STRESS-DEFORMED STATE OF THE ACROMIOCLAVICULAR JOINT IN CASE OF DAMAGE TO THE UPPER ACROMIOCLAVICULAR LIGAMENT SUPERIOR AND VARIOUS METHODS OF FIXATION

Abstract

During the operative stabilization of the acromial end of the clavicle (AEC) for its dislocation, there are two ways: clavicle – beaklike process, clavicle – acromial process. Fixation of the AEC to the acromial process of the scapula is a priority. Competing metal structures are the hook plate and the Weber method. The significant disadvantages of using the Weber method of fixation are the migration of the tips and the violation of their integrity andthe wire. Objective. To conduct a comparative analysis of the fixation of the acromial end of the clavicle according to Weber, hook plate and the proposed construction, by studying the stressed-deformed state of the clavicular-acromial joint in case of damage to the lig. acromioclavicular superior and various methods of fixation. Methods. A finite-element model of the clavicular-acromial joint was constructed. Damage to the ligaments was modeled. claviculo-acoacromiale superior, as well as fixation of AEC in three ways: according to Weber, hook plate and the proposed construction. Results. The best results, from the point of view of reducing the level of stresses in intact ligaments, are provided by fixation of the AEC according to Weber, but its use leadsto an increase in the level of stresses on the AEC and the acromial process of the scapula, which can cause destruction of the latter. The hinge-type fixator provides the best stress distribution, both in the bony elements of the model and in intact ligaments. The hook plate holder occupies an average position,both in terms of the level of stress and the magnitude of the relative deformations in the ligaments. Conclusions. Weber fixation provides the best results for reducing the level of stresses and relative strains in the intact ligaments, but leads to a several-fold increase in the level of stresses on the AEC and acromial process of the scapula. The hook plate holder occupies an average position, both in terms of the stress level and the magnitude of the relativedeformations in the ligaments. The proposed design provides the best stress distribution, both in the bony elements of the model and in the intact ligaments.