title: [Bipolar hip hemiarthroplasty].
abstract: OBJECTIVE
  The femoral head of a bipolar hip prosthesis (BHP) consists of a steel outer shell and polyethylene liner with an inner steel head moving inside. In this study, indications for and advantages of this endoprosthesis are evaluated.
  
  
  METHODS
  The author presents indications and the surgical technique on a group of 79 patients, mostly physically active women aged 70 to 80 years. A BHP is largely indicated in patients with femoral neck fractures, and then in injuries to the proximal femur that leave the articular surface of the acetabulum intact.
  
  
  RESULTS
  In the group of 79 patients, four had dislocation of the prosthesis which, in two, occurred due to stem malalignment. This was repaired by reimplantation. At 3- to 9-year follow-up, 54 patients were evaluated. Protrusion into the acetabulum, which is a feared complication of classical hemiarthroplasty, was not found. Nor was stem failure detected. The endoprosthesis was pain free in nearly all the patients. The Harris hip score was influenced by co-existing diseases of old age. DISCUSSION Most of the authors dealing with BHP appreciate its advantages in comparison with classical hemiarthroplasty, some even prefer it to total hip arthroplasty and also in indications other than acute injury. The main advantage of BHP is its better stability and, in comparison with total hips arthroplasty, its simpler implantation, which makes the surgical procedure less demanding for both the patient and the surgeon.
  
  
  CONCLUSIONS
  Bipolar hip hemiarthroplasty is a treatment option in acute surgery for proximal femoral fractures. Its advantages include less stress and strain for the patients than in total hip arthroplasty, and greater stability and lower risk of protrusion into the acetabulum than in classical hip hemiarthroplasty.
authors.affiliation: Ortopedicko-úrazové oddelení Nemocnice Kladno, a.s.petr.zofka@seznam.cz
authors.forename: P
authors.initials: P
authors.lastname: Zofka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D005265:Femoral Neck Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D011859:Radiography