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 observe the therapeutic effect of absorbable screw in medial malleolus fracture and discuss its clinical application in orthopedics. Methods： A total of 129 patients with simple medial malleolus fract...Objective： To observe the therapeutic effect of absorbable screw in medial malleolus fracture and discuss its clinical application in orthopedics. Methods： A total of 129 patients with simple medial malleolus fracture were studied. Among them, 64 patients were treated with poly-D, L-lactic acid （PDLLA） absorbable screws, while the others were treated with metal screws. All the patients were followed up for 12-20 months （averaged 18.4 months） and the therapeutic effect was evaluated according to the American Orthopaedic Foot and Ankle Society clinical rating systems. Results： In absorbable screw group, we obtained excel- lent and good results in 62 cases （96.88%）; in steel screw group, 61 cases （93.85%） achieved excellent and good results. There was no significant difference between the two groups. Conclusion： In the treatment of malleolus fracture, absorbable screw can achieve the same result compared with metal screw fixation. Absorbable screw is preferred due to its advantages of safety, cleanliness and avoiding the removal procedure associated with metallic implants.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 observe the therapeutic effect of absorbable screw in medial malleolus fracture and discuss its clinical application in orthopedics. Methods： A total of 129 patients with simple medial malleolus fracture were studied. Among them, 64 patients were treated with poly-D, L-lactic acid （PDLLA） absorbable screws, while the others were treated with metal screws. All the patients were followed up for 12-20 months （averaged 18.4 months） and the therapeutic effect was evaluated according to the American Orthopaedic Foot and Ankle Society clinical rating systems. Results： In absorbable screw group, we obtained excel- lent and good results in 62 cases （96.88%）; in steel screw group, 61 cases （93.85%） achieved excellent and good results. There was no significant difference between the two groups. Conclusion： In the treatment of malleolus fracture, absorbable screw can achieve the same result compared with metal screw fixation. Absorbable screw is preferred due to its advantages of safety, cleanliness and avoiding the removal procedure associated with metallic implants.
