Multimodality imaging in shoulder arthroplasties Part 1: Biomechanics, indications, preoperative imaging, and types of arthroplasties – A pictorial review

Abstract

Shoulder biomechanics, shoulder arthroplasty indications and types and appropriate pre-operative imaging are discussed in part one of this two-part pictorial review. Shoulder biomechanics in severe osteoarthritis and following reverse shoulder arthroplasty are represented graphically, with discussion on the principles of reverse shoulder arthroplasty. Case examples are utilized to demonstrate the main indications for shoulder arthroplasty. The decision of whether to proceed with arthroplasty and the arthroplasty type is heavily influenced by the pre-operative imaging. Factors for type of arthroplasty include arthroplasty indication, the integrity of the deltoid and rotator cuff musculature, and the amount of glenoid and humeral head bone stock. The key findings to look for and comment on across a range of imaging modalities are reviewed, using multiple cases including plain radiography, CT, ultrasound, and MRI. Examples of arthroplasty options are provided including humeral head resurfacing arthroplasty, hemiarthroplasty, anatomical total shoulder arthroplasty, and reverse total shoulder arthroplasty. A good understanding of the above principles is crucial for the radiologist to interpret pre-operative imaging correctly and aid in surgical planning.