Tibial post failure is a rare but serious complication of posterior-stabilized total knee arthroplasty that requires revision surgery. Although tibial post fracture has previously been reported, this case involves an implant with a design feature that may predispose patients to the complication. The fracture also occurred later than observed in most other reports. A 72-year-old male who had undergone a posterior stabilized total knee arthroplasty seven years prior presented with knee pain and instability after a fall from standing. Although plain radiographs were not diagnostic, history and physical exam suggested failure of the tibial polyethylene post. This was confirmed during surgery when the fractured component was identified in the suprapatellar pouch. Given absence of malrotation or malalignment of the well-fixed femoral and tibial components, a polyethylene liner exchange was performed. Postoperatively, the patient had complete resolution of pain and instability with 0-120 degrees of stable ROM, which has persisted to latest follow-up at 6 months.
Keywords: polyethylene failure; post fractur; posterior stabilized; total knee revision arthroplasty.