Surgical repair of Salter-Harris type II fracture of the distal humerus: short and long-term outcomes in a case series of three dogs and one cat.

CASE HISTORIES: Three dogs and one cat sustained forelimb trauma and were presented to a university veterinary clinic (Liège, Belgium) and a private veterinary hospital (Beacouzé, France). All four animals were referred for surgery. CLINICAL FINDINGS: Two dogs and the cat were ambulatory on admission but unable to bear weight on the affected limb. One dog was non-ambulatory and lacked voluntary movement and sensation in one forelimb. Salter-Harris type II fractures of the distal humerus were diagnosed by radiography in all cases; avulsion of the brachial plexus and pelvic fractures were also present in the non-ambulatory dog. TREATMENT AND OUTCOME: All Salter-Harris type II fractures were stabilised by open reduction and internal fixation with cross pins. One minor complication (seroma) and three major complications (implant migration) developed after surgery. The pins were completely removed in one case and partially removed in two cases to resolve these complications. At the final follow-up examination (12-31 months after surgery), owners reported no lameness in three of the four cases and grade 2/5 left forelimb lameness in one case. CLINICAL RELEVANCE: This type of fracture is rarely described in the literature; however, it should be included in the differential diagnoses of traumatic humeral fractures in growing dogs and cats. In this case series, we achieved fair-to-excellent short-term and long-term outcomes after osteosynthesis of Salter-Harris type II fractures by cross pinning.

Organic and mechanical properties of Cervidae antlers: a review.

There is a resurgence of interest in the study of deer antlers. Recent research advocates their potential for use in bone xenografts. Using this working hypothesis, we can formulate many questions: do antlers really present unique or interesting mechanical properties, and if so, which factors affect these properties? Many other issues, including tissue compatibility, could be discussed; however, this article will focus on the biomechanical features of antlers. This paper reviews some answers found within current published material, and could help determine the optimal selection of some antlers for further experimental studies and clinical trials. Some general elements like anatomy and histology of deer antlers are briefly summarised. This paper will attempt to define the fundamental differences between skeletal bone and antler bone in terms of their organic and mechanical properties. We will then compare the previously published data, which details the mechanical properties of antlers from different species of Cervidae, by reviewing several aspects such as: sex; geographical situation; morphology; hydration state; and mineral composition. Some findings emerge: mechanical properties do not vary with gender or latitude, and the most important determining factor appears to be the species, alongside morphology and use of antlers. The state of hydration and mineral composition also has an influence on the mechanical properties of Cervidae antlers.

Review of dietary supplements for the management of osteoarthritis in dogs in studies from 2004 to 2014.

Osteoarthritis (OA) is a chronic, painful, degenerative and inflammatory disease that affects the synovial joints and leads finally to the loss of mobility. It is highly prevalent in dogs. Nowadays, no cure exists, and the pharmacological treatment is limited to clinical signs alleviation. Some positive beneficial effects have been highlighted with dietary supplements in the course of dog OA. The goals of this narrative review are to summarize the scientific data available in the literature on dietary supplements assessed in dog OA and to discuss some trails about how to improve several aspects of research and issues with dietary supplements, such as bioavailability and dosage regimen. Chondroitin sulphate, glucosamine, undenaturated type II collagen, avocado-soya bean unsaponifiables, curcumin and polyunsaturated fatty acids were studied in dog OA and therefore discussed in the present review. Most of them showed anticatabolic and anti-inflammatory effects. Unfortunately, few data exist concerning their pharmacokinetics. Their bioavailability is low, but new formulations are developed to enhance their gastrointestinal absorption. The clinical relevance of these new formulations compared to native forms should be demonstrated in good clinical trials. Even if further investigations are needed, dietary supplements should be considered in OA management.

Complications and outcome of a new modified Maquet technique for treatment of cranial cruciate ligament rupture in 82 dogs.

OBJECTIVES: To describe the complications, short and long-term outcome and owner satisfaction of dogs with cranial cruciate ligament rupture treated with a recently described new osteotomy for the modified Maquet technique (N-MMT). MATERIALS AND METHODS: Medical records and radiographs of 82 dogs (84 stifles) were reviewed. Details regarding short-term outcome and complications were recorded from the medical records. Long-term follow-up information was obtained by telephone interview. Historical data and complications were statistically analysed. RESULTS: Major complications occurred in 34/84 stifles. Intra-operative complications occurred in 26/84 stifles, all of which were fissures or fractures of the cortical hinge. Twenty-one of these fractures or fissures were repaired with a figure-of-eight wire. The second most common major complication was late meniscal tears in 3/84 stifles. One dog sustained a complete tibial fracture. Non-displaced fracture of the cortical hinge was the most common postoperative minor complication, which occurred in 5/84 stifles. The median preoperative lameness score was 3 out of 6. Final in-hospital re-evaluation of limb function was available in 58 dogs. The median lameness score at that time was 0 out of 6. Development of osteotomy related complications was not associated with a significant change in the postoperative lameness score. CLINICAL SIGNIFICANCE: Subjectively assessed clinical outcome with the N-MMT was good to excellent in this cohort of dogs. However, a high rate of intra- and postoperative complications of the N-MMT procedure was also present in these dogs.

Biomechanical testing of a ß-tricalcium phosphate wedge for advancement of the tibial tuberosity.

OBJECTIVES: to evaluate in vitro the strength of different compositions of beta-tricalcium phosphate (ß-TCP) wedges in comparison with titanium foam and cages. To study the response to cyclic loading of the strongest ß-TCP wedge, titanium foam and titanium cage. METHODS: Compression test: Twenty-five tibiae were prepared for tibial tuberosity advancement using the modified Maquet technique. Five groups were defined depending on the material used to maintain the tibial tuberosity: Group 1=titanium cage; Group 2=wedges of porous titanium foam with 50% porosity (OrthoFoam®); Group 3=blocks of biphasic synthetic bone (60% hydroxyapatite [HAP] and 40% ß-TCP, porosity 80%); Group 4=blocks of biphasic synthetic bone (60% HAP and 40% ß-TCP, porosity 70%) and Group 5=blocks of biphasic synthetic bone (65% HAP and 35% ß-TCP, porosity 60%). Loads to failure were calculated for each implant. Cyclic study: Five additional tibiaes of group 1, 2 and 5 were fatigue tested from 100 to 500 N at a rate of 4 Hz for 200,000 cycles or until failure. RESULTS: Compression test: For the five groups, the mean load at failure was 1895 N, 1917 N, 178 N, 562 N and 1370 N respectively. Cyclical study: All samples in the three groups tested withstood 200,000 cycles without failure. CLINICAL SIGNIFICANCE: The ideal implant to maintain tibial tuberosity advancement after the modified Maquet technique would be absorbable and allow osteoconduction and osteoinduction. As such, ß-TCP wedges have many advantages and our study shows that they can withstand loads in the patellar tendon up to 500 N over 200,000 cycles in vitro and deserve more investigation.

Mechanical testing of a new osteotomy design for tibial tuberosity advancement using the Modified Maquet Technique.

OBJECTIVES: To evaluate the mechanical properties of the distal cortical hinge associated with a new osteotomy design for the Modified Maquet Technique (MMT). STUDY DESIGN: Ex vivo mechanical study. METHODS: The osteotomy was started 10 mm caudal to the tibial tuberosity and extended over 150% of the length of the tibial crest; it was slightly curved distally to stay at a distance of 2 to 4 mm from the cranial cortex, according to the body weight. Ninety-six tibiae were tested in advancement, and 60 tibiae were axially loaded perpendicular to the tibial plateau, until failure of the crest. Desired advancement was measured using the common tangent method in 60 tibiae. Angle of opening, thickness, and area of the cortical hinge were recorded. RESULTS: Desired advancement of 6 mm, 9 mm, 12 mm and 15 mm was recorded in 16, 12, 18 and 14 tibiae respectively. Mean maximal advancement in these bones was 15.6 ± 6.4 mm, 20.8 ± 5.2 mm, 21.3 ± 5.2 mm and 22.7 ± 5.2 mm respectively. The desired advancement was reached in all but one tibia. Advancement was mainly influenced by the angle of opening and the stiffness of the cortical hinge. Mean ultimate load to failure was 6.12 ± 2.4 times the body weight. It was significantly associated with the body weight, thickness, and area of the cortical hinge. CLINICAL RELEVANCE: Mean maximal advancement was higher than clinically required without occurrence of fissure or fracture. Ultimate load to failure and maximal advancement could be predicted using calculated formulae.

Relationship between arthroscopic joint evaluation and the levels of Coll2-1, Coll2-1NO(2), and myeloperoxidase in the blood and synovial fluid of horses affected with osteochondrosis of the tarsocrural joint.

OBJECTIVE: To evaluate the levels of plasmatic and synovial Coll2-1, Coll2-1NO(2) and myeloperoxidase (MPO) in horses with osteochondral lesions of the tarsocrural joint and to investigate how these levels relate to arthroscopic findings of inflammation and degeneration. MATERIALS AND METHODS: Venous blood and synovial fluid samples were collected from 63 horses presented for arthroscopic removal of osteochondral fragments in the tarsocrural joint. Prior to removal of the osteochondral fragment, an exploration of the joint was performed and an inflammatory and degenerative score was determined. The blood and synovial levels of Coll2-1, Coll2-1NO(2) and MPO were also measured. The effects of the arthroscopic evaluation (inflammatory and degenerative classes) on the blood and synovial markers were evaluated using a linear model (GLM procedure), and correlations between biochemical markers in the blood and synovial fluid and the arthroscopic evaluation (inflammatory and degenerative classes) were established (Pearson's correlations). RESULTS: Significantly higher levels of Coll2-1 were detected in synovial fluid of higher degenerative classes. There was a significant correlation between the degenerative score and the synovial levels of Coll2-1 (r=0.27). According to the logistic regression model, there was a significant effect of the degenerative class on synovial levels of Coll2-1. CONCLUSIONS: Coll2-1 correlates well with the degenerative state of tarsocrural joints as evaluated by arthroscopy. This marker can therefore be classified as a burden-of-disease marker in the assessment of joint disease in horses.

Preliminary experience of a modified Maquet technique for repair of cranial cruciate ligament rupture in dogs.

The modified Maquet technique (MMT) uses the same principle as the tibial tuberosity advancement (TTA) for stabilization of the cranial cruciate ligament-deficient stifle in the dog. In the MMT, the tibial tuberosity is advanced in a similar manner to that used in the TTA, however the means by which the tibial crest is stabilized differs. The plate and fork originally described by Montavon et al. are not used (7). The MMT was first described by Maquet for use on humans; it leaves intact a distal bony attachment to the tibial shaft, and the tuberosity is either reinforced or not by a figure-of-eight wire. In this paper, we describe the MMT, and we report the results of our first 20 canine patients with cranial cruciate ligament rupture that were treated by the MMT. Mean clinical bone healing time was 6.8 weeks (range 4 to 12 weeks). The evidence provided by this clinical communication suggests that it is technically possible to achieve an advancement of the tibial tuberosity without the need for a plate. The MMT deserves consideration as a primary treatment option for cranial cruciate ligament rupture in dogs, and further evaluation in large clinical studies. Long-term follow-up and force plate analysis would be necessary to compare the MMT to both the TTA and the tibial plateau levelling osteotomy.

Theoretical discrepancy between cage size and efficient tibial tuberosity advancement in dogs treated for cranial cruciate ligament rupture.

OBJECTIVES: To calculate the difference between the desired tibial tuberosity advancement (TTA) along the tibial plateau axis and the advancement truly achieved in that direction when cage size has been determined using the method of Montavon and colleagues. To measure the effect of this difference on the final patellar tendon-tibial plateau angle (PTA) in relation to the ideal 90°. METHODS: Trigonometry was used to calculate the theoretical actual advancement of the tibial tuberosity in a direction parallel to the tibial plateau that would be achieved by the placement of a cage at the level of the tibial tuberosity in the osteotomy plane of the tibial crest. The same principle was used to calculate the size of the cage that would have been required to achieve the desired advancement. The effect of the difference between the desired advancement and the actual advancement achieved on the final PTA was calculated. RESULTS: For a given desired advancement, the greater the tibial plateau angle (TPA), the greater the difference between the desired advancement and the actual advancement achieved. The maximum discrepancy calculated was 5.8 mm for a 12 mm advancement in a case of extreme TPA (59°). When the TPA was less than 31°, the PTA was in the range of 90° to 95°. CLINICAL SIGNIFICANCE: A discrepancy does exist between the desired tibial tuberosity advancement and the actual advancement in a direction parallel to the TPA, when the tibial tuberosity is not translated proximally. Although this has an influence on the final PTA, further studies are warranted to evaluate whether this is clinically significant.

Mechanical testing of a modified stabilisation method for tibial tuberosity advancement.

OBJECTIVES: This in vitro study evaluated three modified techniques of tibial tuberosity advancement (TTA). Loads to failure were calculated for each technique. METHODS: A 9 mm TTA procedure was performed in the tibiae of dogs weighing between 32 and 38 kg. In group 1 (n = 12), the distal part of the tibial crest was left attached to the tibia by the cranial cortex, and a figure-of-eight wire was added for stabilisation. In group 2 (n = 12), the tibial crest was left attached but no additional device was used for stabilisation. In group 3 (n = 12), the tibial crest was completely separated from the tibia and fixed by a figure-of-eight wire so that, in this group, only the wire opposed avulsion of the tibial crest. Unidirectional axial force was applied via the patella to determine the maximal load to failure of the model. RESULTS: There was no significant difference between group 1 and group 2. These two groups both had a significantly stronger construct than that of group 3. CLINICAL SIGNIFICANCE: We described modifications to the TTA procedure without plate fixation that warrant clinical investigation. When the crest is broken during its advancement, the tension sustained by the repair is significantly weaker from a biomechanical point of view and the use of such a repair clinically is not recommended by the authors.

Traumatic partial elbow luxation in a dog.

Traumatic partial elbow luxation (unilateral medial humeroulnar) was diagnosed in a 2.5-year-old crossbreed dog. Previous reports of traumatic elbow luxation in the dog described lateral and less frequently medial humeroradioulnar luxations. The treatment consisted of closed reduction of the affected joint under general anaesthesia. The functional outcome was excellent.

Non-destructive characterization of deer (Cervus Elaphus) antlers by X-ray microtomography coupled with image analysis.

X-ray microtomography coupled with image analysis was tested as a non-destructive alternative method for the textural characterization of the trabecular part of deer antlers (Cervus Elaphus). As gas adsorption and mercury intrusion cannot be applied on this soft and spongy material, its pore texture was, up to now, determined from histological sections that give only two-dimensional information. In this work, X-ray microtomography is used to scan entire or half pieces of antlers and three-dimensional image analysis is performed in order to assess the differences between samples collected at various antler locations. Results clearly show a porosity profile along the sample diameter. The pore size distribution is showed to be dependent on the sample original site.

Hemiurothorax following diaphragmatic hernia and kidney prolapse in a cat.

A 3-year-old cat was presented with increasing dyspnoea over the past four days. Unilateral pleural effusion was diagnosed and a modified transudate was drained several times. Surgical exploration revealed intra-thoracic prolapse of the left kidney and partial herniation of the spleen through a dorsal, circumferential diaphragmatic tear. Biochemical analysis of the pleural fluid confirmed urothorax. Due to excessive fibrin deposit on the well-vascularised kidney it was impossible to re-establish left urinary pathways. Left-sided nephrectomy and diaphragmatic herniorrhaphy were performed. Postoperative recovery was uneventful and complete. This is the first report of an urothorax in veterinary medical literature.

Metabolic and structural abnormalities in dogs with early left ventricular dysfunction induced by incessant tachycardia.

OBJECTIVE: To assess morphologic and metabolic abnormalities in dogs with early left ventricular dysfunction (ELVD) induced by rapid right ventricular pacing (RRVP). ANIMALS: 7 Beagles. PROCEDURE: Plasma carnitine concentrations were measured before and after development of ELVD induced by RRVP. At the same times, transvenous endomyocardial biopsy was performed, and specimens were submitted for determination of myocardial carnitine concentrations and histologic, morphometric, and ultrastructural examination. RESULTS: In 4 dogs in which baseline plasma total carnitine concentration was normal, RRVP induced a decrease in myocardial total and free carnitine concentrations and an increase in myocardial esterified carnitine concentration. In 3 dogs in which baseline plasma total carnitine concentration was low, plasma and myocardial carnitine concentrations were unchanged after pacing. Structural changes associated with pacing included perinuclear vacuolization in 3 dogs. Morphometric analyses indicated there was a decrease in myofiber cross-sectional diameter and area following pacing. Electron microscopy revealed changes in myofibrils and mitochondria following pacing. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that moderate to severe alterations in myocyte cytoarchitecture are present in dogs with ELVD induced by RRVP and that in dogs with normal plasma carnitine concentrations, myocardial carnitine deficiency may be a biochemical marker of ELVD. Results also indicated that transvenous endomyocardial biopsy can be used to evaluate biochemical and structural myocardial changes in dogs with cardiac disease.

Hormonal response to dobutamine cardiac stress testing in a conscious canine model of early left ventricular dysfunction induced by chronic rate overload.

The aims of this study were to investigate (1) hormonal activation before and during dobutamine cardiac stress testing (DST) in a canine model of early left ventricular dysfunction (ELVD) induced by rapid right ventricular pacing (RRVP) and (2) the relationship between this hormonal profile and carnitine concentrations. Before the pacing period, the 6 dogs were assigned to 2 groups according their baseline total plasma carnitine concentration. A DST was performed on each dog before activation of the pacemaker and every 3 to 4 days during development of 3 progressive stages of ELVD (stages 1, 2 and 3). Plasma atrial natriuretic factor (ANF), angiotensin II (ANG II) and endothelin-1 (ET-1) levels were measured at the start and at the end of each DST. Effects of ELVD, DST and plasma carnitine concentration on these measurements were tested. The RRVP induced a significant increase of ANF and ANG II and a non significant trend toward increase of ET-1 in all dogs. Before the pacing period, ANF remained constant during the DST in dogs with normal total plasma carnitine concentration, while it significantly decreased in dogs with low total plasma carnitine concentration. Dobutamine stress testing induced a significant decrease in ANF in all dogs in ELVD. Dobutamine infusion induced a significant increase in ANG II in all dogs before as well as during the pacing period while ET-1 was unchanged. These results suggest that investigation of the hormonal profile before and after a dobutamine challenge might provide important diagnostic information in dogs with asymptomatic or mildly symptomatic cardiac dysfunction of different origins.

Magnetic resonance arthrography of the cubital joint in dogs affected with fragmented medial coronoid processes.

OBJECTIVE: To evaluate efficacy of intra-articular injection of gadolinium tetra- azacyclododecane tetraacetic acid (gadolinium-DOTA) for delineating fragmented medial coronoid processes (FMCP) and lesions on the medial aspect of the humeral condyle (MAHC). SAMPLE POPULATION: 14 cubital joints in 9 dogs. PROCEDURE: Magnetic resonance imaging (MRI) was performed with and without intra-articular injection of a solution of 2 mmol of gadolinium-DOTA/L. Arthrographic images obtained after injection of contrast medium were compared with those obtained without contrast medium. Evidence of contrast medium around or in the medial coronoid process and infiltration of contrast medium in subchondral bone lesions was recorded. Twenty-four hours after imaging, arthroscopy was performed, and lesions detected were correlated with results of MRI. RESULTS: An abnormal coronoid process was diagnosed in 13 of 14 joints. A fragmented process (free) was seen in 7 of 14 joints; nondisplaced mineralized medial (in situ) coronoid processes were evident in 4 joints; and nondisplaced unmineralized medial coronoid processes were evident in 2 joints. Lesions on the MAHC were diagnosed in 4 of 12 joints. In 5 joints, a hyperintense signal resulted from contrast medium that infiltrated between the fragmented process and ulna. In 2 joints, contrast medium did not infiltrate completely around the process and was stopped by an isointense structure (ie, abnormal cartilage). Subchondral bone lesions were enhanced by use of contrast medium. CONCLUSION AND CLINICAL RELEVANCE: Use of arthrography enabled us to identify FMCP easily, but did not provide important additional information about changes on the medial coronoid process, compared with MRI performed without contrast medium.