Nontraumatic fracture of the femoral condylar prosthesis in a total knee arthroplasty leading to mechanical failure

Abstract

This paper reports a case of fatigue fracture of the femoral component in a cruciate-retaining cemented total knee arthroplasty (TKA). A 64-year-old man had undergone a primary TKA for osteoarthritis 10 years previously at another institution using the PFC-Sigma prosthesis. The patient recovered fully and was back to his regular activities. He presented with a history of sudden onset pain and locking of the left knee since the preceding three months. There was no history of trauma, and the patient was mobilizing with difficulty using crutches. Radiographs revealed fracture of the posterior condyle of the femoral prosthesis. Revision surgery was performed as an elective procedure revealing the broken prosthesis. The TC3RP-PFC revision prosthesis was used with a medial parapatellar approach. The patient recovered fully without any squeal. Mechanical failure of the knee arthroplasty prosthesis is rare, and nontraumatic fracture of the femoral metallic component has not been reported before.

Figure 1

An anteroposterior radiograph of the knee showing evidence of the fracture of the medial femoral condylar prosthesis.

Figure 2

A lateral radiograph of the knee showing the broken prosthesis.

Figure 3

An oblique radiograph of the knee demonstrating the broken prosthesis.

Figure 4

Intraoperative evidence of the fracture through the medial femoral condylar implant.

Figure 5

Broken femoral component was cleaned and sent for metallurgical analysis.