Dysostosis Enchondralis of the Ulnar Bone in the Basset Hound

Ninety-four Basset Hounds were examined for the clinical features, the radiographical changes and the nutritional and hereditary possibilities connected with the development of decreased longitudinal growth of the ulnar bone. In six puppies the possibility was examined of the development of the disease being due to overloading of the foreleg. Ten of the dogs were examined for gross pathology and 4 by histology post mortem.Clinical symptoms and radiographical changes were not seen until the age of 31/2 months. In all cases there were broadening of the joint space in the elbow joint and degeneration of the articular cartilage at the semilunar notch. An abnormally broad and irregular growth plate was seen in the affected young dogs, and histology revealed obvious abnormalities in the growth plate located in the zone of resting cartilage indicating degenerative disturbances in the cartilage. There were no signs of rickets, and it was not possible to demonstrate that the disease was caused by misleading.It is concluded that the disease corresponds to similar anomalies found in the other chondrodystrophic breeds of dogs, and it is suggested that the decreased growth of the ulnar bone may be hereditary.     

Evaluation of Collagen as a Retainer for Autogenous Cancellous Bone Used in Repair of Full Thickness Cortical Bone Defects

A commercially available collagen sponge acting as a cylindrical retainer containing autogenous cancellous bone graft was proposed for treatment of full thickness cortical defects in dogs. Three groups of three dogs each were subjected to removal of at least 1.5 cm of the tibial diaphyses. All tibias were stabilized with bilateral external fixators. Group 1 received collagen surrounding an autogenous cancellous bone graft. Group 2 received collagen and group 3 received no treatment of the ostectomy site. The collagen sponge appeared to allow vascularization of the bone graft as evidenced by new bone formation and was resorbed by 3 months after implantation. Radiographic, histomorphologic, and histomorphometric evaluation at 3 months after surgery showed a greater per cent of bone in the ostectomy site in group 1.     

Arthroscopic Subchondral Bone Plate Microfracture Technique Augments Healing of Large Chondral Defects in the Radial Carpal Bone and Medial Femoral Condyle of Horses

OBJECTIVE: To evaluate the effect of arthroscopic subchondral bone microfracture on healing of large chondral defects in horses. STUDY DESIGN: Short- (4 months) and long-term (12 months) in vivo experimental chondral defect model. ANIMALS: 10 horses, aged 2 to 5 years. METHODS: Each horse had a 1 cm2 full-thickness chondral defect created in both radial carpal bones and both medial femoral condyles. One carpus and one femoral condyle of each horse had the subchondral bone plate under the defect perforated using an orthopedic awl. All horses were exercised, five horses were evaluated after 4 months and five horses after 12 months. Gross, histologic, and histomorphometric examination of defect sites and repair tissues was performed, as was collagen typing of the repair tissue. RESULTS: On gross observation a greater volume of repair tissue filled treated defects (74%) compared with control defects (45%). Histomorphometry confirmed more repair tissue filling treated defects, but no difference in the relative amounts of different tissue types was observed. There was an increased percentage of type II collagen in treated defects compared with control defects and evidence of earlier bone remodeling as documented by changes in porosity. CONCLUSIONS: In full-thickness chondral defects in exercised horses, treatment with subchondral bone microfracture increased the tissue volume in the defects and the percentage of type II collagen in the tissue filling the defects when compared to nontreated defects. CLINICAL RELEVANCE: No negative effects of the microfracture technique were observed and some of the beneficial effects are the basis for recommending its use in patients cases with exposed subchondral bone.     

Efficacy and Toxicity of Doxorubicin/Cyclophosphamide Maintenance Therapy in Dogs with Multicentric Lymphosarcoma

Doxorubicin/cyclophosphamide were evaluated as maintenance drugs for dogs with multicentric lymphosarcoma (n = 28). Median remission time of all dogs was 173 days. Remission duration was shorter, however, in dogs with stage IV/V disease, in dogs with pretreatment hypoalbuminemia, and in dogs that had received glucocorticoids before initiation of chemotherapy (P less than 0.04). Nineteen dogs were evaluable for toxicity. Dose-limiting gastrointestinal toxicosis was observed in three dogs, neutropenia was observed in three dogs, and cardiomyopathy was observed in three dogs. The doxorubicin/cyclophosphamide protocol described in this report is safe and effective in treating canine multicentric lymphosarcoma. Clinical stage, pretreatment steroid therapy, and hypoalbuminemia are prognostic factors for response to this protocol.     

Mechanical Evaluation of Three Methods of Plating Distal Radial Osteotomies

Eighteen intact canine cadaver radii underwent nondestructive axial testing, and were osteotomized, plated, and retested. Each bone was tested with and without mediolateral or craniocaudal restriction of motion. Fixation of the osteotomies was performed under static compression with a cranially applied 5-hole 3.5 mm dynamic compression plate, a cranially applied 7-hole 3.5 mm T-plate, or a medially applied 7-hole 2.7 mm dynamic compression plate. There was no loss of axial stiffness after osteotomy and fixation, and there were no differences in axial stiffness between the methods of fixation. Mediolateral stiffness (bending around the craniocaudal axis) was consistently greater than craniocaudal stiffness (bending around the mediolateral axis) before and after osteotomy and plate fixation. There was no difference in the axial stiffness of otherwise intact radii when craniocaudal or mediolateral screw holes were drilled; however, all radii with craniocaudal screw holes and one radius with mediolateral screw holes fractured at a screw hole at high axial loads.     

Comparison of Three Methods of Ulnar Fixation in Horses

Objective- This study compares the mechanical properties of three methods of equine ulnar fixation: dynamic compression plating, pins and wires tension band, and a prototype grip system.
Study Design- The mechanical properties of dynamic compression plating, pins and wires tension band, and a prototype grip system repair of equine ulnar fractures were evaluated in a cadaveric osteotomy model.
Animals or Sample Population- Fifteen pairs of the radius and ulna from equine cadavers.
Methods- The three repair techniques were evaluated to mimic the pull of the triceps brachii muscle in single cycle to failure and in cyclic fatigue loading. Single cycle results were evaluated as the axial and angular displacement. Cyclic fatigue results were evaluated as the number of cycles to failure.
Results- Dynamic compression plate fixation and pins and wires tension band had significantly less axial displacement of the proximal fragment than the grip system ( P <.05). No significant difference in angular rotation of the proximal fragment was present between the three techniques. Dynamic compression plating had significantly greater fatigue resistance than the grip system ( P <.05). Cyclic failure was characterized by screw loosening or breakage and wire breakage.
Conclusions- Dynamic compression plates were better than the other techniques at maintaining compression of a transverse ulnar osteotomy at the level of the anconeal process just proximal to the trochlear notch.
Clinical Relevance- Knowledge of fixation technique mechanical properties is essential for surgeons to select the proper method of fracture repair.     

Biomechanical Comparison of Two Plating Techniques for Fixation of Acetabular Osteotomies in Dogs

OBJECTIVE: To compare the failure properties of a 5-hole, 2.7-mm curved acetabular plate (AP) to a 5-hole, 3.5-mm reconstruction plate (RP) when applied to acetabular osteotomies. STUDY DESIGN: Cadaver study. ANIMALS OR SAMPLE POPULATION: Pelves of 8 mature, large-breed dogs. METHODS: A 5-hole, 2.7-mm AP and a 5-hole, 3.5-mm RP were contoured and applied to the dorsal acetabulum of each pelvis. A central acetabular fracture was simulated after plate application by a transverse osteotomy with a fine saw. Each acetabulum was loaded in a weight-bearing direction. A load-deformation curve was produced for each construct, and biomechanical properties of the AP and RP were compared with the Student's paired t-test. A P value of < .05 was considered significant. RESULTS: For the AP and RP composite respectively, the mean +/- SD maximum load to failure was 2,721 +/- 632 N and 2,488 +/- 800 N, the stiffness was 4.8 +/- 1.8 N/m and 5.3 +/- 1.9 N/m, and the energy absorbed was 15.1 +/- 5.2 Nm and 16.3 +/- 8.3 Nm. None of these differences was statistically significant. CONCLUSIONS: Both fixation techniques provided comparable strength, stiffness, and energy absorbed under the loading conditions of this study. CLINICAL RELEVANCE: Because of the relative ease of application, the 2.7-mm curved AP may be the practical choice for acetabular fracture repair in large dogs.     

Healing of Mandibular Body Osteotomies after Plate and Intramedullary Pin Fixation

Osteotomies were created in the left body of the mandible of nine dogs and immediately stabilized with either a six hole dynamic compression bone plate or an intramedullary pin. Cortical bone healing and vascular supply were evaluated at weeks 2, 5, and 10 by microradiography, microangiography, and correlated histology of selected mandibular slices. Perforating arterioles from the buccal mucosa maintained vascular supply to rostral mandibular segments. The mandibular body rostral to the osteotomy site and caudal to the canine tooth suffered an interruption of vascular supply that was replaced by a temporary extraosseous supply during healing of the osteotomy. Intramedullary pin placement resulted in destruction of rostral teeth. There was an inflammatory response around the rostral portion of all intramedullary pins. Osteotomy sites involving tooth roots resulted in no disruption of the normal vascular or neural structures of the tooth pulp.     

In Vivo Evaluation of Intramedullary Interlocking Nail Fixation of Transverse Femoral Osteotomies in Foals

Objective—To evaluate an intramedullary interlocking nail for stabilization of transverse femoral osteotomies in foals.
Study Design—A transverse osteotomy and restabilization with an intramedullary interlocking nail was performed on the right femur in three foals and the left femur in three foals. Animals—Six foals weighing 149 to 207 kg.
Methods—The femur was destabilized with a transverse middiaphyseal osteotomy and repaired with a 0.5-in (12.7 mm) interlocking nail. The implanted femurs were radiographed monthly until completion of the study 6 months after surgery. At the completion of the study, all foals were observed for evidence of lameness, gluteal thickness was determined by ultrasonographic measurement, and a necropsy was performed.
Results—Healing was satisfactory in all foals. Five of the six had osseous bridging of the osteotomy apparent radiographically by 3 to 4 months. The sixth foal had postoperative infection but was healed radiographically in 5 months. There was a mean decrease in gluteal muscle thickness of 6.6 mm ( P = .04) in the operated limb of the five foals that healed without complication. Two foals were lame at the completion of the project; one foal with varus deformities of the contralateral limb was mechanically lame, and another was grade 2/5 lame on the operated limb. On necropsy, there was circumferential enlargement of the diaphysis of all operated limbs with the majority of the callus at the cranial and medial aspects of the cortex. All nails were solid within the medullary cavity.
Conclusions —The intramedullary interlocking nail provided adequate stabilization for repair of the transverse osteotomy.
Clinical Relevance —Further investigation is warranted before use for stabilization of spontaneously occurring fracture configurations.     

The Effects of Plaster of Paris and Autogenous Cancellous Bone on the Healing of Cortical Defects in the Femurs of Dogs

Four one quarter inch evenly spaced circular defects were created bilaterally in the lateral femoral diaphysis of 12 clinically normal adult dogs. The defects were left unfilled (control), or were filled with one of the following: (1) plaster of Paris, (2) an equal-volume mixture of plaster of Paris and autogenous cancellous bone, and (3) autogenous cancellous bone. The degree of bone healing was evaluated radiographically and histologically at 2, 4, 6, 8, 10, and 12 weeks. Radiographically, no objective conclusions could be drawn due to the small size of the defects and limited amount of plaster of Paris implanted. Histologically, there was no inflammatory reaction to the plaster of Paris. No differences were determined in the degree of bone healing between autogenous cancellous bone, plaster of Paris, and a mixture of plaster of Paris and autogenous cancellous bone. All implants were superior to the control defect in degree of bone healing.     

Ulnar Subluxation Following Repair of a Fractured Radius in a Foal

Compression plating of a transverse mid-diaphyseal radial fracture in a 4-month-old Arabian filly resulted in subluxation of the ulna. Two screws transfixed the radius to the ulna and resulted in synostoses. This was followed by uncoordinated growth of the radius and ulna, and subluxation of the ulna. Progressive remodeling of the ulna subsequently reestablished articular congruity between the humerus and ulna.     

Repair of an Ulnar Fracture With Radial Luxation in a Horse

An ulnar fracture with radial luxation (Monteggia fracture) was repaired in a horse. Reduction of the radial luxation was difficult, requiring 2 incisions, limb traction, neuromuscular blockade, and direct radial manipulation. The ulnar fracture was repaired by use of a dynamic compression plate. Three months postoperatively, the horse was free of any apparent lameness.     

预防性养护在公路养护中的应用

预防性养护是在公路还没有发生大的损害,或还没有破损严重之前,采取积极有效的措施,把公路病害控制、处治在初期阶段。在能行之有效的养护公路,保障公路正常运行的同时,最大限度的节约成本,延长公路使用寿命。本文从前期的调查摸底,到具体养护措施的实施;从整体的预防目标,到有针对性的操作进行了深入的探讨。     

桥梁预防性养护在高速公路养护中的应用

本文通过查阅大量的资料,结合对混凝土的碳化、裂缝、钢筋锈蚀、支座损坏等桥梁病害进行了总结,提出了混凝土碳化预防性养护技术、混凝土裂缝的预防性养护技术、钢筋锈蚀的预防性养护技术等桥梁预防性养护技术进行了分析,以保证桥梁的质量,促进桥梁预防性养护技术的优化发展。     

Full-thickness Thoracic and Abdominal Wall Reconstruction in Dogs Using Carbon/Polycaprolactone Composite

Square 9 × 9 cm full-thickness defects were created in the thoracic wall of five dogs and the abdominal wall of five dogs. The skin was retained. Ten centimeter squares of carbon fabric with a thin polycaprolactone (PCL) lining were sutured into the defects with the PCL lining facing the viscera. The dogs were observed for 5 months. The surgical technique was simple and fast. All implants were well tolerated. Cosmetic results were excellent in nine dogs. One dog (abdominal implant) developed an infection and draining tract, and a second dog (thoracic implant) had a subclinical infection. Thoracic implants caused brief serosanguinous pleural transudate. Mild paradoxical respiratory motion disappeared by 8 weeks. Lungs were radiographically normal. At necropsy, fibrous tissue was present but lacked orientation. Loose adhesions covered 20 to 80% of implant linings. There was no significant difference in ultimate tensile strength of implant/fibrous tissue compared to control abdominal wall. No carbon fragments were observed in lymph nodes. Increased numbers of secondary follicles, plasma cells, eosinophils, and sinus histiocytes in lymph nodes suggested immunologic stimulation of undetermined significance.     

A Combined Tension Band and Lag Screw Technique for Fixation of Olecranon Osteotomies

A combined tension band and lag screw technique for fixation of olecranon osteotomies was used in six canine clinical patients weighing 4.5 to 19 kg. After the proximal part of the ulnar shaft was exposed, a screw hole was drilled and tapped just cranial to the caudal cortex of the olecranon. An osteotomy was performed and the hole in the olecranon fragment was overdrilled to form a gliding hole. For reconstruction, the olecranon was reduced anatomically and compressed with a screw placed in lag fashion. With the trochlear notch exposed, a Kirschner wire was inserted cranial to the screw, using care not to enter the elbow joint. A double-twist figure-eight tension band wire was placed around the Kirschner wire in five dogs and around the screw in one dog. In this dog, a spiked washer was used with the screw because a small olecranon fragment had been produced by incorrect osteotomy position. A painful soft tissue swelling over the prominent washer, which resolved after implant removal, was the only complication attributed to the technique. The combined tension band wire and lag screw technique was a rapid and reliable method for fixation of olecranon osteotomies.     

高速公路养护机械维修保养管理探析

随着我国公路建设事业的不断发展,公路的等级也在持续提升,同时对公路养护所需的机械也在不断的增置,因此,在增置各种进口机械设备的过程中,高速公路养护机械化管理中的出现的问题也与日俱增。机械化养护具有效率高、安全性能强、养护质量高等特点,能有效地提高养护作业的质量及效率。在新时期新阶段,养护机械设备管理是高速公路养护领域的关键部分,也是确保现代化养护方式快速发展的重要前提。