This retrieval study examined tribocorrosion at the modular taper junctions of 36 explanted anatomic shoulder arthroplasty implants. It asked whether taper corrosion, well described in hip trunnionosis, also occurs in the shoulder. It compared titanium versus cobalt-chromium stems and stemmed versus stemless designs.
Taper corrosion is not just a hip problem. This retrieval series confirms fretting and corrosion happen at the modular head-stem junction in most explanted anatomic shoulder implants.
Two design factors mattered. Titanium stems paired with CoCr heads corroded more than same-metal CoCr constructs, and stemmed designs corroded more than stemless. The proposed mechanisms are galvanic corrosion between dissimilar metals and higher torque transmitted through diaphyseal fixation.
The practical caution is interpretive, not surgical. Unlike the hip, no shoulder study has yet linked taper corrosion to elevated metal ions, pseudotumor, or implant failure. The time-to-revision correlation was weak, and this retrospective design cannot connect corrosion to clinical outcomes.
So recognize tribocorrosion as a real phenomenon at shoulder tapers and keep it on the differential in a failing modular implant, but do not assume it is the cause of failure without ion levels or imaging.
This retrieval study examined tribocorrosion at the modular taper junctions of 36 explanted anatomic shoulder arthroplasty implants. It asked whether taper corrosion, well described in hip trunnionosis, also occurs in the shoulder. It compared titanium versus cobalt-chromium stems and stemmed versus stemless designs.
Taper corrosion is not just a hip problem. This retrieval series confirms fretting and corrosion happen at the modular head-stem junction in most explanted anatomic shoulder implants.
Two design factors mattered. Titanium stems paired with CoCr heads corroded more than same-metal CoCr constructs, and stemmed designs corroded more than stemless. The proposed mechanisms are galvanic corrosion between dissimilar metals and higher torque transmitted through diaphyseal fixation.
The practical caution is interpretive, not surgical. Unlike the hip, no shoulder study has yet linked taper corrosion to elevated metal ions, pseudotumor, or implant failure. The time-to-revision correlation was weak, and this retrospective design cannot connect corrosion to clinical outcomes.
So recognize tribocorrosion as a real phenomenon at shoulder tapers and keep it on the differential in a failing modular implant, but do not assume it is the cause of failure without ion levels or imaging.