Wear of the Christiansen hip prosthesis

The wear was examined in 39 Christiansen total hip prostheses, which were removed because of mechanical loosening after being used 5 (3-11) years. In the polyacetal acetabular cups, the head had made an eccentric defect, the mean volume of which was 680 (180-3310) mm³. The mean penetration of the head into the wall of the cup was 0.8 (0.1-3.2) mm. In two additional cups the head had penetrated right through the wall of the cup. In three prostheses the polyacetal sleeve of the trunnion was so worn that the head bore directly on the stem. There was a positive correlation between wear and the time the prostheses had been used before symptoms of loosening presented.     

The ultrastructure of the tissue surrounding the Christiansen total hip

Tissue samples obtained from 24 consecutive Christiansen total hip revision operations were examined with transmission electron microscopy. An abundance of wear particles of plastic, originating from the polyoxymethylene socket, were found in the periprosthetic tissue, where they induced fibrinoid necrosis and macrophage activation. Phagocytosing cells revealed degenerative signs of varying degrees. It seems probable that this strong tissue reaction results in excessive bone resorption and is associated with the disastrous rate of socket loosening recorded with the Christiansen prosthesis.     

Failure of the Christiansen hip. Survival analysis of 265 cases

Totally, 265 primary Christiansen total hip arthroplasties were followed clinically and radiographically for a median of 6 years. The operations were performed for arthrosis in 220 cases, failed fracture in 23, and rheumatoid arthritis in 13. The influence of 11 presumed determinants on the radiographic outcome was studied. In all, 96 hips were exchanged because of aseptic loosening, 35 stems were loose, and 210 sockets were definitely or probably loose at the last radiographic examination. The survivorship analyses revealed the probability of having a radiographically intact stem after 10 years as 67 percent and for the socket 0 percent. None of the 11 determinants influenced the radiographic outcome.     

Wear and loosening of the hip prosthesis: A roentgen stereophotogrammetric 3-year study of 14 cases

Fourteen patients were followed by roentgen stereophotogrammetry for 3 years after hip arthroplasty. In 11 of the 14 acetabular components, definite wear was identified. The mean wear rate was 0.13 mm per year. There was no correlation between the wear and loosening of either the acetabular or the femoral component. Our findings indicate that products of wear do not initiate prosthetic loosening.     

Wear and loosening of the hip prosthesis: A roentgen stereophotogrammetric 3-year study of 14 cases

Fourteen patients were followed by roentgen stereophotogrammetry for 3 years after hip arthroplasty. In 11 of the 14 acetabular components, definite wear was identified. The mean wear rate was 0.13 mm per year. There was no correlation between the wear and loosening of either the acetabular or the femoral component. Our findings indicate that products of wear do not initiate prosthetic loosening.     

Wear of alumina ceramics prosthesis

To investigate the process of wear in the total knee prosthesis consisting of alumina ceramics (Al-ceramics) and ultra-high molecular weight polyethylene (UHMWP) in vivo, we observed the fine structures of the articular surface of the prostheses used for four patients with osteosarcoma of the distal femur. We also examined the wear debris in the surrounding soft tissues. The prostheses were extracted at autopsy between 13 and 48 months after surgery. An increase of pores, indicating where Al-ceramics grains fell off, and many streaks on the UHMWP running parallel to the gliding direction of the joint were observed on the articular surface. The streaks had similar widths to the Al-ceramics grains. Al-ceramics debris was detected in the soft tissues around the joint mixed with UHMWP debris. We concluded that the wear of UHMWP in Al-ceramics prosthesis was promoted by interposition of Al-ceramics debris. Received: 3 February 1998     

Recurrent dislocation of the hip prosthesis

Recurrent dislocation of a hip prothesis is a severe complication. For the patient it is debilitating both physically and mentally. In most such cases one or more revision operations are necessary. Reintervention is more likely to be successful if the cause and the mechanism of luxation are understood. Recurrent hip dislocation is often seen after insertion of socalled tumor prostheses, after the "southern" approach and in the case of fracture treatment. One helpful and secure method seems to be the conversion of a non-linked prosthesis to a linked prosthesis. For elderly patients the simplest method seems to be cementing the head of a bipolar hip prosthesis.     

Wear and loosening of the hip prosthesis. A roentgen stereophotogrammetric 3-year study of 14 cases

Fourteen patients were followed by roentgen stereophotogrammetry for 3 years after hip arthroplasty. In 11 of the 14 acetabular components, definite wear was identified. The mean wear rate was 0.13 mm per year. There was no correlation between the wear and loosening of either the acetabular or the femoral component. Our findings indicate that products of wear do not initiate prosthetic loosening.     

Hydroxylapatite-coated total prosthesis of the hip

Since 1987, 80 hydroxyapatite-coated (HA) cementless total hip prostheses have been implanted. Thirty patients were examined 21 months postoperatively and the results compared with data for uncoated prosthesis. Earlier mobilization and freedom from pain, together with evidence of bone ingrowth without connective tissue membrane formation, confirmed the benefits of HA-coated prostheses.     

Separation of the Christiansen prosthetic components following dislocation of hemiarthroplasty for hip fracture

During the period from April 1980 to July 1982 a total of 148 patients with acute femoral neck fractures had primary hemiarthroplasties with the Christiansen trunnion-bearing endoprosthesis. Dislocations occurred in six patients (4 per cent). Five of these required reoperation due to separation of the femoral head in relation to the stem or of the plastic head and the metallic cap of the prosthetic head.     

Revision of the uncemented hip prosthesis

In a series of 213 consecutive total hip replacements a.m. Lubinus, the clinical course after 72 revisions and 141 primary procedures was compared after 5 years. The revised THRs were uncemented Ring prostheses. Dislocation and peroperative fracture were more common in the revision group. Two failures because of aseptic loosening occurred in the revision group and 3 in the control group. No excisional arthroplasty was required, and no infections occurred. Radiographic evaluation of prosthetic positioning, component loosening, calcar resorption, and paraarticular ossification disclosed only slightly inferior results in the revision group. Clinically, the revised cases were not inferior to the primary ones. Revision of the uncemented hip seems less difficult than of the cemented hip.     

Revision of the uncemented hip prosthesis

In a series of 213 consecutive total hip replacements a.m. Lubinus, the clinical course after 72 revisions and 141 primary procedures was compared after 5 years. The revised THRs were uncemented Ring prostheses. Dislocation and peroperative fracture were more common in the revision group. Two failures because of aseptic loosening occurred in the revision group and 3 in the control group. No excisional arthroplasty was required, and no infections occurred. Radiographic evaluation of prosthetic positioning, component loosening, calcar resorption, and paraarticular ossification disclosed only slightly inferior results in the revision group. Clinically, the revised cases were not inferior to the primary ones. Revision of the uncemented hip seems less difficult than of the cemented hip.     

The Charnley versus the Christiansen total hip arthroplasty. A comparative clinical study

Charnley total hip arthroplasties (THA) and Christiansen THA were carried out in two concurrent groups of patients, consisting of 113 hips in 87 patients and 90 hips in 81 patients respectively. The mean age of the patients was about 65 years, two thirds had idiopathic arthrosis, and only two had rheumatic hip disease. The two groups of patients were similar with regard to sex, age, weight, etiology of arthrosis, and standard laboratory tests, but different with regard to the surgeons who operated on them. Postoperative films showed that the stems of the prostheses were in the neutral and the varus position in the Christiansen group, and in the valgus, neutral and varus position in the Charnley group. Neither group had any deaths, or deep infections in the postoperative period. Only minor postoperative complications were noted. At follow-up, 5-8 years later, the failure (revision) rate of Charnley THA to Christiansen THA was 1 to 7.7 and 1 Charnley cup was revised as against 19 Christiansen cups. The methodological weaknesses in the comparative clinical trial did not explain the inferior long-term results of the Christiansen THA.