This 2017 JAAOS review by Keener, Chalmers, and Yamaguchi synthesizes proximal humeral anatomy, implant design evolution, fixation strategies, and outcomes across hemiarthroplasty, anatomic TSA, and reverse TSA. It covers the shift from Neer's monoblock diaphyseal stems to contemporary modular metaphyseal and stemless designs. The central question: which fixation strategies optimize durability while minimizing revision complexity?
When you look at a postoperative shoulder arthroplasty radiograph and see radiolucent lines around the humeral stem, the data say do not panic. Rates of 50–57% are reported at medium-term follow-up with no revisions for aseptic loosening in those series.
When osteolysis appears around a humeral implant, trace it to the glenoid: polyethylene debris from glenoid wear drives this process, which is why it is essentially absent in hemiarthroplasty. The humeral component is rarely the culprit.
When planning conversion from a prior TSA to reverse TSA, the humeral stem is the operative crux. A well-fixed cemented diaphyseal stem carries 17% intraoperative fracture and 23% cement extrusion risk on removal. Platform stems that allow humeral head exchange without removing the fixed body exist for exactly this reason, though they introduce their own modularity concerns.
For stemless implants, know the absolute contraindications: proximal humeral bone loss, compromised bone quality or vascularity, and prior radiation. Outside these settings, early data show equivalent outcomes with shorter OR time and less blood loss, but long-term evidence is still accumulating.
This 2017 JAAOS review by Keener, Chalmers, and Yamaguchi synthesizes proximal humeral anatomy, implant design evolution, fixation strategies, and outcomes across hemiarthroplasty, anatomic TSA, and reverse TSA. It covers the shift from Neer's monoblock diaphyseal stems to contemporary modular metaphyseal and stemless designs. The central question: which fixation strategies optimize durability while minimizing revision complexity?
When you look at a postoperative shoulder arthroplasty radiograph and see radiolucent lines around the humeral stem, the data say do not panic. Rates of 50–57% are reported at medium-term follow-up with no revisions for aseptic loosening in those series.
When osteolysis appears around a humeral implant, trace it to the glenoid: polyethylene debris from glenoid wear drives this process, which is why it is essentially absent in hemiarthroplasty. The humeral component is rarely the culprit.
When planning conversion from a prior TSA to reverse TSA, the humeral stem is the operative crux. A well-fixed cemented diaphyseal stem carries 17% intraoperative fracture and 23% cement extrusion risk on removal. Platform stems that allow humeral head exchange without removing the fixed body exist for exactly this reason, though they introduce their own modularity concerns.
For stemless implants, know the absolute contraindications: proximal humeral bone loss, compromised bone quality or vascularity, and prior radiation. Outside these settings, early data show equivalent outcomes with shorter OR time and less blood loss, but long-term evidence is still accumulating.