Biomechanical comparison of bionic, screw and Endobutton fixation in the treatment of tibiofibular syndesmosis injuries.
BACKGROUND
The two prevalent fixation methods in the treatment of syndesmosis injuries, the rigid screw fixation and flexible Endobutton fixation, are not without issues; thus, we have designed a novel bionic fixation method which combines the features of both rigid and flexible fixations. The aim of this study was to compare the biomechanical properties of the bionic fixation to the screw and Endobutton fixations.


METHODS
Six normal fresh-frozen legs from amputation surgery were used. After initial tests of intact syndesmosis, screw, bionic and Endobutton fixations were performed sequentially for each specimen. Axial loading as well as rotation torque were applied, in five different ankle positions: neutral position, dorsiflexion, plantar flexion, varus, and valgus. The displacement of the syndesmosis and the tibial strain were analysed using a biomechanical testing system.


RESULTS
Whether receiving axial loading or rotation torque, in most situations (neutral position, dorsiflexion, varus, plantar flexion with low loading, valgus with high loading, internal and external rotation), the bionic group and Endobutton group had comparable displacements, and there was no significant difference among the intact, bionic, and Endobutton groups; whereas the displacements of the screw group were smaller than any of the other three groups. Results of the tibial strain were similar with that of the displacement.


CONCLUSIONS
The bionic fixation at least equals the performance of Endobutton fixation; it also allows more physiologic movement of the syndesmosis when compared to the screw fixation and may serve as a viable option for the fixation of the tibiofibular syndesmosis.
Department of Anatomy, Hebei Medical University, No.361 Zhongshan East Road, Chang'an District, Shijiazhuang, Hebei, 050011, China.|Trauma Emergency Center, The Third Hospital of Hebei Medical University, Hebei Province, Shijiazhuang, 050051, China.|Orthopaedic Research Institute of Hebei Province & Key Laboratory of Orthopaedic Biomechanics of Hebei Province, No.139 Ziqiang Road, Qiaoxi District, Shijiazhuang, Hebei, 050051, China.
Lin
L
Wang
Department of Anatomy, Hebei Medical University, No.361 Zhongshan East Road, Chang'an District, Shijiazhuang, Hebei, 050011, China.
Baozhi
B
Wang
Department of Orthopaedics, The Third Hospital of Hebei Medical University, Hebei Province, Shijiazhuang, 050051, China.
Guohui
G
Xu
Trauma Emergency Center, The Third Hospital of Hebei Medical University, Hebei Province, Shijiazhuang, 050051, China.|Orthopaedic Research Institute of Hebei Province & Key Laboratory of Orthopaedic Biomechanics of Hebei Province, No.139 Ziqiang Road, Qiaoxi District, Shijiazhuang, Hebei, 050051, China.
Zhaohui
Z
Song
Department of Anatomy, Hebei Medical University, No.361 Zhongshan East Road, Chang'an District, Shijiazhuang, Hebei, 050011, China. cuihx1120@yeah.net.
Huixian
H
Cui
Trauma Emergency Center, The Third Hospital of Hebei Medical University, Hebei Province, Shijiazhuang, 050051, China. zhangyz_dr@sina.cn.|Orthopaedic Research Institute of Hebei Province & Key Laboratory of Orthopaedic Biomechanics of Hebei Province, No.139 Ziqiang Road, Qiaoxi District, Shijiazhuang, Hebei, 050051, China. zhangyz_dr@sina.cn.
Yingze
Y
Zhang
D000328:Adult; D064386:Ankle Fractures / Q000601:surgery*; D016512:Ankle Injuries / Q000601:surgery*; D000843:Ankle Joint / Q000503:physiopathology / Q000601:surgery; D001696:Biomechanical Phenomena; D001701:Bionics; D001863:Bone Screws; D002102:Cadaver; D005260:Female; D005360:Fibula / Q000293:injuries*; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013977:Tibia / Q000293:injuries*
Ankle fracture; Biomechanical; Surgical fixation; Syndesmosis