Genetic alterations in periprosthetic soft-tissue masses from patients with metal-on-metal hip replacement

High-grade Pleomorphic Sarcoma Associated with Metallosis in a Patient with Total Hip Arthroplasty

Although the relationship between hip arthroplasty and the development of sarcoma was first described in the literature about forty years ago, this association is extremely rare. In the present case report, we describe the association between orthopedic implants and soft tissue sarcoma in a 79-year-old man who underwent primary total hip arthroplasty (THA) for coxarthrosis 24 years ago. In the present case report, we describe the clinical evolution and the radiographic and histopathological findings of the lesion. In the intraoperative period of the second revision surgery, loosening of the acetabular and femoral components in association with extensive areas of necrosis and metallosis was evidenced. We performed debridement of the hip and right thigh region and removed the implants. Due to the extent of the lesion and to necrosis, it was not possible to perform a new joint reconstruction. The histopathological diagnosis of high-grade undifferentiated pleomorphic sarcoma associated with extensive areas of metallosis was confirmed in tissue adjacent to the implant. The patient developed pulmonary metastases and died 6 months after the diagnosis. Despite the rarity of this association, sarcomas should be considered in the differential diagnosis of aseptic loosening, especially in the presence of metallosis in the peri-implant tissue. To our knowledge, the 24-year latency period between primary THA and the establishment of a sarcoma diagnosis is one of the longest reported to date.

Cancer-Causing Effects of Orthopaedic Metal Implants in Total Hip Arthroplasty

BACKGROUND

Metal implants have been preferentially used in THA due to its biocompatibility, mechanical stability and durability. Yet concerns have emerged regarding their potential to release metallic ions, leading to long-term adverse effects, including carcinogenicity. This study aimed to investigate the risk of cancer development in patients with orthopaedic metal implants in total hip arthroplasty (THA).

METHODS

Patients with THA conducted at a local tertiary implant centre from 2001-2008 were linked to the local cancer registry and followed up to the end of 2023. Standardized incidence ratios (SIRs) for cancer incidence and its confidence interval by Poisson distribution were calculated. Survival analysis was depicted using the Kaplan-Meier method, and the log-rank test was used to assess the differences across groups.

RESULTS

The study cohort included 388 patients and 53 cancers diagnosed during follow-up, at least 5 years post THA. All-site cancer risks were increased in patients with THA (SIR: 1.97; 95% CI: 1.48-2.46), validated with chi-square analysis (chi-square = 15.2551, N = 100,388, p < 0.01). A statistically significant increase in multiple site-specific cancers including haematological cancers were identified.

CONCLUSIONS

Patients with THA were found to have an increased risk for cancer compared to the general population during a mean follow-up of 16 years.

Myocardial Infarction-Induced INSL6 Decrease Contributes to Breast Cancer Progression

Myocardial infarction (MI) induces early-stage breast cancer progression and increases breast cancer patients' mortality and morbidity. Insulin-like peptide 6 (INSL6) overexpression can impede cardiotoxin-induced injury through myofiber regeneration, playing a significant role in MI progression. To investigate the diverse significance of INSL6 in a variety of malignant tumors, we explored INSL6 through MI GEO dataset and multiple omics data integrative analysis, such as gene expression level, enriched pathway analysis, protein-protein interaction (PPI) analysis, and immune subtypes as well as diagnostic value and prognostic value in pancancer. INSL6 expression was downregulated in the MI group, and overall survival analysis demonstrated that INSL6 could be the prognostic biomarkers in the overall survival of breast cancer (BRCA). INSL6 expression differs significantly not only in most cancers but also in different molecular and immune subtypes of cancers. INSL6 might be a potential diagnostic and prognostic biomarker of cancers due to the high accuracy in diagnostic and prognostic value. Furthermore, we focused on BRCA and further investigated INSL6 from the perspective of the correlations with clinical characteristics, prognosis in different clinical subgroups, coexpression genes, and differentially expressed genes (DEGs) and PPI analysis. Overall survival and disease-specific survival analysis of subgroups in BRCA demonstrated that lower INSL6 expression had a worse prognosis. Therefore, INSL6 aberrant expression is associated with the progression and immune cell infiltration of the tumor, especially in KIRP and BRCA. Therefore, INSL6 may serve as a potential prognostic biomarker and the crosstalk between MI and tumor progression.

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 THA patients 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.

Diffuse Large B-Cell Lymphoma Associated with a Chronic Inflammatory Condition Induced by Metallic Implants: A Case Report

Chronic inflammatory condition associated with metallic implant insertion is a risk factor for diffuse large B-cell lymphoma (DLBCL). Metal ions play a role in the pathogenesis of lymphoma. We report a rare case of DLBCL in a patient who had a metallic implant in the proximal tibia for 15 months. Radiologic studies, including US and MRI, showed disproportionately large extraosseous soft-tissue mass and bone marrow involvement without prominent bone destruction. Multiple complications are associated with metallic implants, and misdiagnosis may lead to inappropriate treatment. Therefore, distinguishing lymphomas caused by a metallic implant-induced chronic inflammatory condition from other periprosthetic benign lesions and malignant soft tissue masses is challenging, but it is critical.

Incidence of Pseudotumors in a Dual Modular Stem Construct With and Without Metal-on-Metal Bearing Surface

BACKGROUND

The purpose of this study was to compare the incidence of pseudotumors in metal-on-metal (MoM) titanium modular neck hip arthroplasties to non-MoM modular neck hip arthroplasties. A secondary goal was to determine whether a correlation exists between elevated metal concentrations and pseudotumor incidence.

METHODS

The data were collected and evaluated from 49 MoM joints and 26 non-MoM joints between the years 2012 and 2017. Hip ultrasonography was done after a minimum of 5 years postimplantation. Whole serum metal (titanium, cobalt, and chromium) concentrations were measured at the hip ultrasonography study.

RESULTS

The average time elapsed between surgery and ultrasonography visit was 7.6 years. In the 49 patients with MoM joints, 22.4% (n = 11) had a pseudotumor. In the 26 patients with non-MoM joints, 9.1% of metal-on-polyethylene hips (n = 1) and 0% of ceramic-on-ceramic/polyethylene hips developed a pseudotumor. No significant statistical correlation was observed between serum metal concentrations and pseudotumor formation (P > 0.05). A significant correlation was observed of serum titanium concentration to pseudotumor size (P = 0.024).

CONCLUSION

The incidence of pseudotumor formation in MoM total hip arthroplasties was more than five times the incidence associated with non-MoM bearings. The correlation between serum titanium concentration and pseudotumor size suggests that titanium levels may be a useful indicator for pseudotumor formation in patients with this particular titanium modular neck femoral implant. No notable correlation was observed between serum cobalt and chromium concentration and pseudotumor formation or size.

Genotoxic properties of materials used for endoprostheses: Experimental and human data

Approximately 2 million endoprostheses are implanted annually and metal ions as well as particles are released into the body from the materials which are used. This review describes the results of studies concerning genotoxic damage caused by artificial joints. DNA damage leads to various adverse long-term health effects in humans including cancer. Experiments with mammalian cells showed that metal ions and particles from orthopedic materials cause DNA damage. Induction of chromosomal aberrations (CA) was found in several in vitro experiments and in studies with rodents with metals from orthopedic materials. Human studies focused mainly on induction of CA (7 studies). Only few investigations (4) concerned sister chromatid exchanges, oxidative DNA damage (2) and micronucleus formation (1). CA are a reliable biomarker for increased cancer risks in humans) and were increased in all studies in patients with artificial joints. No firm conclusion can be drawn at present if the effects in humans are due to oxidative stress and if dissolved metal ions or release particles play a role. Our findings indicate that patients with artificial joints may have increased cancer risks due to damage of the genetic material. Future studies should be performed to identify safe materials and to study the molecular mechanisms in detail.

Comparison of Harris Hip Scores and Revision Rates in Metal-on-Metal Versus Non-Metal-on-Metal Total Hip Arthroplasty

INTRODUCTION

This study compares functional outcome scores and revision rates between metal-on-metal (MoM) and non-MoM total hip arthroplasty patients.

METHODS

A cohort of 75 patients who underwent implantation of the same dual modular hip arthroplasty between the years of 2004 and 2010 was enrolled. Patients were subsequently evaluated in 2015 to 2017 for joint revision history and functionality, as measured by the Harris hip score (HHS). Patients requiring a revision arthroplasty were not included in the HHS analysis.

RESULTS

A total of 49 patients had MoM implants (65.3%), and 26 patients had non-MoM implants (34.8%). At a mean follow-up of 7.6 years, 10.2% (5/49) of MoM prostheses required revision, whereas 3.8% (1/26) of non-MoM prostheses required revision (P = 0.334). The mean HHS in the MoM cohort was 89.8, compared with 88.1 in the non-MoM cohort (P = 0.69).

CONCLUSION

HHSs were not notably different between cohorts. The MoM cohort had three times as many revisions as the non-MoM cohort, but given the numbers available, this difference did not reach significance. Given the clinical importance of these revision data, further study is warranted to determine survivorship of the MoM versus non-MoM total hip arthroplasty at long-term follow-up.

Development of Primary Diffuse Large B-Cell Lymphoma Around an Internal Fixation Implant After Lumbar Fusion Surgery: A Case Report and Review of the Literature

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is the most commonly diagnosed primary non-Hodgkin lymphoma of the spine and can induce spinal compression. Reports of lymphoma arising in bone adjacent to metallic prostheses are increasing. However, to our knowledge, DLBCL arising from a scar after lumbar fusion surgery has not been reported previously.

CASE DESCRIPTION

A 63-year-old man complained of a 2-month history of severe pain in the back and both legs, radiating down to the ankle, similar to sciatica with a past history of L2-S1 decompression and fusion 7 years ago. Imaging revealed an irregular mass in the epidural space and around the internal fixation surgical site, which was initially diagnosed as an epidural infectious abscess. Most of the lesion was completely excised and a detailed immunohistopathologic analysis was performed revealing the diagnosis of a DLBCL. After surgery and chemotherapy, he was discharged without complications. Unfortunately, he died 2 years later because of brain metastasis.

CONCLUSIONS

This case highlights the need to consider malignancy in the differential diagnosis and carefully examine surgical specimens in revision surgery. Further understanding of the role of metal implants in the development of lymphoma is required.

Midterm risk of cancer with metal-on-metal hip replacements not increased in a Finnish population

Background and purpose - Metal-on-metal (MoM) total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) have been widely used during the early 21st century. We assessed the midterm risk of cancer of patients treated with modern MoM hip implants compared with patients with non-MoM hip implants and the general Finnish population with special interest in soft tissue sarcomas and basalioma due to the findings of our previous report. Patients and methods - All large-diameter head MoM THAs and hip resurfacings performed in Finland between 2001 and 2010 were extracted from the Finnish Arthroplasty Register (10,728 patients). Patients who underwent conventional THA formed the non-MoM reference cohort (18,235 patients). Data on cancer cases up to 2014 were extracted from the Finnish Cancer Registry. The relative risk of cancer in the general population was expressed as the ratio of observed to expected number of cases, i.e., standardized incidence ratio (SIR). Poisson regression analysis was used to compare the cancer risk between the cohorts. The mean follow-up was 7.4 years (1-14) in the MoM cohort and 8.4 years (1-14) in the non-MoM cohort. Results - The overall risk of cancer in the MoM cohort was comparable to the general Finnish population (SIR 0.9, 95% CI 0.9-1.0). Risk of basalioma in the MoM cohort was higher than in the general Finnish population (SIR 1.2, CI 1.1-1.4) and higher than in the non-MoM cohort in the stratified regression analysis (RR 1.2, CI 1.0-1.4, p = 0.02). The SIR of soft-tissue sarcoma in the MoM cohort was 1.4 (CI 0.6-2.8); the incidence was same as in the non-MoM cohort. Interpretation - Metal-on-metal hip implants are not associated with an increased overall risk of cancer during midterm follow-up.

Biological effects of metal degradation in hip arthroplasties

Metals and metal alloys are the most used materials in orthopedic implants. The focus is on total hip arthroplasty (THA) that, though well tolerated, may be associated with local and remote adverse effects in the medium-long term. This review aims to summarize data on the biological consequences of the metal implant degradation that have been attributed predominantly to metal-on-metal (MoM) THA. Local responses to metals consist of a broad clinical spectrum ranging from small asymptomatic tissue lesions to severe destruction of bone and soft tissues, which are designated as metallosis, adverse reactions to metal debris (ARMD), aseptic lymphocytic vasculitis associated lesion (ALVAL), and pseudotumors. In addition, the dissemination of metal particles and ions throughout the body has been associated with systemic adverse effects, including organ toxicity, cancerogenesis, teratogenicity, and immunotoxicity. As proved by the multitude of studies in this field, metal degradation may increase safety issues associated with THA, especially with MoM hip systems. Data collection regarding local, systemic and long-term effects plays an essential role to better define any safety risks and to generate scientifically based recommendations.

Presence of cancer-associated mutations in exhaled breath condensates of healthy individuals by next generation sequencing

Exhaled breath condensate (EBC) is a non-invasive source that can be used for studying different genetic alterations occurring in lung tissue. However, the low yield of DNA available from EBC has hampered the more detailed mutation analysis by conventional methods. We applied the more sensitive amplicon-based next generation sequencing (NGS) to identify cancer related mutations in DNA isolated from EBC. In order to apply any method for the purpose of mutation screening in cancer patients, it is important to clarify the incidence of these mutations in healthy individuals. Therefore, we studied mutations in hotspot regions of 22 cancer genes of 20 healthy, mainly non-smoker individuals, using AmpliSeq colon and lung cancer panel and sequenced on Ion PGM.

In 15 individuals, we detected 35 missense mutations in TP53, KRAS, NRAS, SMAD4, MET, CTNNB1, PTEN, BRAF, DDR2, EGFR, PIK3CA, NOTCH1, FBXW7, FGFR3, and ERBB2: these have been earlier reported in different tumor tissues. Additionally, 106 novel mutations not reported previously were also detected. One healthy non-smoker subject had a KRAS G12D mutation in EBC DNA.

Our results demonstrate that DNA from EBC of healthy subjects can reveal mutations that could represent very early neoplastic changes or alternatively a normal process of apoptosis eliminating damaged cells with mutations or altered genetic material. Further assessment is needed to determine if NGS analysis of EBC could be a screening method for high risk individuals such as smokers, where it could be applied in the early diagnosis of lung cancer and monitoring treatment efficacy.

Development of malignant lymphoma after metal-on-metal hip replacement: a case report and review of the literature

A number of previous studies have reported a potential risk of malignancy, particularly hematological malignancy, developing in patients receiving a metal-on-metal (MoM) hip replacement. We report a case of malignant lymphoma that arose in a patient who had an MoM hip arthroplasty complicated by development of a pseudotumour. The tumour was a B cell follicular lymphoma that involved lymph nodes and bone. Metal ions are known to have a genotoxic effect on lymphoid cells. Although epidemiological studies have not established that there is an increased risk of lymphoma associated with MoM implants, only a relatively short time period has elapsed since re-introduction of this type of implant and long-term follow-up of patients with MoM implants is indicated.