Evolution of shoulder arthroplasty

In the more than century-long history of shoulder arthroplasty, scientists have gone from primitive ivory designs to high-tech implants made of rare metal alloys. Along the way, surgeons and inventors have faced challenges, made mistakes, and succeeded. This literature review reflects trends in the development of shoulder arthroplasty, evolutionary changes in endoprosthesis designs and principles of surgical treatment of shoulder pathology, from the late 19th century to the present. This paper details the stages of formation of the major modern philosophies of shoulder arthroplasty, such as those of Ch. Neer (anatomical prosthetics), P.M. Grammont (reversible prosthetics), and J. Zippel (surface prosthetics). In the 70s and 80s of the 20th century the components of shoulder prostheses as well as their fitting techniques continued to be improved from a biomechanical point of view. It was found that if the shoulder head and scapular component have different radii of curvature during arthroplasty, a shoulder-b lade mismatch is formed. A non-congruent joint (the radius of curvature of the head is smaller than the radius of curvature of the glenoid component) increases eccentric loads on the scapula joint implant, increases the risk of implant fracture, and reduces stability in the joint. However, such a joint allows reproduction of the natural gliding of the head. Restricting the required glide increases stress at the fixation site and can lead to loosening of the glenoid component. A number of studies have shown that a mismatch of more than 10 mm increases the risk of loosening and fractures of the scapular component, while a mismatch of 5-7 mm can be considered optimal, as it provides long-term survival of the glenoid component and the best reproduction of normal movements in the shoulder joint.