Metal ion levels in a triathlete with a metal-on-metal resurfacing arthroplasty of the hip

Return to Sport After Hip Resurfacing Arthroplasty

Background

Femoroacetabular impingement and degenerative hip osteoarthritis (OA) affect athletes across a wide variety of sports. Hip resurfacing arthroplasty (HRA) has emerged as a surgical treatment for active individuals with end-stage hip OA to provide pain relief and allow return to high-impact activities. Return to professional sports after HRA has not been well characterized.

Purpose/Hypothesis

The aim of this study was to report on a series of elite athletes in a variety of sports who underwent HRA. We hypothesized that professional and elite-level athletes would be able to return to sports after HRA for end-stage hip OA.

Study Design

Case series; Level of evidence, 4.

Methods

A retrospective case series was conducted on professional athletes who underwent HRA at a single institution between 2007 and 2017. All surgeries were performed by a single surgeon using the posterolateral approach. Athletes' return to play and sport-specific performance statistics were obtained using self-reported and publicly available data sources. Athletes were matched to an age- and performance-based cohort to determine changes in performance-based metrics.

Results

Eight professional athletes were identified, including 2 baseball pitchers, 1 ice hockey defenseman, 1 foil fencer, 1 men's doubles tennis player, 1 basketball player, 1 ultramarathoner, and 1 Ironman triathlete. All 8 patients returned to sports; 6 of 8 (75%) patients were able to return for at least 1 full season at a professional level after surgery. There were no significant differences between performance statistics for athletes who returned to play and their preoperative performance measures for the years leading up to surgery or the age- and performance-matched cohort.

Conclusion

HRA remains a surgical alternative for end-stage hip OA in young, high-impact, active patients. While the primary goals of surgery are pain control and quality of life improvement, it is possible to return to elite-level sporting activity after HRA.

Impingement of metal-polyethylene hip prostheses : Potential cause of high systemic titanium levels?

High blood metal levels have been described in the past, primarily in metal-on-metal bearings. Other possible causes are often underestimated. This report presents the case of a 70-year-old female patient who suffered from pronounced neurological symptoms (especially fatigue and concentration problems) 13 years after implantation of a hip endoprosthesis with metal-polyethylene (ME-PE) bearing. An osteolysis in the pelvis and loosening of the acetabular component were detected. In addition, large quantities of metallic black discolored granulomas were detected in the periarticular environment during surgery. A ventral impingement with destruction of the titanium cup and the PE insert was identified as the suspected cause of this condition. The postoperative course of the blood metal levels was unexpected as titanium levels increased massively in the blood. Anamnesis, course of the disease and the surgical procedure as well as especially the course of the metal values in the blood of the patient are presented. Possible causes for the excessive occurrence of metal abrasion, the systemic distribution and potential toxic effects of titanium are explained and discussed in detail. In addition, the currently available literature on the subject is critically examined.

Metal ion concentrations after metal-on-metal hip arthroplasty are not correlated with habitual physical activity levels

INTRODUCTION

Metal-on-metal (MoM) hip arthroplasties have shown high clinical failure rates with many patients at risk for a revision and under surveillance for high metal ion concentrations. Implant wear releasing such ions is assumed to be a function of use, i.e. the patient's physical activity. This study aimed to assess whether habitual physical activity levels of MoM patients are correlated with metal ion concentrations and are higher in patients with high (at risk) than in patients with low (safe) metal ion concentrations.

METHODS

A cohort study was conducted of patients with any type of MoM hip prosthesis. Metal ion concentrations were determined using ICP-MS. Habitual physical activity of subjects was measured in daily living using an acceleration-based activity monitor. Outcome consisted of quantitative and qualitative activity parameters.

RESULTS

In total, 62 patients were included. Mean age at surgery was 60.8 ± 9.3 years and follow-up was 6.3 ± 1.4 years. Cobalt concentrations were highly elevated overall (112.4 ± 137.9 nmol/L) and significantly more in bilateral (184.8 ± 106.5 nmol/L) than in unilateral cases (87.8 ± 139.4 nmol/L). No correlations were found between physical activity parameters and metal ion concentrations. Subgroup analysis of patients with low versus high cobalt concentration showed no significant differences in habitual physical activity.

DISCUSSION

No correlation was found between physical activity levels and metal ion concentrations. Implant use by normal habitual activities of daily living seems not to influence metal ion concentrations.

The correlation between activity level, serum-ion concentrations and pseudotumours in patients with metal-on-metal hip articulations and metal-on-polyethylene total hip articulations

Purpose

Young and physically active patients have mainly received metal-on-metal (MoM) total hip arthroplasty (THA) and resurfacing hip arthroplasty (RHA). However, the correlation between daily physical activity (PA) levels, serum-ion concentrations of chromium and cobalt and pseudotumours formation of patients who underwent MoM THA/RHA is insufficiently explored.

Methods

Ninety-nine patients with 134 hip articulations, 71 MoM THA/RHA and 63 MoP THA participated in a cross-sectional study at XXX University Hospital, Denmark, at mean 7.3 (range: 0.4–21.7) years after surgery. Patients' daily PA was monitored during a two-week period using a triaxial accelerometer. Metal artefact reduction sequence magnetic resonance imaging scans, estimation of serum-ion concentrations of chromium and cobalt and the Copenhagen Hip and Groin Outcome Score (HAGOS) questionnaire were completed on Day 14.

Results

Patients with a pseudotumour who underwent MoM THA/RHA had a higher average cadence of median 101.4 [interquartile range (IQR: 95.5–105)] steps/min than patients without a pseudotumor, median 96.7 (IQR: 92.2–103) steps/min (p = 0.02). Serum-ion concentrations of chromium and cobalt were higher in patients with a pseudotumour who underwent MoM THA/RHA, median 2.57 (IQR: 1.4–3.4) μg/L and 1.80 (IQR: 1.2–2.6) μg/L, respectively, than in patients without a pseudotumour, median 1.85 (IQR: 1.1–3.2) μg/L and 1.34 (IQR: 0.9–2.2) μg/L in MoM THA/RHA (p = 0.04 and p = 0.03). There was no statistical difference in these parameters between patients with and without a pseudotumour who underwent MoP THA. Daily PA levels of patients who underwent MoM THA/RHA were significantly correlated with serum-ion concentrations of chromium (p = 0.0002, r = 0.44) and cobalt (p = 0.005, r = 0.34), whereas no correlations were seen among patients who underwent MoP THA (p > 0.12).

Conclusion

The daily PA level of patients who underwent MoM THA/RHA influences the serum-ion concentrations of chromium and cobalt and the risk of pseudotumour formation.

Translational potential of this article

Results of this article add important knowledge on potential recommendations of prosthesis selection for patients with a high level of physical activity.

Competitive Running After Total Hip Arthroplasty: The World's Fastest Total Hip: A Case Report

CASE

We report the case of a young man who underwent total hip arthroplasty (THA) for osteonecrosis at the age of 20 years, and subsequently competed in collegiate long-distance running. The pinnacle of his career was setting the school record time of 3:47.64 (min:sec) in the 1,500-m "metric mile" run (equivalent to 4:05.09 for the "English" mile). This is the fastest known time for any patient who has undergone THA. Excellent clinical and radiographic outcomes had been maintained at 6 years postoperatively.

CONCLUSION

Patients who undergo arthroplasty procedures may be capable of remarkable physical accomplishments, but pursuing such feats is not advised.

Prevalence of Pseudotumor in Patients After Metal-On-Metal Hip Arthroplasty Evaluated with Metal Ion Analysis and MARS-MRI

The purpose of this study is to quantify the prevalence of pseudotumors in patients with well-functioning and painful metal-on-metal total hip arthroplasty, to characterize the pseudotumor with the use of MARS-MRI, and to assess the relationship between pseudotumors and metal ions. We retrospectively reviewed 102 single surgeon patients. The results showed that 68.6% developed pseudotumor with 60.9% of the asymptomatic group developing pseudotumor. The symptomatic group had a higher proportion of patients with elevated serum cobalt levels (P=0.035). There was no difference found with elevated metal ions and prevalence of pseudotumor, but elevated cobalt levels were associated with larger pseudotumor size (P=0.001). The available evidence indicated that most patients that develop pseudotumors are asymptomatic, and that elevated serum cobalt levels may be associated with symptoms and pseudotumor size.

Blood metal ion testing is an effectivescreening tool to identify poorly performing metal-on-metal bearingsurfaces

Objectives

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.

Methods

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.

Results

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.

Conclusions

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.

Contact patch to rim distance predicts metal ion levels in hip resurfacing

BACKGROUND

Component design, size, acetabular orientation, patient gender, and activity level have been suggested as factors leading to elevated metal ion concentrations after-on-metal hip resurfacing arthroplasty (MMHRA). The calculation of the contact patch to rim (CPR) distance integrates component size, design, and acetabular orientation and may be a good predictor of elevated metal ion levels.

QUESTIONS/PURPOSES

We evaluated the effects and the predictive value of the CPR distance on serum cobalt (CoS) and chromium (CrS) ion levels.

METHODS

We retrospectively studied 182 patients with Conserve Plus MMHRAs at a minimum of 12 months after surgery (median, 57 months; range, 12-165 months). CoS and CrS levels were analyzed using inductively-coupled plasma mass spectrometry. Multiple logistic regression was performed to determine which if any of the factors related to serum ion levels.

RESULTS

Patients with CPR distances of 10 mm or less had a 37-fold increased risk of having elevated CoS of 7 μg/L or higher. Similarly, these patients had an 11-fold increased risk of having elevated CrS of 7 μg/L or higher. Sex and University of California Los Angeles activity scores did not influence the postoperative CoS and CrS levels. The negative predictive value for CPR distance less than 10 mm was 99.3% for CoS greater than 7 μg/L and 98.0% for CrS greater than 7 μg/L.

CONCLUSIONS

Our observations suggest the CPR distance would be a useful indicator to determine which patients are at risk for elevated ion levels. Patients with CPR distances greater than 10 mm need not be monitored unless they become symptomatic.

Hip replacement in the athlete: is there a role?

Sport and total hip arthroplasty (THA) have been regarded by many as being mutually exclusive. The primary indication for hip arthroplasty has always been pain. With advances in the technology surrounding hip replacement surgery and increasing patient expectations of what THA can offer, there is a growing demand for hip replacement with the aim of returning to sporting activity. The aim of this review article is to report the advances in hip replacement surgery that aim to make the procedure more suitable for the sporting individual and to summarise the literature on the subject of returning to sports after THA.

Insufficient acetabular version increases blood metal ion levels after metal-on-metal hip resurfacing

BACKGROUND

Many factors affect the blood metal ion levels after metal-on-metal (MOM) hip arthroplasty. The main surgically adjustable variable is the amount of coverage of the head provided by the cup which is a function of the inclination and version angles. However, most studies have used plain radiographs which have questionable precision and accuracy, particularly for version and large diameter metal heads; further, these studies do not simultaneously assess version and inclination. Thus the relationship between version and blood metal ions levels has not been resolved.

QUESTIONS/PURPOSES

We determined whether cup inclination and version influence blood metal ion levels while adjusting for age at assessment, gender, body mass index, horizontal femoral offset, head size, manufacturer hip type, and Oxford hip score.

PATIENTS AND METHODS

We prospectively followed 100 individuals (51 females, 49 males) with unilateral MOM hip resurfacing who underwent clinical assessment, CT scanning, and blood metal ion measurement. Multiple regression analysis was used to determine which variables were predictors of blood metal ion levels and to model the effect of these variables.

RESULTS

Only cup inclination, version angles, and gender influenced blood cobalt or chromium levels. Cobalt and chromium levels positively correlated with inclination angle and negatively correlated with version angle. The effect of changes in version angle was less than for inclination angle. Based on our observations, we developed a formula to predict the effect of these parameters on metal ion levels.

CONCLUSIONS

Our data suggest insufficient cup version can cause high blood metal ions after MOM hip arthroplasty. We were unable to show that excessive version caused high levels.

LEVEL OF EVIDENCE

Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Neurotoxicity of cobalt

Cobalt exerts well-known and documented toxic effects on the thyroid, heart and the haematopoietic system, in addition to the occupational lung disease, allergic manifestations and a probably carcinogenic action. Cobalt neurotoxicity is reported in isolated cases, and it has never been systematically treated. Bilateral optic atrophy and retinopathy, bilateral nerve deafness and sensory-motor polyneuropathy have been described long ago as a result of chronic occupational exposure to cobal powder or during long-term treatment of anaemia with cobalt chloride. Recently, some patients with high levels of cobalt released from metal prosthesis have been referred as presenting with tinnitus, deafness, vertigo, visual changes, optic atrophy, tremor and peripheral neuropathy. The aim of this work is to group these cases and to identify a possible mechanism of cobalt neurotoxicity, focusing on hypothetic individual susceptibility such as altered metal-binding proteins, altered transport processes in target cells or polymorphic variation of genetic background.

Elements in sera of elite taekwondo athletes: effects of vitamin E supplementation

Many researchers have emphasized the relation between nutrition and development and sustaining performance. Two methods are commonly employed to identify the interaction between physical activity and nutrition. The first consists of administering food with a variety of contents to people engaged in physical activity and observing their performance responses, and the other is concerned with determining the effects of physical activity on nutrition. Therefore, it can be said that there has been a growing interest in the explorations into the relation between exercise and vitamins, minerals, and elements. The present study reports the effects of 6 weeks administration of 300 mg/day vitamin E on the distribution of serum elements in elite taekwondo athletes. Seven male athletes, mean ages 22.1 ± 0.5 years weighing on average 66.4 ± 2.4 kg were included in the study. The athletes had been practicing taekwondo for 10-12 years. Resting blood samples were collected in duplicate before and after supplementation for determination of serum levels of cobalt, boron, cadmium, chromium, nickel, manganese, sulfur, copper, iron, zinc, phosphorus, sodium, potassium, and calcium. Supplementation resulted in significant increases of all elements relative to values before supplementation (p < 0.001), with the exception of boron and sulfur, which remained without change. The results of the present study demonstrate that vitamin E supplementation crucially influences the element and mineral metabolism in elite athletes.

[Implant wear and aseptic loosening. An overview]

Wear of total joint implants is multifactorial in nature. Even for identical materials and geometries, the interaction of those parameters can generate different numbers of particles as well as different particle sizes and shapes. These different wear-particle characteristics will directly influence the biological response to an implant and thereby its clinical success. The long-term success of a total joint replacement requires an optimized compromise among implant material, design, surgical procedure, and biological performance.

Cup inclination angle of greater than 50 degrees increases whole blood concentrations of cobalt and chromium ions after metal-on-metal hip resurfacing

A cup inclination angle greater than 45 degrees is associated with increased wear rates of metal on polyethylene (MOP) hip replacements. The same maybe true for metal on metal (MOM) hips yet this has not been clearly shown. We measured the acetabular inclination angle from plain radiographs, and whole blood metal ion levels using Inductively Coupled Plasma Mass Spectrometry of 26 patients (mean Harris Hip Score 94 and mean time post op of 22 months) with Birmingham Hip Resurfacings. We identified a threshold level of 50 degrees cup inclination. Below this threshold, the mean whole blood cobalt and chromium were 1.6 ppb and 1.88 ppb respectively; above this threshold, the mean blood cobalt and chromium were 4.45 ppb and 4.3 ppb respectively. These differences were significant cobalt (p<0.01) and chromium (p=0.01). All patients above the threshold had metal levels greater than any of the patients below the threshold. For 14 patients, who returned one year later for a repeat blood metal level measurement, cobalt and chromium levels were very similar. The effect of an acetabular inclination angle of greater than 50 degrees on wear rates of MOM hips, as measured through blood metal ion levels, appears to be similar to that seen with MOP hips. Additionally, our new analytical methods may allow blood metal levels to be used as a realistic biomarker of in vivo wear rate of MOM hips. The implication is that metal levels can be minimised with optimal orientation of the acetabular component.

The exercise-related rise in plasma cobalt levels after metal-on-metal hip resurfacing arthroplasty

Wear of metal-on-metal bearings causes elevated levels of cobalt and chromium in blood and body fluids. Metal-on-metal bearings have two distinct wear phases. In the early phase, the wear rate is high. Later, it decreases and the bearing enters a steady-state phase. It is expected that as the wear rates decline, the level of cobalt detected in plasma will also decrease. We studied the baseline and exercise-related cobalt rise in 21 patients (13 men and eight women) with a mean age of 54 years (38 to 80) who had undergone successful hip resurfacing at a mean of 44 months (10 to 96) earlier. Our results showed that circulating baseline cobalt levels were not significantly correlated with the time since implantation (r = 0.08, p = 0.650). By contrast, the exercise-related cobalt rise was directly correlated with the inclination angle of the acetabular component (r = 0.47, p = 0.032) and inversely correlated with the time since implantation (r = −0.5, p = 0.020).

Inclination of the acetabular component should be kept less than 40° to decrease the production of wear debris.

Chronic inflammation, joint replacement and malignant lymphoma

This paper considers the increased risk of the development of lymphoma in patients with chronic inflammatory disease who undergo metal-on-metal arthroplasty.