[Biomechanical analysis of lateral malleolar's anatomical hook-plate for fixation of Weber A-type ankle fracture].
OBJECTIVE
To evaluate the biomechanical action of lateral malleolar's anatomical hook-plate in treating Weber A-type ankle fracture.


METHODS
Forty-eight cadaveric specimens of adult's inferior extremities from June 2005 to October 2006 were observed, consisting of 26 males and 22 females and aged 18-55 years. The external malleolus of the specimens were transected by using a wire saw at the ankle joint level, and then were divided into 4 groups randomly (groups A, B, C and D). Four distinct internal fixation instruments were used: lateral malleolar's anatomical hook-plate in group A, general screws in group B, 1/3 tubular plate in group C and standard tension band in group D. Each group was further divided into 2 subgroups, A1-D1 and A2-D2. A1-D1 groups underwent anti-pressure and A2-D2 groups underwent anti-torsion biomechanically comparative analysis.


RESULTS
The peak values of anti-pressure experiments in groups A1-D1 were (799.83 +/- 105.47), (699.17 +/- 63.81), (598.83 +/- 123.14) and (453.00 +/- 111.67) N respectively, group A1 was significantly higher than groups B1, C1 and D1 (P < 0.01); meanwhile, the peak values of anti-torsion experiments in groups A2-D2 were (37.17 +/- 1.81), (30.33 +/- 2.22), (20.50 +/- 2.92), (24.83 +/- 3.47) Nm respectively, group A2 was significantly higher than groups B2, C2 and D2 (P < 0.01).


CONCLUSIONS
The lateral malleolar's anatomical hook-plate represents a definite biomechanical superiority, when compared with other 3 internal fixation instruments in treating fracture of external malleolus.
Sun
Tao
T
Department of Orthopedics and Traumatology, Yantai Mountain Hospital, Yantai Shandong, 264001, PR China. sunt519@126.com
Wang
Dan
D
Zhou
Zhiyong
Z
Yu
Ruixiang
R
D000293:Adolescent; D000328:Adult; D016512:Ankle Injuries / Q000601:surgery*; D001696:Biomechanical Phenomena; D001860:Bone Plates; D016267:External Fixators; D005260:Female; D005592:Fracture Fixation / Q000295:instrumentation; D050723:Fractures, Bone / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic