The number of total shoulder arthroplasties performed in the United States has increased substantially in the past decade. In fact, since 2006, more total shoulder arthroplasties have been performed than hemiarthroplasties. Because of this surge in the number of total shoulder arthroplasties being performed, various techniques have been developed to address glenoid bone loss in patients with arthritic shoulder conditions. Indeed, primary glenoid bone loss usually occurs in association with osteoarthritis and is characterized by posterior wear patterns, whereas secondary glenoid bone loss usually occurs in association with trauma, glenoid loosening, and iatrogenic injury during revision surgery.
In the July 2015 issue of JBJS Reviews, Gowda et al. review a number of important issues related to this condition, including normal glenoid anatomy, pathological changes in glenoid substance, primary glenoid bone loss, proper imaging studies for the evaluation of the glenoid, principles of glenoid restoration, and the effects of poor implant position. Other topics, such as glenoid bone-grafting, the use of augmented components, glenoid insert design, patient-specific instrumentation, and the emergence of reverse total shoulder arthroplasty as an important component of the armamentarium of the shoulder arthroplasty surgeon, are also addressed.
The authors assert that proper preoperative imaging is critical in order to ascertain glenoid characteristics, including size, version, and depth of the vault. The treatment of glenoid bone loss is dependent on the degree of version correction that is required and consists of eccentric reaming, bone or polyethylene augmentation, and, as noted above, the potential use of reverse shoulder arthroplasty.
In the future, shoulder arthroplasty research should evaluate the long-term outcomes of biomaterial-augmented glenoid components, the use of other materials (such as ceramics), the utility of fixation within the glenoid and endosteal vault, and the use of reverse-polarity implants.
Thomas A. Einhorn, MD
Editor, JBJS Reviews