Long-term outcomes after arthroscopic treatment of dogs affected by osteochondrosis dissecans of the humeral trochlea, with or without medial coronoid disease: 23 cases (2012-2020).

The objective of this study was to report long-term clinical and radiographic outcomes following arthroscopic reparative treatment - flap removal, curettage, and osteostixis of subchondral bone - in dogs with humeral trochlea osteochondritis dissecans (OCD). Dogs were included in this retrospective multicenter case series if they had a computed tomography diagnostic of humeral trochlear OCD, with or without medial coronoid disease, that was treated by arthroscopic reparative technique, and a detailed follow-up at least 6 mo postoperatively. The latter included a clinical examination, assessment of lameness, measurement of the brachial circumference and elbow amplitude, International Elbow Working Group (IEWG) radiographic score, owner-completed canine brief pain inventory (CBPI) score, and visual analogue scale (VAS) rating. A generalized linear model and tests for symmetry and marginal homogeneity were used to compare data. Twenty-three dogs (30 affected elbows) were included. Long-term (median: 22 mo; range: 6 to 98 mo) postoperative lameness, CBPI, VAS, joint distension, and pain scores were significantly improved compared with the preoperative values. Long-term postoperative range of motion and brachial circumference did not reveal any significant difference between OCD-affected and unaffected elbows. Long-term IEWG scores were similar to preoperative values in 56% of elbows and had progressed by 1 grade in 44%. Long-term complications included persistent Grade-1 lameness and occurred in 23% of dogs. Long-term outcomes based on lameness and CBPI scores were considered excellent in 67% of dogs, good in 27%, and intermediate in 6%. Arthroscopic treatment is thus a suitable surgical procedure for OCD of the humeral trochlea in dogs and provides good long-term results.

Cette étude rapporte les résultats cliniques et radiographiques à long terme après un traitement arthroscopique chez des chiens atteints d'ostéochondrite disséquante (OCD) de la trochlée humérale. Les chiens inclus ont reçu un diagnostic d'OCD de la trochlée humérale par tomographie, un traitement réparateur par arthroscopie et un suivi post-opératoire d'au moins 6 mois. Ce dernier comprenant un examen clinique et orthopédique, la mesure de la circonférence brachiale et de l'amplitude du coude, le score radiographique de l'International Elbow Working Group (IEWG), le score Canine Brief Pain Inventory (CBPI) et l'échelle visuelle analogique (EVA). Un modèle linéaire généralisé et des tests de symétrie et d'homogénéité marginale ont permis de comparer les données. Vingt-trois chiens (30 coudes affectés) ont été inclus. Les scores postopératoires à long terme (médiane, 22 mois), de boiterie, de CBPI, d'EVA, de distension articulaire et de douleur étaient significativement améliorés. L'amplitude de mouvement et la circonférence brachiale postopératoires à long terme entre les coudes affectés et non affectés n'ont pas révélé de différence significative. Les scores IEWG à long terme étaient similaires aux valeurs préopératoires dans 56 % des coudes et avaient progressé d'un grade dans 44 %. Les résultats à long terme basés sur la boiterie et les scores CBPI ont été considérés comme excellents chez 67 % des chiens, bons chez 27 % et intermédiaires chez 6 %. Le traitement arthroscopique est donc une procédure chirurgicale appropriée pour l'OCD de la trochlée humérale chez le chien et donne de bons résultats à long terme.(Traduit par les auteurs).

Effects of Transfixation Pin Positioning on the Biomechanical Properties of Acrylic External Skeletal Fixators in a Fracture Gap Model.

OBJECTIVE: The aim of this study was to evaluate the biomechanical effects of transfixation pin positioning in acrylic columns of external skeletal fixators (ESF). STUDY DESIGN: Twenty-four type I acrylic ESF were built simulating a fracture gap-model. Transfixation pins were placed centric (n = 12) or eccentric at » of the column diameter (n = 12) in the acrylic columns. Six constructs from each group were subjected to axial compression and four-point bending tests. Stiffness, yield load and mode of failure were recorded. RESULTS: Stiffness was not influenced by centring (p = 0.373), but it was higher in four-point bending than in axial compression (p < 0.001). Pin positioning had no influence on the yield (p = 0.535) and failure loads (p = 0.715) in axial compression, nor on the yield load in bending (p = 0.135). Eccentric pin positioning decreased failure loads by 28% in bending (p < 0.001). CONCLUSION: Eccentric position of transfixation pins within the acrylic columns alters the biomechanical properties of type I ESF constructs. While acrylic offers several advantages, when forming the columns, frame strength will be optimized if pins are centrally located.

On the nature of canine aural haematoma and its treatment with continuous vacuum drainage.

OBJECTIVES: To evaluate continuous vacuum drainage from the convex side of the pinna for surgical treatment of aural haematoma in dogs. To investigate aural haematoma fluid and cartilage samples harvested during surgery in an attempt to elucidate the etiopathogenesis of the lesion. MATERIALS AND METHODS: Ten client-owned dogs with aural haematoma were treated by convex-side vacuum drainage using different types of vacuum drains and containers and were followed-up for at least 6 months. Systemic blood samples and aural haematoma fluids were analysed for biochemical, haematologic and electrophoretic content. Cartilage samples were examined histologically. RESULTS: Nine of the 10 dogs were successfully treated without recurrence at 6 months postoperatively and with excellent cosmetic results. In one case, infection required early drain removal and delayed healing was associated with wrinkling of the pinna. Fluid sample analysis suggested that "aural haematoma" contains a transudate that accumulates within a cartilage-lined cavity. Histologic examination of the tissue samples revealed clefts of the pinna cartilage, with the luminal surface often lined with granulation tissue. Fluids and cartilage lacked evidence of inflammation. CLINICAL SIGNIFICANCE: This technique was characterised by patient comfort, tolerance of drains, absence of dressings and good cosmetic outcome. The results of fluid analysis suggest that the term "aural seroma" would be more appropriate for this condition.