Trunnionosis in metal-on-polyethylene total hip arthroplasties: Report two cases

Abstract

Introduction and importance: Several studies have discussed trunnionosis in metal-on-metal total hip arthroplasties. However, trunnionosis in metal-on-polyethylene total hip arthroplasties has been less frequently discussed.

Case presentation: In this study, trunnionosis in two male patients undergoing metal-on-polyethylene total hip arthroplasty, which was done to treat femoral head osteonecrosis were reported and discussed adequately.

Clinical discussion: Total hip arthroplasties (THA) were done for the treatment of femoral head osteonecrosis in these cases. In the first case, trunnionosis occurred one year after the revision of the primary THA, and in the second case occurred ten years after the primary THA. Both of these cases were presented with reduced range of motion. After surgery, the symptoms were resolved, and the patients remained complication-free until the last follow-up.

Conclusion: This report raises awareness regarding the importance of trunnionosis as a serious complication of modular total hip arthroplasty.

Keywords: Modular prosthesis; Total hip arthroplasty; Trunnionosis.

Fig. 1

Anteroposterior radiographshowing the dissociation of the femoral head from the femoral stem trunnion and severe metallosis of the left hip (arrow) (case 1).

Fig. 2

Intraoperative photographs showing granulation tissue as well as metal-stained debris (case 1).

Fig. 3

Anteroposterior radiograph showing the dissociation of the femoral head from the femoral stem trunnion of the right hip. No evidence of osteolysis or loosening of his acetabular component was observed (arrows) (case 2).

Fig. 4

Intraoperative photographs showing huge dark metallic debris onthe stem taper and trunnion (case 2).