Introduction: Fractures of the femoral stem component in total hip Arthroplasty have been a well documented complication. The incidence over recent years has decreased due to improvements in surgical technique and implant design and manufacture.

Methods/Results: We report two cases of femoral stem fracture. Both occurred in CDH stems from the C-stem system (Depuy International, Leeds, UK). These are the first reported fractures in this stem. Both patients were women weighing 83kgs and 98kgs at the time of fracture giving them BMI’s of 31 and 41 respectively. In both cases the BMI had increased since the time of operation.

Discussion: The design of the CDH stem is fundamentally different from the rest of the standard stems with absence of the medial strut. In addition to this factor, both stems fractured through the insertion hole which acted as a stress raiser. Finally both patients BMI’s were above 25. At the time of operation no weight limit was imposed on this prosthesis.

We conclude that if possible, a standard C-stem should be inserted but if a CDH stem is used attention to patients’ weight is paramount.