PLA is presently considered as the most attractive compound for temporarytherapeutic application in the biomedical field. In this paper we give an overview of thepresent knowledge on the degradation behavior,processin...PLA is presently considered as the most attractive compound for temporarytherapeutic application in the biomedical field. In this paper we give an overview of thepresent knowledge on the degradation behavior,processing technology of PLA and itsapplication in the fixation of bone fracture.展开更多
A high Mw of PLLA was synthesized, it intended to be used in the manufacture ofbioabsorbable screw applied in bone fracture internal fixation. The optical reactionconditions have been discussed.
Purpose： Tibial pilon fractures remain challenging for an orthopaedic surgeon to repair. External fixation （ExFix） and open reduction and internal fixation （ORIF） are two widely used methods for repairing tibial ...Purpose： Tibial pilon fractures remain challenging for an orthopaedic surgeon to repair. External fixation （ExFix） and open reduction and internal fixation （ORIF） are two widely used methods for repairing tibial pilon fractures. However, conclusions of comparative studies regarding which method is superior are controversial. Our aim is to compare ORIF and ExFix and clarify which method is better in terms of reduction and union results and major complications. Methods： A computerized research of MEDLINE, EMBASE, Springer, and Cochrane Library （before December 2014） for studies of any design comparing ORIF and ExFix was conducted. Weighted mean difference （WMD）, risk ratio （RR） and corresponding 95% confidence intervals （Cl） were used for esti- mating the effects of the two methods. Statistical analyses were done using Review Manager Version 5.2. Results： Ten cohort studies and one randomized clinical trial were included in our ultimate analysis. And the analysis found no significant difference between the two methods in deep infection （p = 0.13）, reduction （p = 0.11）, clinical evaluation （p = 0.82）, post-traumatic arthrosis Cp = 0.87）, and union time （p = 0.35）. Besides, ExFix group was found to have a higher rate of superficial infection （p = 0.001）, malunion （p = 0.01） and nonunion （p= 0.02）, but have a lower risk of unplanned hardware removal （p = 0.0002）. Conclusions： We suggest that ORIF has a relatively lower incidence rate of superficial infection, malunion and nonunion, hut a higher rate of unplanned hardware removal. No difference was found in deep infection, reduction, clinical evaluation. ~ost-traumatic arthrosis and union time.展开更多
Starling with the L- and D,L-lactide copolymer (L:DL = 9:1) [P(L-DL)LA] of M-W = 32.1 x 10(4), rods were obtained through a two stage process: (1) melt-extrusion at 155 degreesC, and (2) hot-drawing at 90 degreesC to ...Starling with the L- and D,L-lactide copolymer (L:DL = 9:1) [P(L-DL)LA] of M-W = 32.1 x 10(4), rods were obtained through a two stage process: (1) melt-extrusion at 155 degreesC, and (2) hot-drawing at 90 degreesC to various drawing ratios. The molecular weight of P(L-DL)LA fell to 9.3 x 10(4) as a consequence of the production process. The crystallization and molecular orientation of P(L-DL)LA developed as a result of the hot-drawing. The mechanical strengths of the rods increase with the drawing ratio; The maximum for tensile strength, bending strength, bending modulus, and shear strength are 329 MPa, 237 MPa, 8.8 GPa, and 157 MPa, respectively.展开更多
文摘PLA is presently considered as the most attractive compound for temporarytherapeutic application in the biomedical field. In this paper we give an overview of thepresent knowledge on the degradation behavior,processing technology of PLA and itsapplication in the fixation of bone fracture.
文摘A high Mw of PLLA was synthesized, it intended to be used in the manufacture ofbioabsorbable screw applied in bone fracture internal fixation. The optical reactionconditions have been discussed.
文摘Purpose： Tibial pilon fractures remain challenging for an orthopaedic surgeon to repair. External fixation （ExFix） and open reduction and internal fixation （ORIF） are two widely used methods for repairing tibial pilon fractures. However, conclusions of comparative studies regarding which method is superior are controversial. Our aim is to compare ORIF and ExFix and clarify which method is better in terms of reduction and union results and major complications. Methods： A computerized research of MEDLINE, EMBASE, Springer, and Cochrane Library （before December 2014） for studies of any design comparing ORIF and ExFix was conducted. Weighted mean difference （WMD）, risk ratio （RR） and corresponding 95% confidence intervals （Cl） were used for esti- mating the effects of the two methods. Statistical analyses were done using Review Manager Version 5.2. Results： Ten cohort studies and one randomized clinical trial were included in our ultimate analysis. And the analysis found no significant difference between the two methods in deep infection （p = 0.13）, reduction （p = 0.11）, clinical evaluation （p = 0.82）, post-traumatic arthrosis Cp = 0.87）, and union time （p = 0.35）. Besides, ExFix group was found to have a higher rate of superficial infection （p = 0.001）, malunion （p = 0.01） and nonunion （p= 0.02）, but have a lower risk of unplanned hardware removal （p = 0.0002）. Conclusions： We suggest that ORIF has a relatively lower incidence rate of superficial infection, malunion and nonunion, hut a higher rate of unplanned hardware removal. No difference was found in deep infection, reduction, clinical evaluation. ~ost-traumatic arthrosis and union time.
文摘Starling with the L- and D,L-lactide copolymer (L:DL = 9:1) [P(L-DL)LA] of M-W = 32.1 x 10(4), rods were obtained through a two stage process: (1) melt-extrusion at 155 degreesC, and (2) hot-drawing at 90 degreesC to various drawing ratios. The molecular weight of P(L-DL)LA fell to 9.3 x 10(4) as a consequence of the production process. The crystallization and molecular orientation of P(L-DL)LA developed as a result of the hot-drawing. The mechanical strengths of the rods increase with the drawing ratio; The maximum for tensile strength, bending strength, bending modulus, and shear strength are 329 MPa, 237 MPa, 8.8 GPa, and 157 MPa, respectively.
