Ceramic-on-polyethylene Research Articles

Comparative postoperative prognosis of ceramic-on-ceramic and ceramic-on-polyethylene for total hip arthroplasty: an updated systematic review and meta-analysis.

To compare the clinical outcomes between ceramic-on-ceramic (CoC) and ceramic-on-polyethylene (CoP) bearing surfaces in patients undergoing total hip arthroplasty (THA) through a pooled analysis and evidence update. We performed a systematic literature search using PubMed, Embase, Cochrane Library and Web of Science up to March 2023 for studies that compared the bearing surfaces of CoC and CoP in patients undergoing THA. The primary outcomes were the incidence of common postoperative complications and the rate of postoperative revision. The secondary outcome was the Harris Hip Score. A total of 10 eligible studies involving 1,946 patients (1.192 CoC-THA versus 906 CoP-THA) were included in the evidence synthesis. Pooled analysis showed no significant difference in the rates of common postoperative complications (dislocation, deep vein thrombosis, infection, wear debris or osteolysis) and of revision. After eliminating heterogeneity, the postoperative Harris Hip Score was higher in the CoC group than in the CoP group. However, the strength of evidence was moderate for the Harris Hip Score. CoC articulations are more commonly used in younger, healthier, and more active patients. While the performance of conventional polyethylene is indeed inferior to highly cross-linked polyethylene, there is currently a lack of sufficient research comparing the outcomes between highly cross-linked polyethylene and CoC bearing surfaces. This area should be a focal point for future research, and it is hoped that more relevant articles will emerge. Given the limited number of studies included, the heterogeneity and potential bias of those included in the analysis, orthopaedic surgeons should select a THA material based on their experience and patient-specific factors, and large multicentre clinical trials with >15 years of follow-up are needed to provide more evidence on the optimal bearing surface for initial THA.

IS IT SAFE TO USE A CERAMIC-ON-POLYETHYLENE BEARING IN REVISIONS FOR CERAMIC FRACTURE?

Ceramic bearing fracture is a rare complication following implantation using modern day ceramic bearing materials. Revision bearing options in such cases is debated, with the choice between ceramic-on-ceramic and ceramic-on-polyethylene bearings. Revision to a hard on soft bearing raises concerns about potential catastrophic wear secondary to a third-body reaction caused by the fractured ceramic particles.Data was collected retrospectively from the NJR, electronic patient records, revision database and picture archiving and communication system. Templating software was used to determine linear wear between first post-operative radiograph and the latest available follow up. Univariate analysis was used to examine patient demographics and the wear rates for revision of ceramic bearing fractures to ceramic on polyethylene components. The intra and inter-rater reliability of wear measurements was calculated.There were twelve patients identified as meeting the inclusion criteria. The average age at revision was 62 years (54–72). There were 6 liner and 6 head fractures revised to delta ceramic heads and cross-linked polyethylene acetabular components. The most frequently used head size was 32mm. At mean follow up of 3.8 years (0.5 6.1 years), median 4.4 years, linear wear rate was calculated at 0.08± 0.06 mm/year. Both intra-rater and inter-rater reliability was excellent with ICC scores of 0.99 at all timepoints.Revision to ceramic on polyethylene (CoP) bearings following ceramic fracture does not cause early catastrophic wear at early follow up. It appears safe to use this hard on soft bearing combination, given that wear rates are comparable to what is expected in a primary hip replacement setting. Longer follow up is required to establish if this trend persists.

RWD139 The Use of Oxidized Zirconium Result in Fewer Readmission Rates in Hip Replacement Patients Due to Hip Fracture

The Comprehensive Care for Joint Replacement (CJR) Model from the Centers for Medicare and Medicaid Services and similar programs from other payers make hospitals and healthcare systems more responsible for better clinical and economical outcomes of total hip arthroplasty (THA) aimed at slowing Medicare spending growth. Oxidized Zirconium◊ (OxZr) implants have been shown in numerous registry and clinical studies to be clinically effective when used on elective THA. The objective of this study was to evaluate 30, 90 and 180- and one-year outcomes in hip replacement due to hip fracture for patients using OxZr implants compared to ceramic-on-polyethylene (CoP) implants.

Stripe Wear - Ceramic on Polyethylene Bearing Surface: A Case Report

Background: Stripe wear is a well-known phenomenon that might be caused by rim impingement, edge loading, metal particle entrapment, micro-separation, and transient subluxation. Stripe wear is felt to represent metal transfer and has been associated with squeaking in ceramic-on-ceramic bearings. In our paper, we report the presence of stripe wear on a retrieved modular ceramic femoral head from a patient with ceramic-on-polyethylene-bearing total hip arthroplasty. Method: We report a case of a 57-year-old male who originally had metal-on-metal (MOM) THA and underwent debridement and exchange of the bearing surface from MOM to ceramic-on-polyethylene (COP) articulation for pain and metallosis. He subsequently developed sepsis and underwent resection arthroplasty. Result: Intraoperatively, a cross-table lateral radiograph revealed the forward flexion of the acetabular component and femoral neck to posterior acetabular margin impingement. By analyzing the retrieved components macroscopically and microscopically, linear scars were found on the polyethylene liner, femoral neck, and femoral head in a pattern consistent with the X-ray finding. Conclusion: If metallosis is encountered after THA, the source of the metal wear should be identified. Component malposition is a possible cause, and the surgeon should consider revision or repositioning of the components if evidence of impingement is seen, as a simple bearing exchange may not solve the problem. This report indicates that stripe wear is not limited to ceramic on ceramic articulations.

No increased risk of cancer associated with metal-on-metal or ceramic-on-ceramic procedures compared to other bearing surfaces in patients with total hip arthroplasty: A nationwide linked registry cohort analysis of 167,837 patients.

Studies have identified increased cancer risk among patients undergoing total hip arthroplasty (THA) compared to the general population. However, evidence of all-cause and site-specific cancer risk associated with different bearing surfaces has varied, with previous studies having short latency periods with respect to use of modern Metal-on-Metal (MoM) bearings. Using the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) linked to Australasian Association of Cancer Registries data, our aim was to evaluate risk of all-cause and site-specific cancer according to bearing surfaces in patients undergoing THA for osteoarthritis and whether risk increased with MoM bearings. Standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated by comparing number of observed cancer cases to expected number based on incidence rate in the Australian population. All-cause and site-specific cancer rates were calculated for all conventional stemmed THA (csTHA) and resurfacing THA (rsTHA) procedures performed for osteoarthritis. Cox proportional hazards models were used to compare cancer rates for MoM, ceramic-on-ceramic (CoC) and resurfacing procedures with a comparison group comprising metal-on-polyethylene (MoP) or ceramic-on-polyethylene (CoP) procedures. There were 156,516 patients with csTHA procedures and 11,321 with rsTHA procedures for osteoarthritis performed between 1999 and 2012. Incidence of all-cause cancer was significantly higher for csTHA (SIR 1.24, 95% CI 1.22-1.26) and rsTHA (SIR 1.74, 95% CI 1.39-2.04) compared to the Australian population. For csTHA, there was no significant difference in all-site cancer rates for MoM (Hazard Ratio (HR) 1.01, 95%CI 0.96-1.07) or CoC (HR 0.98, 95%CI 0.94-1.02) compared to MoP and CoP bearings. Significantly increased risk of melanoma, non-Hodgkins lymphoma, myeloma, leukaemia, prostate, colon, bladder and kidney cancer was found for csTHA and, prostate cancer, melanoma for rsTHA procedures when compared to the Australian population, although risk was not significantly different across bearing surfaces. csTHA and rsTHA procedures were associated with increased cancer incidence compared to the Australian population. However, no excess risk was observed for MoM or CoC procedures compared to other bearing surfaces.

Cementless metal-on-metal versus ceramic-on-polyethylene hip arthroplasty in under-50 year-olds with 20 to 22 years’ follow-up: Was it a good idea to abandon the small-diameter metal-on-metal bearing?

In 2005 and 2011, we reported results for a comparative study of two types of 28-mm bearing (metal-on-metal (MoM) and ceramic-on-polyethylene (CoP) in active patients with respectively 5 and 12 years’ follow-up. The present report is an update at a mean 20 years’ follow-up, addressing 2 issues: (1) implant survival at a mean 20 years; and (2) long-term complications with the metal-on-metal bearing. Twenty-eight millimeters MoM bearings show good survival at 20 years in young active subjects. Two groups of cementless hip prostheses were compared: Metasul™ 28mm MoM versus 28mm CoP. The MoM group comprised 30 patients (39 hips), with a mean age of 40±6.7 years [range, 22.6–49 years], and the CoP group comprised 32 patients (39 hips), with a mean age of 40.5±8.7 years [range, 15–50 years]. The groups were matched in 2005 for age, activity level and preoperative Harris score. At a mean 20±5.3 years’ follow-up [range, 5–23 years], in the MoM group 2 hips (5%) showed limited non-progressive acetabular osteolysis, not requiring revision surgery; in the CoP group, there were 21 revision procedures (54%), including 15 for polyethylene wear. In the MoM group, the median total blood cobalt concentration was 1.03g/L [range, 0.3–3.5] and the median chromium concentration was 1.07g/L [range, 0.3–3.2]. Twenty-year all-cause survival was 100% in the MoM group, and 46% (95% CI, 37–59%) in the CoP group (p<0.0001). At long-term follow-up, MoM implants showed better survival than CoP implants in a young active population. Level of evidence: III, matched case series.

Revision in Ceramic-on-Ceramic and Ceramic-on-Polyethylene Bearing in Primary Total Hip Arthroplasty with Press-fit Cups: A Systematic Review and Meta-analysis of Different Methodological Study Designs.

The influence of bearing on revision, especially in press-fit modular cup total hip arthroplasty (THA), remains underexposed. A systematic literature review was conducted in PubMed, Embase, Cochrane Library, and ClinicalTrials.gov in line with the PRISMA guidelines. The primary outcome was overall revision between ceramic-on-ceramic (CoC) and all sorts of ceramic-on-polyethylene (CoPE) bearings. As secondary outcomes complications and reasons for revision were compared between bearings. Outcomes were presented in subgroups based on study design (randomized controlled trials (RCT), non-randomized comparative, and registry studies). The quality of evidence was assessed using the GRADE. The risk of bias was assessed using the Cochrane collaboration's tool and the MINORS criteria. This meta-analysis included twelve RCTs, three non-randomized comparative studies and two registry studies, including 38,772 THAs (10,909 CoPE and 27,863 CoC). Overall revision showed a lower risk in CoPE compared to CoC in the two registry studies (HR 0.71 (95%CI 0.53; 0.99)) (very low-quality GRADE evidence). In RCTs and non-randomized comparative studies, no difference was observed (low-quality GRADE evidence). Loosening, dislocation, infection, and postoperative periprosthetic fracture showed no significant differences in risk ratio for all designs. The lower risk of overall revision in registry studies of primary THA with a press-fit modular cup using CoPE bearing compared to CoC should be considered preliminary since this outcome was just slightly significant, based on very low-quality GRADE evidence and based on only two studies with several limitations. Since no difference was observed in the other methodological designs and the separate reasons for revision showed no significant difference in all designs either, no preference for CoC or CoPE can be expressed, and therefore both seem suitable options based on the available literature. More comparative long-term studies are needed to confirm the potential advantages of wear-reduction of both bearings since the currently available literature is limited.

Higher risk of 2-year cup revision of ceramic-on-ceramic versus ceramic-on-polyethylene bearing: analysis of 33,454 primary press-fit total hip arthroplasties registered in the Dutch Arthroplasty Register (LROI).

The influence of bearing on short-term revision in press-fit total hip arthroplasty (THA) remains under-reported. The aim of this study was to describe 2-year cup revision rates of ceramic-on-ceramic (CoC) and ceramic-on-polyethylene (CoPE). Primary press-fit THAs with one of the three most used cups available with both CoC or CoPE bearing recorded in the Dutch Arthroplasty Register (LROI) were included (2007-2019). Primary outcome was 2-year cup revision for all reasons. Secondary outcomes were: reasons for revision, incidence of different revision procedures and use of both bearings over time. 2-year Kaplan-Meier cup revision rate in 33,454 THAs (12,535 CoC; 20,919 CoPE) showed a higher rate in CoC (0.67% [95% CI, 0.54-0.81]) compared to CoPE (0.44% [95% CI, 0.34-0.54]) (p = 0.004). Correction for confounders (age, gender, cup type, head size) resulted in a hazard ratio (HR) of 0.64 [95%CI, 0.48-0.87] (p = 0.019). Reasons for cup revision differed only by more cup revision due to loosening in CoC (26.2% vs.1 3.2%) (p = 0.030). For aseptic loosening a revision rate of 0.153% [95% CI, 0.075-0.231] was seen in CoC and 0.058% [95%CI 0.019-0.097] in CoPE (p = 0.007). Correction for head size resulted in a HR of 0.475 [95% CI, 0.197-1.141] (p = 0.096). Incidence of different revision procedures did not differ between bearings. Over time the use of CoPE has increased and CoC decreased. A higher 2-year cup revision rate in press-fit THA was observed in CoC compared to CoPE. Cup loosening was the only significantly different reason for revision and seen more often in CoC and mostly aseptic. Future randomised controlled trials need to confirm causality, since the early cup revision data provided has the potential to be useful when choosing the bearing in press-fit THA, when combined with other factors like bone quality and patient and implant characteristics.

Ceramic-on-polyethylene hip arthroplasty reduces the risk of postoperative periprosthetic joint infection.

Metal-on-polyethylene (MoP) total hip arthroplasty (THA) prostheses are known to release metal debris. Basic science studies suggest that metal implants induce a pro-inflammatory response that ultimately chemoattracts leukocytes including macrophages and neutrophils to the surgical site. This raises concern of higher risk of infection with these prostheses through the "trojan horse" mechanism by which neutrophils and macrophages transport intracellular pathogens from a remote site. This study compared the infection occurrence between MoP and ceramic-on-polyethylene (CoP) implants to determine if a higher infection rate in MoP is present. We reviewed a consecutive series of 6052 CoP and 4550 MoP primary THApatients from 2015 to 2019. The occurrence of periprosthetic joint infection at 2 years was defined according to the 2018 ICM definition. Statistical analysis consisted of descriptive statistics, univariate analysis, and regression modeling. When compared to CoP, MoP patients were older, included more females, had a higher body mass index, and more commonly affected by comorbidities according to Elixhauser's score. Total revisions were higher in the MoP group (3.19% vs. 2.41%) The absolute incidence of PJI was higher in MoP (2.40% vs. 1.64%). When we adjusted for confounding factors, MoP was found independently associated with a higher PJI risk. Despite MoP and CoP both being widely used for primary THA, we found a higher incidence of PJI in MoP patients. The association remained significant when controlled for possible confounders. We hypothesize that leukocyte recruitment to these implants may play a role and should be further investigated.

Ceramic-on-ceramic versus ceramic-on-polyethylene in total hip arthroplasty: a comparative study at a minimum of 13\u2009years follow-up

BackgroundNowadays hip replacement is one of the most successful surgery in terms of clinical outcome and patient’s satisfaction. Therefore, the choice of biomaterials in hip replacement is increasingly important with the aim of obtaining a long-term satisfaction of patient and a greater survivorship of the implants. Ceramic-on-polyethylene (COP) and ceramic-on-ceramic (CoC) bearings are two common coupling used in total hip arthroplasty. The aim of this retrospective study was to compare clinical and radiological outcomes between patients treated using CoC and CoP THA at a mean follow-up of 15 years.Methods86 patients, average age 65.6, were included in the study: 43 in group A bearing CoC and 43 in group B bearing CoP. Minimum follow-up was 13 years.Primary outcome was a clinical evaluation assessed by HOOS and SF-12 questionnaires.Secondary outcome was a radiological evaluation on a A-P pelvis x-ray calculating acetabular cup inclination and anteversion and detecting osteolysis.ResultAfter a multivariate analysis was performed, our results show clinical outcomes in group B significantly better than in group A: statistically significant value (p < 0,05) was found in the mean HOOS-symptoms subscale (83.0 ± 15.4 in Group A vs 90.3 ± 12.2 in group B) in the SF-12 physical component score (39.7 ± 11.0 in Group A vs 48.1 ± 10.1 in group B) and in HOOS (79.0 ± 16 in Group A vs 87.0 ± 16 in group B). 3 squeaking was found in group A. The calculated mean acetabular cup inclination value was 44,87 in group A and 44,5 in group B and the mean socket version was 17,54 in group A and 15,10 in group B. No significant statistically relationship between radiographic parameters analyzed and clinical outcomes was noted.ConclusionThe current results provide us important information about the THA long-term outcome. CoP offered significantly better results compared with CoC at long-term follow up, and thus it should be considered in the choose of bearing in THA.

National Trends in Total Hip Arthroplasty Bearing Surface Usage in Extremely Young Patients Between 2006 and 2016.

BackgroundLong-term implant durability is a key concern when considering total hip arthroplasty (THA) in young patients. The ideal bearing surface used in these patients remains unknown. The purpose of this study was to analyze trends in THA bearing surface use from 2006 to 2016 using a large, pediatric national database.MethodsThis was a retrospective review from January 1, 2006, to December 31, 2016, using the Kids’ Inpatient Database. International Classification of Diseases, 9th revision and 10th revision codes were used to identify patients who underwent THA and create cohorts based on bearing surfaces: metal-on-metal, metal-on-polyethylene, ceramic-on-polyethylene (CoP), and ceramic-on-ceramic (CoC). Annual utilization of each bearing surface and associated patient and hospital demographics were analyzed.ResultsA total of 1004 THAs were identified during the 11-year study period. The annual number of THAs performed increased by 169% from 2006 to 2016. The mean patient age was 17.1 years. The most prevalent bearing surface used in 2006 was CoC (37.3%), metal-on-metal (31.8%) in 2009, and CoP in 2012 and 2016 (50.6% and 64.8%, respectively). From 2006 to 2016, utilization of CoP increased from 5.0% to 64.8%, representing a 1196% increase over the study period.ConclusionsThe number of THAs performed in pediatric patients is increasing significantly. Although CoC was previously the most commonly used bearing surface in this patient population, CoP is currently the most common. Further investigation is needed to determine whether bearing longevity and clinical outcomes with CoP are superior to other bearing surfaces.

Ceramic Bearings Are Associated With a Significantly Reduced Revision Rate in Primary Hip Arthroplasty: An Analysis From the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man

BackgroundProsthetic joint infection (PJI) is a devastating complication. Studies have suggested reduction in PJI with the use of ceramic bearings. MethodsAdult patients who underwent total hip arthroplasty (THA) using an uncemented acetabular component with ceramic-on-ceramic (CoC), ceramic-on-polyethylene (CoP), or metal-on-polyethylene (MoP) bearing surfaces between 2002 and 2016 were extracted from the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man. A competing risk regression model to investigate predictors of each revision outcome was used. Time-to-event was determined by duration of implantation since primary surgery with competing risks being death or revision. The results were adjusted for age, gender, American Association of Anaesthesiologists grade, body mass index, surgical indication, intraoperative complications, and implant data. ResultsIn total, 456,457 THAs (228,786 MoP, 128,403 CoC, and 99,268 CoP) were identified. Multivariable modeling showed that the risk of revision for PJI was significantly lower with CoC (risk ratio 0.748, P < .001) and CoP (risk ratio 0.775, P < .001) compared to MoP. Significant reduction in risk of aseptic and all-cause revision was also seen. The significant protective effect of ceramic bearing was predominantly seen 2 years after implantation. Aseptic revision beyond 2 years reduced by 18.1% and 24.8% for CoC and CoP (P < .001), respectively. All-cause revision rate beyond 2 years reduced by 21.6% for CoC and 27.1% for CoP (P < .001) ConclusionThis study demonstrates an association between the use of ceramic as part of the bearing, with lower rates of revision for all causes, revision for infection, and revision for aseptic causes, supporting ceramic bearings in THA.

Ceramic-on-Ceramic Bearing in Total Hip Arthroplasty Reduces the Risk for Revision for Periprosthetic Joint Infection Compared to Ceramic-on-Polyethylene: A Matched Analysis of 118,753 Cementless THA Based on the German Arthroplasty Registry.

Periprosthetic joint infection (PJI) is one of the most common complications in total hip arthroplasty (THA). The influence of bearing material on the risk of PJI remains unclear to date. This registry-based matched study investigates the role of bearing partners in primary cementless THA. Primary cementless THAs recorded in the German Arthroplasty Registry since 2012 with either a ceramic-on-ceramic (CoC) or ceramic-on-polyethylene (CoP) bearings were included in the analysis. Using propensity score matching (PSM) for age, sex, obesity, diabetes mellitus, Elixhauser comorbidity index, year of surgery and head size, we compared the risk for revision for PJI for CoC and CoP. Within the 115,538 THAs (87.1% CoP; 12.9% CoC), 977 revisions were performed due to PJI. There was a significantly higher risk for revision for PJI for CoP compared with CoC over the whole study period (p < 0.01) after 2:1 matching (CoP:CoC) with a hazard ratio of 1.41 (95% confidence interval (CI), 1.09 to 1.80) After 3 years, the risk for revision for PJI was 0.7% (CI 0.5–0.9%) for CoC and 0.9% (CI 0.8–1.1%) for CoP. The risk for revision for all other reasons except PJI did not significantly differ between the two groups over the whole study period (p = 0.4). Cementless THAs with CoC bearings were less likely to be revised because of infection in mid-term follow-up. In the future, registry-embedded studies focusing on long-term follow-up, including clinical data, as well as basic science studies, may give a deeper insight into the influence of the bearing partners.

Ceramic-on-ceramic vs ceramic-on-polyethylene, a comparative study with 10-year follow-up.

BACKGROUNDIn press-fit total hip arthroplasty (THA) ceramic-on-ceramic (CoC) bearings are a potential for overcoming the wear that is seen in ceramic-on-polyethylene (CoPE) bearings, and can lead to wear-induced osteolysis, resulting in loosening of the implant. However, CoC bearings show disadvantages as well, such as squeaking sounds and being more fragile, which can cause ceramic head or liner fracture. Because comparative long-term studies are limited, the objective of this study was to determine the long-term difference in wear, identify potential predictive factors for wear, investigate radiological findings such as osteolysis, and evaluate clinical functioning and complications between these bearings.AIMTo determine 10-year differences in wear, predictive factors for wear, and investigate radiological findings and clinical functioning between CoC and CoPE.METHODSThis observational prospective single-center cohort study with a 10-year follow-up includes a documented series of elective THAs. Primary outcome was wear measured by anteroposterior (AP) radiographs. Secondary outcomes were potential predictive factors for wear, complications during follow-up, Harris hip score (HHS), and radiological findings such as presence of radiolucency, osteolysis, atrophy, and hypertrophy around the cup. Due to the absence of wear in the CoC group, stratified analysis to identify risk factors for wear was only performed in the CoPE group by use of univariate linear regression analysis. HHS was expressed as a change from baseline and the association with bearing type was assessed by use of multivariate linear regression analysis, adjusted for potential confounders.RESULTSA total of 17 CoPE (63.0%) and 25 CoC (73.5%) cases were available for follow-up and showed a linear wear of respectively 0.130 mm/year (range 0.010; 0.350) and 0.000 mm/year (range 0.000; 0.005), which was significant (P < 0.001) between both groups. Wear always occurred in the cranial direction. Cup inclination was the only predictive factor for polyethylene (PE) wear. No dislocations, ceramic head, or liner fractures were seen. The HHS showed a mean change from baseline of 37.1 points (SD 18.5) in the CoPE group and 43.9 (SD 17.0) in the CoC group. This crude difference of 6.8 (range -5.2; 18.7) in favor of the CoC group was not significant (P = 0.26) and was not significant when adjusted for age, gender, and diagnosis either (P = 0.99). No significant differences in complications and radiological findings were seen between groups. CONCLUSIONCoC bearing shows lower wear rates compared to CoPE at 10-year follow-up with cup inclination as a predictive factor for wear and no differences in complications, HHS, and radiological findings.

Early Post-operative Rises in Serum Metal Ion Levels in Total Hip Arthroplasty

Background: Serum Cobalt (Co) and Chromium (Cr) forms part of the diagnostic process for metallosis following Total Hip Arthroplasty (THA). While knowledge exists on longer term metal ion levels, expected early post-operative rises in serum Co and Cr in Metal-on-Polyethylene (MoP) THAs are currently unknown. This study aims to describe early rises in serum Co and Cr at 6 months post-operatively. Methods: A prospective cohort study of 100 consecutive patients with an uncemented titanium stem from a single THA manufacturer was performed. Patients had either a metal (n=50) or ceramic (n=50) head articulating with a highly cross-linked polyethylene. Serum Co and Cr levels were measured 6 months post-operatively. Analysis compared mean values between groups and to determined baseline levels. Subgroup analysis investigated the effect of femoral head size and offset on metal ion levels. Results: A mean difference of 2.259 nmol/L (95% CI 0.449-4.069; p=0.015) was found when comparing 6-month serum Co in the metal head group compared to baseline. No significant differences were found in serum Cr (p=0.943). Mean serum Co levels were higher in the MoP group compared to the CoP (Ceramic-on-Polyethylene) comparator group (p=0.012). There were no differences in serum Cr (p=0.976). Variations in femoral head size and offset did not impact metal ion levels. Conclusion: At six months, a higher magnitude of serum Co exists in metal heads when compared to baseline (p=0.015) and to ceramic heads (p=0.012). Further study is required to determine whether serum concentrations of metal ions will continue to increase over time.

A systematic review and meta-analysis of survivorship and wear rates of metal and ceramic heads articulating with polyethylene liners in total hip arthroplasty.

The major joint registries report better survivorship for ceramic on polyethylene over metal on polyethylene bearings in total hip arthroplasty and it is generally accepted that this is due to a lower polyethylene wear rate. We used evidence synthesis to compare survivorship, polyethylene wear rates and metal ion levels for metal-on-polyethylene (MoP) and ceramic-on-polyethylene (CoP) bearings. If wear rates are not dissimilar in vivo this difference in revision rate may have another cause. Modular junctions are a potential source of corrosion and it is postulated that this may result in higher revision rates. We performed a systematic review and meta-analysis comparing the survivorship of MoP and CoP bearings. Odds ratio (95% CI) of revision was calculated. Mean difference (MD) and 95% confidence intervals (CI) were used to compare secondary outcomes of polyethylene wear and metal ion levels. Meta-analysis was performed with a Mantel-Haenszel Random-Effects Model. 6 randomised controlled trials were included. There was no statistically significant difference between MoP and CoP revision rate (OR 1.04; 95% CI, 0.37-2.90, I2 = 0%, p = 0.94), linear bearing wear (MD 0.00 mm; 95% CI, -0.05 -0.05, I2 = 98%, p = 0.90), nor volumetric bearing wear (MD 33.57 mm3; 95% CI, -215.56-282.70, I2 = 98%, p = 0.79). No studies evaluated metal ion levels. We found no evidence of a difference in revision rates nor linear and volumetric wear between MoP and CoP bearings in the randomised controlled trials currently available. Our study therefore does not advocate the additional cost associated with the use of ceramic heads in combination with polyethylene bearings in order to minimise revision rates. This contrasts the findings of in vitro studies and the major joint registries.

Can the Choice of Cementless Implants and Bearings during Total Hip Arthroplasty Have an Impact on the Overall Costs within a Bundled Payment Model?

AbstractThe comprehensive care for joint replacement model from the Center for Medicare and Medicaid Services and similar programs from other payers make hospitals and health care systems more responsible for better clinical and economic outcomes of total hip arthroplasty (THA) patients. The objective of the study was to evaluate hospital-related clinical and economic outcomes of using the cementless R3 cup and Polarstem with an oxidized zirconium bearing compared with other cementless hip systems using a ceramic bearing in THA patients. We retrospectively reviewed primary THA patients from the premier perspective database between 2014 and 2018Q3. Patients with R3 cup and Polarstem with an oxidized zirconium bearing were identified using appropriate keywords from billing records and compared against cementless and ceramic-on-polyethylene (CoP) THA patients who did not meet the keywords' criteria. Patients were excluded if they were &lt; 21 years of age; outpatient hospital discharges; evidence of revision THA; bilateral THA in same discharge or different discharges. 1:3 propensity score matching was used to control patients' demographic, clinical, and hospital characteristics. Generalized estimating equation model with appropriate distribution and link function was used to estimate hospital-related cost while logistic regression models were used to estimate discharged status, transfusion, and 30-days readmission. The study matched 818 R3/Polarstem with oxidized zirconium bearing patients with 2,454 CoP cementless THA patients. Length of stay for the R3/Polarstem patients (mean = 1.61 days; confidence interval [CI] = 1.41–1.80) was significantly lower (p-value ≤ 0.0001) than CoP THA patients (mean = 2.06 days; CI = 1.95–2.17). R3/Polarstem hip patients were 36% (odds ratio [OR] = 1.36; CI = 1.07–1.72; p-value = 0.0112) more likely to be discharged to home/home health care, 18% (OR = 0.82; CI = 0.63–1.06; p-value = 0.1235) less likely to be discharged to a skilled nursing facility (SNF), 84% less likely to have transfusion (OR = 0.16; CI = 0.09–0.29; p-value ≤ 0.0001), and 44% (OR = 0.56; CI = 0.32–0.98; p-value = 0.0412) less likely to readmitted within 30 days than CoP THA patients. Mean total hospital costs was marginally higher for R3/Polarstem patients (mean = $15,611; vs. $15,002; p-value = 0.0041) than CoP THA patients. While the total hospital costs for the R3/Polarstem was higher than CoP, the reduced length of stay, reduced discharge to SNF, and lower readmission rates can help to save money in the bundled payment and make the use of certain cementless hip systems a potential cost saving solution.

Revision reasons and prosthesis selection of Crowe Ⅳ developmental dysplasia of hip after total hip arthroplasty

To investigate revision reasons and prosthesis selection of Crowe Ⅳ developmental dysplasia of the hip (DDH) after total hip arthroplasty (THA). A clinical data of 14 patients (15 hips) with Crowe Ⅳ DDH, who underwent a revision hip arthroplasty between January 2008 and May 2018, was retrospectively reviewed. There were 1 male (1 hip) and 13 females (14 hips). The age ranged from 27 to 63 years (mean, 45.0 years). There were 7 cases of left hip, 6 cases of right hip, and 1 case of bilateral hips. The prosthetic interfaces of primary THA were metal-on-polyethylene (MOP) in 9 hips, ceramic-on-ceramic (COC) in 4 hips, ceramic-on-polyethylene (COP) in 1 hip, and ceramic-on-metal in 1 hip. The time from primary THA to revision was 3-204 months (mean, 65.0 months). The causes of revision included aseptic loosening in 7 hips, dislocation in 3 hips, periprosthetic joint infection in 2 hips, osteolysis in 1 hip, nonunion of osteotomy in 1 hip, and a small-angle of femoral anteversion in 1 hip. Preoperative Harris score was 54.1±17.8 and the range of motion (ROM) of flexion was (92.7±20.2)°. Preoperative X-ray films showed the acetabular bone defect in 11 hips and osteolysis of femoral side in 4 hips. During the revision, the prostheses with COP and COC interfaces were used in 5 hips and 10 hips, respectively. Both acetabular and femoral revisions were performed in 11 hips and only femoral revision was performed in 4 hips. The mean operation time was 3.7 hours (range, 1.5-6.0 hours). The mean intraoperative blood loss was 940.0 mL (range, 200-2 000 mL). All patients were followed up 16-142 months (mean, 73.9 months). Postoperative X-ray films showed no difference in inclination and anteversion between primary THA and revision ( P>0.05). The height of rotation center and offset after revision were higher than those after primary THA, and the difference in offset was significant ( P<0.05). At last follow-up, the Harris score and ROM of flexion were 85.0±7.3 and (115.0±17.0)°, respectively, which were significantly higher when compared with those before revision ( t=8.909, P=0.000; t=4.911, P=0.000). Three hips underwent a re-revision operation. All protheses were fixed well and no radiolucent line, loosening, or subsidence was observed at last follow-up. The most common reason for revision in patients with Crowe Ⅳ DDH after THA was aseptic loosening. Due to high activity demand of this population, the prosthesis with MOP interface should be prevented and the prosthesis with COC interface could be alternative. Metal block, cup-cage, and reinforcement ring were reasonable solutions for reconstruction of acetabulum with severe bone defects and have satisfactory effectiveness. S-ROM prosthesis should be the preferred stem for neither primary THA or revision.

Corrosion Concerns? Trends in Metal-on-Polyethylene Total Hip Arthroplasty Revision Rates and Comparisons Against Ceramic-on-Polyethylene up to 10 Years of Follow-Up

BackgroundWe compared the revision risk between metal-on-polyethylene (MOP) and ceramic-on-polyethylene (COP) total hip arthroplasty patients and evaluated temporal changes in short-term revision risks for MOP patients. MethodsPrimary MOP (n = 9480) and COP (n = 3620) total hip arthroplasties were evaluated from the Medicare data set (October 2005 to December 2015) for revision risk, with up to 10 years of follow-up using multivariate analysis. Temporal change in the short-term revision risk for MOP was evaluated (log-rank and Wilcoxon tests). ResultsRevision incidence was 3.8% for COP and 4.3% for MOP. MOP short-term revision risk did not change over time (P ≥ .844 at 1 year and .627 at 2 years). Dislocation was the most common reason for revision (MOP: 23.5%; COP: 24.8%). Overall adjusted revision risks were not different between MOP and COP up to 10 years of follow-up (P ≥ .181). ConclusionsConcerns with corrosion for metal heads do not appear to result in significantly elevated revision risk for MOP at up to 10 years. Corrosion does not appear as a primary reason for revision compared to other mechanisms.

What Is the Frequency of Fracture of Ceramic Components in THA? Results from the Norwegian Arthroplasty Register from 1997 to 2017.

Ceramic bearings in THA have been used to reduce wear and, more recently, to avoid metals in the bearing because of the risk of metal ions adverse effects. Potential disadvantages to ceramic bearings are their brittleness and the ceramic fracture risk, which may lead to revision surgery. The frequency of revision for a fracture ceramic bearing, however, has not been thoroughly studied. (1) What is the frequency of revision for a fractured ceramic bearing in ceramic-on-polyethylene (CoP) and ceramic-on-ceramic (CoC) THAs, and is there any difference between alumina ceramics and alumina matrix composites (AMC)? (2) What are the factors associated with this complication? (3) To what extent did the patients who underwent revision for a fractured ceramic bearing undergo subsequent revisions, and for what reason? The Norwegian Arthroplasty Register has collected data on hip arthroplasty since 1987 and has a completeness of reporting of 97.3% for primary THAs and 93.3% for revision. From 1997 to 2017, 146,171 primary THAs were registered in the Norwegian Arthroplasty Register. Of these, 31,479 had a CoP articulation and 5790 had a CoC articulation. Two manufacturers produced ceramic heads; one produced 25,678 alumina heads and the other made 2465 alumina heads. All 7901 AMC heads were made by the same manufacturer. Patients who underwent CoP THA were a median (range) of 63 years old (11 to 98) and CoC THA were a median (range) 61 years old (17 to 95); 38% (11,833 of 31,479) of the patients who underwent CoP THA and 41% (2379 of 5790) of the patients who underwent CoC THA were males. Femoral heads made of alumina (n = 28,143), zirconia (n = 1225), and AMC (n = 7901) ceramics were used. To assess revision frequency, we identified patients who underwent revision because of fracture of a ceramic head and/or liner, and calculated the Kaplan-Meier survivorship free of revision for fracture in CoC and CoP articulations. Alumina ceramics and AMC were compared. In terms of factors potentially associated with revision, patient factors (age, sex, and diagnosis), type of articulation (CoP or CoC), femoral head size, and femoral head/neck length were evaluated with Cox regression models to evaluate any association with ceramic fracture and a Poisson regression to compare alumina and AMC head fractures. To evaluate subsequent revisions, hips that were revised for ceramic fracture were evaluated for any further revisions; Kaplan-Meier survivorship free of further revisions was calculated, and revision causes were identified. Survivorship free from revision for ceramic fracture was 99.9% (95% CI 99.9 to 99.9) for CoP bearings, and 99.8% (95% CI 99.6 to 100) for CoC bearings at 10 years, with 7467 and 1884 hips at risk in the two groups, respectively. The hazard ratio for ceramic head fracture was 3.6 (95% CI 1.7 to 7.6) for CoC compared with CoP. The risk of fracture was greater for alumina ceramics than for AMC heads (adjusted HR 14.1 [95% CI 4.2 to 47.0]; p < 0.001). Factors that were associated with revision for fracture of a ceramic head were male sex (HR 5.2 [95% CI 2.6 to 10.4]; p < 0.001), a CoC articulation compared with CoP (HR 3.6 [95% CI 1.7 to 7.6]; p = 0.001), a 28-mm femoral head compared with a 32-mm head (HR 2.7 [95% CI 1.1 to 6.4]; p = 0.02), and short head/neck length compared with a medium head/neck length (HR 2.5 [95% CI 1.1 to 5.3]; p = 0.03). Five of 50 patients undergoing revision for ceramic fracture underwent further revisions, resulting in a 5-year survivorship free from re-revision of 86% (95% CI 74.4 to 98.0). The reasons for re-revision were infection (n = 2), another ceramic head fracture (n = 2), and cup loosening (n = 1). Fracture of a ceramic THA bearing is rare and seems to affect about one in 1000 patients who receive such a bearing. To minimize the risk of this complication, surgeons should avoid small femoral heads (< 32 mm) and the shortest head/neck lengths. Surgeons should also know that the risk is increased in CoC articulations and in males. Bearings made of AMC appear to be at lower risk than those made from alumina ceramics. However, the long-term clinical wear performance of AMC bearings has not been extensively studied and should be studied further. Level III, therapeutic study.