Cemented Charnley Total Hip Arthroplasty Research Articles

Use of kernel-based Bayesian models to predict late osteolysis after hip replacement

We studied the relationship between osteolysis and polyethylene wear, age at surgery, body mass index and height in 463 subjects (180 osteolysis and 283 controls) after cemented Charnley total hip arthroplasty (THA), in order to develop a kernel-based Bayesian model to quantitate risk of osteolysis. Such tools may be integrated into decision-making algorithms to help personalize clinical decision-making. A predictive model was constructed, and the estimated posterior probability of the implant failure calculated. Annual wear provided the greatest discriminatory information. Age at surgery provided additional predictive information and was added to the model. Body mass index and height did not contain valuable discriminatory information over the range in which observations were densely sampled. The robustness and misclassification rate of the predictive model was evaluated by a five-times cross-validation method. This yielded a 70% correct predictive classification of subjects into osteolysis versus non-osteolysis groups at a mean of 11 years after THA. Finally, the data were divided into male and female subsets to further explore the relationship between wear rate, age at surgery and incidence of osteolysis. The correct classification rate using age and wear rate in the model was approximately 66% for males and 74% for females.

Femoral Remodeling Around Charnley Total Hip Arthroplasty Is Unpredictable

There are two unusual remodeling patterns of the proximal femur around well-fixed Charnley total hip arthroplasties: cortical thinning leading to endosteal widening around the femoral component and hypertrophy of the distal femoral cortex. Previous studies have shown remodeling patterns are affected by stem design and occur early postoperatively. It is unclear if these changes are related to patient demographics or if they progress throughout the lifetime of the implant. We determined if patient demographic variables influence remodeling patterns after cemented Charnley total hip arthroplasty and if the observed remodeling changes persist long-term. We retrospectively reviewed the radiographs of 106 well-fixed Charnley femoral components. Using a novel digital edge detection program, we determined the femoral remodeling pattern and time-related changes in femoral dimensions. The minimum followup was 20 years (mean, 25.3 years; range, 19.5-37 years). We found no association between remodeling type and age at surgery, sex, preoperative diagnosis, body mass index, or postoperative activity level. There was also no association between initial implant alignment and remodeling type. Cortical thickening in the distal hypertrophy group was an early phenomenon occurring primarily within the first 2 years, whereas cortical thinning begins later and is a more progressive process. These data show remodeling after cemented Charnley total hip arthroplasty is not related to patient demographic variables; however, distal cortical hypertrophy can be predicted in the early postoperative period.

Individual susceptibility to periprosthetic osteolysis is associated with altered patterns of innate immune gene expression in response to pro‐inflammatory stimuli

Susceptibility to osteolysis after total hip arthroplasty (THA) varies between individuals. We examined whether patients susceptible to osteolysis (group I, n = 34 subjects) after cemented Charnley THA have quantitatively different innate immune responses to pro-inflammatory stimuli versus patients without this susceptibility (group II, n = 28 subjects) at a mean of 14 years after primary surgery. Extracted peripheral blood mononuclear cells were stimulated for 3 h using endotoxin (lipopolysaccharide-LPS, 100 ng/mL), endotoxin-stripped titanium particles (Ti) or endotoxin-stripped particles with adherent LPS added-back (TI + LPS). Subjects returned 1 week later and the experimental protocol was repeated. Assays for mRNA induction for interleukin (IL)-1alpha, IL-1beta, IL-1Ra, IL-6, IL-10, IL-18, and tumor necrosis factor (TNF) were made using quantitative real-time PCR. Although baseline levels of mRNA expression were slightly lower in group I, inducibility of mRNA expression was markedly greater in group I versus group II for all cytokines in response to LPS or Ti + LPS, and for IL-1alpha in response to Ti (P < 0.05). LPS or Ti + LPS stimulation also resulted in an increase in the IL-1/IL-1Ra mRNA ratio in group I versus group II (P < 0.05). mRNA induction was highly reproducible between subject visits (r > 0.7, P < 0.001). Osteolysis-susceptible patients show repeatable, quantitatively different patterns of innate cytokine gene expression in response to pro-inflammatory stimuli versus THA patients who do not display this susceptibility. These innate immune differences may contribute to the variation in osteolysis-susceptibility observed clinically between individuals.

Furlong Hydroxyapatite-Coated Hip Prosthesis vs the Charnley Cemented Hip Prosthesis

We report the results of a prospective trial comparing uncemented Furlong hydroxyapatite-coated total hip arthroplasty and cemented Charnley total hip arthroplasty. One hundred ninety-one patients were allocated into 2 groups depending on their year of birth. One group received a Furlong hydroxyapatite-coated total hip arthroplasty and the other group received a cemented Charnley total hip arthroplasty. At a mean follow-up of 14 years (12-16 years), Harris hip scores showed no difference between the 2 groups. The longitudinal multilevel model analysis shows that the mean slope of the change in the Harris hip score was −0.02 for the Furlong group and −0.05 for the Charnley group; the difference is 0.03 ( P = .002). The survival analysis using Kaplan-Meier regression analysis (the log-rank test λ 2 1 = 0.031, P = .58) does not show a significant difference between the 2 groups. Overall survival was 93.6% in the Furlong group and 94.8% in the Charnley group.

Minimal Surgical Approach for Recurrent Hip Dislocation Using the Posterior Lip Augmentation Device for the Charnley Hip Arthroplasty

We present the management of recurrent posterior dislocations in cemented Charnley total hip arthroplasties treated with acetabular augmentation. Certain patients are elderly with comorbid conditions and diminished reserves. We have used a minimal surgical approach to implant 21 posterior lip augmentation devices in elderly patients. Ninety percent of the hips are stable with follow-up of 1 to 3 years (mean, 1.9 years). Eighty-four percent of the patients were satisfied with the outcome. Two cases, which redislocated, were further stabilized by changing the position of the posterior lip augmentation device and are stable. Because of a minimal surgical approach, the time duration of surgery, blood loss, transfusion requirement, inpatient stay, and morbidity are reduced. Posterior lip augmentation device surgery with a minimal approach is a safe and effective procedure for elderly patients who do not have any obvious cause for dislocation.

Genetic susceptibility to hip arthroplasty failure—association with the RANK/OPG pathway

The OPG/RANK/RANKL system has been implicated in the biological cascade of events initiated by particulate wear debris and bacterial infection resulting in periprosthetic bone loss around total hip arthroplasties (THA). Individual responses to such stimuli may be dictated by genetic variation caused by single nucleotide polymorphisms (SNPs). Case control study of the osteoprotegerin and RANK genes for possible association with deep sepsis or aseptic loosening. All patients were Caucasian and had had a cemented Charnley THA and polyethylene acetabular cup. Cases consisted of 91 patients with early aseptic loosening and 71 patients with deep infection. Controls were 150 clinically and radiologically well-fixed THAs. DNA samples were genotyped using Taqman allelic discrimination. The A allele (p<0.001) and genotype A/A (p<0.001) for the OPG-163 SNP were associated with aseptic failure. Additionally, the RANK +575 (C/T SNP) T allele (p=0.004) and T/T genotype (p=0.008) frequencies were associated with aseptic failure. Comparing the septic group with the controls, the frequency of the A allele (p<0.001) and the genotype A/A (p<0.001) for the OPG-163 SNP were statistically significant. Aseptic loosening and deep infection of THA may be under the influence of susceptibility genes. SNP markers may serve as predictors of implant survival.

Validation of a digital image processing software package for the in vivo measurement of wear in cemented Charnley total hip arthroplasties

Computer-generated images were used to assess image processing software employed in the radiographic evaluation of penetration in total hip replacement. The images were corrupted using Laplacian noise and smoothed to simulate different modulation transfer functions in a range associated with hospital digital radiographic systems. With no corruption, the penetration depth measurements were both precise and accurate. However, as the noise increased so did the inaccuracy and imprecision to levels that may make changes in the penetration observed clinically difficult to discern between follow-up assessments. Simulated rotation of the wire marker produced significant bias in the measured penetration depth. The use of these simulated radiographs allows the evaluation of the software used to process the digital images alone rather than the whole measurement system.

Polyethylene wear rate and osteolysis: critical threshold versus continuous dose–response relationship

We studied the relationship between polyethylene wear and osteolysis in 230 subjects after cemented Charnley total hip arthroplasty in order to examine the validity of the wear rate threshold concept. Polyethylene wear measured using image analysis (EBRA) software was compared in 115 subjects with osteolysis versus 115 control subjects that were individually matched for age, sex, and follow up period. Subjects with osteolysis had almost twice the mean annual wear rate versus the controls. The incidence of osteolysis increased in a linear manner with each quintile increase in wear rate throughout the range 0.01–0.54 mm/year. The odds-ratio for osteolysis approximately doubled with each quintile increase in wear rate above the middle quintile (wear rate 0.08–0.11 mm/year), and decreased at a similar rate with each quintile decrease in wear rate below the middle quintile. Our data suggests that the association of osteolysis with polyethylene wear rate represents a continuous dose–response relationship and does not support the concept of a discrete critical wear rate threshold above which the risk of osteolysis is disproportionately increased.

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

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

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.

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 (<50 years), heavy (>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.

A New System to Produce Intraoperatively Custom Femoral Prosthesis From Measurements Taken During the Surgical Procedure

A system has been developed that allows the surgeon to match a prosthesis to any femoral cavity. The surgeon may choose how and where it will preferentially fit. The surgeon does not have to create a cavity to suit a premade prosthesis. The system is based on a novel technique for making a mold of the prepared femoral cavity. This is accurately and thoroughly measured using a laser. An implant is designed and manufactured while the operation is in progress using state-of-the-art computer and machining techniques. All important parameters such as neck length, offset, and anteversion are fully variable intraoperatively. To date, more than 800 consecutive procedures have been carried out. In a limited trial, no subjective difference was found with a cemented Charnley total hip arthroplasty at one year. It currently takes about 40 minutes to manufacture the implant and make it available in the operating room, and this time is being continually reduced. Using a femur first approach, operating time is not greatly extended. In the future, perhaps the operating time will not be extended at all. All data including cavity geometry are centrally recorded for analysis.