Objective: To study the memory biomechanical character of anatomic distal radius Nitinol memory connector (DRMC) in treating distal radius fracture. Methods: Establishing three dimensional model and finite element ana...Objective: To study the memory biomechanical character of anatomic distal radius Nitinol memory connector (DRMC) in treating distal radius fracture. Methods: Establishing three dimensional model and finite element analysis, we calculated the stress in and around the fracture faces when distal radius fracture was fixated with DRMC. Results: Axial holding stress produced by holding part of DRMC on distal radius was 14.66 MPa. The maximum stress of holding part was 40-70 MPa, the minimum stress was 3-7 MPa,and the stress of compression part was 20-40 MPa. Conclusion: The distribution of stress produced by DRMC around the fracture line is reasonable, and axial holding stress can help stabilize fracture during earlier period. The existence of longitudal compression and memory effect can transfer fixated disused section into developed section and enhance fracture healing.展开更多
Intraarticular nonunion of tibial plateau is rare. In the literature, only 9 patients were found to be treated for intraarticular tibial plateau nonunion and they got varying results. Internal fixation along with bone...Intraarticular nonunion of tibial plateau is rare. In the literature, only 9 patients were found to be treated for intraarticular tibial plateau nonunion and they got varying results. Internal fixation along with bone grafting was done as a standard treatment in all cases. We treated 4 different profile cases of intraarticular tibial plateau nonunion in our institution by 4 different methods. We treated these cases with plaster of paris cast, internal fixation along with bone graft, arthrodesis with K-nail and total knee replacement. Case 1 was treated with plaster of paris （POP） cast as the patient refused surgery. The fracture was united and the patient was fully satisfied with full range of motion despite valgus malalignment. Case 2 was managed with open reduction internal fixation along with bone grafting. Thepatient had a good union and got full range of motion at the knee joint. Case 3 was treated with total knee arthroplasty due to her old age and got satisfactory result. Case 4 was an infected nonunion. Arthrodesis was done and the patient could walk with full weight bearing independently. We conclude that internal fixation along with bone grafting may not be suitable in all cases of intraarticular nonunion of tibial plateau. Causes of nonunion, present condition and range of motion of the knee joint, as well as the age of patient should be all considered and the treatment should be individualised according to each patient＇s situation.展开更多
Objective: To sutdy the mechanical properties and the clinical results of minimum-contact plate in the treatment of fractures. Methods: Four-point bending and torsion tests were conducted to compare the new minimum co...Objective: To sutdy the mechanical properties and the clinical results of minimum-contact plate in the treatment of fractures. Methods: Four-point bending and torsion tests were conducted to compare the new minimum contact plate (MCP) with dynamic compression plate (DCP) and limited contact dynamic compression plate (LC-DCP). The fracture healing time and growth of bony callus were observed in 29 cases of long bone fracture fixed with MCP to evaluate the advantages of this kind of plate. Results: The 29 patients who underwent MCP were followed up from 6 to 14 months. The average healing time for femoral, tibial and humeral fractures was 12, 13 and 10 weeks, respectively. All fractures were healed. No displacement of fracture, screw pullout, deformation or break of the plate were found. Conclusions: The bending stiffness of MCP is significantly greater than that of DCP and LC-DCP (P< 0.05). MCP can protect the periosteal blood supply against avascular osseous necrosis and accelerate bone healing. It is a kind of reliable and effective plate in treatment of fractures.展开更多
Objective： To evaluate the interface characteristics of the new-designed locking plate （LP） and limited contact-dynamic compression plate （LC-DCP） and compare the fracture healing between LP and LC-DCP in a goat ...Objective： To evaluate the interface characteristics of the new-designed locking plate （LP） and limited contact-dynamic compression plate （LC-DCP） and compare the fracture healing between LP and LC-DCP in a goat tibia fracture model. Methods： Eight-hole LP and LC-DCP were applied to fix fresh goat tibiae in a reproducible manner. The average pressure, force and interface contact area were calculated using Fuji prescale pressure sensitive film interposed among the plate and the bone and image analysis system, Eighthole LP and LC-DCP were applied to each tibia in a goat tibia fracture model. The fracture healing was evaluated by X-ray photography at postoperative 8 weeks. The goats were sacrificed at postoperative 12 weeks. Three-point bending test was conducted in the tibiae. Results： The interface contact of LP system was smaller than that ofLC-DCP （P〈0.05）, while interface contact force of LP system was higher than that of LC-DCP （P〈0.05）. Radiographs revealed that the fracture line disappeared in the LP group, while the fracture line was visible in DCP group at postoperative 8 weeks. At postoperative 12 weeks, the bending strength and bending load of fractured tibia were higher in LP group than in DCP group, respectively.展开更多
文摘Objective: To study the memory biomechanical character of anatomic distal radius Nitinol memory connector (DRMC) in treating distal radius fracture. Methods: Establishing three dimensional model and finite element analysis, we calculated the stress in and around the fracture faces when distal radius fracture was fixated with DRMC. Results: Axial holding stress produced by holding part of DRMC on distal radius was 14.66 MPa. The maximum stress of holding part was 40-70 MPa, the minimum stress was 3-7 MPa,and the stress of compression part was 20-40 MPa. Conclusion: The distribution of stress produced by DRMC around the fracture line is reasonable, and axial holding stress can help stabilize fracture during earlier period. The existence of longitudal compression and memory effect can transfer fixated disused section into developed section and enhance fracture healing.
文摘Intraarticular nonunion of tibial plateau is rare. In the literature, only 9 patients were found to be treated for intraarticular tibial plateau nonunion and they got varying results. Internal fixation along with bone grafting was done as a standard treatment in all cases. We treated 4 different profile cases of intraarticular tibial plateau nonunion in our institution by 4 different methods. We treated these cases with plaster of paris cast, internal fixation along with bone graft, arthrodesis with K-nail and total knee replacement. Case 1 was treated with plaster of paris （POP） cast as the patient refused surgery. The fracture was united and the patient was fully satisfied with full range of motion despite valgus malalignment. Case 2 was managed with open reduction internal fixation along with bone grafting. Thepatient had a good union and got full range of motion at the knee joint. Case 3 was treated with total knee arthroplasty due to her old age and got satisfactory result. Case 4 was an infected nonunion. Arthrodesis was done and the patient could walk with full weight bearing independently. We conclude that internal fixation along with bone grafting may not be suitable in all cases of intraarticular nonunion of tibial plateau. Causes of nonunion, present condition and range of motion of the knee joint, as well as the age of patient should be all considered and the treatment should be individualised according to each patient＇s situation.
文摘Objective: To sutdy the mechanical properties and the clinical results of minimum-contact plate in the treatment of fractures. Methods: Four-point bending and torsion tests were conducted to compare the new minimum contact plate (MCP) with dynamic compression plate (DCP) and limited contact dynamic compression plate (LC-DCP). The fracture healing time and growth of bony callus were observed in 29 cases of long bone fracture fixed with MCP to evaluate the advantages of this kind of plate. Results: The 29 patients who underwent MCP were followed up from 6 to 14 months. The average healing time for femoral, tibial and humeral fractures was 12, 13 and 10 weeks, respectively. All fractures were healed. No displacement of fracture, screw pullout, deformation or break of the plate were found. Conclusions: The bending stiffness of MCP is significantly greater than that of DCP and LC-DCP (P< 0.05). MCP can protect the periosteal blood supply against avascular osseous necrosis and accelerate bone healing. It is a kind of reliable and effective plate in treatment of fractures.
文摘Objective： To evaluate the interface characteristics of the new-designed locking plate （LP） and limited contact-dynamic compression plate （LC-DCP） and compare the fracture healing between LP and LC-DCP in a goat tibia fracture model. Methods： Eight-hole LP and LC-DCP were applied to fix fresh goat tibiae in a reproducible manner. The average pressure, force and interface contact area were calculated using Fuji prescale pressure sensitive film interposed among the plate and the bone and image analysis system, Eighthole LP and LC-DCP were applied to each tibia in a goat tibia fracture model. The fracture healing was evaluated by X-ray photography at postoperative 8 weeks. The goats were sacrificed at postoperative 12 weeks. Three-point bending test was conducted in the tibiae. Results： The interface contact of LP system was smaller than that ofLC-DCP （P〈0.05）, while interface contact force of LP system was higher than that of LC-DCP （P〈0.05）. Radiographs revealed that the fracture line disappeared in the LP group, while the fracture line was visible in DCP group at postoperative 8 weeks. At postoperative 12 weeks, the bending strength and bending load of fractured tibia were higher in LP group than in DCP group, respectively.
