ObjectiveTo compare difference in the establishment of animal model of cartilage defect by resection of medial collateral ligament and meniscus and by cartilage excavation so as to provide a proper way for the choose of animal model preparation of catilage defect. MethodsTen healthy beagles, male or female, weighing 5.0-10.0 kg, were randomly divided into 3 groups. Resection of knee collateral ligament and meniscus was performed on 4 beagles of group A, cartilage excavation of knee-joints in 4 beagles of group B, and no treatment on 2 beagles of group C as controls. At 16 weeks after modeling, MRI, gross observation, HE staining, Safranin O staining, and toluidine blue staining were performed, and Osteoarthritis Research Society International (OARSI) score was recorded. ResultsMRI and histology observation showed no obvious cartilage defect in group A; obvious cartilage defects were observed in group B and gross observation showed dramatic dark red cartilage defects. OARSI score was significantly lower in group A (0.940±0.574) than group B (4.500±0.516) (t=18.461, P=0.000). ConclusionThe cartilage excavation is better than resection of both meniscus and medial collateral ligament, which provides a good method of establishing an animal model of cartilage defect at 16 weeks after operation.
ObjectiveTo evaluate the effect of nickel-titanium three-dimensional memory alloy mesh combined with autologous bone for living model of canine tibial plateau collapse fracture by biomechanical testing. MethodsSixteen healthy 12-month-old Beagle dogs were randomly divided into 4 group, 4 dogs in each group. The dogs were used to establish the tibial plateau collapse fracture model in groups A, B, and C. Then, the nickel-titanium three-dimensional memory alloy mesh combined with autologous bone (the fibula cortical bone particles), the artificial bone (nano-hydroxyapatite), and autologous fibula cortical bone particles were implanted to repair the bone defects within 4 hours after modeling in groups A, B, and C, respectively; and the plate and screws were fixed outside the bone defects. The dogs were not treated in group D, as normal control. At 5 months after operation, all animals were sacrificed and the tibial specimens were harvested and observed visually. The destructive axial compression experiments were carried out by the biomechanical testing machine. The displacement and the maximum failure load were recorded and the axial stiffness was calculated. ResultsAll animals stayed alive after operation, and all incisions healed. After 1-3 days of operation, the animals could stand and move, and no obvious limb deformity was found. The articular surfaces of the tibial plateau specimens were completely smooth at 5 months after operation. No obvious articular surface collapse was observed. The displacement and maximum failure load of specimens in groups A and D were significantly higher than those in groups B and C (P<0.05). But no significant difference was found between groups A and D and between groups B and C (P>0.05). ConclusionThe nickel-titanium three-dimensional memory alloy mesh combined with autologous bone for subarticular bone defect of tibial plateau in dogs has good biomechanical properties at 5 months after operation, and has better axial stiffness when compared with the artificial bone and autologous bone graft.
ObjectiveTo verify the feasibility of a self-designed magnetic anchoring and traction device (MATD) for assisting two-port video-assisted thoracoscopic esophagectomy.MethodsThree Beagle dogs were selected as animal models with age ranging from 1-6 years and weight ranging from 8-12 kg, and they underwent two-port video-assisted thoracoscopic esophagectomy after general anesthesia. We used the MATD to retract the esophagus to different directions, which assisted mobilizing esophagus, detecting the nerves along esophagus and dissecting paraesophagus lymph nodes. The operation time, blood loss and feasibility of the MATD were recorded.ResultsWith the aid of the MATD, we successfully retracted and mobilized the esophagus, detected the nerves and dissected the lymph nodes in three Beagle dog models. During the operation, the MATD provided sufficient and steady traction of esophagus to achieve a good exposure of the operative field, effectively decreasing the interference between working instruments. The MATD worked well. The mean operation time was 30 min, and the mean intraoperative blood loss was about 10 mL.ConclusionIt is effective to use the MATD to assist retracting esophagus during video-assisted thoracoscopic esophagectomy. The magnetic anchoring and traction technique can assist to expose the surgical field, decrease the interference between the working instruments and have the potential clinical application.