ABSTRACT
ObjectiveTo discuss the biomechanical properties of clavicle intramedullarynail in fixing middle fracture of clavicle and compare with the traditional plate and screw and single Kirschner wire,in order to provide scientific evidence for clinical application.MethodsFifteen adult cadaver were collected to make middle fracture of clavicle models.According to the clinical operation methods,the fracture models were divided into three groups with 5 specimens each:clavicle intramedullary nail group,plate and screwfixation group,and Kirschner wire internal fixation group.Biomechanical properties of three groups were tested and compared by experimental stress analysis method.ResultsIn the load 1000 N,the bending strength and bending stiffness of clavicle intramedullary nail group[ (57.41±4.72),( 2.28±0.17) N ] had no significant difference compared with those of plate and screw fixation group[(58.50 ±t4.14),(2.26 ±0.20) N ] (P ＞ 0.05),while had statistical significance compared with Kirschner wire internal fixation group [(51.14±4.32),(1.54±0.16) N] (P ＜ 0.05).The bending strength and bending stiffness had statistical significance between plate and screw fixation group and Kirschner wire internal fixation group (P＜ 0.05).In the torsional mechanical test,torque of clavicle intramedullary nail group had no significant difference compared with plate and screw fixation group (P ＞ 0.05 ),but had statistical significance compared with Kirschner wire internal fixation group (F =14.88,P ＜0.05).In compression test of the clavicle,the compression limit load of clavicle intramedullary nail grotup [ ( 1246±87) N ] had no statistical significance compared with plate and screw fixation group [ ( 1348±121 ) N ] ( P ＞ 0.05 ),and had significant difference compared with Kirschner wire internal fixation group [ ( 870±72 ) N ] (F =14.74,P ＜ 0.05 ).Conclusions Clavicle intramedullary nailing for treating middle fracture of clavicle can provide better biomechanical strength,stiffness and stability.Meanwhile as a minimally invasive operation,this operation method is feasible.Compared to other internal fixation methods,it has certain advantages.
ABSTRACT
Objective To design an intramedullary nail that had the same ends and could be connected to hairline pointer and employ it to fixate mid-shaft clavicular fractures. Methods Sixty adult clavicles and five fresh adult cadaveric clavicles were employed to measure full length, angle between lateral and middle segments, angle between middle and medial segments as well as the narrowest outer and inner diameters of the clavicle. The interlocked intramedullary nail with the same structure of two ends was designed and used to fixate mid-shaft clavicular fractures. The nail was inserted in retrograde manner and locking screws could be inserted at beth ends. Results The full length, angle between lateral and middle segments, angle between middle and media] segments as well as the narrowest outer and inner diameters of the clavicle were (14.82 ± 1.15) cm, 30°, 30°, (1.00±0.16) cm and (0.50± 0. 18) cm respectively. After conversely placing guide pin from the fracture end, expanding medullary cavity and adjusting the nail, the designed nail was inserted into the medullary cavity from the distal or proximal ends of the clavicle, which was locked by interlocked screws. Conclusions Self-made nail takes advantages of less surgical invasion, visible fracture reduction and stable fracture fixation for treatment of mid-shaft clavicular fractures. While the biomechanieal properties of the nail need further investigation.
ABSTRACT
[Objective]To design an intramedullary nail for mid-shaft clavicular fractures based on the anatomic study of human clavicles.[Method]Sixty adult clavicles and 5 fresh cadaveric clavicles were used to survey data about full length,angle between lateral and middle segments,angle between middle and medial segments and the narrowest outer and inner diameter of clavicle.The designed interlocked intramedullary nail was used to fix mid-shaft clavicular fractures.[Result]The full length of clavicle was about(14.82?1.15) cm.The included angle between lateral and middle segment and included angle between middle and medial segment were all about 30?,the narrowest outer diameter of clavicle was about(1.00~0.16) cm,the narrowest inner diameter of clavicle was about(0.50~0.18) cm.After conversely placing guide pin from fracture end,expanding medullary cavity and adjusting the nail,the designed nail was inserted into the medullary cavity from the distal or proximal ends of clavicle,and the proximal and distal ends of the nail were locked by interlocked screws at last.[Conclusion]Treatment of mid-shaft clavicular fractures with the self-made nail has such advantages as less surgical invasion,visible fracture reduction and stable fracture fixation.The biomechanical properties of the nail will be further investigated.
ABSTRACT
Objective To investigate two fixation methods for reconstruction of anterior cruciate ligament(ACL)with autogenous patellar tendon graft and their instant stability.Methods 15 specimens were divided into three groups.The first group was treated with 1/3 bone-patellar ligament-bone replacement and in terference screw fixation,the second group was treated with 1/3 bone-patellar ligament and Krackow locked bilateral suture,and in the third group the intact ACL was not treated.The mono-axial tensile tests were performed on a versatile hydraulic material testing machine(WE-5A)to compare the linear load,maximum load,linear straining,maximum straining,linear displacement,maximum displacement,rupture displacement,destructive energy,elastic modulus,and ultimate strength of ACL in the three groups.Results The ACL stability and rigidity in the group of 1/3 bone-patellar-bone replacement and interference screw fixation were higher than those in the other two groups.The differences between test results were statistically significant.Conclusion The ACL reconstruction with 1/3 bone-patellar ligament-bone replacement and interference screw fixation is a good method to ensure higher strength of graft and better joint stability.