Ex vivo biomechanical evaluation of 2.4 mm LCP plate rod constructs versus 2.7 mm LCP applied to the feline tibia.

OBJECTIVE: To compare the stiffness and strength of three plate and rod fixation constructs applied to a feline tibial gap model. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Thirty-three unpaired tibiae obtained from skeletally mature cats. METHODS: The tibiae were randomly divided into three groups. The following implants were then applied to the feline tibiae prior to the creation of a 10 mm diaphyseal gap. Group 1: 2.4 mm locking compression plate (LCP) and 1.0 mm intramedullary pin (IMP). Group 2: 2.4 mm LCP and 1.6 mm IMP. Group 3: 2.7 mm LCP. Subsequently, each specimen was tested for torsion, axial compression, and axial load until construct failure. Student's t-tests were used to compare the torsional and axial stiffness, yield load, and maximum axial force. RESULTS: Group 2 had higher axial stiffness than group 3 (p = .013). Group 1 showed a lower maximum axial force and yield point than groups 2 and 3 (p < .01; p < .05, respectively). There were no among-group differences in torsional stiffness. CONCLUSION: Constructs with a 2.4 mm LCP and 1.6 mm IMP provided the strongest and most rigid constructs in a feline tibia gap model. CLINICAL SIGNIFICANCE: A plate-rod construct combining a 2.4 mm LCP and a 1.6 mm IMP is appropriate for achieving high implant stiffness and resisting maximum axial force in treatment of tibial fractures in cats.

Three-dimensional computer-assisted corrective osteotomy with a patient-specific surgical guide for an antebrachial limb deformity in two dogs.

INTRODUCTION: We describe patient-specific surgical guide prototyping and surgical treatment of a complex antebrachial deformity in two skeletally mature dogs presented with chronic lameness. Computer-assisted surgery was elected to increase accuracy in the correction of the complex deformity. Radiographs and computed tomography (CT) scans revealed a biplane deformity with valgus, procurvatum and external torsion of the right radius in both cases. The pre-surgical planning started from the quantification of the angular deformity, followed by computer simulated correction and to end up with a rehearsal surgery on 3D printed bone models. During the surgery, the custom-made osteotomy guides closely fitted the bone, allowing for a precise corrective osteotomy, that was stabilized with two locking plates. Postoperative radiographs showed the successful correction of the deformity. Eight and 12 weeks postoperative follow up examinations showed improved lameness, weight-bearing and progression of bone healing in both dogs. Patient-specific surgical guides allowed for a satisfactory correction of the antebrachial deformity. Additional benefits of using customized surgical devices include standardization and reduced surgical time.

INTRODUCTION: Nous décrivons le prototypage d'une procédure chirurgicale spécifique au patient et le traitement chirurgical d'une déformation antébrachiale complexe chez deux chiens ayant atteint leur maturité squelettique et présentant une boiterie chronique. La chirurgie assistée par ordinateur a été choisie pour accroître la précision de la correction de la déformation complexe. Les radiographies et la tomodensitométrie (TDM) ont révélé une déformation dans deux plans avec valgus, procurvatum et torsion externe du radius droit dans les deux cas. La planification préopératoire a commencé par la quantification de la déformation angulaire, suivie par une correction simulée sur ordinateur et a abouti à une opération de répétition sur des modèles d'os imprimés en 3D. Pendant l'intervention, des guides d'ostéotomie sur mesure ont ajusté l'os de manière exacte, permettant ainsi une ostéotomie correctrice précise, stabilisée avec deux plaques de verrouillage. Les radiographies postopératoires ont montré la réussite de le correction de la déformation. Les examens de suivi postopératoires effectués à huit et douze semaines ont montré une amélioration de la boiterie et de la mise en charge ainsi que la progression de la cicatrisation des os chez les deux chiens. Les guides chirurgicaux spécifiques au patient ont ­permis une correction satisfaisante de la déformation antébrachiale. L'utilisation de matériel chirurgical personnalisé comporte d'autres avantages, tels que la standardisation et la réduction du temps de l'intervention chirurgicale.

[Arthroscopic-assisted stabilization of medial shoulder instability in a Miniature Poodle]. / Arthroskopisch-assistierte Stabilisation einer medialen Schulterinstabilität bei einem Zwergpudel.

INTRODUCTION: A 12-year old female miniature Poodle was presented because of a 4/4 right fore-limb lameness. The orthopedic examination demonstrated pain at palpation of the right shoulder and an abduction angle of 55 °. MRI examination confirmed injuries consistent with a traumatic medial shoulder instability with no evidence of shoulder dysplasia. A partial rupture of the subscapularis tendon and complete detachment of the cranial gleno- humeral ligament were confirmed with arthroscopy. The joint was successfully stabilized using an arthroscopic assisted prosthetic suture.

Repair of a canine patellar ligament rupture using the ComPact UniLock 2.4/3.0 mm System.

An 11-year old, female, Mix Breed dog was presented after being hit by a car with a rupture of the left patellar ligament. Due to a suspected wound infection close to the stifle joint, surgical repair was delayed for 10 days. The ruptured ligament was sutured and augmented with fascia lata. Additionally, two ComPact UniLock 2.4/3.0 mm plates connected with 1.0 mm orthopaedic wire were used to protect the primary repair. No immobilization of the stifle joint was needed. The implants were removed after 7 weeks, because of suspected infection and loosening. The successful utilization of an alternative surgical technique for the repair of the patellar ligament rupture in the dog has also been documented by pre- and post-operative temporal-spatial gait analysis (GaitFour®).