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Metal-on-polyethylene versus metal-on-metal bearing surfaces in total hip arthroplasty: A prospective randomised study investigating metal ion levels and chromosomal aberrations in peripheral lymphocytes
Abstract
The long term biological effects of wear products following total hip arthroplasty (THA) are unclear. However, the indications for THA are expanding, with increasingly younger patients undergoing the procedure.
This prospective, randomised study compared two groups of patients undergoing THA after being randomised to receive one of two different bearing surfaces: metal-on-polyethylene (MoP) n = 22 and metal-on-metal (MoM) n = 23. We investigated the relationship between three variables: bearing surface (MoP vs MoM), whole blood levels of chromium (Cr) and cobalt (Co) and chromosomal aberrations in peripheral lymphocyte pre-operatively and at one, two and five years post-surgery.
Our results demonstrated significantly higher mean cobalt and chromium (Co and Cr) blood levels in the MoM group at all follow-up points following surgery (p < 0.01), but there were no significant differences in the chromosomal aberration indices between MoM and MoP at two or five years (two years: p = 0.56, p = 0.08, p = 0.91, p = 0.51 and five years: p = 0.086, p = 0.73, p = 0.06, p = 0.34) for translocations, breaks, loss and gain of chromosomes respectively. Regression analysis showed a strong linear relationship between Cr levels and the total chromosomal aberration indices in the MoM group (R ² = 0.90016), but this was not as strong for Co (R ² = 0.68991). In the MoP group, the analysis revealed a poor relationship between Cr levels and the total chromosomal aberration indices (R ² = 0.23908) but a slightly stronger relationship for Co (R ² = 0.64292). Across both groups, Spearman’s correlation detected no overall association between Co and Cr levels and each of the studied chromosomal aberrations. There remains no clear indication which THA bearing couple is the most biocompatible, especially in young active patients. While THA continues to be very successful at alleviating pain and restoring function, the long-term biological implications of the procedure still require further scrutiny.
Cite this article: Bone Joint J 2015;97-B:1183–91.
... The effect of this long-term nickel exposure is unknown. Generally, little is known about potential long-term consequences of trace metal contamination, as its biological effects and potential toxicity are poorly understood [11,24]. In particular, the biological effects of an internal exposure to chromium after a steady release from an articulating implant have rarely been investigated [25]. ...
... In particular, the biological effects of an internal exposure to chromium after a steady release from an articulating implant have rarely been investigated [25]. In patients undergoing hip arthroplasty, tissue oxidative damage and chromosomal aberrations have been found after chromium contamination [24,26]. One group demonstrated a correlation of chromium concentration and chromosomal damage in vitro [27], whereas others failed to show a correlation [24]. ...
... In patients undergoing hip arthroplasty, tissue oxidative damage and chromosomal aberrations have been found after chromium contamination [24,26]. One group demonstrated a correlation of chromium concentration and chromosomal damage in vitro [27], whereas others failed to show a correlation [24]. Nickel contamination may have a carcinogenic effect and can also result in damage to the immune system and DNA [28]. ...
Background
Minimally-invasive repair of pectus excavatum (MIRPE) has been shown to be associated with high release of trace metals into patient’s body. The aim of our study was to analyze the kinetics of metal contamination after MIRPE and after bar removal.
Methods
We prospectively assessed nickel and chromium changes in blood, urine, and local tissue in patients undergoing MIRPE with stainless-steel bar(s). Baseline samples were taken prior to surgery, further samples were taken at six defined time points until 30 months after bar removal. Clinical symptoms were evaluated at the time of every sample collection.
Results
28 patients were included (mean age 16.4 years). At four weeks after MIRPE and persisting up to bar removal, we found significantly elevated trace metal levels in blood and urine. Tissue nickel and chromium levels were significantly elevated at the time of bar removal. After bar removal, the concentration of trace metal in urine and the concentration of chromium in plasma decreased gradually. In contrast, nickel levels in blood further increased. Five patients showed irritative symptoms after MIRPE, all symptomatic patients had elevated metal levels.
Conclusions
Following MIRPE, we found a rapid systemic increase of nickel and chromium. Our data indicate that trace metal release could cause irritative symptoms. The prolonged elevated systemic nickel levels beyond bar removal necessitate further investigations of the long-term side effects of MIRPE.
... One option to lower the release of metals is material substitution. In orthopedics, chromium and cobalt contamination after metal-on-metal (MoM) hip arthroplasty has been successfully reduced by using metal-on-polyethylene implants instead [13,14]. Pectus bars consist of stainless steel and could be substituted by titanium. ...
... Wear and metal sensitivity were found as a potential causes of implant failure [27,28]. This clinical problem as well as the metal contamination could be reduced by change of the material to metal-on-polyethylene [13,14]. Another effective protection against wear debris following orthopedic procedures can be coating of the regular implant with TiN [17,28]. ...
Introduction
Previous studies demonstrated a release of toxic metals, e.g. nickel and chromium, from stainless steel bars used for minimally invasive repair of pectus excavatum (MIRPE). In the present study, we investigated the impact of titanium nitride coating on the metal release and exposure of MIRPE patients.
Material and methods
We analyzed the courses of nickel and chromium levels in blood, urine and local tissue in patients undergoing MIRPE with a titanium nitride coated pectus bar between 03/2017 and 10/2018. Sample collection was scheduled prior to MIRPE, at defined postoperative time points and at bar removal. Additionally, we evaluated irritative symptoms. Results were compared to a control group who received uncoated stainless steel bars in a previous time period (03/2015–02/2017).
Results
12 patients received coated pectus bars (mean age 15.7 years). The control group included 28 patients. After implantation of a titanium nitride coated bar, significant increase in systemic nickel and chromium levels after one, two and three years was noted. In an interim analysis one year after MIRPE, we observed patients with coated bars to have significantly elevated trace metal values compared to the control group. This elevation persisted throughout the observation period. Tissue metal values were also significantly increased. Irritative symptoms occurred significantly more often in study patients compared to controls (50.0% vs. 14.3%).
Conclusions
Coating of pectus bars with titanium nitride failed to reduce metal contamination after MIRPE. Instead, it resulted in a significant increase of trace metal levels after MIRPE, compared to patients with stainless steel bars, which may be explained by wear of the coating and inter-component mobilization processes.
... Then the prototype was prepared by using commercial grade die-steel (DIN 40CrMnMo7) in order to achieve good quality core and cavity to be required for compression molding under high temperature and pressure. 21 The die block consists of three parts such as top plate (core), middle plate (pressure plate) and bottom plate (cavity part). Common outer diameter of die plates for all parts is taken as 125 mm, total height was 92 mm, thickness of top plate 30 mm, middle plate 17 mm and bottom plate 30 mm. ...
The study of tribological performance of metal-on-plastic type of hip prostheses has drawn the attention of researchers since the last few decades. These studies mainly focus on the friction and wear behaviour of acetabular cups made of different polymer biomaterials with a view to enhance the prostheses life. In this study, a novel biomaterial coded as LHHA has been prepared for the acetabular cup in three different blends with help of bioprocess engineering by mixing low-density polyethylene and high-density polyethylene with10, 20 and 30 percent of hydroxyapatite to improve the mechanical properties. A popular decision-making method was applied to select the best alternative from these three blends on the basis of hardness, roughness and ultimate strength and LHHA-30 is found to be the best. Furthermore, experimental wear investigation was carried out in a well-designed hip simulator to control such biological system under a series of random loads, within 600N and 1500N acting at different points on prosthesis for 10 million gait cycles run followed by theoretical wear analysis. Wear rates are found to be 12.651 and 26.247 mg per million cycle with marginal differences of 0.1 and 0.6 for LHHA-30 and ultrahigh molecular weight polyethylene (UHMWPE) acetabular cups against cobalt–chromium (Co–Cr) alloy femoral head, respectively. Morphological studies carried out by scanning electron microscope revealed that LHHA-30 scored less compared to UHMWPE surface.
... Revising the literature for the genotoxic effects following hip arthroplasty revealed a controversy; Christian et al 88 reported that DNA effects would be highly unlikely to occur as a result of wear debris from a CoCr implant. On the other hand, Briggs et al 33 reported a significant increase in the chromosomal aberration indices following both MOM and MOP hip arthroplasty. The United Kingdom Government's Committee on Mutagenicity of Chemicals in Food, Consumer Products, and the Environment stated that some MOP implants can induce genetic damage. ...
Introduction:
Hip arthroplasty (HA) using implantable metal components is among the commonest orthopedic interventions. However, it can be followed by several complications following corrosion and the release of metal ions. Several studies proved that damaged genomic DNA may contribute to the pathophysiology of mental disorders.
Aim:
The current work aims to evaluate the psychiatric disorders in metal on polyethylene hip arthroplasty (MOP-HA) patients and its correlation to cobalt/chromium (Co/Cr) levels and genotoxicity.
Methods:
The work was a longitudinal follow-up study including 34 adults with unilateral primary MOP-HA meeting the inclusion and exclusion criteria. Preoperatively, 6, 12-months-postoperatively, patients were examined for cognitive impairment using mini-mental-state-examination (MMSE), depression using major-depressive-inventory (MDI), and blood samples were collected for estimation of Co/Cr, detection of genotoxicity by single-cell-gel-electrophoresis (comet assay) and serum 8-hydroxy-2'-deoxyguanosine (8-OHdG).
Results:
Cognitive impairment was reported in 18.5% and 14.8% at 6-months, and 12-months postoperative, respectively. Depressive disorder was recorded in 22.2% at 6-months and 14.8% at 12-months postoperative. The marginal homogeneity tests proved a non-significant difference. There was a non-significant difference in preoperative, 6-months, 12-months postoperative MMSE, and MDI scores. There were significantly increased Co/Cr levels at 6-months postoperative. The levels decreased at 12-months postoperative, however, still significantly higher than preoperative values. There was a significant increase in serum 8-OHdG and the levels were positively correlated to cobalt levels at both 6 and 12-months-postoperative. There was a non-significant difference among preoperative, 6-months, and 12-months postoperative comet assay measurements.
Conclusion:
From previous findings, we can conclude that will-functioning MOP hip arthroplasty can induce increased ion levels and positively correlated increase in biochemical markers of genotoxicity (8-OHdG).
... The hip bone's socket portion of an anatomy is kept intact while replacing the ball portion of the femoral bone in the hip joint. The selection of an optimal orthopedic material in all senses is a complex task [51][52][53][54][55][56][57][58]. ...
Biomechanics is the interdisciplinary area comprising biomedical and mechanical domain, continuations in research of alternative and sustainable materials, which refers to the mechanical examine. This current work focuses on hip implant material development through analytical and finite element analysis. The femur bone head is 3D modeled through computed tomography (CT) images extracted data and modeled in SOLIDWORKS. The analytical analysis is performed on the femur head through Hertzian theory. The finite element analysis (FEA) (static structural analysis) is carried out in the ANSYS 19.2. The materials considered for the FEA are NbTiZrMo alloy, PEEK and CFR-PEEK for the hip implant. The analytical analysis is performed for eight different human routine activities, and the highest peak stress value is obtained for walking fast. The peak stress values obtained in FEA for CFR-PEEK material implant are lower than the maximum peak stress obtained by analytical analysis. The stress value obtained for CFR-PEEK material is somewhat higher than PEEK, but the contact pressure for PEEK material is way higher than CFR-PEEK material implant. So, it is concluded that the CFR-PEEK material is the ideal alternative as compared to other materials.
The development of metallic joint prostheses has been ongoing for more than a century alongside advancements in hip and knee arthroplasty. Among the materials utilized, the Cobalt-Chromium-Molybdenum (Co-Cr-Mo) and Titanium-Aluminum-Vanadium (Ti-Al-V) alloys are predominant in joint prosthesis construction, predominantly due to their commendable biocompatibility, mechanical strength, and corrosion resistance. Nonetheless, over time, the physical wear, electrochemical corrosion, and inflammation induced by these alloys that occur post-implantation can cause the release of various metallic components. The released metals can then flow and metabolize in vivo, subsequently causing potential local or systemic harm. This review first details joint prosthesis development and acknowledges the release of prosthetic metals. Second, we outline the metallic concentration, biodistribution, and elimination pathways of the released prosthetic metals. Lastly, we discuss the possible organ, cellular, critical biomolecules, and significant signaling pathway toxicities and adverse effects that arise from exposure to these metals.
The present systematic review investigated the concentration of chromium (Cr) and cobalt (Co) in serum in patients who have undergone total hip arthroplasty (THA). The first outcome of interest was to investigate the mean concentration in serum of Cr and Co using different material combinations and to verify whether their concentrations change significantly using different patterns of head and liner in THA. The second outcome of interest was to investigate whether the time elapsed from the index surgery to the follow-up, BMI, sex, and side exert an influence on the mean concentration of Cr and Co in serum in patients who have undergone THA. The following material combinations were investigated (head-liner): Ceramic-Co Cr (CoCr), CoCr-CoCr, CoCr-Polyethylene, CoCr high carbide-CoCr high carbide. Data from 2756 procedures were retrieved. The mean length of follow-up was 69.3 ± 47.7 months. The ANOVA test evidenced good comparability in age, length of follow-up, BMI, and sex (P > 0.1). In patients who have undergone THA, the mean concentration in the serum of Co ranged between 0.5 µg/L and 3.5 µg/L, and the mean concentration of Cr from 0.6 to 2.6 µg/L. The difference in the concentration of Co and Cr in serum is strictly related to the implant configuration, with the coupling CoCr-CoCr showing the highest and CoCr-Polyethylene showing the lowest concentration. Patient characteristics, BMI, sex, side and the time elapsed from the index surgery to the last follow-up did not exert a significant influence on the concentration of Co and Cr in serum in patients who have undergone total hip arthroplasty (THA).
Case:
Two cases of revision total hip arthroplasty (THA) for pseudotumor and infection with persistent postoperative bleeding because of angiosarcoma are presented. After surgery, both patients' health deteriorated because of hypovolemic shock despite transfusion, pressors, embolization, and prothrombotics. Diagnosis was obscure and delayed despite extensive imaging. Standard and computed tomography angiogram were nondiagnostic and did not localize the tumors or bleeding. Repeat surgeries and biopsies requiring special staining ultimately revealed epithelioid angiosarcoma.
Conclusion:
A diagnosis of angiosarcoma was etiologic for persistent postoperative bleeding after revision THA and should be considered in such cases.
Objectives:
We aimed to make comparisons of different bearing surfaces in patients after cementless total hip arthroplasty.
Methods:
The network meta-analysis was guided by the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guideline. The primary outcomes were implant survival and Harris hip score (HHS). Secondary outcomes included linear wear rates and serum level of metal ions. Subgroup analyses were performed by: 1) classifying head sizes as small and large; 2) femoral heads as ceramic and metal; and 3) liners as metal, ceramic, polyethylene, highly cross-linked polyethylene (HXP), or vitamin E-infused highly cross-linked polyethylene (HXPE). A total of 64 eligible RCTs with different bearings were assessed. Overall inconsistency and heterogeneity were acceptable.
Results:
In the 10 years follow-up, metal-on-polythene and ceramic-on-polythene bearings with small heads showed higher risk for revisions compared with metal-on-HXP and ceramic-on-HXP bearings with small heads. Similarly, only metal or ceramic-on-polythene bearings with small heads showed inferiority in HHS compared with other bearings. Conventional polyethylene liners showed higher linear wear rates compared with HXP, HXPE, and ceramic liners at 5 and 10 years after surgery, while metal-on-metal and ceramic-on-metal bearings showed higher serum level of cobalt and chromium.
Conclusions:
Bearings containing HXP, HXPE, and ceramic liners showed comparable survivorship and hip function at follow-up of 5 and 10 years. Hard-on-hard bearings containing metal had higher serum level of metal ions than others. Bearings containing conventional polyethylene had worse performance in terms of implant survival, hip function, and wear rates.
The long-term biological effects of wear debris are unknown. We have investigated whether there is any evidence of cumulative mutagenic damage in peripheral blood lymphocytes of patients undergoing revision arthroplasty of predominantly metal-on-plastic total hip replacements compared with those at primary arthroplasty.
There was a threefold increase in aneuploidy and a twofold increase in chromosomal translocations which could not be explained by the confounding variables of smoking, gender, age and diagnostic radiographs. In the patients with TiVaAl prostheses there was a fivefold increase in aneuploidy but no increase in chromosomal translocations. By contrast, in patients with cobalt-chrome prostheses there was a 2.5-fold increase in aneuploidy and a 3.5-fold increase in chromosomal translocations. In six patients with stainless-steel prostheses there was no increase in either aneuploidy or chromosomal translocations.
Our results suggest that future epidemiological studies of the putative long-term risks of joint replacement should take into account the type of alloy used in the prosthesis.
We prospectively assessed the efficacy of a ceramic-on-metal (CoM) hip bearing with uncemented acetabular and femoral components in which cobalt–chrome acetabular liners and alumina ceramic heads were used.
The cohort comprised 94 total hip replacements (THRs) in 83 patients (38 women and 45 men) with a mean age of 58 years (42 to 70). Minimum follow-up was two years. All patients had pre- and post-operative assessment using the Western Ontario and McMaster Universities osteoarthritis index (WOMAC), Oxford hip score and Short-Form 12 scores. All showed a statistically significant improvement from three months post-operatively onwards (all p < 0.001).
After two years whole blood metal ion levels were measured and chromosomal analysis was performed. The levels of all metal ions were elevated except vanadium. Levels of chromium, cobalt, molybdenum and titanium were significantly higher in patients who underwent bilateral THR compared with those undergoing unilateral THR (p < 0.001). Chromosomal analysis demonstrated both structural and aneuploidy mutations. There were significantly more breaks and losses than in the normal population (p < 0.001). There was no significant difference in chromosomal aberration between those undergoing unilateral and bilateral procedures (all analyses p ≥ 0.62).
The use of a CoM THR is effective clinically in the short-term, with no concerns, but the significance of high metal ion levels and chromosomal aberrations in the long-term remains unclear.
Cite this article: Bone Joint J 2013;95-B:1040–44.
The aims of this piece of work were to: 1) record the background concentrations of blood chromium (Cr) and cobalt (Co) concentrations in a large group of subjects; 2) to compare blood/serum Cr and Co concentrations with retrieved metal-on-metal (MoM) hip resurfacings; 3) to examine the distribution of Co and Cr in the serum and whole blood of patients with MoM hip arthroplasties; and 4) to further understand the partitioning of metal ions between the serum and whole blood fractions.
A total of 3042 blood samples donated to the local transfusion centre were analysed to record Co and Cr concentrations. Also, 91 hip resurfacing devices from patients who had given pre-revision blood/serum samples for metal ion analysis underwent volumetric wear assessment using a coordinate measuring machine. Linear regression analysis was carried out and receiver operating characteristic curves were constructed to assess the reliability of metal ions to identify abnormally wearing implants. The relationship between serum and whole blood concentrations of Cr and Co in 1048 patients was analysed using Bland-Altman charts. This relationship was further investigated in an in vitro study during which human blood was spiked with trivalent and hexavalent Cr, the serum then separated and the fractions analysed.
Only one patient in the transfusion group was found to have a blood Co > 2 µg/l. Blood/Serum Cr and Co concentrations were reliable indicators of abnormal wear. Blood Co appeared to be the most useful clinical test, with a concentration of 4.5 µg/l showing sensitivity and specificity for the detection of abnormal wear of 94% and 95%, respectively. Generated metal ions tended to fill the serum compartment preferentially in vivo and this was replicated in the in vitro study when blood was spiked with trivalent Cr and bivalent Co.
Blood/serum metal ion concentrations are reliable indicators of abnormal wear processes. Important differences exist however between elements and the blood fraction under study. Future guidelines must take these differences into account.
Background:
Release and dispersion of particles arising from corrosion and wear of total hip arthroplasty (THA) components has raised concerns about a possible increased risk of cancer. Concerns have been heightened by a recent revival in the use of metal-on-metal (MoM) hip prostheses.
Methods:
From a linked database of hospital discharge, cancer registration, and mortality records, we selected a cohort of patients who underwent primary THA (1990–2009) or primary resurfacing arthroplasty (mainly 2000–2009) in Scotland, with follow-up to the end of 2010. Available operation codes did not enable us to distinguish MoM THAs. Indirectly standardised incidence ratios (SIRs) were calculated for selected cancers with standardisation for age, sex, deprivation, and calendar period.
Results:
The study cohort included 71 990 patients yielding 547 001 person-years at risk (PYAR) and 13 946 cancers diagnosed during follow-up. For the total period of observation combined, the risks of all cancers (SIR: 1.05; 95% CI: confidence interval 1.04–1.07), prostate cancer (SIR: 1.07; 95% CI: 1.01–1.14), and multiple myeloma (SIR: 1.22; 95% CI: 1.06–1.41) were increased. These modest increases in risk emerged in the context of effectively multiple tests of statistical significance, and may reflect inadequate adjustment for confounding factors. For 1317 patients undergoing primary resurfacing arthroplasty between 2000 and 2009 (PYAR=5698), the SIR for all cancers (n=39) was 1.23 (95% CI: 0.87–1.68).
Conclusion:
In the context of previous research, these results do not suggest a major cause for concern. However, the duration of follow-up of patients receiving recently introduced, new-generation MoM prostheses is too short to rule out a genuinely increased risk of cancer entirely.
Lately, concerns have arisen following the use of large metal-on-metal bearings in hip replacements owing to reports of catastrophic soft-tissue reactions resulting in implant failure and associated complications. This review examines the literature and contemporary presentations on current clinical dilemmas in metal-on-metal hip replacement.
Wear debris from conventional total hip arthroplasty (THA) induces chromosomal aberrations and DNA damage, which may promote cancerogenesis. A long latent period is required for solid tumors. We therefore re-analyzed a large THA cohort for cancer.
We updated a cohort of 24,636 patients with primary osteoarthritis and metal-on-polyethylene THA who had been entered in the Finnish Arthroplasty Register between 1980 and 1995, and linked it to the Finnish Cancer Registry for cancer risk assessment up to 2005. The mean follow-up time was 13 years. The numbers of cancer cases observed were compared with expected rates based on incidence in the general population.
The standardized incidence ratio (SIR) for the whole follow-up period was 0.95 (95% confidence interval (CI): 0.92-0.97). After 10 years of follow-up, the SIR was equal to that in the normal population (SIR = 0.98, 95% CI: 0.94-1.03). Incidence of lung cancer was low throughout the follow-up time and that of prostate cancer was slightly elevated. The incidence rates for all other forms of cancer did not deviate significantly from those in the normal population.
We found no increased cancer risk in patients with conventional THA after an average of 13 years and up to 25 years of follow-up.
The purpose of this review is to summarise the data concerning genotoxicity and carcinogenicity of Co and Sb. Both metals have multiple industrial and/or therapeutical applications, depending on the considered species. Cobalt is used for the production of alloys and hard metal (cemented carbide), diamond polishing, drying agents, pigments and catalysts. Occupational exposure to cobalt may result in adverse health effects in different organs or tissues. Antimony trioxide is primarily used as a flame retardant in rubber, plastics, pigments, adhesives, textiles, and paper. Antimony potassium tartrate has been used worldwide as an anti-shistosomal drug. Pentavalent antimony compounds have been used for the treatment of leishmaniasis. Co(II) ions are genotoxic in vitro and in vivo, and carcinogenic in rodents. Co metal is genotoxic in vitro. Hard metal dust, of which occupational exposure is linked to an increased lung cancer risk, is proven to be genotoxic in vitro and in vivo. Possibly, production of active oxygen species and/or DNA repair inhibition are mechanisms involved. Given the recently provided proof for in vitro and in vivo genotoxic potential of hard metal dust, the mechanistic evidence of elevated production of active oxygen species and the epidemiological data on increased cancer risk, it may be advisable to consider the possibility of a new evaluation by IARC. Both trivalent and pentavalent antimony compounds are generally negative in non-mammalian genotoxicity tests, while mammalian test systems usually give positive results for Sb(III) and negative results for Sb(V) compounds. Assessment of the in vivo potential of Sb2O3 to induce chromosome aberrations (CA) gave conflicting results. Animal carcinogenicity data were concluded sufficient for Sb2O3 by IARC. Human carcinogenicity data is difficult to evaluate given the frequent co-exposure to arsenic. Possible mechanisms of action, including potential to produce active oxygen species and to interfere with DNA repair systems, still need further investigation.
An increasing number of young patients are undergoing knee arthroplasties. Thus, the long-term risks of having a knee prosthesis must be evaluated. This study focuses on the potential carcinogenic effects of the prosthesis; it is a long-term follow-up of all patients in Sweden between 1975 and 2006.
The incidence of cancer in a total population of operated individuals was compared to the overall national cancer incidence in Sweden by means of standardised incidence ratios. Analysis of cancer latency period was performed to identify potential aetiological factors.
For male and female patients with rheumatoid arthritis (RA) or osteoarthritis (OA), the overall cancer risks were elevated, ranging from 1.10 (95% confidence interval (CI): 1.03-1.18) for men with OA to 1.26 (1.23-1.29) for men with RA. The greatest increases in risk were observed for the leukaemia subtypes, myelodysplastic syndromes (MDS) and essential thrombocytosis (ET), ranging from 3.31 (1.24-8.83) for ET in men with OA to 7.38 (1.85-29.51) for ET in women with RA. Increases in risk were also observed for breast cancer, prostate cancer and melanoma. The latency analysis revealed elevated risks late in the study period for both solid and haematopoietic cancers. However, only increases in MDS and possibly prostate cancer and melanoma rates appeared to be connected to the operation.
This study showed that OA and RA arthroplasty patients have a significantly higher risk of cancer than the general population. Elevated risks of MDS and possibly prostate cancer and melanoma indicated a potential connection to exposure to metals in the implant. The observed excessive incidence of ET was likely associated with the inflammatory disease.