone healing was 8 weeks (range: 4-14). Median time to last follow-up was 9 weeks (4-468). Median lameness score (scale 0-4) improved from 2 to 1. No major complications were reported. Short-term clinical outcome was graded by the surgeons as full function in four cases and acceptable function in seven. CONCLUSION AND CLINICAL RELEVANCE: Radiographic and arthroscopic radiohumeral articulation were improved and short-term clinical improvement was documented following AUS in all 11 dogs.

Delayed union, non-union and mal-union in 442 dogs.

OBJECTIVES: (1) To estimate the prevalence of delayed union, non-union and mal-union in canine fractures; (2) to describe fracture, demographic, and treatment characteristics for these outcomes; (3) to identify risk factors for delayed or non-union. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Four hundred and forty two dogs (461 fractures). METHODS: A review was conducted of clinical records and radiographs from 2 teaching hospitals. "Union," "delayed union," "non-union" and "mal-union" were defined, and fracture, demographic, treatment, and outcome variables described. Differences in proportions or medians between "union," "delayed union" and "non-union" were tested using χ2 and Mann-Whitney U-tests for categorical and continuous variables respectively. Potential explanatory variables for "delayed or non-union" were tested using logistic regression to identify risk factors. RESULTS: Median radiographic follow up was 53 days (14-282). Delayed union occurred in 13.9% of fractures (64/461), non-union in 4.6% (21/461), and mal-union in 0.7% (3/461). Risk factors for delayed or non-union were age (OR 1.21, 95% CI 1.12-1.31); comminuted fracture (OR 4.24, 95% CI 2.4-7.5); treatment with bone graft (all types) (OR 3.32, 95% CI 1.3-8.5); surgical site infection (OR 3.24, 95% CI 1.17-8.97), and major implant failure (OR 12.94, 95% CI 5.06-33.1). CONCLUSION: Older dogs, dogs with comminuted fractures, surgical site infection, or major implant failure were at increased odds of delayed or non-union. Radius and ulna fractures in toy breed dogs were not at increased odds of delayed or non-union. CLINICAL SIGNIFICANCE: The identified risk factors should inform fracture planning and prognosticating. The prognosis for radial fractures in toy breeds appears better than historically believed.

Use of coccygeal vertebra autograft and platelet-rich plasma for treating a distal radial nonunion fracture in a small-breed dog.

A 4.3-kg, 11-month-old, spayed female poodle was presented for treatment of a right radio-ulnar nonunion fracture. Clinical history included failed surgical correction of a radius fracture with internal fixation 1 mo before presentation. Radiographic examination revealed a 1.5-cm lytic lesion on the right distal radius. Surgery was planned with a coccyx autograft and platelet-rich plasma. A 2.8-cm-long bone defect was created, and the lytic lesion was removed. Caudectomy was performed; the 6th and 7th coccygeal bones were harvested, placed into the defect, and fixed to the radius with a locking plate. Remnants of coccygeal bone were ground, mixed with platelet-rich plasma, and used to fill the bone defects. There was no evidence of nonunion or delayed union at the 18-month follow-up examination. Key clinical message: Based on the study findings, we inferred that a coccyx autograft and platelet-rich plasma can be used for successful reconstruction of a distal radial defect.

Utilisation d'une autogreffe de vertèbre coccygienne et de plasma riche en plaquettes pour le traitement d'une fracture radiale distale avec non-union chez un chien de petite race. Une femelle caniche stérilisée de 4,3 kg, âgée de 11 mois, a été présentée pour le traitement d'une fracture radio-ulnaire droite avec non-union. Les antécédents cliniques comprenaient l'échec de la correction chirurgicale d'une fracture du radius avec fixation interne 1 mois avant la présentation. L'examen radiographique a révélé une lésion lytique de 1,5 cm sur le radius distal droit. La chirurgie était prévue avec une autogreffe de coccyx et du plasma riche en plaquettes. Un défaut osseux de 2,8 cm de long a été créé et la lésion lytique a été retirée. Une caudectomie a été réalisée; les 6e et 7e os coccygiens ont été prélevés, placés dans le défaut et fixés au radius avec une plaque de verrouillage. Les restes d'os coccygien ont été broyés, mélangés avec du plasma riche en plaquettes et utilisés pour combler les défauts osseux. Il n'y avait aucune évidence de non-union ou de retard de consolidation lors de l'examen de suivi à 18 mois.Message clinique clé :Sur la base des résultats de l'étude, nous avons déduit qu'une autogreffe de coccyx et du plasma riche en plaquettes peuvent être utilisés pour une reconstruction réussie d'un défaut radial distal.(Traduit par Dr Serge Messier).

A Retrospective Study of Postoperative Development of Implant-Induced Osteoporosis in Radial-Ulnar Fractures in Toy Breed Dogs Treated with Plate Fixation.

OBJECTIVE: This study aimed to evaluate implant-induced osteoporosis (IIO) development in toy breed dogs treated using internal fixation with digital radiographs as the index of pixel values. STUDY DESIGN: There were 226 cases (236 limbs) of toy breed dogs with radial-ulnar fractures. Pixel values were measured on radiographs immediately, 2 weeks and 1 to 12 months after surgery. The ratio of pixel values (PVR) represented the bone mineral areal density based on the humeral condyle in the same image. The dogs were grouped based on the fixation methods, age and status of destabilization. RESULTS: There was a significant decrease in the PVR at 1 to 12 months postoperatively for all cases. There were not any significant differences in PVR of antebrachial fractures between those repaired with plates using locking head screws, cortex screws or a combination of locking and cortex screws. Implant-induced osteoporosis persisted at 1 to 12 months postoperatively in dogs aged ≧6 months, while the PVR increased after 3 months in dogs aged <6 months. Based on the destabilization method, there was a significant increase in the PVR at 3 months in the plate removal group. CONCLUSION: This study suggests that IIO occurs in small dogs treated with plates and screws. Moreover, patients aged < 6 months showed an early postoperative recovery of bone mineral areal density. Further, screw and plate removal could contribute to the recovery of bone mineral areal density.

Clinical outcomes of orthogonal plating to treat radial and ulnar fractures in toy-breed dogs.

OBJECTIVES: To describe the results of orthogonal plating (OP) as a treatment for fractures of the radius and ulna in toy-breed dogs. MATERIALS AND METHODS: The medical records (June 2011 to April 2019) of toy-breeds in which the OP technique using non-locking cuttable plates was employed to treat radial and ulnar fractures were reviewed. The inclusion criteria included a bodyweight of 3.5 kg or less, fracture of the diaphysis of the radius and ulna of one or both forelimbs, and the availability of follow-up radiographs. Revision surgeries were also included. RESULTS: Fifteen limbs that underwent initial fracture repair and five that underwent revision surgery met the inclusion criteria. The radial and ulnar fractures healed in 19 limbs at the final follow-up. Synostosis of the radius and ulna at the fracture sites was observed in one limb. Re-fracture after cranial plate removal was observed in one case. All dogs exhibited successful return of normal limb function at the final clinical and radiographic follow-up (mean, 104.7 ± 67.1 days; median, 79.5 days; range: 35 to 248 days). Long-term follow-up data obtained via telephone interviews to owners or referring veterinarians were available for 15 cases and confirmed maintenance of normal limb function in all dogs (mean, 32.5 ± 17.6 months; median, 26 months; range: 11 to 69 months). CLINICAL SIGNIFICANCE: OP allowed the successful open reduction of radial and ulnar fractures, facilitating bone union in both the radius and ulna and a return to normal limb function in a series of toy-breed dogs.

Congenital elbow luxation grade I treated by radial head ostectomy in an English Bulldog / Luxação congênita de cotovelo grau I tratada por ostectomia da cabeça do rádio em um Bulldog Inglês

The aim of this study is to report a long term follow up of a congenital luxation of the radial head (CLRH) case of a young Bulldog treated by radio head ostectomy (RHO). CLRH is an uncommon condition in dogs, but it is the most commom form of elbow dislocation (grade I). An English Bulldog, male, 6 months, 14 kilograms, was suspected of elbow dislocation. Physical examination revealed a lateral proeminence on the lateral surface of the right elbow, as well as grade I lameness and mild pain. Range of motion was normal. Previous radiographs and tomography confirmed CLHR. RHO was chosen instead of corrective techniques, due to the age of the animal at the time of the procedure and the difficulty in repositioning the radial head in the joint. Three and a half years after surgery, new clinical and radiographic examaminations were performed. The patient had no pain, good limb support and good range of motion, allowing good elbow movement. There was a partial regrowth of the proximal segment of the radial head causing better readjustment of it in the joint. Mild signs of joint degeneration were present. RHO proved to be effective in this case, proving to be a good technique to be used in cases of CLRH when conservative treatment or reduction techniques can no longer be used.

O objetivo deste relato foi o de apresentar o acompanhamento tardio de um caso de luxação congênita de cabeça de rádio (LCCR) em um Buldog Inglês jovem, tratada por ostectomia da cabeça radial (OCR). A LCCR é uma condição incomum nos cães, mas é a forma mais comum de luxação de cotovelo nos mesmos (grau I). Um Bulldog Inglês, macho, 6 meses, 14 quilos, foi atendido com suspeita de luxação do cotovelo. Exame físico revelou uma proeminência na superfície lateral do cotovelo direito, além de claudicação grau I e dor leve. Amplitude de movimento apresentava-se normal. Radiografias e tomografia prévias confirmaram LCCR. Optou-se pela OCR ao invés de técnicas corretivas, devido à idade do animal à época do procedimento e à dificuldade no reposicionamento do rádio na articulação. Após 3 anos e meio de pós-operatório, foram realizados novos exames clínicos e radiográficos. O paciente não apresentava dor, apresentava bom apoio do membro e boa amplitude de movimento, permitindo bom movimento do cotovelo. Houve um novo crescimento parcial do segmento proximal da cabeça do rádio ocasionando melhor readequamento do mesmo na articulação. Sinais leves de degeneração articular estavam presentes. A OCR se mostrou efetiva neste caso, provando ser uma boa técnica a ser utilizada nos casos de LCCR quando tratamento conservativo ou técnicas de redução já não podem ser mais utilizados.

Biocompatibilidade do gel de quitosana associado ao glicerol fosfato na reparação de defeitos ósseos induzidos experimentalmente no rádio de coelhos (Oryctolagus cuniculus) / [Biocompatibility of chitosan gel associated with glycerol phosphate for the healing of experimentally induced radial defects in rabbits (Oryctolagus cuniculus)]

A engenharia de tecidos caracteriza-se como ciência interdisciplinar, a qual vem desenvolvendo biomateriais para a regeneração do tecido ósseo no âmbito das medicinas humana e veterinária. O objetivo desta pesquisa foi avaliar a regeneração óssea obtida da aplicação do hidrogel de quitosana associado ao glicerol fosfato em falha óssea experimentalmente induzida no rádio de coelhos. Foram utilizados 15 coelhos adultos, distribuídos aleatoriamente em dois grupos, representados por cada um dos rádios de cada animal, sendo um grupo tratado com hidrogel de quitosana associado ao glicerol fosfato (grupo biomaterial - GB) e um grupo que não recebeu tratamento com o biomaterial (grupo controle - GC). Os animais foram avaliados radiograficamente, por densitometria óptica e análise histológica, nos períodos 30, 60 e 90 dias pós-operatórios. Houve superioridade estatística na média geral das avaliações radiográficas do GB (2,33±0,48) sobre o GC (1,77±0,06). As médias gerais de avaliação densitométrica do GB foram superiores às do GC, sendo 6,207±1,374 e 5,71±1,512, respectivamente. A avaliação histopatológica do GB foi superior à do GC nos períodos de 30, 60 e 90 dias. Assim, é possível afirmar que o hidrogel de quitosana constitui biomaterial de características desejáveis, promovendo consolidação óssea mais rápida e eficiente, sem causar reações adversas.(AU)

Tissue engineering is an interdisciplinary science that has been developing biomaterials for bone regeneration in medicine and veterinary medicine, following an imminent need. The aim of this study was to evaluate bone regeneration after use of chitosan hydrogel associated with glycerol phosphate in experimentally induced bone gap in the radius of rabbits. Fifteen adult rabbits were randomly distributed in two experimental groups, represented by each radius of every single animal. The animals in the Biomaterial Group (GB) were treated with a glycerol phosphate-associated chitosan hydrogel and in the Control Group (GC) they received no treatment with the biomaterial. The animals were evaluated clinically, radiographically, histologically and by optic densitometry at 30, 60 and 90 days postoperatively. There was statistical superiority in the general average of the radiographic estimates of GB (2.33 ± 0.48) over the CG (1.77 ± 0.06). The general averages of GB densitometric evaluation were higher than the CG, being 6.207 ± 1.374 and 5.71 ± 1.512, respectively. Histopathological evaluation of GB was superior to CG in periods of 30, 60 and 90 days. Chitosan hydrogel constitutes a biomaterial of desired characteristics, promoting faster and more efficient bone repair when compared to GC.(AU)

Human placenta-derived matrix with cancellous autograft and demineralized bone matrix for large segmental long-bone defects in two dogs with septic nonunion.

OBJECTIVE: To report the successful treatment of septic nonunion in two dogs with large segmental defects secondary to long-bone fractures by using a novel human placenta-derived matrix (hPM) as adjunct to fixation. ANIMALS: One 3-kg 9-year-old neutered male Yorkshire terrier with a distal antebrachial fracture and one 6-kg 4-year-old spayed female miniature pinscher with a distal humeral fracture. STUDY DESIGN: Short case series. METHODS: Both dogs presented for septic nonunion after internal fixation of Gustilo type II open diaphyseal fractures from dog bite injuries. During revision, debridement of nonviable bone resulted in segmental defects of 32% and 20% of the bone length for the antebrachial and humeral fractures, respectively. The antebrachial fracture was stabilized with a circular external fixator, and the humeral fracture was stabilized with biaxial bone plating. The fracture sites were not collapsed, and full length was maintained with the fixation. Autogenous cancellous bone graft and canine demineralized bone allograft were packed into the defects, and hPM was injected into the graft sites after closure. RESULTS: Radiographic union was documented at 8 weeks and 6 weeks for the antebrachial and humeral fractures, respectively. Both dogs became fully weight bearing on the affected limbs and returned to full activity. CONCLUSION: Augmenting fixation with grafts and hPM led to a relatively rapid union in both dogs reported here.

Repair of a pathological radial fracture secondary to radioulnar ischemic necrosis in a dog.

CASE DESCRIPTION: A 3-year-old 2.5-kg (5.5-lb) sexually intact male Pomeranian was presented with a 1-day history of non-weight-bearing lameness of the right forelimb. CLINICAL FINDINGS: Signs of pain were localized to the proximal portion of the right antebrachium. Radiography revealed a minimally displaced fracture of the proximal portion of the radius that had propagated from a well-demarcated, ovoid, osteolytic lesion within the cortex of the caudolateral aspect of the radius. Computed tomographic findings supported the radiographic findings and did not reveal lesions in other evaluated body sites. TREATMENT AND OUTCOME: At surgery, the lateral aspect of the radial cortex appeared expanded, and tenacious fibrous tissue filled the gap between the fracture fragments. Fibrous tissue was resected and submitted for histologic examination, and the fracture was reduced and stabilized with a bone plate and a positional screw. Histologic examination revealed the presence of viable bone, fibrous tissue, and areas of coagulative necrosis. Imaging and histologic findings were consistent with radioulnar ischemic necrosis (RUIN). The patient ambulated normally at reexamination 12 days after surgery. At reexamination 15 weeks after surgery, the patient continued to ambulate normally, and radiography and CT indicated healing of the fracture and resolution of the RUIN lesion. CLINICAL RELEVANCE: RUIN should be considered as a differential diagnosis for a dog with forelimb lameness and radiographic focal osteolysis between the proximal and middle thirds of the diaphysis of the radius or ulna. Prognosis for dogs with RUIN may be good with surgical intervention.

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.

SUCCESSFUL REPAIR OF ANTEBRACHIAL FRACTURES WITH EXTERNAL SKELETAL FIXATION IN THREE MACROPODS.

Three captive macropods comprising three different species sustained unilateral antebrachial fractures. All fractures were assumed to be trauma related, although the specific circumstances surrounding each case was unknown. Each fracture was surgically repaired with type Ia (unilateral, monoplanar) external skeletal fixators, which were all removed approximately 3 mo postoperatively. Although each animal experienced at least one complication, all animals showed adequate bridging and remodeling at the fracture sites and had good-to-excellent return to normal function after fixator removal. This case series is the first to describe the successful repair of antebrachial fractures using external skeletal fixation in captive macropods and details some of the complications that can occur with postoperative management of captive animals.

Characteristics of antebrachial fractures associated with a successful outcome among free-ranging birds of prey that received treatment in a rehabilitation program.

OBJECTIVE: To identify characteristics of antebrachial fractures associated with a successful outcome (ie, bird released back into the wild after regaining normal flight ability, without being returned to the rehabilitation program within 1 month afterward) for free-ranging birds of prey admitted to a rehabilitation program. ANIMALS: 620 birds of prey (representing 24 species) with antebrachial fractures admitted alive to a rehabilitation program from August 1986 through December 2015. PROCEDURES: The medical record of each bird was reviewed to obtain information on species, age, sex, year of admission, fracture characteristics, and treatments administered. Outcome was classified as successful or unsuccessful on the basis of available data. Multivariable logistic regression was used to identify fracture characteristics associated with outcome. RESULTS: 519 of 620 (84%) birds received treatment, and a successful outcome was recorded for 245 (47%) treated birds. Birds with closed (vs open) fractures were significantly more likely to have a successful outcome. Birds with concomitant radial and ulnar fractures involving the same third of the antebrachium (vs other types of antebrachial fractures) were significantly less likely to have a successful outcome, although birds with this type of fracture were significantly more likely to have a successful outcome when the fracture was localized to the middle or distal (vs proximal) third of the antebrachium. CONCLUSIONS AND CLINICAL RELEVANCE: The characteristics of antebrachial fractures associated with a successful or unsuccessful outcome in this study may be useful in the development of triage protocols for birds of prey in other rehabilitation centers.

Release Rates and Complications for Birds of Prey With Antebrachial Fractures at a Veterinary Teaching Hospital.

A retrospective case series that included 253 free-ranging birds of prey admitted to a rehabilitation center was conducted to describe the treatment and outcome of antebrachial fractures. Medical records from birds of prey belonging to 21 species admitted with antebrachial fracture between 1989 and 2015 at the University of California, Davis, were reviewed. Species distribution on admission, treatment, outcome, and complications were described by fracture category and species. Among 134 birds treated after initial triage on the day of admission, 4 bone/ wing categories were identified: 83 birds had an ulnar fracture only; 18 birds had a radial fracture only; 28 birds had a concomitant fracture of the radius and ulna on the same wing; and 5 birds had bilateral antebrachial fractures. Logistic regressions were performed to determine which factors were associated with a positive outcome within each of these 4 categories. Among birds having only an ulnar fracture, those with a closed fracture were significantly more likely to be released than birds with open fractures (P = .03; odds ratio = 5.43, 95% confidence interval: 1.29-28.12). In addition, birds with a fracture of the middle third of the ulna were significantly more likely to be released than birds diagnosed with a single fracture of the proximal third of the ulna (P = .02; odds ratio = 4.54, 95% confidence interval: 1.35-16.64). No significant prognostic factor was detected in other fracture categories.

Bilateral radial and ulnar fractures in a red kangaroo (Macropus rufus).

CASE DESCRIPTION: An 11-month-old sexually intact male red kangaroo (Macropus rufus) was examined because of bilateral radial and ulnar fractures. CLINICAL FINDINGS: Radiography of the forelimbs revealed bilateral, short oblique fractures in the proximal to mid diaphyses of the radii and ulnae. Fractures were overriding and moderately displaced. Wider than expected gaps were evident in the humeroulnar and humeroradial joints bilaterally. Although several physes remained open, no proximal radial physis was radiographically evident. TREATMENT AND OUTCOME: Dual bone fixation was performed bilaterally, and dynamic luxation of the left radial head was identified and stabilized intraoperatively. Although satisfactory function of both forelimbs was evident at 8 weeks and 26 months after surgery, a persistent gait abnormality affecting the right forelimb was noted. Twenty-six months after surgery, radiography revealed bilateral proximal radial physes and resolution of the abnormally wide gaps in the humeroradial and humeroulnar joints. Despite dual bone fixation, synostoses formed bilaterally and may have contributed to the persistent lameness in the kangaroo's right forelimb. CLINICAL RELEVANCE: Veterinarians treating kangaroos should be aware of difficulties in determining skeletal maturity and planning fracture stabilization because of potential differences in skeletal growth and fracture healing, compared with other species. We described critical issues observed in the treatment and outcome of the kangaroo of the present report and provided lessons learned as well as potential explanations of these issues to facilitate future treatment of kangaroos with forelimb fractures.

A Biomechanical Comparison of Three Miniature Locking Plate Systems in a Rabbit Radial and Ulnar Fracture Model.

OBJECTIVE: The aim of this study was to evaluate the biomechanical properties of three different miniature locking plate systems used to fixate radial and ulnar fractures in toy breed dogs. Implant size, shape, material and locking systems differ, and their influence on the fracture healing process is unknown. In the present study, we aimed to investigate this matter in vivo using rabbit radial and ulnar fracture models. STUDY DESIGN: Eighteen rabbits were randomly divided into three groups, and the left radius and ulna were osteotomized to create fracture models. The osteotomies were then fixated using either the TITAN LOCK 1.5, Fixin micro or LCP 1.5 system. Radiographs were obtained 2, 3 and 4 weeks after surgery. Four weeks after surgery, the radiuses were collected and used for biomechanical testing or histological examinations. RESULTS: During the 4 weeks of observation, no adverse effects due to the implants occurred. The radiographic scores in each group did not differ significantly at any time point. The maximum load in the LCP group was significantly higher than that in the TITAN and Fixin groups. There was no significant difference in bending stiffness or work to failure among the groups. Initial fracture healing via woven bone was evident at histological evaluation. CONCLUSIONS: All three miniature locking plate systems provided adequate fracture stabilization 4 weeks after surgery, despite their differences, in rabbit models.

Clinical outcomes of 119 miniature- and toy-breed dogs with 140 distal radial and ulnar fractures repaired with free-form multiplanar type II external skeletal fixation.

OBJECTIVE: To report the clinical outcomes of miniature- and toy-breed dogs with primary and previously treated distal radial and ulnar fractures (RUF) treated with a free-form multiplanar type II external skeletal fixation (ESF). STUDY DESIGN: Retrospective study. ANIMALS: One hundred nineteen dogs with 140 distal RUF. METHODS: Medical records (2003-2017) were reviewed for dogs weighing up to 7 kg that had been treated for distal RUF with a free-form multiplanar type II ESF. Data collected included signalment, fracture location and configuration, fracture reduction, intraoperative realignment, time to bone union and implant removal, duration of destabilization and postoperative splint, complications, and outcomes. Follow-up consisted of clinical and radiographic evaluation or telephone interview. RESULTS: All fractures healed, with a median time of 60 days, and entire ESF was removed, with a median time of 89 days. Major complications occurred in four fractures: premature pin loosening, elbow subluxation, osteomyelitis, and delayed union. Minor complications occurred in 52 fractures (61 events). All dogs had a successful return to normal limb function at final follow-up (median, seven months; range, 2-97). CONCLUSION: All primary and previously treated distal RUF in miniature- and toy-breed dogs healed and allowed return to normal function after fixation with a free-form multiplanar type II ESF. CLINICAL SIGNIFICANCE: The free-form multiplanar type II ESF provides an alternative for minimally invasive fixation of distal RUF in miniature- and toy-breed dogs that facilitates fracture reduction, intraoperative realignment, adequate initial fixation stability, destabilization, and implant removal.

Biomechanical Properties of the 1.5 mm Locking Compression Plate: Comparison with the 1.5 and 2.0 mm Straight Plates in Compression and Torsion.

OBJECTIVES: The purpose was to compare the biomechanical properties of a 1.5 mm locking compression plate (1.5 LCP) to the 1.5 mm straight plate (1.5 P), 1.5 mm straight plate stacked (1.5 PSt) and 2.0 mm straight plate (2.0 P) in compression and torsion. We hypothesized that biomechanical properties of the 1.5 LCP would be equivalent to properties of the 1.5 P and would represent an alternative for the treatment of radial fractures in miniature breed dogs in which those plates would be used. MATERIALS AND METHODS: A 1 mm fracture gap model was created with a bone surrogate stabilized with a six-hole plate. Sixteen constructs were built for each of the four plate configurations. Eight constructs from each group were tested in compression to failure and eight constructs were tested in torsion to failure. RESULTS: In compression testing, the 1.5 LCP was stiffer than the 1.5 P, and had similar stiffness than the 1.5 PSt and the 2.0 P. The load at yield of the 1.5 LCP was slightly lower than the 1.5 P. In torsion, the 1.5 LCP and 1.5 P had similar stiffness, but 1.5 LCP was slightly stronger than 1.5 P. The 1.5 PSt and 2.0 P were overall superior to the 1.5 LCP but only marginally so for the 1.5 PSt. CLINICAL RELEVANCE: The 1.5 LCP can be considered biomechanically equivalent to the 1.5 P under the present experimental conditions. The use of the 1.5 LCP can be considered as an option for radial fracture repair in dogs in which a 1.5 P would have otherwise been used. The use of a locking plate to improve overall success rate, in these fractures, remains to be confirmed clinically.