[Bipolar hip hemiarthroplasty]. / Bipolární endoprotéza kycelního kloubu.

PURPOSE OF THE STUDY: 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. MATERIAL AND 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.

[Results of acetabular reconstruction with solid bone graft in primary and revision hip arthroplasty]. / Výsledky rekonstrukce acetabula solidním kostním stepem pri primární a revizní aloplastice kycle.

PURPOSE OF THE STUDY: To evaluate the results of acetabular reconstruction in total hip replacement and to compare them in view of the use of autologous or allogenic solid bone grafts. MATERIAL AND METHODS: The author evaluates a group of 48 total hip replacements carried out in the years 1990-1999, in which solid bone graft was used for reconstruction of an insufficient acetabulum. In 25 hips, the patient's own femoral head was used in primary surgery and, in 23 hips, a frozen femoral head from a tissue bank was used in revision arthroplasty. Most of the acetabular components used in this study were cemented. The patients were evaluated at 5- to 15-year follow-up. Each group was assessed separately and the results were divided into three categories according to X-ray and intra-operative findings, as follows: I. No radiographic evidence of cup loosening and incorporated graft II. Loosened cup and incorporated graft suitable for use in reimplantation III. Loosened cup and graft non-union or resorption RESULTS: In the autograft group, 80 % of the patients fell in category I and 12 % in category II; in the allograft group, 82 % of the patients were in category I and 9 % in category II. Complete failure, i.e., graft resorption and acetabular loosening, was recorded in 8 % and 9 % of group I and group II patients, respectively. Biopsy samples obtained during revision hip surgery showed good incorporation of both autografts and allografts. DISCUSSION: Other authors' views on the function of solid bone grafts after implantation and on methods of treating a defective acetabulum are discussed. The author puts the good outcomes shown in this study down to a careful implantation technique and thorough preoperative planning. CONCLUSIONS: By using a solid graft, the surgeon will achieve good primary fixation of a standard hip socket in a defective acetabulum and will make conditions for repair of defective bone tissue. The results imply that incorporation of both graft and acetabular component can be expected regardless of whether the graft is fresh or frozen. Although this method has its drawbacks and contraindications, it should be considered one of the options when planning total hip arthroplasty for an insufficient acetabulum.

[The Beznoska uncemented acetabular cup in hip joint arthroplasty]. / Necementovaná plást'ová jamka Beznoska v aloplastice kycelního kloubu.

PURPOSE OF THE STUDY: To present the results of a trial of the non-cemented Beznoska cup. MATERIAL: During the period from 1993 to 1997, a total of 43 Beznoska cups were implanted in 40 patients, 17 men and 23 women, with the average age of 61 and 65 years, respectively. Primary hip arthritis was the most frequent indication for arthroplasty. Most cups were used in combination with a cemented stem. METHODS: In 2002, 37 patients were examined. The follow-up period ranged from 5 to 10 years. Clinical evaluation was based on the Harris hip scores. X-ray films were examined for cup osteointegration and wear, and para-articular ossification. RESULTS: During the follow-up period, two patients died and one underwent reimplantation. The remaining 37 patients were satisfied with the surgical outcome. The Harris hip scores higher than 80 points were achieved in 80% of the patients. No loosening or wear of the cup was found at the follow-up. DISCUSSION: Good primary fixation in the acetabulum is the results of reliable anchorage by means of 16 spikes on the metal surface of the cup. Good secondary fixation is shown by the results of this study, although to confirm that the incorporation of a surface without a bioactive coat is long lasting will require at least 5 more years of follow-up. CONCLUSIONS: Total hip arthroplasty with the Beznoska cup achieved good outcomes. It was used several times to manage situations in which a press-fit cup initially indicated lacked sufficient primary retention because of the bone being too soft or the acetabulum defective.