Fatigue fracture of an uncemented Zweymüller femoral stem at the neck-shoulder junction.

A fracture through the neck of the femoral stem in total hip arthroplasty is extremely rare. We report a neck fracture of a cementless Zweymüller stem, one of the most implanted stems worldwide. According to our knowledge, this is the first thorough case description of a neck fracture of a cementless Zweymüller stem. The case concerns a 53-year-old man, with a body weight of 103 kg and a body mass index of 31. We consider potential risk factors for a femoral stem fracture, such as patient-related factors, suboptimal implant positioning, surgical technique and implant characteristics.