Humeral Head, Stem Design and Fixation in Shoulder Arthroplasty

Following Neer’s original humeral design in the 1950’s with monoblock stems in three sizes, over 70 different shoulder arthroplasty systems have been developed.  Modern prosthetic design has evolved to include expanded sizes and increased modularity.  Prostheses have become more anatomic, with features like variable neck-shaft angles and eccentric heads to allow the surgeon to more closely replicate the patient’s normal anatomy.  Surgeons can choose between prostheses designed for cemented or uncemented use.  Purported advantages of one prosthetic design over another have been claimed.  Despite this, no clinical studies of sufficient quality comparing different designs and fixation options were identified.  Thus, the current available literature is insufficient to recommend for or against a specific type of humeral prosthetic design or method of fixation when performing shoulder arthroplasty in patients with glenohumeral osteoarthritis.