Rim Fracture of a Tibial Base-Plate Due to Retained Cement as a Cause of Catastrophic Failure of Unicompartmental Knee Arthroplasty: A Case Report.

CASE: We report a case of catastrophic implant failure due to fatigue fracture of a well-functioning unicompartmental knee arthroplasty at 7 years in an active 55-year-old man, who presented with sudden onset of atraumatic knee pain and effusion. The patient underwent revision to total knee arthroplasty. Intraoperative findings included a metallic fragment fractured off the rim of the tibial base-plate and cement retained in the tibial tray.

CONCLUSION

Retained cement in the tibial tray resulted in increased tibial tray contact stresses and fatigue fracture of the rim of the tray, creating a free metallic loose body that produced symptoms.