Translate this page into:
Reassuring early serum metal ion levels with a specific modular dual mobility system
, Brenna E. Blackburn, Claire R. Kapron, Lucas A. Anderson, Jeremy M. Gililland, Christopher L. Peters, Christopher E. Pelt
⁎Corresponding author: Christopher E. Pelt. chris.pelt@hsc.utah.edu
-
Received: ,
Accepted: ,
This article was originally published by Reed Elsevier India Pvt. Ltd. and was migrated to Scientific Scholar after the change of Publisher.
Abstract
Abstract
The popularity of modular dual mobility (MDM) acetabular components has increased. Concerns have been raised about the potential for corrosion related complications in these modular implants. The purpose of this study was to prospectively monitor serum ion levels in a series of patients with a modular dual mobility system.
Twenty-six patients with the Zimmer Biomet G7 DM construct were enrolled and followed for a minimum of one year. Serum cobalt, chromium, and titanium levels were obtained prior to six-weeks postoperatively and at one and two-years postoperatively. Five-year labs were obtained if previous labs were elevated.
At 0-6 weeks postoperatively, 4/26 patients had mildly elevated cobalt levels (1-2.8 μg/L) and 2/26 had mildly elevated chromium levels (1.6, 2.0 μg/L). None of the 19 patients showed elevated cobalt levels at one or two years, while 4/19 reported mildly elevated chromium levels (1.1-1.3 μg/L) at one-year with a slight decrease (1-1.4 μg/L) at two-years. No patients at any time point had metal ion levels exceeding the initial early threshold of 5 μg/L. No patient was symptomatic and no MRIs were indicated or obtained.
In this series of a specific modular DM system, the early mildly elevated cobalt levels in four patients all subsequently normalized. Chromium was mildly elevated in four patients through year two. While these findings are reassuring in the short term as mildly elevated chromium (<2 μg/L) has not been associated with clinical toxicity, additional follow-up is needed to establish the long-term safety and efficacy of this specific modular DM implant.
Keywords
Dual mobility
Modular dual mobility
Acetabular component
Metal ions
1 Introduction
Despite the use of larger femoral heads, the increasing popularity of anterior approaches, and the use of technology in hip replacement, instability remains the second most common reason for failure in hip arthroplasty.1 To reduce the prevalence of instability, the use of dual mobility constructs has increased. According to the American Joint Replacement Registry 2020 Annual Report, dual mobility constructs are used in over 8% of all primary total hip arthroplasties, and 23% of revision procedures in the United States.1
The earliest dual mobility construct used in Europe was a nonmodular anatomic dual mobility (ADM) design consisting of a monoblock cobalt chrome shell that articulated with the “dual mobility” bipolar femoral head.2 This design allowed for a large-diameter bipolar polyethylene femoral head, which has been associated with reduced incidence of dislocation.3,4 Building on the advantages of modularity, modular dual mobility (MDM) constructs were introduced. This consists of a titanium acetabular shell and a cobalt chrome inner liner mated by a tapered interface. Additional modular dual mobility designs have subsequently been developed and introduced.
Concerns regarding the potential for fretting and corrosion of this titanium–cobalt chrome interface and the development of secondary adverse local tissue reaction (ALTR) have been expressed by many authors. Early reports describe issues of liner malseating, femoral neck impingement with notching, and elevation in metal ion levels were reported 5–7. Subsequent retrieval studies documented findings of fretting and corrosion, raising the level of concern for possible local tissue reaction to the metallic debris.8,9 Adverse local tissue reaction has been identified in two reports.10,11 A recent systematic review and meta-analysis of MDM components reviewed 16 articles and found a 0.3% incidence of reported ALTR requiring revision, a 7.9% incidence of “mildly raised” ion levels, a 1.8% incidence of “significantly raised” ion levels, a 0.8% dislocation rate. Additionally, they warned of the potential added issues of prominent screw heads and malseating of the liner as contributing factors.12
While the published studies have investigated other modular dual mobility construct available in the United States, several other designs have been developed and widely adopted. The primary purpose of this study was to evaluate the modular G7 Dual Mobility construct by tracking the metal ion levels present in blood serum. Secondary outcomes include patient reported outcomes, radiographic findings, and post operative complications.
2 Materials and methods
Following institutional review board approval and obtaining patient informed consent, we prospectively enrolled 26 patients between 2016 and 2019 undergoing a primary or revision hip arthroplasty in whom we planned to use a G7 dual mobility acetabular component (Zimmer Biomet, Warsaw, IN, USA) with either the PPS (primary) or OsseoTi (revision) acetabular cups (both Zimmer Biomet). Stem choices were up to the surgeon's discretion; the majority of patients received Taperloc with some use of Echo Bi-Metric, Avenir, and Arcos (revision) (all Zimmer Biomet). Details regarding inclusion and exclusion criteria can be found in Appendix A. The MDM design investigated in this report (Zimmer Biomet G7) has a 10-degree taper fit, a centering sleeve for implantation and, when implanted, sits flush with the surface of the outer shell for improved visual inspection of proper seating.
Serum cobalt, chromium and titanium levels were obtained in the early postoperative period (day of surgery to six weeks postoperatively). This was to allow the labs to be early enough after surgery to obtain baseline ion levels before significant corrosion or fretting would likely occur. We obtained metal ion levels again at one, two, and five years postoperatively. Patients were only asked to come in at five years as a safety follow-up visit if they had elevated ion levels at a prior visit. Whole blood was sent to ARUP National Reference Laboratories (Salt Lake City, UT). This lab reported cobalt and chromium levels as < 1.0 μg/L or a specific value if higher. Titanium levels were reported as “undetectable” or as a specific value if present. We queried all patients charts and radiographs to identify any hardware that the patient had implanted elsewhere. Given this was an observational study, the study was not planned to be stopped based upon adverse events. As the evolving body of evidence has added more information to the issue of metallosis since the original study design in 2016, the definitions of elevated ion levels were modified for the reporting in this manuscript, such that Co or Cr values between 1.0 and 4.5 are now described as mildly elevated, and >4.5 described as significantly elevated.
Physical function levels, as measured by the Patient-Reported Outcomes Measurement Information System (PROMIS) v1.2 - Physical Function computerized adaptive test, were used to demonstrate the change in physical function from pre to postoperative time points. Additionally, other patient reported outcomes (PROs), including the Hip Disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS JR) and PROMIS Global-10, and radiographic assessments were collected pre-operatively and at each follow-up visit as standard of care. Adverse events including complications and dislocations were also recorded. The study is designed as a single center prospective non-controlled observational case series. See Table 1 for the data collection scheme.
| Clinical and Radiographic Exams | |||||
| Data Collection item | Baseline | Intra-operative | Discharge (0-6 weeks) | 1 & 2 Year post-op | 5 Year safety evaluation |
| Demographic and Medical History | X | ||||
| Operative Record | X | ||||
| Serum metal ion analysis via venous blood draw | X1 | X | X | ||
| Clinical Evaluation | X | X | X | ||
| Radiographic Evaluation | X | X | X | ||
| Patient Reported Outcomes | X2 | X | X | X | |
| Dislocation | X | X | X | ||
| MARS MRIa | If obtained | If obtained | |||
| Adverse events including revisions | As required | ||||
2.1 Surgical technique
The surgical technique included reaming of the acetabulum line to line or 1 mm under and impacting the outer titanium shell with a press fit. Eight (five primaries, three revisions) of the shells had supplemental screw fixation. We confirmed that all screws were countersunk below the level of the inner shell. We then placed a trial liner and completed the femoral reconstruction. Once the positioning of the acetabular shell, leg length and offset were confirmed via stability testing and intraoperative imaging, the shell was prepared for implantation of the inner dual mobility liner.
The inside face of the shell was irrigated and dried with a lap sponge. The centering sleeve (G7 hard bearing inserter ring) was then placed on the outer rim of the cobalt chrome modular liner and the construct was placed into the clean and dry shell. Once confirmed to be well centered, it was impacted with three to five aggressive blows. The impaction device and centering sleeve were removed. The entire circumference of the face of the component was inspected to confirm that the inner liner was fully seated and completely flush with the outer shell. Once the appropriate head length was determined, the bipolar construct was assembled on the back table with the bearing press. The dual mobility bearing consisted of highly cross-linked polyethylene (Zimmer Biomet). The ceramic head was confirmed to be freely mobile within the polyethylene liner and the construct was impacted onto a clean and dry morse taper. The hip was reduced, and usual closure and postoperative rehabilitation protocols were followed.
Radiographic assessment was performed at each follow-up visit, using standard standing anteroposterior (AP) pelvic hip radiographs and groin lateral radiographs. Acetabular component inclination and acetabular component version was measured. Radiographs were reviewed for presence of femoral radiolucent lines and scored according to the zones described by Gruen et al..4 Peri-acetabular radiolucencies were assessed according to the three zones of De Lee and Charnley.3
As this was a prospective observational case series, descriptive statistics were used to describe patient demographics, PROs, serum levels and the proportion of patients who were found to have elevated levels of serum metal ions (as indicated by levels greater than those reported by the lab as the reference range). Due to the small sample size, simple statistical tests were used to compare patient characteristics between those with normal levels and those with elevated levels. The limited sample size prohibits more conventional time-to-event regression modeling.
As the lab was not able to detect cobalt and chromium values < 1 μg/L, values were categorized for analysis according to the definition above for not elevated, mildly elevated, or elevated. Analysis of variance (ANOVA) models were used to determine whether elevation status changed over time (baseline to two years). For the secondary analyses, paired t-tests were used to test whether the patient reported outcomes changed pre-operatively to final follow-up. The presence of radiolucent lines and adverse events are reported.
The sample size was based on a convenience sample of all patients presenting for, or that had received, the DM construct within the previous six weeks and consent to participate in the study. We estimated that, during the study period, 30–50 primary THA patients would be approached and approximately 40-50% would enroll. For revision THA we estimated approximately 20-30 revision THA patients would be approached within 18 months, and about 50% or 10-15 will enroll. Enrollment for the study was planned to be stopped if the lower bound of the 95% CI exceeds 10% at any time during the study. With 10-20 patients per acetabular cup, we would be able to detect problematic adverse events exceeding our 10% threshold if adverse events occurred in about 40% or more patients.
3 Results
We prospectively enrolled a total of 26 patients (20 primary, and 6 revision total hips) all of whom received a G7 Modular Dual Mobility acetabular component with a ceramic head. There were 14 female and 12 male patients with a mean age of 65.6 (range 28-89) and mean BMI of 31.7 (range 17.0-44.1) (Table 2). Eight patients were lost to follow-up and three were withdrawn (two moved out of state, and one was revised to an articulating spacer for recurrent infection). All patients who had hardware at other anatomic locations, which theoretically could provide additional sources for metal ion release, were identified and are reported in Table 1. We could find no correlation of any mild ion elevation to the presence of alternative hardware. HOOS JR PROs significantly improved from a mean 50.5 (0 to 92) to a mean 78.4 (43-100) at final follow-up (p-value = 0.0003) (Fig. 1).
| Total population N = 26 | No elevated ion levels N = 15 | Mildly elevated ion levels N = 11 | ||
| Demographics | ||||
| Sex | N (%) | N (%) | N (%) | p-value |
| Female | 14 (53.9%) | 9 (60.0%) | 5 (45.5%) | 0.4623 |
| Male | 12 (46.2%) | 6 (40.0%) | 6 (54.6%) | |
| Mean (std) | Mean (std) | Mean (std) | p-value | |
| Age | 65.6 (13.5) | 68.3 (7.6) | 61.9 (18.6) | 0.3002 |
| BMI | 31.7 (7.9) | 34.1 (6.6) | 28.4 (8.8) | 0.0715 |
| ASA | 2.4 (0.7) | 2.4 (0.7) | 2.4 (0.7) | 0.8986 |
| Patient-reported outcomes | ||||
| Pre-operatively | ||||
| Physical function | 33.4 (7.8) | 33.9 (8.2) | 32.8 (7.7) | 0.7473 |
| Physical health | 37.7 (8.0) | 37.0 (7.2) | 38.6 (9.2) | 0.6523 |
| Mental health | 45.9 (10.8) | 46.2 (9.4) | 45.5 (12.8) | 0.8894 |
| Pain | 53.2 (29.7) | 53.3 (27.7) | 53.0 (33.4) | 0.9798 |
| HOOS JR | 50.5 (20.0) | 50.7 (22.5) | 50.3 (17.5) | 0.971 |
| Post-operatively | ||||
| Physical function | 40.4 (6.6) | 41.6 (5.6) | 38.4 (8.0) | 0.3315 |
| Physical health | 46.1 (8.2) | 47.7 (6.9) | 43.5 (10.1) | 0.3387 |
| Mental health | 50.1 (9.6) | 50.4 (6.8) | 49.5 (13.8) | 0.8627 |
| Pain | 33.8 (11.5) | 30.0 (24.5) | 40.0 (32.9) | 0.4971 |
| HOOS JR | 78.4 (16.2) | 82.3 (11.7) | 72.0 (21.4) | 0.2294 |
| Radiograph (n = 19) | ||||
| Acetabular component inclination | 46.7 (7.4) | 46.4 (6.1) | 47.2 (9.5) | 0.7910 |
| Acetabular component version | 33.1 (11.5) | 31.7 (10.8) | 35.3 (12.7) | 0.4726 |
| Any radiolucency | 1 (5.3%) | 1 (7.1%) | 0 (0%) | 1.0000 |
At early evaluation (0-6 weeks postoperatively) all primary total hips demonstrated cobalt, chromium, and titanium levels that were undetectable (<1.0 μg/L) (Table 3). Due to handling errors, one patient was missing a cobalt level, and one was missing a titanium level. Of the six revision total hip replacements, four had an elevated cobalt level (1.0 to 2.8 μg/L)(believed to be related to the mechanism of failure of the hip replacement being revised or a contralateral hip), two had elevated chromium levels (1.6, 2.0 μg/L), and one had an elevated titanium level (75 μg/L) (believed to be related to extensive titanium spinal hardware as the only other source of titanium in the patient).
| Procedure | Baseline | One year | Two years | Five years | |||||||||
| Co | Cr | Ti | Co | Cr | Ti | Co | Cr | Ti | Co | Cr | Ti | Remote hardware | |
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | <1 | <1 | UD | Bilateral G7 MDMs | |||
| Primary THA | <1 | <1 | UD | ||||||||||
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | |||||||
| Primary THA | <1 | <1 | <1 | <1 | UD | <1 | <1 | UD | |||||
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | <1 | 1.4 | UD | Contralateral THA, TKA | |||
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | |||||||
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | |||||||
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | TKA | ||||||
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | TKA | ||||||
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | <1 | <1 | UD | Spine hardware | |||
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | <1 | <1 | UD | Spine hardware | |||
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | <1 | 1.3 | 0 | 1.2 | 3.9 | Spine hardware | |
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | Titanium femoral plate | ||||||
| Primary THA | <1 | <1 | UD | <1 | 1.2 | UD | <1 | 1 | UD | Spine hardware, SC stimulator | |||
| Primary THA | <1 | <1 | UD | Contralateral MDM | |||||||||
| Primary THA | <1 | <1 | UD | ||||||||||
| Primary THA | <1 | <1 | UD | <1 | <1 | UD | <1 | 1.1 | UD | ||||
| Primary THA | <1 | <1 | UD | ||||||||||
| Primary THA | <1 | UD | |||||||||||
| Primary THA | <1 | <1 | UD | <1 | 1.3 | UD | <1 | 1.4 | UD | Contralateral MDM | |||
| Revision THA | 2.8 | 2.0 | UD | Contralateral THA | |||||||||
| Revision THA | 1.4 | <1 | UD | <1 | 1.1 | UD | <1 | <1 | UD | 0 | 0 | 4.9 | |
| Revision THA | 1 | <1 | UD | <1 | <1 | UD | 0 | 0 | 2.2 | ||||
| Revision THA | 1 | <1 | 75 | <1 | <1 | 50 | 5.5 | 0 | 4.2 | Titanium spine hardware | |||
| Revision THA | <1 | <1 | UD | <1 | 1.1 | UD | TKA | ||||||
| Revision THA | <1 | 1.6 | UD | ||||||||||
At one year, 15 of the 20 primary THA patients had labs drawn (five missed the lab interval). All 15 had undetectable cobalt levels and titanium levels, two had mild elevation of chromium levels (1.2 and 1.3 μg/L). Of the six revision patients, four had labs obtained at one-year. None had detectable cobalt levels, two had elevated chromium levels (1.1 and 1.1 μg/L), and the one patient with extensive spinal hardware had elevated titanium levels (50 μg/L). There was no significant difference over time in ion levels for any of the three ions tested (Table 4).
| Baseline N = 26 | One year N = 19 | Two year N = 9 | p-value | |
| N (%) | N (%) | N (%) | ||
| Elevated cobalt | 4 (16.0%) | 0 (0%) | 0 (0%) | 0.1289 |
| Elevated chromium | 2 (7.7%) | 4 (21.1%) | 4 (44.4%) | 0.0839 |
| Elevated titanium | 1 (4.0%) | 1 (5.3%) | 0 (0%) | 0.6275 |
At the two-year interval, nine of the twenty primary THA patients had labs drawn and none had detectible cobalt, five had elevated chromium levels (1 to 1.4 μg/L), and none had elevated titanium levels. Of the six revision patients, only one had labs obtained and the cobalt, chromium and titanium levels were undetectable (Table 4).
Overall, there were no significant differences in demographics, patient-reported outcomes or cup inclination and version between the patients who had mildly elevated ion levels (>1.0 μg/L) at any time (Table 1). While there was a significant increase in PROs from pre-op to final follow-up for physical function, physical health, and HOOS JR, only 38%, 33%, and 53%, respectively, met published minimal clinically important differences (MCID) for each PRO.13,14 Sub-analyses were performed stratifying by primary/revision surgery. No significant differences were observed in patient-reported outcomes or cup inclination. However, patients who underwent primary THA and had elevated ion levels had significantly higher anteversion (44.0 ± 9.6 vs. 31.7 ± 10.8, p = 0.039). Follow-up radiographs were available for 19 patients. One patient in the primary group had a nonprogressive radiolucency in zone 1. There were no cases of symptoms necessitating further workup or three-dimensional imaging. There were no dislocations. Beyond the elevated ion levels, no adverse events related to the component were observed.
4 Discussion
The use of dual mobility constructs, especially modular options, has gained significant popularity with approximately 8% of all primary surgeries and up to 23% of all revision procedures in the United States.1 Although dual mobility constructs has been found to reduce the incidence of dislocation,3,4 concerns about potential complications including polyethylene wear, intra-prosthetic dislocation, and corrosion of the modular liner interface have been expressed.10,15,16 In this prospective observational study of 26 patients undergoing primary or revision hip replacements with a G7 dual mobility component, no patients demonstrated elevated cobalt (>1 μg/L) at 1 and 2-year follow-up, suggesting a low likelihood for clinically significant corrosion at these time points. Mild chromium elevations (1.1–1.3 μg/L) were observed in four patients at one-year and in five patients at two-years (1.0–1.4 μg/L). One patient had detectable titanium levels, attributed to pre-existing titanium spinal hardware. There were no cases that required MRI scan imaging and no dislocations. Although this study presents early data, the findings provide encouraging reassurance regarding the metal ion profile of this device. Longer term follow-up is needed to determine the durability of these findings.
Concerns about fretting and corrosion have been identified as a potential issue in modular designs. Matsen et al. reported on 100 consecutive total hips and found that 21% of patients had serum ion levels exceeding 1 μg/L and 2 had evidence of ALTR on MRI at 27.6 months.5 Romero et al. observed a 5.8% (32/551) incidence of radiographically identified liner malseating in a similar device,and using a simulated corrosion chamber model, found a lower fretting onset load and greater fretting current values at all peak loads greater than 800N in malseated liners suggesting a potential mechanism for corrosion at this interface.6 Kolz et al. analyzed 12 retrieved implants and documented liner-shell corrosion of varying severity in all implants (2 severe, 5 moderate, 4 mild, and 1 without visible).8 Hemmerling et al. recently reported on 60 retrieved MDM liners and identified fretting in 88% and corrosion in 97% with inflammatory reaction to corrosion debris in 6/48 for which tissues were examined.9 A recent systematic review and meta-analysis reviewed 16 articles and found a 0.3% incidence of reported ALTR requiring revision, a 7.9% incidence of “mildly raised” ion levels, a 1.8% incidence of significantly raised ion levels, a 0.8% dislocation rate and warned of the potential added issues of prominent screw heads and malseating of the liner as potentiating factors.12 Additionally, there have been several case reports of adverse local tissue reaction related to these MDM constructs10,11 and one reporting femoral neck notching secondary to impingement.7
One notable mild ion elevation that was seen in our study, does not appear to be concerning, and may not be related to corrosion of the modular interfaces, the primary concern that we set out to detect with this prospective metal ion monitoring study. Mild chromium level elevation above the detectable limit of 1 μg/L was seen in 4 patients, which we do not feel was a concerning finding, and could easily be from other sources than the modular dual mobility liner. Chromium levels <2 μg/L are not generally considered clinically significant and there is little evidence linking these low levels with clinical toxicity.17 In fact, slightly elevated blood chromium can have sources other than joint implants, including dietary intake, environmental exposure, and sample contamination.18 Most clinical concern centers on cobalt rather than chromium, as cobalt is more likely to cause systemic toxicity.17,19,20 In most cases of implant wear or corrosion, cobalt tends to be equal to or higher than chromium, and isolated mild chromium elevation is uncommon in this context.17,21,22 Finally, given that the main concern of the modular dual mobility interface would be for corrosion, expected metal ion level elevations would be expected to be an elevation of cobalt ion levels greater than chromium, which has become a diagnostic tool to help diagnose mechanically assisted crevice corrosion (MACC)-associated adverse local tissue reactions.23 The preferential release of cobalt over chromium at CoCr-Ti modular junctions appears to be due to electrochemical differences between cobalt and chromium, which drive differential ion release, as well as chemical fate differences, wherein chromium ions (particularly Cr3+) tend to accumulate locally in interface membranes and form insoluble complexes with phosphate (CrPO4), while cobalt ions disseminate into circulation 24–26. In short, we feel that the slight elevation of chromium in the 4 patients we identified are mild, do not represent the ion that typically rises in the setting of CoCrMo–Ti modular junctions, and could be from alternative sources than implant corrosion, such as environmental or dietary sources.
Design differences in modular dual mobility constructs between different designs may influence performance. The device used in the present study has a 10-degree taper for fixation, an insertion ring to help avoid malseating, and a liner that sits flush with the perimeter of the acetabular component. These features may minimize the concerns regarding malseating and neck impingement on a prominent inner cobalt chromium liner. Additionally in the present series, all screw heads were confirmed by the surgeons to be seated and recessed to further minimize the risk of both prominent screws or malseating leading to the risks of corrosion that were seen in the prior studies. To the authors’ knowledge, this represents the first published investigations of this modern MDM design.
This study does have several limitations. The exclusion criteria did not include patients with other potential sources of metal ions making the revision group more difficult to evaluate with several having elevated metal ion levels at baseline. However, all early postoperative elevation in cobalt levels returned to <1 μg/L at one year. Another limitation is the ARUP Reference Laboratories reporting on metal ion levels; they only report on levels greater than 1 μg/L for Co and Cr making early detection at lower levels more difficult. As chromium levels can be labile depending on uncontrolled factors such as supplementation consumption, it is difficult to discern if the mildly elevated chromium levels at one and two years in four patients is of clinical significance. Additionally, many patients had other orthopaedic implants either prior to their index surgery or placed after, which may be a confounding factor, though we could not identify any association with the mild chromium elevations and the one patient with the elevated titanium. Next, the low enrollment size was an unforeseen limitation as our surgeons’ indications and use of dual mobility implants was likely less than anticipated due to evolving practice preferences during the study period. Finally, despite significant efforts to contact all study patients, loss to follow-up of participants was not insignificant in the study cohort.
5 Conclusion
This prospective series of 26 patients treated with a G7 MDM demonstrated reassuring metal ion levels at short term follow-up. Long-term follow-up is needed to confirm the durability of these results.
Patient consent
Informed consent was obtained from all individual participants in the study.
Ethical approval
This study was approved as exempt by the University of Utah (IRB #89804).-The study has been conducted in accordance with the ethical principles mentioned in the Declaration of Helsinski (2013)
Author contributions
MJA: Data curation, writing – original draft, review & editing.
BEB: Data curation, formal analysis, methodology, writing – review & editing.
CRA: Data curation, writing – review & editing.
LAA: Data curation, writing - review & editing.
JMG: Data curation, supervision, funding acquisition, writing – review & editing.
CLP: Supervision, investigation, writing – review & editing.
CEP: Conceptualization, funding acquisition, investigation, supervision, writing – original draft, review & editing.
Funding
This study was an investigator-initiated project that was funded by Zimmer Biomet. The sponsor was involved in the study design. They were not involved in the collection, analysis, or interpretation of the data.
References
- Low rate of dislocation of dual-mobility cups in primary total hip arthroplasty. Clin Orthop Relat Res. 2013;471(12):3891-3900.
- [Google Scholar]
- Dual-mobility constructs in primary and revision total hip arthroplasty: a systematic review of comparative studies. J Arthroplast. 2019;34(3):594-603.
- [Google Scholar]
- Outcomes of dual mobility components in total hip arthroplasty: a systematic review of the literature. Bone Jt J. 2018;100-b(1):11-19.
- [Google Scholar]
- Serum metal ion levels following total hip arthroplasty with modular dual mobility components. J Arthroplast. 2016;31(1):186-189.
- [Google Scholar]
- otto aufranc award: malseating of modular dual mobility liners. Bone Jt J. 2020;102-b(7_Supple_B):20-26.
- [Google Scholar]
- Femoral neck notching in dual mobility implants: is this a reason for concern? J Arthroplast. 2021;36(8):2843-2849.
- [Google Scholar]
- In vivo corrosion of modular dual-mobility implants: a retrieval study. J Arthroplast. 2020;35(11):3326-3329.
- [Google Scholar]
- Fretting and corrosion of metal liners from modular dual mobility constructs : a retrieval analysis. Bone Jt J. 2021;103-b(7):1238-1246.
- [Google Scholar]
- Adverse local tissue reaction due to acetabular corrosion in modular dual-mobility constructs. Arthroplast Today. 2020;6(4):976-980.
- [Google Scholar]
- Severe corrosion of modular dual mobility acetabular components identified during revision total hip arthroplasty. Arthroplast Today. 2021;8:78-83.
- [Google Scholar]
- Adverse reaction to metal debris due to fretting corrosion between the acetabular components of modular dual-mobility constructs in total hip replacement: a systematic review and meta-analysis. EFORT Open Rev. 2021;6(5):343-353.
- [Google Scholar]
- Establishing minimum clinically important difference values for the patient-reported outcomes measurement information system physical function, hip disability and osteoarthritis outcome score for joint reconstruction, and knee injury and osteoarthritis outcome score for joint reconstruction in orthopaedics. World J Orthoped. 2018;9(3):41-49.
- [Google Scholar]
- The minimal clinically important difference (mcid) for total joint arthroplasty outcome measures varies substantially by calculation method. J Bone Joint Surg Am. 2025;107(9):994-999.
- [Google Scholar]
- Dissociation and intrapelvic entrapment of a dual-mobility polyethylene component. Clin Orthop Relat Res. 2016;474(4):1072-1076.
- [Google Scholar]
- Migration and wear of a dual mobility acetabular construct at 3 years measured by radiostereometric analysis. J Arthroplast. 2020;35(4):1109-1116.
- [Google Scholar]
- Whole blood chromium concentration is very rarely elevated independently of whole blood cobalt. Sci Rep. 2021;11(1)
- [Google Scholar]
- Synchrotron analysis of human organ tissue exposed to implant material. J Trace Elem Med Biol. 2018;46:128-137.
- [Google Scholar]
- Cardiotoxicity of metal implant wear: emerging insights into the roles of cobalt and chromium. Tissue Eng Part B 2025
- [Google Scholar]
- Serum metal levels for diagnosis of adverse local tissue reactions secondary to corrosion in metal-on-polyethylene total hip arthroplasty. J Arthroplast. 2017;32(9s):S272.
- [Google Scholar]
- What do we know about taper corrosion in total hip arthroplasty? J Arthroplast. 2014;29(4):668-669.
- [Google Scholar]
- Reactive oxygen species, electrode potential and ph affect cocrmo alloy corrosion and semiconducting behavior in simulated inflammatory environments. Acta Biomater. 2024;186:507-519.
- [Google Scholar]
- In vivo corrosion on retrieved hip endoprostheses and in vitro effects of corrosion products on bone mineralization. Bone. 2023;175
- [Google Scholar]
- Bone and soft tissue reaction to co(ii)/cr(iii) ions stimulation in a murine calvaria model: a pioneering in vivo study. Acta Biomater. 2023;164:659-670.
- [Google Scholar]