A case of an atraumatic implant failure after primary rotating-hinge total knee arthroplasty.

Rotating-hinge knee implants are fully constrained knee prostheses commonly used for revision total knee arthroplasty. Nevertheless, rotating-hinge devices have been increasingly utilized in primary setting. Complications are inevitable in orthopedic surgery, however, implant breakage after RHK arthroplasty has been rarely described in medical literature. We present a rare case of 70-year-old Caucasian, male patient who suffered an atraumatic femoral stem breakage in a primary NexGen ® Rotating Hinge Knee (Zimmer-Biomet ® , Warsaw, IN, USA).