Fracture of posterior-stablized tibial insert in a Genesis knee prosthesis.

We report a case of acute failure of a Genesis total knee arthroplasty (Smith and Nephew Orthopaedics, Memphis, TN) resulting from fracture of the eminence of the polyethylene posterior-stabilized tibial insert implanted in a revision procedure. A hyperflexion movement was responsible for shear stress on the insert with subsequent breakage. The correct diagnosis was obtained by arthroscopy, and the open substitution of the broken insert led to complete recovery of the prosthesis. This is the first report of mechanical breakage of a Genesis prosthesis.