Incidence Of Pseudotumors Research Articles

Do polyethylene wear particles affect the development of pseudotumor in total hip arthroplasty? A minimum 15-year follow-up

BackgroundAdverse local tissue reactions have been problematic as an implant-related complication in total hip arthroplasty (THA). Despite the absence of significant metal wear and corrosion, granulomatous pseudotumor has been reported to be caused by polyethylene wear. We performed a long-term follow-up study investigating the relationship between polyethylene wear and pseudotumor formation in THA.MethodsThis study included 57 patients (64 hips) that underwent primary THA with metal-on-polyethylene or ceramic-on-polyethylene bearing over a minimum follow-up of 15 years. They were stratified into pseudotumor and non-pseudotumor groups and their linear wear rates of polyethylene liner and serum cobalt (Co) and chromium (Cr) ion levels were compared. Pseudotumor was diagnosed on metal artifact reduction sequence-MRI according to its composition and wall thickness using the Hauptfleisch classification.ResultsThe incidence of pseudotumor was 34% (22/64 hips) at the mean follow-up of 16.9 years. Metal ion levels did not differ between the pseudotumor and non-pseudotumor groups, and none of the patients exceeded the Co/Cr ratio of 2.0 μg/L. Moreover, the wear rate in the pseudotumor group was 1.8 times greater than in the non-pseudotumor group (0.14 vs. 0.08 mm/year, P < 0.001). According to an analysis of the receiver operating characteristic curves, the cutoff level of the wear rate to discriminate between pseudotumor and non-pseudotumor patients at 15 years was 0.11 mm/year (area under the curve = 91%; sensitivity = 95%; specificity = 78%; accuracy = 87%).ConclusionsOur results might provide new insights into excessive polyethylene wear potentially leading to the future development of both pseudotumor and osteolysis. Further studies are needed to clarify the direct relationship between polyethylene wear and pseudotumor and the mutual effects of osteolysis and pseudotumor in particle reactions.

Pseudotumors in Total Joint Arthroplasty.

The true incidence of pseudotumors in association with total joint arthroplasty is underestimated. Pseudotumors occur with metal-on-metal, metal-on-polyethylene, and metal-on-ceramic articulations. Metal ion levels should not be the only factor in decision-making regarding revision surgery. Revision surgery is only indicated in symptomatic patients with clinical and radiographic findings and elevated metal ion levels. Revision to a non-metal articulation is strongly suggested.

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

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. 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. 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). 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.

Metal ions related complications after hip arthroplasty

The problems of metal ions accumulation and related complications after metal-on-metal hip arthroplasty have been concerned by joint surgeons. Furthermore, metal ions released resulting from taper fretting and corrosion at the head-neck junction of prosthesis are also research hotspot in the field of arthroplasty. Whether the complications associated with metal ions are as serious as expected, its specific manifestations, mechanisms and other issues are still controversial. There is no consensus on the clinical detection methods and standards of metal ions. The present study reviews the literatures and summarizes the above issues, in order to have a deeper understanding of these issues. As far as the form of complication is concerned, there are local and systemic reactions. The former is mainly an adverse reaction of local tissue, especially pseudotumor. However, the incidence of pseudotumor and its risk factors are controversial. There is no clear evidence of systemic complications such as carcinogenicity and teratogenicity. The molecular mechanism of cobalt-chromium toxicity involves many signal transduction pathways, and its histopathological mechanism includes macrophage-mediated nonspecific immunity and lymphocyte-mediated specific immunity. The former is mainly related to the wear dose, while the latter is related to metal sensitivity with great individual difference. The method of metal ion concentration determination is still controversial. The inductively coupled plasma mass spectrometry (ICP-MS) is widely used at present, and the determination of metal ion concentration critical value has important guiding significance for clinical practice. Britain's 7 μg/L proposal was once discussed as a standard, while there are many different views currently. In summary, it is thought that the complication of metal ion after hip arthroplasty is the result of cobalt chromium metal ion activating nonspecific immunity and specific immunity. Abnormal activation of many signaling pathways leads to local soft tissue reactions, while systemic complications do not have clear evidence. Furthermore, there is no uniform standard for the detection of metal ion concentration. This index is not recommended in clinical practice. We should have a comprehensive assessment of the patient's situation.

Midterm follow-up study of metal on metal total hip replacement

Background: Metallosis and pseudotumors are long discussed complications with metal on metal bearing total hip replacement which has increased the rate of revision total hip replacements in these patients. Aims and Objective: To evaluate the levels of metal ion (Cobalt and Chromium), factors affecting theses metal ion levels and incidence of pseudotumors in metal on metal total hip replacement patients. Materials And Methods: Prospective descriptive study done on 25 patients who had metal on metal bearing surface replacement and total hip replacement with a mean post-op period of 6 years. Serum metal ion levels (Cobalt and Chromium), MARS-MRI (Metal Artifact Reduction Sequence) and acetabular cup inclination angle on X-rays and functional score were recorded in theses patients on two follow-up visits with mean follow-up period of 1 year. Result: Mean cobalt was 1.64 and mean chromium was 3.06. 28% of the study population showed asymptomatic pseudotumors but were less than 5cm. Mean cup inclination angle was 41.8* on X-rays which did not have any influence on serum metal ions and functional score. Gender (Male / Female) and type of arthroplasty (Articular surface replacement / Total hip replacement) has no affect on serum metal ions. Functional scores of these metal on metal patients comparable to metal on polyethylene bearing patients. Revison total hip replacement done in one metal on metal THR patient who had a dislocated cup in his second follow-up. Conclusion: Metal on metal hip arthroplasty patients were functionally doing well like the regular metal on polyethylene patients. Chromium values were significant and higher than cobalt. Incidence of asymptomatic pseudotumors was 28%.

CORR Insights(®): do patients with a failed metal-on-metal hip implant with a pseudotumor present differences in their peripheral blood lymphocyte subpopulations?

T he study by Catelas and colleagues adds to the current scientific consensus that adaptive immune responses to metals occurs in a subset of all people with metal implants. The study authors also found that the incidence of pseudotumors correlates with systemic evidence of metal-related delayed-type hypersensitivity (DTH) responses and elevated metal ion levels. The current study identifies alterations in circulating adaptive immune cells in people with elevated levels of metal debris and pseudotumors. These findings support past histological and T-cell function studies, indicating pseudotumors are more prevalent in people with DTH-type immune reactivity. This highlights the growing recognition of these phenomena as central to implant performance in some individuals/implant designs. Case and group studies [4, 5] indicate that once locally activated, adaptive immune inflammation to metal contributes to (if not, mediates) the pathogenesis of poor implant performance. Metal DTH reactivity is a lymphocyte mediated response, similar to a Type IV DTH reaction. Metal-on-metal (MoM) hip failures have been associated with classic DTH responses including periimplant activated lymphocyte accumulations (aseptic lymphocytic vasculitisassociated lesions, [ALVAL]), and dermal and functional lymphocyte hypersensitivity responses to metals [2, 7, 11]. Elevated metal exposure can also cause different forms of toxicity responses in tissue, bone, and immune cells, including cobalt-induced hypoxia-like responses, postulated as causing pseudotumors [10]. Lymphocyte reactivity (metal DTH responses/ALVAL) and pseudotumors can be caused separately [6, 8]. Currently, there are no accepted thresholds for systemic metal ion levels that necessarily indicate for pseudotumor formation or immune reactions [1, 7]; it remains an increased risk association. This CORR Insights is a commentary on the article ‘‘Do Patients With a Failed Metal-onmetal Hip Implant With a Pseudotumor Present Differences in Their Peripheral Blood Lymphocyte Subpopulations?’’ by Catelas and colleagues available at: DOI: 10.1007/ s11999-015-4466-8. The author certifies that she, or any members of her immediate family, has no funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request. The opinions expressed are those of the writers and do not reflect the opinion or policy of CORR or The Association of Bone and Joint Surgeons. This CORR Insights comment refers to the article available at DOI: 10.1007/s11999015-4466-8. N. J. Hallab PhD (&) Department of Orthopedic Surgery, Rush University Medical Center, 1735 W Harrison, Cohn Research Bldg, #722, Chicago, IL 60612, USA e-mail: nhallab@rush.edu CORR Insights Published online: 13 October 2015 The Association of Bone and Joint Surgeons1 2015

Pseudotumor formation and serum ions after large head metal-on-metal stemmed total hip replacement. Risk factors, time course and revisions in 706 hips.

The incidence and natural course of pseudotumors in metal-on-metal total hip arthroplasties is largely unknown. The objective of this study was to identify the true incidence and risk factors of pseudotumor formation in large head metal-on-metal total hip arthroplasties. Incidence, time course and risk factors for pseudotumor formation were analysed after large femoral head MoM-THA. We defined a pseudotumor as a (semi-)solid or cystic peri-prosthetic soft-tissue mass with a diameter ≥2cm that could not be attributed to infection, malignancy, bursa or scar tissue. All patients treated in our clinic with MoM-THA's were contacted. CT scan, metal ions and X-rays were obtained. Symptoms were recorded. After median follow-up of 3years, 706 hips were screened in 626 patients. There were 228 pseudotumors (32.3%) in 219 patients (35.0%). Pseudotumor formation significantly increased after prolonged follow-up. Seventy-six hips (10.8%) were revised in 73 patients (11.7%), independent risk factors were identified. Best cutoff point for cobalt and chromium was 4μg/l (68 and 77nmol/l). This study confirms a high incidence of pseudotumors, dramatically increasing after prolonged follow-up. Risk factors for pseudotumors are of limited importance. Pain was the strongest predictor for pseudotumor presence; cobalt chromium and swelling were considered poor predictors. Cross-sectional imaging is the main screening tool during follow-up.

Utility of AAOS OITE Scores in Predicting ABOS Part I Outcomes

Residency programs commonly use performance on the Orthopaedic In-Training Examination (OITE) developed by the American Academy of Orthopaedic Surgeons (AAOS) to identify residents who are lagging behind their peers and at risk for failing Part I of the American Board of Orthopaedic Surgery (ABOS) Certifying Examination. This study was designed to investigate the utility of the OITE score as a predictor of ABOS Part I performance. Results for 3132 examinees who took Part I of the ABOS examination for the first time from 2002 to 2006 were matched with records from the 1997 to 2006 OITE tests; at least one OITE score was located for 2852 (91%) of the ABOS Part I examinees. After OITE performance was rescaled to place scores from different test years on comparable scales, descriptive statistics and correlations between ABOS and OITE scores were computed, and regression analyses were conducted to predict ABOS results from OITE performance. Substantial increases in the mean OITE score were observed as residents progressed through training. Stronger correlations were observed between OITE and ABOS performance during later years in training, reaching a maximum of 0.53 in years 3 and 4. Logistic regression results indicated that residents with an OITE score below the 10th percentile were much more likely to fail Part I compared with those with an OITE score above the 50th percentile. OITE performance was a good predictor of the ABOS score and pass-fail outcome; the OITE can be used effectively for early identification of residents at risk for failing the ABOS Part I examination.

The Correlation of Wear with Histological Features After Failed Hip Resurfacing Arthroplasty

Tissue necrosis and a macrophage and perivascular lymphocytic infiltrate are commonly seen in periprosthetic tissues around metal-on-metal hip resurfacing implants, including pseudotumors associated with these implants. The purpose of the present study was to correlate pathological changes in periprosthetic tissues with clinical findings and the amount of implant-derived metal wear. We analyzed morphological changes in the periprosthetic soft tissues around fifty-six failed metal-on-metal hip resurfacing implants. The most common reason for failure was the presence of a symptomatic pseudotumor (n = 45). The extent of necrosis and the nature of the inflammatory cell infiltrate, including aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL), was evaluated semiquantitatively. Bearing surface wear was determined for all patients. Prostheses were considered to be highly worn if the total linear wear rate was ≥4 μm/yr. Substantial necrosis and a heavy macrophage infiltrate were noted in most periprosthetic tissues, including all pseudotumors, many of which contained a prominent ALVAL infiltrate. Most pseudotumors (80%) were associated with highly worn prostheses. It was noted that the extent of necrosis and macrophage infiltration correlated with the volume of generated metal wear. Although increased wear volume moderately correlated with a high ALVAL response, all pseudotumors associated with low wear had a strong ALVAL response. The majority of pseudotumors are associated with increased implant wear. This increased wear is associated with soft-tissue necrosis and a heavy nonspecific foreign-body macrophage response coupled with a variable adaptive or specific immune response (ALVAL). A minority of pseudotumors are associated with low wear and a prominent immune response. These findings confirm that minimizing wear from metal-on-metal hip resurfacing arthroplasty prostheses would lead to a reduction in the incidence of pseudotumor. However, a small number of pseudotumors are still likely to occur, which may be due to an exacerbated adaptive immune response.

Incidence of Pseudotumor and Acute Lymphocytic Vasculitis Associated Lesion (ALVAL) Reactions in Metal-On-Metal Hip Articulations: A Meta-Analysis

We systematically reviewed the peer-reviewed literature to determine a pooled estimate of the incidence of pseudotumor and acute lymphocytic vasculitis associated lesions (ALVAL) in adult patients with primary metal-on-metal (MoM) total hip arthroplasty or resurfacing. Fourteen eligible articles were identified, with a total of 13,898 MoM hips. The incidence of pseudotumor/ALVAL ranged from 0% to 6.5% of hips with a mean follow-up ranging from 1.7 to 12.3years across the studies. The pooled estimated incidence of pseudotumor/ALVAL is 0.6% (95% CI: 0.3% to 1.2%). The rate of revision for any reason ranged from 0% to 14.3% of hips, with a pooled estimate of 3.9% (95% CI: 2.7% to 5.3%).

Hemophilic Pseudotumor in Chinese Patients: A Retrospective Single-Centered Analysis of 14 Cases

Pseudotumor is an uncommon but severe complication in patients with hemophilia. To our knowledge, although China has large population of persons with hemophilia, there is rare information on the incidence, clinical feature, image finding, and management of pseudotumor among Chinese patients. This study aimed at improving our knowledge on clinical diagnosis and management of hemophiliac pseudotumor. In this retrospective study, the medical records of 1248 patients with hemophilia diagnosed between January 1983 and October 2004 at our hospital were reviewed. The clinical feature, imaging finding, management, and outcome of 14 patients with pseudotumor among these patients with hemophilia were analyzed. All patients have hemophilia A (8 severe cases and 6 moderate cases). Eight patients sustained an injury prior to the development of pseudotumor. Main image findings included osteolysis lesion, soft tissue swelling, or lump. Surgical therapy was carried out in 7 patients and 6 achieved remission, with fistula formation remaining in 1. One patient underwent radiotherapy together with replacement therapy achieved remission. Three patients accepted replacement therapy as only management and only 1 patient achieved improvement of swelling. Our study showed that the incidence of pseudotumor in our enrolled patients with hemophilia is 1.12%. Hemophilic history of patients can contribute to the right diagnosis of pseudotumor. Surgical therapy together with sufficient replacement therapy is safe and effective.