Elliptical Humeral Head Implants in Anatomic Total Shoulder Arthroplasty.

Humeral implants for anatomic total shoulder arthroplasty and hemiarthroplasty have typically used spherical humeral heads that have a uniform diameter and radius of curvature. However, the native humeral head has a more elliptical morphology, which has spurred interest in nonspherical implant designs. Cadaveric studies indicate that the native humeral head diameter is 10% longer in the superior-inferior plane than the anterior-posterior plane and has a radius of curvature that is approximately 8% greater.

Shoulder Arthrodesis.

Shoulder arthrodesis is an end-stage, salvage procedure for the glenohumeral joint and can provide a pain-free, stable shoulder with varying levels of function. Common indications include brachial plexus injury, chronic instability with rotator cuff and deltoid dysfunction, and failed shoulder arthroplasty. Multiple techniques are described, including intra-articular and extra-articular arthrodeses.