Journal of the American Academy of Orthopaedic Surgeons, The

The success of total shoulder arthroplasty is dependent on both proper patient selection and restoration of the native anatomy. After proper patient selection, preoperative planning is essential to select implants that will allow the surgeon to properly restore soft-tissue tension and correct for deformity. Although it is possible to template implants with plain radiographs, these do not allow accurate measurements of the complex three-dimensional anatomy of the glenohumeral joint. CT can be used to further examine version of the glenoid and humerus, as well as humeral head subluxation. Three-dimensional reconstructions also allow for virtual implantation, resulting in a more reliable prediction of implant appearance. Commercial software is available that calculates parameters such as version; however, these have been shown to have variability when compared with measurements obtained by surgeons. Patient-specific instrumentation can also be obtained based on preoperative measurements; however, although it allowed for improved measurements when compared with two-dimensional imaging, there has been no difference in version error, inclination error, or positional offset of the glenoid implant when comparing patient-specific instrumentation with standard instrumentation. Intraoperative navigation can also be used to give real-time feedback on implant positioning; however, additional studies are needed to fully evaluate its benefit.

Anatomic total shoulder arthroplasty provides pain relief and improved quality of life for patients suffering from glenohumeral arthritis. The 10-year survival rate for these implants has been most recently reported at 96%. As the number of shoulder arthroplasties per year increases, it is important to evaluate factors associated with failure. Patient-specific variables such as age, sex, medical comorbidities, a history of previous shoulder surgery, and rotator cuff integrity can influence implant survival. Both surgeon and hospital volume have been shown to affect perioperative outcomes. Implant design and glenoid pathoanatomy are important structural considerations because both have a causal relationship with survivorship. Modifiable factors, such as smoking, body mass index, and alcohol or opioid consumption, should be addressed preoperatively when possible. Modifiable factors that pertain to surgery are equally as important; it is the responsibility of the surgeon to be aware of the reported outcomes for varying implants and technique-related pearls and pitfalls. For those perioperative factors that are nonmodifiable, it is prudent to counsel patients accordingly because these individuals may be more likely to require an eventual revision procedure.