Ultrasonographic Evaluation of Dogs with Cranial Cruciate Ligament Rupture Undergoing to Arthrotomy

Background: The cranial cruciate ligament rupture (CrCLR) is the most common disease of the stifle joint in dogs. One of the major concerns in the assessment of these animals is diagnosing the presence of a medial meniscus tears, which is a frequent consequence due to the instability of the joint. Ultrasonography is indicated in the evaluation of the menisci from human and canine patients, and the results are similar to magnetic resonance imaging. The aim of this study was to compare the ultrasonography and the arthrotomy in the evaluation of the cranial cruciate ligament and medial meniscus of dogs with CrCLR undergoing surgery for stifle stabilization.Materials, Methods & Results: Ultrasonographic examination was performed prior to arthrotomy in 23 dogs with diagnosis of complete CrCLR and five with suspected partial CrCLR undergoing for stifle joint stabilization surgery. The ultrasonography identified the complete rupture in 82.6% and the arthrotomy in 100% of the joints with this diagnosis. In the joints with suspected CrCLR during the clinical exam, arthrotomy and ultrasonography identified respectively three and four joints with partial CrCLR, and two and one with healthy ligaments. There was no difference between the two techniques in the assessment of the cranial cruciate ligament (P = 0.20). The ultrasonography identified medial meniscal tears in 39.3%, while arthrotomy was found in 21.4% (P = 0.0006) of the joints. The most frequent meniscal tear type observed in the arthrotomy was folded caudal horn. The ultrasonography was able only in differentiate presence and absence of meniscal injury. Besides the real tear that affects the meniscus morphology, the ultrasound also identified echogenicity and echotexture changes in the medial (5/28) and lateral (8/28) menisci. Other changes observed in all joints evaluated by ultrasound were the presence of effusion and synovial membrane thickening.Discussion: The complete and almost complete CrCLR are diagnosed by clinical examination through the evaluation of instability of the stifle joint, which is not possible in partial CrCLR in stable joints. In this study of the five evaluated stable joints, the ultrasound correctly identified the partial CrCLR in three joints and the ligament integrity in one of the joints when compared to arthrotomy. In animals with stifle joint instability the meniscus assessment is fundamental as it is one of the main causes of persistent lameness in dogs subjected to conservative or surgical treatment. Ultrasonography cannot differentiate the types of meniscal tears but identified approximately 1.8 times more medial meniscus tears compared to arthrotomy. Despite the bucket handle being the most common tear of medial meniscus in dogs with CrCLR, four of the six meniscal tears identified by arthrotomy were folded caudal horn. This lesion causes cranial displacement of the caudal horn which may have facilitated its identification by minimally invasive arthrotomy, being the probable reason for its high incidence in this study. Echogenicity and echotexture changes without affecting the meniscus morphology were related with intrasubstance degeneration described in human medicine. Ultrasonography is not the better technique to assess the CrCL but can assist in identifying partial ruptures. Because it has results similar to magnetic resonance imaging, ultrasonography is an important tool in the diagnosis of meniscus tears

Physics behind the implants used for high strain fractures: literature review

Quando fraturas ósseas ocorrem, forças externas produzem movimentação interfragmentária continuamente e um método de estabilização se faz necessário. É sabido que as condições mecânicas no local de fratura influenciam a formação de calo durante o processo de cicatrização óssea e para que cicatrização óssea primária seja obtida é necessária estabilidade absoluta no foco de fratura. O conceito de strain de Perren determina que a deformação relativa no foco de fratura estabilizado depende do tamanho da lacuna de fratura original. Fraturas redutíveis (sem cominuição) são consideradas de alto strain, pois uma pequena força aplicada a linha de fratura resulta em grande movimentação com efeito deletério ao processo de consolidação. O presente trabalho revisa a literatura disponível a respeito de fatores que influenciam a mecânica de fraturas de alto strain em medicina veterinária, seus métodos de tratamento e a física por trás dos implantes disponíveis. Cada configuração de fratura requer atenção especial e cuidado crítico na escolha do método de osteossíntese e no tipo de estabilidade necessária para que a consolidação ocorra no tempo esperado. Conhecimento da teoria do strain é mandatório para a formação de cirurgiões ortopédicos. Whenever bone fractures occur, external forces produce continuous interfragmentary motion and a stabilization method is necessary. It is known that the mechanical conditions at the fracture site influence bone callus formation during healing process. To achieve primary (direct) bone healing, absolute stability at the fracture site is necessary. Perren’s concept of strain determines that relative deformation at the fracture gap depends on the original gap’s conformation. Simple fractures (without comminution) are considered high strain fractures since a small force applied to the fracture site results in great movement with deleterious effects on the healing process. The purpose of this study is to review the available literature regarding factors that influence the mechanics of high strain fractures in veterinary medicine, its treatment methods and implants available. Each fracture configuration requires special attention and critical care in choosing the osteosynthesis method and the type of stability required for consolidation to occur within the expected time. One must know the strain theory to become an orthopedic surgeon

Comparação biomecânica e da redução óssea de Clamp and Rod Internal Fixation (CRIF) e placa de reconstrução bloqueada em fraturas de acetábulo

Este estudo objetivou comparar, biomecanicamente, por meio dos ensaios de flexão destrutível e ciclagem, bem como a qualidade da redução óssea, após avaliação do molde da superfície articular de osteotomias centrais do acetábulo de cão fixadas com Clamp and Rod Internal Fixation (CRIF) 2,7 mm ou placa de reconstrução bloqueada 2,7 mm. Os implantes foram divididos em dois grupos, denominados grupo CRIF (GC) e grupo Placa (GP). Foram utilizadas nove pelves de cadáveres de cão com peso corporal entre 15 e 35 kg, posteriormente as pelves foram subdivididas em 18 hemipelves e distribuídas aleatoriamente para testar os dois implantes, um contralateral ao outro em uma mesma pelve. Para realização dos testes, foi simulado uma fratura central no acetábulo, por meio de osteotomia linear, realizada com auxílio de serra oscilatória e em seguida, fixadas segundo os padrões AO/SIF, sendo utilizados três parafusos craniais e dois caudais a osteotomia. Após comparação biomecânica de resistência máxima à flexão o GP (22,38±8,44 N.m) demonstrou superioridade estatística em relação ao GC (15,60±5,76 N.m), (p=0,02408). Na comparação do molde da superfície articular após 30 ciclos o GP (0,27 ± 0,24mm) demonstrou valores menores para lacuna da linha articular que o GC (0,49 ± 0,29mm), sendo o GP estatisticamente superior, (p=0,04784). Em conclusão, a aplicação da placa de reconstrução bloqueada é simples e deve ser considerada para redução de fraturas do acetábulo que necessitem de reconstrução anatômica.The aim of this study was to compare the accuracy of reduction and biomechanical characteristics of acetabular osteotomies repaired with 2.7-mm Clamp and Rod Internal Fixation (CRIF) constructs or 2.7-mm locking reconstruction plates in cyclic and load to failure flexion tests. Nine dog cadavers with body weight between 15 and 35 kg were included in this study. All 18 hemipelves were randomly assigned into two groups named after the implants tested, group CRIF (GC) and group Plate (GP). All pelves were used to test both groups with each hemipelvis belonging to a different implant group. Acetabular osteotomies were created with an oscillatory saw and then fixed according to the AO/ASIF standards, using either 5-hole, 2.7-mm locking reconstruction plates with three locked screws cranial and two caudal to the osteotomy line, or CRIF constructs with 5 clamps, three located cranial and two caudal to the osteotomy line. Load to failure at GP (22.38 ± 8.44N.m) was significantly higher than GC (15.60 ± 5.76N.m), (p = 0.02408). Imprinted cast of acetabular reduction gap after 30 cycles was statistically smaller at GP (0.27 ± 0.24mm) than GC (0.49 ± 0.29mm) (p = 0.04784). We concluded that the appliance of locking reconstruction plates is simple and should be considered for acetabular fractures, that require perfect anatomical reconstruction

Interlocking nail with angle stable screws or cortical screws: biomechanical comparison in canine tibia bone model

As hastes convencionais estão sendo usadas para uma gama cada vez maior de fraturas, das mais simples às mais complexas. Hastes de ângulo fixo são uma inovação relativamente nova; no entanto, faltam dados literários sobre seus efeitos na estabilidade em comparação aos modelos convencionais ou com placas bloqueadas. O objetivo desse estudo foi comparar hastes de bloqueio convencional (BCO) e placas de bloqueio por acoplamento cônico (FIX) com hastes de bloqueio angular fixo (BAF). Desenho do estudo três grupos experimentais. População amostral modelos ósseos (n = 19) tratados com hastes convencionais (BCO n = 7), hastes com bloqueio em ângulo fixo (BAF n = 7) e placas de bloqueio angular por acoplamento cônico (FIX n = 5). Métodos as amostras foram testadas por ensaios não destrutivos de torção e flexão mediolateral e craniocaudal. Complacência da construção, deformação angular e folga foram comparados estatisticamente (P<0,05). Resultados independentemente do modo de teste, a complacência das construções foi menor no grupo BAF. Construções com placa (FIX) foram mais complacentes em torção e flexão mediolateral do que as com hastes, com diferença significativa para os grupos BAF e BCO. A deformação angular em flexão mediolateral e torção foi estatisticamente maior no grupo placas (FIX) do que nos grupos BAF e BCO. Comparativamente, as construções BAF tiveram menos deformação em torção e flexão mediolateral do que em outras construções de BCO e FIX. Enquanto as construções de haste convencional tinham folga em ambos os testes, os grupos BAF e FIX não apresentaram folga durante nenhum dos testes. Conclusões o uso de bucha cônica entre o parafuso e orifício da haste anulou a folga entre ambos e melhorou o comportamento mecânico do BAF em torção e flexão, resultando no desempenho mecânico superior do grupo BAF em comparação às placas bloqueadas do grupo FIX. Relevância clínica o mecanismo de bloqueio de ângulo fixo do novo design de haste bloqueada elimina toda a folga no sistema; assim, o movimento interfragmentário no foco de fratura provavelmente será reduzido em comparação à mesma circunstância com a haste intramedular convencional, o que pode melhorar a consolidação da fratura.Conventional nails are used for an expanding range of fractures, from simple to more complex. Angle-stable designs are relatively innovative; however, literary data on their effects on stability compared to conventional models or locked plates is lacking. This study aimed to compare conventional locking nails (BCO) and conical coupling locking plates (FIX) with fixed angular locking nails (BAF). Study design - Three experimental groups. Sample population - Bone models (n = 19) treated with conventional nails (BCO n = 7), nail with fixed angle locking (BAF n = 7) and angular locking plate by conical coupling (FIX n = 5). Methods - Samples were tested in mediolateral and craniocaudal flexion and torsion. Construction compliance, deformation, and slack were statistically compared (P<0.05). Results - Regardless of the test mode, the compliance of the constructs was lower in the BAF group. Plate constructions (FIX) were more compliant in torsion and mediolateral flexion than nails, with a significant difference for the BAF and BCO groups. The angular strain in mediolateral flexion and torsion was statistically higher in the plates (FIX) group than in the BAF and BCO groups. Comparatively, the BAF constructs had less torsion and mediolateral flexion deformation than the other BCO and FIX constructs. While the conventional nail constructions had slack in both modes, the BAF and FIX, groups had no slack during either test. Conclusions - Using a conical bushing between the screw and the nail hole nullified the slack between them. They improved the mechanical behavior of the BAF in torsion and bending, resulting in superior mechanical performances of the BAF compared to the locked plates of the FIX group. Clinical Relevance - Fixed-angle locking mechanism of the new locked nail design eliminates all slack in the system; thus, interfragmentary movement at the fracture focus is likely to be reduced compared to conventional intramedullary nailing, which may improve fracture healing

Ultrasonographic Evaluation of Dogs with Cranial Cruciate Ligament Rupture Undergoing to Arthrotomy

Background: The cranial cruciate ligament rupture (CrCLR) is the most common disease of the stifle joint in dogs. One of the major concerns in the assessment of these animals is diagnosing the presence of a medial meniscus tears, which is a frequent consequence due to the instability of the joint. Ultrasonography is indicated in the evaluation of the menisci from human and canine patients, and the results are similar to magnetic resonance imaging. The aim of this study was to compare the ultrasonography and the arthrotomy in the evaluation of the cranial cruciate ligament and medial meniscus of dogs with CrCLR undergoing surgery for stifle stabilization.Materials, Methods & Results: Ultrasonographic examination was performed prior to arthrotomy in 23 dogs with diagnosis of complete CrCLR and five with suspected partial CrCLR undergoing for stifle joint stabilization surgery. The ultrasonography identified the complete rupture in 82.6% and the arthrotomy in 100% of the joints with this diagnosis. In the joints with suspected CrCLR during the clinical exam, arthrotomy and ultrasonography identified respectively three and four joints with partial CrCLR, and two and one with healthy ligaments. There was no difference between the two techniques in the assessment of the cranial cruciate ligament (P = 0.20). The ultrasonography identified medial meniscal tears in 39.3%, while arthrotomy was found in 21.4% (P = 0.0006) of the joints. The most frequent meniscal tear type observed in the arthrotomy was folded caudal horn. The ultrasonography was able only in differentiate presence and absence of meniscal injury. Besides the real tear that affects the meniscus morphology, the ultrasound also identified echogenicity and echotexture changes in the medial (5/28) and lateral (8/28) menisci. Other changes observed in all joints evaluated by ultrasound were the presence of effusion and synovial membrane thickening.Discussion: The complete and almost complete CrCLR are diagnosed by clinical examination through the evaluation of instability of the stifle joint, which is not possible in partial CrCLR in stable joints. In this study of the five evaluated stable joints, the ultrasound correctly identified the partial CrCLR in three joints and the ligament integrity in one of the joints when compared to arthrotomy. In animals with stifle joint instability the meniscus assessment is fundamental as it is one of the main causes of persistent lameness in dogs subjected to conservative or surgical treatment. Ultrasonography cannot differentiate the types of meniscal tears but identified approximately 1.8 times more medial meniscus tears compared to arthrotomy. Despite the bucket handle being the most common tear of medial meniscus in dogs with CrCLR, four of the six meniscal tears identified by arthrotomy were folded caudal horn. This lesion causes cranial displacement of the caudal horn which may have facilitated its identification by minimally invasive arthrotomy, being the probable reason for its high incidence in this study. Echogenicity and echotexture changes without affecting the meniscus morphology were related with intrasubstance degeneration described in human medicine. Ultrasonography is not the better technique to assess the CrCL but can assist in identifying partial ruptures. Because it has results similar to magnetic resonance imaging, ultrasonography is an important tool in the diagnosis of meniscus tears

Fratura cominutiva e articular distal de úmero tratada com fixador esquelético externo transarticular em três gatos

Background: Humeral fractures account for 13% of all fractures in cats and commonly affect the middle diaphysis and supracondylar region with comminution. They are usually the result of high energy traumas such as falls, car accidents and firearm injuries. There are few treatment options for these types of fractures and since they are joint injuries, early surgical repair is mandatory to achieve perfect anatomical reduction, to maintain joint congruence and to allow early weight bearing. Our purpose is to report four subacute and chronic fractures of the distal diaphysis associated with comminuted supra and intercondylar fractures, stabilized with transarticular external skeletal fixator in three domestic felines.Cases: (1)- A 3-year-old male docile Siamese cat with 3.7 kg of body weight was presented for consultation with a 14-day history of high rise syndrome after falling from a 12-meter high. It presented distal comminuted humeral fracture that involved the inter and supracondylar regions. It also had right carpal-ulnar subluxation and comminuted right olecranon fracture involving the articular surface in the left thoracic limb. Fracture and joint stabilization was achieved by use of a transarticular hybrid external skeletal fixator on the right front limb. Fracture healing was observed at 150 days postoperatively. (2)- A 10-year-old female aggressive mixed breed cat with 4.1 kg of body weight was presented for consultation with a 16-day history of high rise syndrome after falling from a 9-meter high. The cat had a comminuted right humeral articular fracture with supra and intercondylar involvement and scapular fracture on the contralateral limb. The humerus fracture was treated with a transarticular linear external skeletal fixator and fracture healing was obtained at 240 postoperative days. (3)- A 1-year-old female unsociable mixed breed cat with 4.5 kg of body weight was presented for consultation with a 15-day history of humeral fractures after falling from a 12-meter high building. The cat had comminuted bilateral humeral articular fracture with supra and intercondylar involvement. Fracture stabilization was achieved by use of a transarticular hybrid external skeletal fixator on both limbs. Fracture healing was achieved after 60 days on the right front limb, and after 120 days on the left front limb.Discussion: Patients with distal humeral diaphyseal fractures should be assessed for peripheral nerve injury. None of the reported cases had neurological damage despite having suffered high energy trauma. Surgical approach to humeral distal fractures may be craniolateral, medial or caudal or even combined. In chronic fractures like those in our study, (fractures with more than 14 days of evolution), perfect anatomic reduction wasn’t considered due to presence of fibrous tissue that would require excessive manipulation, leading to injuries to soft tissues and blood supply, what would increase the risk of infection and bone sequestrum. The gold standard for the treatment of articular fractures is rigid internal fixation by means of compressive screws and compressive plates, and they require open reduction. Whenever anatomical reduction can not be performed, due to either the fracture’s evolution period or by the diminished bone length, closed reduction is indicated and stabilization with transarticular fixators is an alternative. Hybrid constructs are well tolerated by patients since they are lighter than circular apparatus and more versatile than linear fixators. In our study, transarticular fixators were used based on the location of the fractures and fracture period. Despite the ankyloses of the humeral-radio-ulnar joint, all patients adapted to the fixator devices very well and presented satisfactory ambulation weight bearing on the first postoperative day already. A disadvantage of the skeletal fixators is the postoperative care, which includes daily dressings, e-collaring, resting and co-operation on behalf of the owner. Two animals presented aggressive/unsocial behavior and still the prolonged postoperative management and adaptation to the fixator were successful. The results suggest that comminuted humeral distal articular fractures can be treated by the use of transarticular external skeletal fixators in cats

Blood gas parameters and acid-base balance of kids from normal delivery

A adaptação à vida extra-uterina é período crítico para o recém-nascido. Inúmeras alterações ocorrem em diferentes sistemas e órgãos, incluindo a função respiratória e o equilíbrio ácido-básico. O presente trabalho objetivou constatar a ocorrência de acidose em cabritos recém-nascidos e obter parâmetros gasométricos e ácido-básicos dos mesmos, até as 24 horas de vida. Para tanto, foram utilizados 33 cabritos, sem distinção de sexo. Amostras sanguíneas foram colhidas por venopunção jugular, imediatamente após o nascimento, aos cinco, dez e 15 minutos, e às 24 horas de vida, para determinação do pH, pressão parcial de oxigênio (pO2), pressão parcial de dióxido de carbono (pCO2), dióxido de carbono total (TCO2), concentração de bicarbonato (HCO3), excesso de bases (BE) e a saturação de oxigênio (sO2) utilizando-se analisador portátil de gases sanguíneos. Observaram-se diferenças significativas entre os momentos nos valores gasométricos dos cabritos em todas as variáveis estudadas. Os cabritos recém-nascidos apresentaram acidose respiratória no período pós-parto imediato, normalizando-se às 24 horas de vida.The extra-uterine life adaptation is a critical period for the newborn. Several changes occur in different organ systems including respiratory function and acid-base balance. The aim of this study was to hypothesize the occurrence of acidosis in newborn kids and obtain blood gas and acid-base parameters of kids in the first 24 hours of life. For this, 33 goat kids of both sexes were used. The blood samples were collected by jugular venipuncture immediately after birth, 5, 10, 15 minutes and 24 hours of life. The blood pH, oxygen partial pressure (pO2), carbon dioxide partial pressure (pCO2), total carbon dioxide (TCO2), bicarbonate concentration (HCO3), base excess (BE) and oxygen saturation (SO2) were determined with a portable blood gas analyzer. Significant differences were observed between the moments in all variables of the kids blood gas values. The newborn kids had respiratory acidosis during the immediate post-partum period, normalizing at 24 hours of life

Tenorrhaphy of the Common Calcaneal Tendon in Dogs and Cats

Background: Common calcaneal tendon (CCT) is usually affected by injuries in dogs and less frequently in cats. The Achilles mechanism consists of the convergence of three distinct structures: the tendons of the gastrocnemius muscle, superficial digital flexor muscle and the common tendons of the biceps femoris, gracilis, and semitendinosus muscles. Classification of lesions is based upon their location, severity and chronicity. Clinical signs include lameness, plantigrade stance and various degrees of tarsal hyperflexion according to the injury’s severity. The purpose of this study is to report four cases of reconstruction of the common calcaneus in three dogs and a cat.Cases: Case 1. A 10-year-old male canine, Brazilian Terrier, 7.7 kg of body weight, with a 6-month history of nonweightbearing lameness of the right hind limb attended consultation. Orthopedic examination showed plantigrade stance, hyperflexion of the right tibial-tarsal joint (TTJ) and swelling with fibrous thickening of the distal portion of the CCT. Surgical tendon repair was achieved through insertion of a locking screw on the calcaneo-tibial, tenorrhaphy and suture of a titanium plate on the caudal aspect of the CCT. Case 2. A 2-year-old female mongrel canine, with 13.3 kg of body weight was presented with the complaint of chronic left hind leg lameness. The owner described trauma at the area of the hock six months prior to consultation. On orthopedic exam, severe lameness was noted, swelling with fibrous thickening of the distal portion of the common calcaneal tendon and hyperflexion of the left TTJ (plantigrade position) were visible. Tendon repair was performed in the same manner as in case 1, except that in this case a bovine pericardium graft preserved in glycerin 98% was sutured over the tendon/plate conjunction. Case 3. A 6-year-old female mongrel canine, with 18.6 kg of body weight was attended with a 22-day history of right hind limb lameness. On physical exam intermittent lameness during gait performance and non-weight-bearing position in stance were noted. The distal portion of the limb was internally rotated with plantigrade stance and discontinuity of the CCT was palpable. Tenorrhaphy was performed similarly to case 2. Case 4. A 6 kg, 3-year-old, mixed breed male feline was admitted with a wound on the CCT region for 7 days. The wound was originated after animal interaction with a stray feline. On clinical examination the animal was non-weight bearing on the right hind limb, with plantigrade posture and with a 1 cm wound on the caudal portion of the CCT with tendon exposure. Surgical repair was performed by tenorrhaphy with placement of a surgical steel plate on the caudal aspect of the CCT. A bovine pericardium graft preserved in glycerin 98% was sutured on top of the plate. The TTJ was immobilized with a type II transarticular external fixator.Discussion: Ultrasonography is the test of choice to monitor tendon healing after tenorrhaphy. At this report, this exam was crucial to determine when the calcaneal-tibial screw could be removed. Two dogs and the cat from this report received an association of plate and bovine pericardium preserved in glycerin 98%. The purpose of this association was to increase the strength of the tenorrhaphy, and the pericardium graft had also the function of reducing the formation of peritendinous adhesions. Immobilization of the TTJ has the purpose of opposing muscle forces to avoid stress at tenorrhaphy suture increasing the strength of the healed tendon allowing early weight bear while minimizing the recurrence risk and avoiding limb contracture. We chose to perform the procedure with hyperextension of the TTJ in order to promote greater relaxation of the tendon since there was need to remove large portions of calcaneal fibrous tissues of the dogs and devitalized tissue in the cat from this report. Surgical treatment of injuries of the Achilles mechanism has good prognosis in complete closed lesions treated by tenorrhaphy associated with suture of a plate, suture of bovine pericardial graft preserved in 98% glycerin, calcaneal-tibial locking screw and splint for six weeks.Keywords: Achilles tendon, rupture, calcaneo-tibial screw, locking-loop suture pattern