Mechanical factors in loosening of Christiansen and Charnley arthroplasties

A series of 96 Christiansen and 23 Charnley hip arthroplasties, mainly for osteoarthrosis, were followed for an average of 40 (15-93) months. Radiolucent zones at the cement bone interface and resorption of the calcar were more frequent in the Christiansen than in the Charnley hips. Medial and axial migration, and cement fracture often occurred concurrently, with a total frequency of 27/96 in the Christiansen and 4/23 in the Charnley subseries. Wide radiolucent zones in the acetabular cement bone interface were more frequent in the Christiansen hips. Six acetabular protrusions were observed in the Christiansen hips against none in the Charnley hips. The average Harris' hip scores were significantly higher for the Charnley than for the Christiansen hips. Reoperation for loosening was performed in two Charnley hips and 19 Christiansen hips.     

Mechanical loosening of the stem in Charnley arthroplasties. Identification of the "at risk" factors

A retrospective review of 72 cases of Charnley low friction arthroplasty revised for stem loosening, has identified a number of "at risk" factors. These were: previous hip surgery and, in radiographs taken at one year, demarcation of the distal cement and fracture of the cement near the tip of the stem. Separation of the back of the stem from the cement, as an isolated feature, was not considered significant. Endosteal cavitation of the femoral shaft, rare in the first year, indicated loosening of some duration. Patients whose radiographs show the "at risk" changes, should be followed-up indefinitely in order to plan timely revision and avoid gross loss of the femoral bone stock.     

Radiological factors influencing femoral and acetabular failure in cemented Charnley total hip arthroplasties

We have made a retrospective review of 185 cemented Charnley total hip arthroplasties performed between 1970 and 1974 to determine the relationships between radiological variables and failure of the femoral and acetabular components. We measured the acetabular wear, the orientation of the cup, the thickness and consistency of acetabular and femoral cement mantles, radiolucency and femoral alignment. The mean follow-up was for 11.7 years. Femoral loosening was demonstrable radiologically in 15 hips (8.1%), ten (5.4%) of which were revised during the period of follow-up. Only when the first postoperative radiograph showed a thin cement mantle in Gruen zone 5 was there a significant association with failure of the femoral component. There were 12 loose acetabular components (6.5%), nine (4.8%) of which were revised. When the initial radiograph after operation showed radiolucency in DeLee and Charnley zone 1, the incidence of acetabular loosening was 28.21%. If such radiolucency was not present, the incidence of acetabular loosening was only 0.69%. Our findings emphasise the importance of careful cementing.     

Survivorship analysis of 1,041 Charnley total hip arthroplasties

Survivorship analysis of 1,041 cemented Charnley total hip arthroplasties performed as a primary procedure revealed a probability of component survival at 10 years of 92%; the probability of acetabular cup survival was 99% and of femoral component survival was 96%. Three-zone acetabular demarcation was present in 16% of cases, as was migration of the cup greater than 5 mm. However, the acetabular revision rate was 1.65%, confirming the long-term clinical durability of the 22-mm internal diameter cup. Radiographic evidence of definite femoral component loosening was present in 9.6% and high-grade femoral bone-cement demarcation was present in 3.5%. The isolated femoral revision rate was 1.8%. Based on detailed survivorship analysis, a high-risk group of patients was identified for component failure and for femoral component loosening (radiographic). These patients were male, young (less than 50 years), heavy (greater than 170 pounds), and active (not Charnley class C). Given these findings, it is difficult to justify the widespread use of noncemented total hip systems, except in identifiable high-risk patients.     

Bone-membrane interface in aseptic loosening of total joint arthroplasties

In 19 patients who underwent revision arthroplasty for aseptic loosening of total joint arthroplasty, specimens were taken at the time of operation to include the bone-membrane interface. In 16 (84%) of the specimens, sufficient visualization of the interface was possible to allow histologic interpretation. In 13 of these cases, there was prominent evidence of classic bone remodeling with osteoclastmediated resorption and active new bone formation. These results suggest that the osteolysis in aseptic loosening is mediated through osteoclastic bone resorption and that the bone found in such areas is extremely active. The findings help to explain the efficacy of impacted morselized bone-graft in the treatment of bone lysis in aseptic loosening.     

Wear and loosening of the socket in the Charnley low-friction arthroplasty

In the Charnley low-friction arthroplasty, wear of the HDP socket and the dimensional changes resulting from it are more important than the tissue response to wear debris. Study of wear and the related mechanical factors is likely to be more rewarding than the search for alternative methods of fixation.     

A ten-year follow-up study of 170 Charnley total hip arthroplasties

Between 1971 and 1974, 352 low-friction hip arthroplasties were performed on 296 patients using the precise Charnley technique. One hundred seventy hips in 145 patients were followed either for ten years or to the point at which revision of the total hip arthroplasty was made necessary by infection, aseptic loosening, chronic dislocation, or similar complications. The results of this evaluation revealed an overall revision rate to the ten-year level of 8.8% in 171 hips and an infection rate of 1.4% for all 352 cases. Both clinical and radiologic assessments encourage further use of this technique.     

Human leukocyte antigen and aseptic loosening in Charnley total hip arthroplasty

Human leukocyte antigen phenotypes and radiographic course were studied in 70 Japanese patients (90 hips) who had Charnley low friction arthroplasty. Of the 28 hips diagnosed as radiographically loose less than 15 years after surgery, seven hips (25.0%) were in patients who had a positive human leukocyte antigen A31(19). Of the 62 hips that were radiographically stable more than 15 years, two hips (3.2%) were in patients who had a positive human leukocyte antigen A31(19). Of the nine hips in patients who were positive to human leukocyte antigen A31(19), seven hips were diagnosed as radiographically loose (loosening rate was 77.8%) 15 years after surgery. On the other hand, of the 81 hips in the patients who were negative to human leukocyte antigen A31(19), only 21 hips were diagnosed as radiographically loose (loosening rate was 25.9%) 15 years after surgery. These data suggest that individual immune response to implant materials, linked to human leukocyte antigen, may participate in the process of aseptic loosening in Charnley low friction arthroplasty.     

A fifteen-year follow-up study of one hundred Charnley low-friction arthroplasties

This two-part study concerns the fate of 100 Charnley low-friction arthroplasties performed in 92 patients at The Hospital for Special Surgery. The first part of the study is a clinical and radiographic evaluation of the 40 hips that were available for follow-up at an average of 15.3 years after surgery. The second part is a survival analysis of the arthroplasty, the individual components, and the patients, using data from all 100 arthroplasties. The authors conclude that the vast majority of older patients who undergo cemented total hip arthroplasty will not require a subsequent arthroplasty, and will have satisfactory pain relief for the remainder of their lives.     

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.     

Radiological features predictive of aseptic loosening in cemented Charnley femoral stems

The radiological features of the cement mantle around total hip replacements (THRs) have been used to assess aseptic loosening. In this case-control study we investigated the risk of failure of THR as predictable by a range of such features using data from patients recruited to the Trent Regional Arthroplasty Study (TRAS). An independent radiological assessment was undertaken on Charnley THRs with aseptic loosening within five years of surgery and on a control group from the TRAS database. Chi-squared tests were used to test the probability of obtaining the observed data by chance, and odds ratios were calculated to estimate the strength of association for different features. Several features were associated with a clinically important increase (>twofold) in the risk of loosening, which was statistically significant for four features (p < 0.01). Inadequate cementation (Barrack C and D grades) was the most significant feature, with an estimated odds ratio of 9.5 (95% confidence interval 3.2 to 28.4, p < 0.0001) for failure.     

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.     

Prediction of Charnley femoral stem aseptic loosening by early post-operative radiological features

We describe the association between immediate post-operative radiological appearances and early aseptic failure of total hip replacement. Sixty-three hips were entered into the aseptic failure group and 138 into the control group. Alignment of the femoral stem was not associated with failure (p=0.283). Thickness of the cement mantle was associated with failure in Gruen zones 6 (p=0.040) and 7 (p=0.003). A significant association for the presence of radiolucent lines was found for Gruen zones 3 (p=0.0001) and 5 (p=0.0001). Grade of cementation was associated with failure for Barrack grades C (p=0.001) and D (p=0.001). This study has demonstrated that easily applied radiological criteria can be used to identify hip arthroplasties at risk from the immediate post-operative radiograph.

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Résumé Nous décrivons lassociation entre laspect radiologique postopératoire immédiat et léchec aseptique précoce de larthroplastie totale de la hanche. Soixante-trois hanches sont entrées dans le groupe de léchec aseptique et 138 dans le groupe témoin. Lalignement de la tige fémorale nétait associé à l› échec (p=0.283). Lépaisseur du manteau de ciment était associé à l› échec dans les zones de Gruen 6 (p=0.040) et 7 (p=0.003). Une association significative a été trouvée avec la présence de liserés dans les zones de Gruen 3 (p=0.0001) et 5 (p=0.0001). Le niveau de cimentation a été associé à léchec pour les grades C (p=0.001) et D (p=0.001) de Barrack. Cette étude montre que des critères radiologiques simples peuvent être utilisés pour identifier les ‹ arthroplasties à risque› sur les clichés post-opératoires immédiats.

     

A radiographic review of 135 total hip Charnley arthroplasties followed between 15 and 35 years

The long-term radiologically interpreted results of low-friction Charnley hip arthroplasties have been previously suggested to be influenced by surgical details, such as orientation of the femoral component, degree of coverage of the plastic acetabulum and other features. We carefully analyzed the radiographs of 135 Charnley arthroplasties that had remained functional, had not been revised and had follow-ups between 15 and 35 years. Several common denominators were identified amongst these radiographs: 93.5% arthroplasties had 100% coverage of the acetabular component; 88% had acetabular inclination between 40-45 degrees ; 84.5% had a proximal/medial column of cement between 3 and 5 millimeters at the level of femoral head resection; 81% had a femoral canal/stem ratio more than 50%; and 84% had a column of cement that extended below the tip of the prosthesis. This study supports the importance of technical surgical details that enhance the chances of long-term survival of cemented total hip arthroplasties.     

Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis

Background  

Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure.     

The pathogenesis of loosening of total hip arthroplasties. The production of factors by periprosthetic tissues that stimulate in vitro bone resorption

The production of factors capable of stimulating bone resorption in the newly formed periprosthetic capsule and in the bone-cement membrane obtained from patients reoperated due to aseptic loosening of cemented total hip prostheses was studied using organ culture techniques. Addition of culture media conditioned by membranes from six patients and bone-cement membranes from two patients to the mouse calvarial cultures resulted in a significantly increased release of calcium. The effect of capsule-conditioned media on calcium release was dose- and time-dependent and significantly reduced by the osteoclast inhibitor of calcitonin. Histologic analysis of bones at the end of the culture period showed that capsule-conditioned media enhanced the breakdown of mineralized bone and increased the number of osteoclasts. The observations showed that newly formed periprosthetic tissues from patients with loose total hip arthroplasties (THAs) can produce one or several factors that stimulate bone resorption in vitro by an osteoclast-mediated mechanism. Not only mechanical failure but also biologic reactions in the periprosthetic tissues eventually lead to osteoclast activation and may contribute to the loosening of THAs.     

Radiographic loosening after revision with gentamicin-containing cement for deep infection in total hip arthroplasties

Seventy-two infected total hip arthroplasties were revised with cement containing gentamicin and were followed up with regular radiograms for periods of up to six years. The infection healed in 61 cases and persisted in 11. An analysis of the radiographic changes in regard to the signs of loosening showed that about half of the cases with a healed infection had a minimal demarcation between bone and cement. In about one-third of the patients, a radiolucent zone of up to 2 mm in thickness developed during the first one to two years and then seemed to remain stable. In the other cases, a progressive resorption, indicating true loosening, was observed. All the cases with remaining infection (except one patient who died of heart disease) exhibited progressively increasing resorption zones. Progress, however, was possibly slowed by the effects of the gentamicin cement and the systemic antibiotic treatment.