Mechanical Failure of Modular Rotating Hinge Femoral Component.

Hinge constructs can be used in revision total knee arthroplasty in cases of major collateral ligament deficiency, global knee instability, repeated failure of constrained implants, or large bone defects. Although the success of this construct in revision total knee arthroplasty varies depending on the type of surgery and bone quality, hinged implants can solve a wide array of complex problems while preserving stable flexion-extension motion for ambulation. The most common reasons for re-revision include patellofemoral complications, aseptic loosening, and infection. Most cases of mechanical failure for these hinged constructs occur at the hinge component. Here, we report the first instance of catastrophic femoral component failure in a modular rotating hinge via a low-energy mechanism.