The Development Of Micromovement And Anatomical Acromioclavicular Plate And Its Biomechanical Study

Objective: To develop a new kind of internal fixture, micromovement and anatomicalacromioclavicular plate, which was accorded with micromovement of acromioclavicularjiont. In order to treat the dislocation of acromioclavicular jiont and facture of distalclavicle. By the study of biomechanic test, whether acromioclavicular plate was accordedwith micromove- merit of acromioclavicular jiont or not.Methods: 1,The acromioclavicular plate was designed according to anatomical andmicromovement of acromioclavicular jiont made of Ti-6A1-4V (GB/T13810-1997) titaniumalloy; 2,Biomechanic test: Ten pairs of fresh adult moist cadaveric upper limbs specimenswere used to experiment. Defferent sign object was install on distal clavicle and acromion,each specimens was tested in turn: normal, acromioclavicular ligament rupture,acromioclavicular ligament and coracoclavicular ligament rupture,tension band wiringfixtion,AO-plate fixtion,micromovement and anatomical acromioclavicular plate fixtionand Dewar' s procedure. Bring each speciment to bear 50N in each state, after bring eachspeciment to bear, measure space and angle of the two sign object in x,y,z axis(x delegateclavicle axis, y delegate coronal section, z delegate sagittal axis). Biomeehanic test. wasperformed on all specimens and the data were analysed by statistic sPss 12.0 software.Results: 1,Micromovement and anatomical acromioclavicular plate has been developed. 2,The results of biomechanic test"①In the X axis, there was not significance betweennormal state and micromovement and anatomical acromioclavicular plate in the displacementand circumrotation (P＞0.05). the micromovement and anatomical acromioclavicular plateunlimit the movement of the AC jiont. there was obvious significance among normal state,tension band wiring and AO-plate fixtion in the displacement and circumrotation (P＜0.01),tension band wiring and AO-plate fixtion limit the movement of the AC jiont, there was not significance between normal state and Dewar' s procedure in the displacement andcircumrotation (P＞0.05).②In the Y axis, There was not significance between normal stateand micromovement and anatomical acromioclavicular plate in the displacement andcircumrotation (P＞0.05). the micromovement and anatomical acromioclavicular plateunlimit the movement of the AC jiont, there was obvious significance betweeen normal stateand tension band wiring fixtion in the displacement and circumrotation (P＜0.01), tensionband wiring fixtion limit the movement of the AC jiont. There was not significance betweeennormal state and AO-plate fixtion in the displacement (P=0.89＞0.05), but There wasobvious significance betweeen normal state and AO-plate fixtion in the circumrotation (P＜0.01). After the AO-plate fixtion, the AC jiont can movement displacement in the Yaxis, but it can not circumrotate in the Y axis. there was not significance between normal stateand Dewar' s procedure in the displacement and circumrotation.③In the Z axis, Therewas not significance between normal state and micromovement and anatomicalacromioclavicular plate in the displacement and circurnrotation (P＞0.05) themicromovement and anatomical acromioclavicular plate unlimit the movement of the ACjiont in the Z axis. there was obvious significance betweeen normal state and tension bandwiring fixtion in the displacement and circumrotation (P＜0.01). There was significancebetweeen normal state and AO-plate fixtion in the displacement (P＜0.05), but There wasnot significance betweeen normal state and AO-plate fixtion in the circumrotation(P=0.87＞0.5). After the AO-plate fixtion, the AC jiont can not movement displacement in the Zaxis, but it can circumrotate in arrowy axis. there was not significance between normal stateand Dewar' s procedure in the displacement and circumrotation.Conclusion: Micromovement and anatomical acromioclavicular plate has micro- movementin the three dimensional space, according with the movement of acromioclavicular jiont.Themovement of acromioclavicular jiont was limited by tension band wiring fixtion. Thedisplacement of acromioclavicular jiont uninfluenced was by the AO-plate fixtion in the Yaxis, and the circumrotation of the acromioclavicular jiont was uninfluenced by the AO-platefixtion in the Z axis.