The locking plate and percutaneous crossing metallic screws and crossing absorbable screws have been used clinically to treat intra-articular calcaneal fractures, but little is known about the biomechanical difference...The locking plate and percutaneous crossing metallic screws and crossing absorbable screws have been used clinically to treat intra-articular calcaneal fractures, but little is known about the biomechanical differences between them. This study compared the biomechanical stability of calcaneal fractures fixed using a locking plate and crossing screws. Three-dimensional finite-element models of intact and fractured calcanei were developed based on the CT images of a cadaveric sample. Surgeries were simulated on models of Sanders type III calcaneal fractures to produce accurate postoperative models fixed by the three implants. A vertical force was applied to the superior surface of the subtalar joint to simulate the stance phase of a walking gait. This model was validated by an in vitro experiment using the same calcaneal sample. The intact calcaneus showed greater stiffness than the fixation models. Of the three fixations, the locking plate produced the greatest stiffness and the highest von Mises stress peak. The micromotion of the fracture fixated with the locking plate was similar to that of the fracture fixated with the metallic screws but smaller than that fixated with the absorbable screws. Fixation with both plate and crossing screws can be used to treat intra-articular calcaneal fractures. In general, fixation with crossing metallic screws is preferable because it provides sufficient stability with less stress shielding.展开更多
Objective： To evaluate the effectiveness of the rigid internal fixation for comminuted and redisplaced zygomatic arch fractures by modified preauriculartemporal approach with the resorbable bone fixation. Methods： ...Objective： To evaluate the effectiveness of the rigid internal fixation for comminuted and redisplaced zygomatic arch fractures by modified preauriculartemporal approach with the resorbable bone fixation. Methods： Totally twenty patients aged from 14 to 68 years and admitted to our hospital between September 2006 and June 2011 were reviewed, of whom seventeen had a unilateral comminuted zygomatic arch fracture and three re displaced arch fracture after failed closed reduction. The fracture segments were aligned to restore the preinjury form of the arch by rigid fixation with resorbable plates and screws through a modified preauriculartemporal incision. Results： The fractures were well reduced, preauricu lartemporal scar and lateral facial contour were aestheti cally satisfying, and no case had limited mouth opening as well as facial palsy. The resorbable plates were not palpated one year after the operation. Conclusion： The rigid internal fixation through the preauriculartemporal approach with the resorbable bone is an effective method for the comminuted and redisplaced zyomatic arch fractures.展开更多
基金supported by the Shanghai Municipal Commission of Health and Family Planning(20144Y0250,20134Y207)the National Natural Science Foundation of China(11302154,11272273)The Hong Kong Research Grant Council GRF(PolyU152216/14E,PolyU5326/11E)
文摘The locking plate and percutaneous crossing metallic screws and crossing absorbable screws have been used clinically to treat intra-articular calcaneal fractures, but little is known about the biomechanical differences between them. This study compared the biomechanical stability of calcaneal fractures fixed using a locking plate and crossing screws. Three-dimensional finite-element models of intact and fractured calcanei were developed based on the CT images of a cadaveric sample. Surgeries were simulated on models of Sanders type III calcaneal fractures to produce accurate postoperative models fixed by the three implants. A vertical force was applied to the superior surface of the subtalar joint to simulate the stance phase of a walking gait. This model was validated by an in vitro experiment using the same calcaneal sample. The intact calcaneus showed greater stiffness than the fixation models. Of the three fixations, the locking plate produced the greatest stiffness and the highest von Mises stress peak. The micromotion of the fracture fixated with the locking plate was similar to that of the fracture fixated with the metallic screws but smaller than that fixated with the absorbable screws. Fixation with both plate and crossing screws can be used to treat intra-articular calcaneal fractures. In general, fixation with crossing metallic screws is preferable because it provides sufficient stability with less stress shielding.
文摘Objective： To evaluate the effectiveness of the rigid internal fixation for comminuted and redisplaced zygomatic arch fractures by modified preauriculartemporal approach with the resorbable bone fixation. Methods： Totally twenty patients aged from 14 to 68 years and admitted to our hospital between September 2006 and June 2011 were reviewed, of whom seventeen had a unilateral comminuted zygomatic arch fracture and three re displaced arch fracture after failed closed reduction. The fracture segments were aligned to restore the preinjury form of the arch by rigid fixation with resorbable plates and screws through a modified preauriculartemporal incision. Results： The fractures were well reduced, preauricu lartemporal scar and lateral facial contour were aestheti cally satisfying, and no case had limited mouth opening as well as facial palsy. The resorbable plates were not palpated one year after the operation. Conclusion： The rigid internal fixation through the preauriculartemporal approach with the resorbable bone is an effective method for the comminuted and redisplaced zyomatic arch fractures.
