Total shoulder arthroplasty. Factors influencing prosthetic design.

There are many anatomic and biomechanical factors that define the structure and function of the normal glenohumeral joint. These factors influence the design and function of the prosthetic shoulder. Our best efforts in shoulder design should reflect an attempt to reproduce the normal structure-function relationships of the natural glenohumeral joint. Prosthetic design must also take into account the variable anatomic abnormalities associated with the pathologic condition. Prosthetic designs should attempt to facilitate the surgical correction of this pathology, with the goal of reproducing normal anatomy. Optimal prosthetic reconstruction of the shoulder is dependent on prosthetic design, prosthetic soft tissues, postoperative healing and rehabilitation, and the long-term biologic response to the implant. The success of any prosthetic reconstruction is dependant on many factors, and in some cases, normal anatomy and function cannot be achieved entirely by prosthetic design.