Fracture of the C-Stem cemented femoral component in revision hip surgery using bone impaction grafting technique: report of 9 cases.

We present a series of 9 fractures of a C-Stem femoral component (6 long stems and 3 conventional stems) that had been implanted with the use of impaction bone grafting (IBG). The length of the long fractured stems was 240 mm in 4 cases and 200 mm in 2. The patients presented had an average BMI of 26.5 and an average of 2.7 previous hip surgeries (range 2-5 surgeries) before the stem fracture. A total of 5 cases presented with a metal mesh fracture in addition to the fractured stem. Bending of the stems or stem defects was not observed in any case. Typical fracture waves consistent with fatigue failure were clearly visible on all the cut surfaces, starting anterolaterally and propagating to the medial side. Although fatigue fracture of a modern cemented tapered polished femoral stem is a rare event, stress due to the absence of proximal femoral bone support could be sufficient to put this stem at a higher risk for fatigue fracture in non-obese patients.