Convertible humeral component in revision shoulder arthroplasty

With the accumulation of arthroplasty cases over the last decades, the revision shoulder arthroplasty has also increased. During conversion surgery from anatomic total shoulder arthroplasty (aTSA) and hemiarthroplasty (HA) to reverse total shoulder arthroplasty (RTSA), humeral stem retention can be tried if a convertible modular humeral stem was used. The precondition for stem retention is a well-fixed humeral stem without periprosthetic infection or aseptic loosening of the humeral stem. However, not all humeral stem retention can be successfully achieved. First, the incompatibility of the humeral stem and new module can occur with the improvement of the prosthesis. Second, soft tissue tension mismatch can occur. In case of tight tension, reduction failure can be observed. If a reduction is achieved with tight tension, decreased shoulder motion with pain, acromial fracture, and neurologic injury can occur. In case of loose tension, instability can be observed. Even for convertible prostheses, surgeons always should be prepared for unexpected stem exchange. Humeral stem retention using convertible humeral prosthesis have various advantages, such as less soft tissue dissection and bleeding, short operation time, fewer intraoperative complications, and neurologic damage. A convertible humeral component is a good option for converting failed aTSA/HA to RTSA.