Biomechanical Study And Clinical Curative Effect Comparison On Internal Fixation Of The Acromioclavicular Joint Dislocation

With the development of science and technology and improve people’s living standard,private cars become more and more popular,but also increasing traffic accidents,trauma caused by the acromioclavicular joint dislocation in the orthopaedic disease proportion rises apparently.People commonly use Rockwood type in clinical,including typeⅠ,Ⅱ recognized should adopt conservative treatment,but type Ⅲ above need surgery,surgery purpose to stabilize the acromioclavicular joint,promote healing of damaged tissue and restore its anatomical features.Rockwood Ⅲ acromioclavicular joint dislocation is the acromioclavicular ligament and beak lock ligament are fracture,joint gap increases with the contralateral more than a quarter.The treatment of acromioclavicular joint dislocation is varied,with different curative effects,the commonly used method is clavicular hook plate,belt line anchor nail repair beak lock ligaments,and Endobutton plate.Objective:The study by biomechanical experiments to understand the biomechanical characteristics of the three kinds of internal fixation and its fixed strength,at the same time,compare the three methods of clinical curative effect,in order to provide the basis for clinical application.Method:1 Choosing 4 fresh specimens of similar size were selected from the Department of anatomy,Hebei University.The specimens were dissected into 8 acromioclavicular joints according to the experimental requirements,keep the acromioclavicular ligament,beak lock ligament,get rid of a joint muscle and fat tissue around the trim for anterior cruciate ligament and bone structure.8 specimens were randomly assigned to four groups,clavicular hook plate for group A,with ground anchor for group B,Endobutton plates for group C,group D not do processing.Electronic universal testing machine tensile specimens with the 1.0mm/min,until the internal fixation failure.Connecting of the grating displacement sensor record stress and displacement of deformation curve and ligament stress values,the study compared three kinds of internal fixation and normal tissue fixation strength of the acromioclavicular joint.2 Retrospectively analyzed 98 cases of closed fresh unilateral Rockwood type Ⅲ acromioclavicular joint dislocation patients ’ clinical data from June 2010 to June 2010,divided into three groups according to the treatment,hook plate group of 34 cases(26 male,8 female),the average age is(35.47±4.69);with ground anchor group of 33 cases(26 male,7 female),Average(34.22±4.07);Endobutton group of 31 cases(25 male,6 female),Average(36.33±4.71).Analysis three groups of intraoperative blood loss,length of incision,complications,out internal fixation and postoperative effect of December(Karlsson standard)to compare the curative effect of three methods.Results:1 When the internal fixation failure,A set of linear load(610.28±58.31)N,maximum load(1380.31±120.29)N,linear displacement is(2.76±0.14)mm,maximum displacement(4.29± 0.38)mm,linear load for group B(804.16±92.21)N,maximum load(1694.24± 200.29)N,linear displacement is(3.35± 0.32)mm,maximum displacement(4.93± 0.47)mm,linear load for group C(811± 90.35)N,maximum load(1708± 198.85)N,linear displacement is(3.28± 0.53)mm,maximum displacement(4.86± 0.53)mm,group D linear load(601.34± 61.39)N,maximum load(1353.25± 146.47)N,linear displacement is(2.80± 0.27)mm,maximum displacement(4.19±0.42)mm.Four groups of data comparison,tensile load,strain displacement group A group D difference is smaller than group B,group C(P< 0.05),group B compared with group C statistical difference(P > 0.05).2 Collecting clinical cases in three groups of postoperative rate of good curative effect in December(94.12% vs93.94 % vs96.77 %),intraoperative blood loss(P > 0.05),were less than clavicular hook plate group(P < 0.05);Clavicular hook plate set 6 cases occurred repeatedly shoulder pain,29 cases of internal fixation,the other two groups have no shoulder pain over and over again,no implants removed.Conclusion:Through this biomechanical study and clinical curative effect comparison,proved that three kinds of internal fixation are effective ways to treat acromioclavicular joint dislocation.