A fracture through the neck of a Charnley Elite-Plus femoral component: a case report

摘要

Fracture of the femoral stem component following hip arthroplasty is an uncommon but recognised complication. The prevalence ranges between 0.23%, according to Charnley, and can be as high as 11% with other stem designs 1,2 . With the improvement of our understanding of biomechanics and the development of stronger metal alloys the prevalence of stem fractures has reduced.Fractures of the neck of femoral stems are even more rare with only a few cases reported 2 .We report a case of a fracture through the neck of a Charnley Elite-Plus femoral stem. To our knowledge this is the first reported case involving this stem. Introduction Fracture of the femoral stem component following hip arthroplasty is an uncommon but recognised complication. The prevalence ranges between 0.23%, according to Charnley, and can be as high as 11% with other stem designs1,2.With the improvement of our understanding of biomechanics and the development of stronger metal alloys the prevalence of stem fractures has reduced.Fractures of the neck of femoral stems are even more rare with only a few cases reported2.We report a case of a fracture through the neck of a Charnley Elite-Plus femoral stem. To our knowledge this is the first reported case involving this stem. Case presentation A 60-year old obese but active woman, weighing 95 kg and with a BMI of 34, underwent a cemented left total hip replacement for osteoarthritis in 1998. She did not have any significant past medical history. The implant inserted was a modular Elite plus stem, flanged 3, with a 28 mm metalic head and a 28mm inner diameter by 47mm outer diameter polyethylene cup.Her immediate post operative recovery was unremarkable. Post operative images showed a satisfactory position of the prosthesis.Ten years later she presented with an acute episode of severe left hip pain and inability to weight bear on that side. There was no history of trauma. Over the period of 10 years her weight had increased further to 115kg and her BMI to 41. She had also become more active as her mobility had improved. Radiographs of the left hip joint revealed a fracture through the neck of the femoral stem at the junction between the head and the neck (fig1).