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SummaryTo date is it unclear whether cementless total hip replacement (THR) in dogs is of clinical advantage in comparison to cemented THR with regard to lameness improvement. Thus the aim of this study was to compare objectively the development of the gait pattern after cemented and cementless THR in dogs. For this purpose, 18 adult dogs with hip dysplasia underwent computer-based gait analysis on an instrumented treadmill prior to unilateral THR and then again ten days, four weeks and four months after surgery. Analysed kinetic parameters were symmetry indices (SI) of vertical ground reaction forces (GRF), which included peak vertical forces (PFz), mean vertical forces (MFz), vertical impulse (IFz), and vertical ground reaction forces of the arthroplasty limbs only. Analysed kinematic parameters were range-of-motion and the flexion and extension angles of hip, stifle and hock joints. The symmetry indice for PVF, MFz and IFz decreased to a value less than six in both THR groups four months after surgery, which is defined as not lame. Improvement in lameness of the arthroplasty limbs during the examination period of four months was not significantly different between the cemented and cementless groups. The results suggest that within a short-term observation period of four months after surgery, neither cementless nor cemented THR have a greater advantage with regard to lameness improvement. Additional studies with larger pools of subjects and longer time periods for follow-up examinations are necessary to verify these findings.

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

SummaryThe goal of this study was to evaluate different minimally invasive surgical options as therapy for cranial cruciate ligament rupture and resulting meniscal injuries. In this study, 81 stifle joints of dogs with complete or partial rupture of the cranial cruciate ligament were treated with minimally invasive surgery at the Small Animal Clinic of the University of Veterinary Medicine in Hannover. The patients were divided into three groups depending on intraoperative diagnosis and the surgical technique applied. The dogs in group I (n = 26) had an isolated rupture of the cranial cruciate ligament (CCLR), while those in groups II (n = 26) and III (n = 29) also had an injury of the medial meniscus. Re-section of the damaged meniscal part was performed by arthroscopically guided partial meniscectomy (AGPM) on the dogs in group II, while minimally invasive medial arthrotomy (MIMA) was used on the dogs of group III. All of the stifles were stabilized with a modified lateral imbrication technique using a braided, synthetic, absorbable suture material (Panacryl®). Six months after surgery 76.5% of all patients were examined clinically and 74.1% radiographically for evaluation of the success of the different treatment techniques. At this examination, there were no signs of lameness in 42.1% of group I (CCLR), 65.0% of group II (AGPM) and 87.0% of group III (MIMA). Upon palpation, 75.8% of these stifle joints were found to be stable. Radiographic evaluations did not show any indication of progression of gonarthrosis in 73.3% of all stifle joints examined here.

Summary Objective: The aim was to compare osseointegration of blood perfused β-tricalcium phosphate cylinders (β-TCPB) with similar composites that were additionally loaded with cancellous bone and bone marrow (β-TCPB/BM/CB) for mandibular reconstruction. Methods: Twelve German Black-Headed sheep with an average weight of 72.5 ± 10 kg underwent segmental re-section of the right hemi-mandible. The animals that were assigned to group A (n=6) were reconstructed using β-TCPB while the sheep that were assigned to group B received β-TCPB/BM/CB grafts. Tissue quality was histologically assessed and bone-, scaffold-, cartilage- and fibrous-tissue area were estimated using semiautomated histomorphometrical software. Results: Composite grafts that were loaded with bone marrow and cancellous bone (β-TCPB/BM/CB) exhibited significant (p Clinical significance: Bone and bone marrow augmented β-tricalcium phosphate composites may qualify as a promising alternative to autograft bone for mandibular reconstruction in human and veterinary medicine.

As rabbits are becoming more popular as pets and owners are willing to pay for specialized care, veterinary practitioners are required to maintain their expertise treating these animals. In recent years, ophthalmic patients have become an important part of the small mammal pet population. Ocular disorders in pet rabbits can be caused by genetic defects, congenital malformations, traumatic events, infections, housing conditions, and nutritional deficiencies. Knowledge of the species-specific anatomy and physiology forms the basis for the interpretation of findings and prevents misinterpretation of a normal state as an abnormality. The ophthalmic examination of rabbits should adhere to the same principles and techniques used for canine and feline patients, although adjustments are required because of different anatomical and physiologic features. Magnification is necessary for accurate assessment. This article summarizes the common ophthalmic disorders of pet rabbits, especially those that are unique to rabbits.

The aim of this study was to test the efficacy of different dosages of low molecular weight heparin (LMWH) in acute DIC which was induced in anaesthetised dogs by 4 h infusions of a canine lung thromboplastin extract. In all animals during the first 2 h, development of acute DIC was characterised by decreasing fibrinogen concentrations, platelet numbers, factor V- and antithrombin activities. Two hours after starting the thromboplastin infusion, intravenous LMWH treatment in different dosages started in groups 2 and 3 to achieve plasma levels between 0.27+/-0.01 and 0.36+/-0.02 anti-FXaUml(-1) or 0.62+/-0.08 and 0.90+/-0.07 antiFXaUml(-1) (mean+/-SD), respectively, during the time period of parallel administration of thromboplastin and LMWH (group 1=control; 4 dogs/group). In this time period, changes in factor V activity and fibrinogen concentration did not differ between group 2 and the control group. This was in contrast to group 3. The results of this study indicate that an efficacious interruption of the consumption reaction in cases of severe canine DIC requires high plasma heparin levels.

A five-year-old, castrated, male chinchilla rabbit was presented for evaluation of recurrent bilateral exophthalmos. Besides a transient and stress-related exophthalmos with protrusion of both third eyelids, the ophthalmological examination was unremarkable. Plain radiography of the thorax revealed a large precardial mass of soft tissue density. Cytological preparations from the thoracic mass were dominated by small, mature lymphocytes with approximately 10 to 20 per cent lymphoblasts. Computed tomography of the head showed a symmetrical laterodorsal deviation of both eyes without evidence of retrobulbar masses. On necropsy a large cystic mass was present in the cranial thorax associated with severe hydrothorax, hydropericardium and ascites. Histology identified the precardial mass as thymic carcinoma with metastases in the kidneys. This case illustrates the difficulty of diagnosing thymic tumours based on cytological or histological features of the primary tumour alone. To the authors' knowledge, this is the first case of recurrent bilateral exophthalmos associated with a metastatic thymic carcinoma in a pet rabbit.

Intramedullary nailing is the treatment of choice for patients with femoral shaft fractures. However, there is an ongoing debate in multiple trauma patients with associated lung contusion when primary or secondary definitive stabilisation of the long bone fracture should be performed, as nailing is thought to play an important role in the pathogenesis of adult respiratory distress syndrome (ARDS). In a standardised sheep model, this study aimed to quantify the development of acute pulmonary endothelial changes, to assess the activation of polymorphonuclear leucocytes (PMNL) and to observe the effects on the coagulation system associated with the reamed nailing procedure. Furthermore, the effect of coexisting lung contusion in an experimental model was evaluated. The animals were randomly assigned to one of four different groups (6 animals/group). In control groups, only a sham operation (thoracotomy) was performed, whereas in study groups, lung contusion was induced prior to femoral stabilisation either by external fixation or reamed femoral nailing. Using bronchoalveolar lavage (BAL) pulmonary permeability changes were quantified and PMNL activation was assessed by chemiluminescence. Additionally PMNL diapedesis and interstitial lung oedema were determined by histological analysis. All animals were sacrificed 4 h after the start of the femoral instrumentation. Without an associated lung injury, instrumentation of the femoral canal with the reamed nailing technique induced a transient increase in pulmonary permeability. In the face of an induced lung contusion, reamed femoral nailing resulted in significant increases in PMNL activation, pulmonary permeability and interstitial lung oedema, compared with external fixation. Without pulmonary contusion, reaming of the femoral canal was associated with a transient increase in pulmonary permeability. This was exacerbated in the presence of lung contusion along with increased PMNL activation. External fixation did not provoke similar changes. The findings of this study support the view that reaming of the femoral canal should be avoided in polytrauma patients with severe chest trauma as it could act as an additional stimulus for adverse outcome. Temporary external fixation appears to be a safe method for fracture stabilisation until inflammatory and coagulatory disturbances after trauma have been normalized.

SummaryIn a retrospective trial over eight years 518 joints from 421 dogs with fragmented medial coronoid process of the ulna (FCP) were included. Seventy-five joints had an additional osteochondrosis dissecans of the medial aspect of the humeral condyle. Forty-six point eight percent of the dogs (197/421) were younger than one year. Two hundred and forty-seven joints were treated by conventional arthrotomy and 271 joints were treated by arthroscopy. Two hundred and thirty-eight cases (103 treated by arthrotomy and 135 by arthroscopy) were re-evaluated clinically and radiographically and 191 cases (88 treated by arthrotomy and 103 by arthroscopy) by means of a questionnaire at an average of 23 and 21 months after the operations, respectively. Forty-two point four percent (81/191) of the cases treated by arthrotomy did not show any lameness, 29.3% (56/191) showed temporary lameness after rest or heavy exercise, and 28.3% (54/191) showed constant lameness. The signs of which had, however, been reduced by surgery in 14 of these cases. Sixty point one percent (143/238) of the cases treated by arthroscopy did not show any lameness, 29.4% (70/238) showed temporary lameness after rest or heavy exercise and 10.5% (25/238) showed constant lameness, out of which four cases had improved after surgery. In the cases treated by arthroscopy, the period of convalescence was shorter. Differences between these methods were not observed with respect to the development of subsequent arthrosis. The results of the study show that arthroscopy, with its minimal invasive character, gives better functional results than conventional arthrotomy. However, the development of secondary arthrosis cannot be avoided by either method.

SummaryIn a retrospective and prospective trial over six years, 17 joints from 13 dogs presented with incomplete ossification of the humeral condyle (IOHC) were included. All dogs showed lameness of the forelimb but no humeral condylar fractures. One dog showed a fracture of the olecranon. Four of the bilaterally affected dogs showed only unilateral lameness. 53.8% of the dogs (7/13) were younger than one year. With regard to breed distribution, the German Wachtel was most frequently represented with three dogs. In 12 dogs the diagnosis was made by radiography in a craniocaudal view, and seven dogs could be further investigated by computed tomography. In one dog the diagnosis was only made during arthroscopy. Two joints showed an additional fragmented medial coronoid process of the ulna and another two an osteochondrosis dissecans of the medial humeral condyle. During arthroscopy, all joints showed a clearly visible fissure line in the joint cartilage between the humeral condyles. In ten joints the I0HC was treated with a transcondylar lag screw under arthroscopic control. Three of the four bilaterally affected dogs were treated only unilaterally because of a lack of lameness on the other side. In the dog with the olecranon fracture, only the fracture was treated. The patients were rechecked clinically and radiologically (n = 10) or by means of a questionnaire (n = 1) at an average of 26 months post operation. Seven cases, six of them treated by lag screw fixation, did not show any lameness. Three joints (one dog with olecranon fracture, two unilaterally affected dogs with lag screw fixation) showed some degree of lameness after heavy strain and one dog showed a continuous slight lameness. The four bilaterally affected and only unilaterally treated dogs showed no lameness on the untreated joint. With regard to development of arthrosis, six radiographically examined joints showed no increase in arthroses. In five joints the increase was mild and in two joints moderate. In six joints with lag screw fixation, the IOHC was radiographically unified and was confirmed by computed tomography in three cases.

Aims Interaction between dronedarone and digitalis has been discussed as a possible cause for increased mortality in the presence of dronedarone observed in the PALLAS trial. The aim of this study was to assess possible proarrhythmic effects of dronedarone in combination with digitalis in an experimental whole heart model. Methods and results Twenty-six female rabbits underwent chronic oral treatment with dronedarone (50 mg/kg/day for 6 weeks). Twenty-four rabbits received placebo. Heart failure was induced by rapid ventricular pacing. Sham-operated rabbits received a right-ventricular pacing lead but were not paced. Thereafter, hearts were isolated and Langendorff-perfused. Monophasic action potentials and a 12 lead electrocardiogram showed a dose-dependent decrease of QT interval, APD90, effective refractory periods, and postrepolarization refractoriness in control hearts and dronedarone-pretreated hearts after application of ouabain (0.1 and 0.2 µM). After acute application of ouabain, ventricular fibrillation (VF) was inducible by programmed ventricular stimulation in 6 of 12 untreated sham hearts (38 episodes) as compared with 7 of 11 dronedarone-pretreated sham hearts (76 episodes). In untreated failing hearts, 6 of 12 hearts were inducible (47 episodes) as compared with 7 of 15 hearts dronedarone-pretreated failing hearts (93 episodes). Conclusion In this study, ouabain treatment resulted in an increased ventricular vulnerability in chronically dronedarone-pretreated control and failing hearts. Ouabain led to a significant abbreviation of ventricular repolarization. This was more marked in dronedarone-pretreated hearts and resulted in an elevated incidence of VF. This may help to interpret the results of the PALLAS trial.

Inadequate mechanical stimuli are a major cause for nonunions following surgery for femoral and tibial shaft fractures. Adapting fixation rigidity during the course of fracture healing requires additional surgery. Nickel–titanium (NiTi) implants can change shape and rigidity by employing a temperature-dependent shape-memory effect. As a first step in the development of advanced intramedullary (IM) NiTi devices for fracture healing, this study aimed to test the feasibility and safety of transcutaneous electromagnetic induction heating of an IM NiTi implant in a rat model. In 51 rats, NiTi implants were introduced into the left distal femur. Forty-four animals were transferred to an induction coil, and the implant was electromagnetically heated to temperatures between 40° and 60 °C Blood samples were drawn before and four hours after the procedure. Interleukin (IL)-1, IL-4, IL-10, tumour necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) were measured. Animals were sacrificed at three weeks. Histological specimens from the hind leg and liver were retrieved and examined for inflammatory changes, necrosis or corrosion pits. All animals successfully underwent the surgical procedure. Following transcutaneous induction heating, target temperature was confirmed in 37/44 rats. Postoperative controls showed no signs of undue limitations. Neither cytokine measurements nor histological specimens showed any significant differences between groups. There were no corrosion pits or necrosis. We conclude that electromagnetic induction heating of IM NiTi implants is feasible and safe in a rat femur model. These findings reflect a further step in the development of novel concepts for IM fracture fixation that might lead to better fracture healing, less patient discomfort and less need for surgical interventions.

Background The present ESC guidelines on atrial fibrillation have introduced vernakalant (VER) for pharmacologic cardioversion of atrial fibrillation. The aim of the present study was to investigate possible proarrhythmic effects of vernakalant in an experimental model of heart failure (HF). Methods and Results In 12 female rabbits, HF was induced with the use of 4 weeks of rapid ventricular pacing. Twelve rabbits were sham operated. Isolated hearts demonstrated a significant prolongation of myocardial repolarization after induction of HF. Vernakalant caused a concentration-dependent (10 μmol/L and 30 μmol/L) increase of action potential duration (APD90) and QT interval without affecting spatial and temporal dispersion of repolarization. The increase in APD90 was accompanied by a greater increase in refractory period resulting in a significant increase in post-repolarization refractoriness. In control conditions, programmed ventricular stimulation and burst pacing led to ventricular fibrillation (VF) in 2 of the 12 sham (4 episodes) and in 3 of the 12 HF (24 episodes) subjects. In the presence of 30 μmol/L vernakalant, VF was no longer inducible in both groups (0 episodes). In the presence of low K+ concentration, neither sham nor HF vernakalant-treated subjects developed early after-depolarizations or ventricular tachyarrhythmias. Conclusion In the present study, application of vernakalant led to a significant prolongation of myocardial repolarization and increased post-repolarization refractoriness but did not induce early after-depolarization and therefore did not cause proarrhythmia in failing hearts.

SummaryIn a prospective trial over seven years (1993-1999), 44 joints from 41 dogs with an ununited anconeal process are reported. The average age of the animals was 23 weeks. With regard to breed distribution, the German Shepherd was most frequently represented with 29 animals.In 35 joints, the anconeal process was stabilised with lag screw and pin, as there was no fibrous connection between the anconeal process and the ulna. Additionally, in all cases an ulna ostectomy was performed. In nine joints, the connection of the anconeal process to the olecranon was firm and only a proximal ulna ostectomy was performed. The patients were rechecked clinically and radiologically, at an average of 13 weeks post operation. With one exception, in all of the cases the apophysis was closed. The implants were removed in 25 patients. The surgical results were examined once more after an average of 20 months in 43 joints (40 dogs). 83.7% of the cases (n = 36) did not show any lameness after the combined therapy with fixation of the isolated anconeal process and osteotomy of the ulna (n = 28) or ulna ostectomy only (n = 8) and were assessed as ‘good’. Six dogs (five with fixation, one with ostectomy) showed some degree of lameness after heavy strain and were only evaluated as ‘satisfactory’. One dog still had a striking low to medium grade lameness, so that the result was regarded as ‘unsatisfactory’. With regard to the development of arthrosis, only nine of the 30 joints (30%) examined radiographically showed a mild increase of the arthroses during later examinations.In many cases excision of the ununited anconeal process leads to unsatisfactory long-term results. Frequently surgical treatment does not lead to fusion. This paper describes a concept for treatment of an ununited anconeal process and the short- and long-term results. Proximal ostectomy of the ulna was performed, as a single measure, when the anconeal process was tightly in place. In joints with a loose anconeal process, the piece of bone was stabilised with implants, in addition to an ostectomy of the ulna. After an average of three months, the anconeal process had fused with the ulna, in all hut one case. In long-term follow-ups, after an average of 20 months, most of the dogs did not show any lameness, even after exercise. In only a few joints was a minor increase of arthrosis noted. The technique described is considered to be useful to treat the ununited anconeal process in young dogs.

SummaryGrafting of large bone defects caused by trauma or tumor resection still remains a problem to solve. In experimental studies as well as in human dentistry, osteoconduction and biodegradation of the β-tricalciumphosphate Cerasorb® as well as osteoinductive capabilities of platelet rich plasma have been proven. In case of luxation of the right tarsal joint, including a compressive fracture of the forth tarsal bone, the recommended use of autologous cancellous bone to support osseous fusion was replaced by the use of a bioartificial bone graft. Biodegradation of the bone graft was proven clinically and radiographically. Complete osseous fusion of the intertarsal joint occurred. The use of the β-tricalciumphosphate Cerasorb in combination with platelet rich plasma to support a partial arthrodesis of the tarsal joint in a dog did not impede the healing process but led to full recovery of the patient, indicating that this concept of bioartificial bone grafting could support bone healing.

The rabbit eye shows several anatomical differences compared to other mammals, some of which are important for surgery. This chapter details the relevant anatomy and looks at decision-making and treatment options. Operative Techniques: Corneal ulcer treatment; Correction of entropian or ectropian; Correction of eyelid dysplasia; Removal of prolapsed superficial gland of third eyelid; Pocket technique for re-placement of prolapsed gland of third eyelid; Surgical treatment of aberrant conjunctival overgrowth; Enucleation and exenteration.

A multicentric basal cell carcinoma was diagnosed in a male multimammate mouse (Mastomys spp.) with widespread cutaneous alterations. Macroscopically, the skin was thickened and extremely wrinkled. Histopathological examination showed multicentric expanding cell-rich tumors composed of basaloid cells interpreted as basal cell carcinoma. Immunohistochemistry detected strong cytokeratin 14 positivity in the epidermal basal layer and in loosely arranged areas of these tumors but only a minimal positive reaction in densely packed areas of tumor cells. Furthermore, samples from the abdomen showed 3 nodular proliferations diagnosed as keratoacanthomas.

Welche Konzepte und Erzählformen bestimmen heute Dauer- und Sonderausstellungen? Wodurch unterscheiden sie sich und wie greifen sie ineinander? Die Praxis zeigt, dass die Grenzen zwischen beiden Formaten zunehmend verschwimmen: Dauerausstellungen wirken ›beschleunigt‹ und instabiler, während Sonderausstellungen in neuer Weise mit dem eigenen Sammlungsbestand arbeiten und ›Altbekanntes‹ neu befragen. Der Band diskutiert diese aktuellen Fragestellungen anhand theoretischer Überlegungen und konkreter Beispiele aus der Praxis.