Biomechanical analysis of different fixation methods of acromioclavicular joint dislocations on acromioclavicular and sternoclavicular joints motions

Abstract

The injury of acromioclavicular joint is one of the causes limitation function of the shoulder joint. Choice of fixation methods of acromioclavicular joint dislocation is actual topic to research. Objective: to study by a biomechanical experiment and to substantiate influence of different fixation methods of acromioclavicular joint dislocation on range of motion of acromioclavicular and sternoclavicular joints during the upper extremity elevation. Methods: 6 prototypes of a natural skeleton 3D technology from ADS plastic were used. The capsuloligamentous components, dynamic and static stabilizations of acromioclavicular and sternoclavicular joint were modeled from artificial materials. Each model of acromioclavicular dislocation was fixed by 6 different fixations methods: «intact joint», «fixation by Weber», «Bosworth screw», «Hook-plate», «DogBone», «External fixation». During the experimental study, the range of motions was fixed in acromioclavicular and sternoclavicular joints in 90 and 180 degrees of arm elevation, each experiment was repeated 5 times. Results: range of motion in acromioclavicular and sternoclavicular joints in position of 90 degree of arm elevation, with fixation of acromioclavicular joint dislocation by Hook-plate and system of 2 mini plates and suture material (DogBone), in position of 180 degree of arm elevation with fixation of «DogBone» was physiological. Other methods of fixation — «Bosworth screw», «Weber fixation», «External fixation», «Hook plate» limited the range of motion in the acromioclavicular joint and increase motion in the sternoclavicular joint at maximal arm elevation. Conclusions: fixation of acromioclavicular joint dislocation by 2 mini plates and suture material (DogBone) gives physiological range of motion in acromioclavicular and sternoclavicular joints during arm elevation.