Aims. This study compared the cobalt and chromium serum ion concentration of patients treated with two different metal-on-metal (MoM) hinged total knee arthroplasty (TKA) systems, as well as a titanium nitride (TiN)-coated variant. Methods. A total of 63 patients (65 implants) were treated using either a MoM-coated (n = 29) or TiN-coated (n = 7) hinged TKA (GenuX mobile bearing, MUTARS; Implantcast, Germany) versus the BPKS (Brehm, Germany) hinged TKA (n = 27), in which the weight placed on the MoM hinge is diffused through a polyethylene (PE) inlay, reducing the direct load on the MoM hinge. Serum cobalt and chromium ion concentrations were assessed after minimum follow-up of 12 months, as well as functional outcome and quality of life. Results. No differences in mean age (69 years, 40 to 86), mean age adapted Charlson Comorbidity Index (3.1 (SD 1.4)), mean BMI (29.2 kg/m. 2. (SD 5.8)), or number of other implants were observed between groups. Significant improvements in outcome scores and pain levels were achieved for all groups, and there was no difference in quality of life (12-Item Short-Form Health Survey questionnaire (SF-12)). Mean cobalt and chromium ion levels were significantly higher for the GenuX versus the BPKS hinged TKA (GenuX vs BPKS: cobalt: 16.3 vs 9.4 µg/l; chromium: 9.5 vs 5.2 µg/l). The TiN-coated implants did not appear to confer improvement in the
Aims. In metal-on-polyethylene (MoP) total hip arthroplasty (THA), large metal femoral heads have been used to increase stability and reduce the risk of dislocation. The increased size of the femoral head can, however, lead to increased taper corrosion, with the release of
The purpose of this study was to evaluate whether concerns about the release of
ZrN-multilayer coating is clinically well established in total knee arthroplasty [1-3] and has demonstrated significant reduction in polyethylene wear and
Systemic
A concern of metal on metal hip resurfacing arthroplasty is long term exposure to Cobalt (Co) and Chromium (CR) wear debris from the bearing. This study compares whole blood
Introduction. Systemic
Metal-on-metal bearings for total hip replacement (THR) are becoming increasingly popular. Improved wear characteristics mean that these articulations are being inserted into younger patients in the form of THR and resurfacing procedures. This has led to concerns regarding potential carcinogenicity because of the increased exposure to
Objectives. Alarm over the reported high failure rates for metal-on-metal (MoM) hip implants as well as their potential for locally aggressive Adverse Reactions to Metal Debris (ARMDs) has prompted government agencies, internationally, to recommend the monitoring of patients with MoM hip implants. Some have advised that a blood ion level >7 µg/L indicates potential for ARMDs. We report a systematic review and meta-analysis of the performance of
We retrospectively analysed concentrations of chromium and cobalt ions in samples of synovial fluid and whole blood taken from a group of 92 patients with failed current-generation metal-on-metal hip replacements. We applied acid oxidative digestion to our trace metal analysis protocol, which found significantly higher levels of
There have been no large comparative studies of the blood levels of
We report serum
Aims. We have previously demonstrated raised cobalt and chromium levels in patients with larger diameter femoral heads, following metal-on-polyethylene uncemented total hip arthroplasty. Further data have been collected, to see whether these associations have altered with time and to determine the long-term implications for these patients and our practice. Methods. Patients from our previous study who underwent Trident-Accolade primary total hip arthroplasties using a metal-on-polyethylene bearing in 2009 were reviewed. Patients were invited to have their cobalt and chromium levels retested, and were provided an Oxford Hip Score. Serum ion levels were then compared between groups (28 mm, 36 mm, and 40 mm heads) and over time. Results.
Purpose. Total shoulder arthroplasty (TSA) has become a successful treatment option for degenerative shoulder disease. With the increasing incidence in primary TSA procedures during the last decades, strategies to improve implant longevity become more relevant. Implant failure is mainly associated with mechanical or biological causes. Chronic inflammation as a response to wear particle exposure is regarded as a main biological mechanism leading to implant failure.
Hip resurfacing arthroplasty (HRA) became a popular procedure in the early 90s because of the improved wear characteristic, preserving nature of the procedure and the optimal stability and range of motion. Concerns raised since 2004 when
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
Introduction. Dual modular hip prostheses were introduced to optimize the individual and intra-surgical adaptation of the implant design to the native anatomics und biomechanics of the hip. The downside of a modular implant design with an additional modular interface is the potential susceptibility to fretting, crevice corrosion and wear [1–2]. The purpose of this study was to characterize the
In metal-on-polyethylene (MoP) THA large femoral metal heads are designed to increase stability and to reduce dislocation risk. The increased head size could lead to increased taper corrosion with the release of
Background. Metal-on-metal hip implants can produce adverse tissue reactions to wear debris. Increased
The purpose of this randomized controlled trial was to evaluate serum
Introduction. The MHRA guidelines for metal on metal (MOM) suggest cobalt and chromium levels of more than 7ppb as potential for soft tissue reaction. However, in some patients soft tissue reaction is seen even in the presence of normal serum
Increased concentrations of
Introduction. Mechanical or corrosive failure of total knee arthroplasties (TKAs) is difficult to diagnose with current laboratory and radiographic analyses. As such, the goal of this study was to determine the mean blood concentration of cobalt, chromium, and titanium in a series of revision TKAs with mechanical implant failure and evaluate whether they facilitated identification of the underlying TKA failure mechanism. Methods. Serum cobalt, chromium, and titanium levels and synovial fluid characteristics were evaluated in 12 patients (13 aseptic revision TKAs) who underwent revision TKA between 2000 and 2020 at a single academic institution for mechanical implant failure or corrosion. Seventy-five percent were re-revisions of previously revised TKAs. Mean time to revision was 6 years. Modular metallic junctions were present in 100%. Twenty-five percent did not have another in situ total joint arthroplasty, and the remaining patients did not have a metal-on-metal articulation that could lead to elevation in serum
Introduction. Metal-metal surface replacement (MoMSRA) continues to be used in young women. Systemic
High short-term failure rates have been observed with a number of metal-on-metal (MoM) hip designs. Most patients require follow-up with blood
We examined the relationships between the serum levels of chromium and cobalt ions and the inclination angle of the acetabular component and the level of activity in 214 patients implanted with a metal-on-metal resurfacing hip replacement. Each patient had a single resurfacing and no other metal in their body. All serum measurements were performed at a minimum of one year after operation. The inclination of the acetabular component was considered to be steep if the abduction angle was greater than 55°. There were significantly higher levels of
Introduction. Metal on metal (MoM) bearings have been dealt a severe blow in the past few years. The release of
Purpose. There is a postulated association between increased serum
This study evaluates
Introduction: The accepted method of assessing wear following a hip simulator test has been to use a precision balance. As the MoM devices produce significantly less weight loss than hard-on-soft bearings, the measurements of MoM devices are now almost at the detection limit of many balances. There is a need for a method that can be used in conjunction with gravimetric analysis that will provide an accurate assessment of ion concentration levels that will support the gravimetric measurements. Aim: To develop a method to assess wear using
There has been much discussion and controversy in the media recently regarding metal toxicity following large head metal on metal (MoM) total hip replacement (THR). Patients have been reported as having hugely elevated levels of
Introduction. Higher concentrations of
A randomised prospective study of four bearing surfaces in hip replacements is being conducted. The primary objective is to identify the best long term bearing surf ace clinically and radiographically, and
Objectives. We have encountered patients who developed large joint fluid collections with massive elevations in chromium (Cr) and cobalt (Co) concentrations following metal-on-metal (MoM) hip arthroplasties. In some cases, retrieval analysis determined that these ion concentrations could not be explained simply by the wear rates of the components. We hypothesized that these effects may be associated with aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL). Patients and Methods. We examined the influence of the ALVAL grade on synovial fluid Co and Cr concentrations following adjustment for patient and device variables, including volumetric wear rates. Initially restricting the analysis to include only patients with one MoM hip resurfacing device, we performed multiple regression analyses of prospectively collected data. We then repeated the same statistical approach using results from a larger cohort with different MoM designs, including total hip arthroplasties. Results. In the resurfacing cohort (n = 76), the statistical modelling indicated that the presence of severe ALVAL and a large fluid collection were associated with greater joint fluid Co concentrations after adjustment for volumetric wear rates (p = 0.005). These findings were replicated in the mixed implant group (n = 178), where the presence of severe ALVAL and a large fluid collection were significantly associated with greater fluid Co concentrations (p < 0.001). Conclusion. The development of severe ALVAL is associated with elevations in
The biological significance of cobalt-chromium wear particles from metal-on-metal hip replacements may be different to the effects of the constituent
Introduction. Modern metal-on-metal bearing resurfacings have been in use for nearly two decades. Local and systemic
We describe the findings at six years in an ongoing prospective clinicoradiological and
Introduction: The increasing use of metal-metal bearings in hip arthroplasty raises concerns of elevated systemic metal levels. Lubrication theory and in-vitro studies suggest that larger diameter bearings generate less wear. Does this hold true in real life?. Methods: This is a cross-sectional study of 181 patients with either a Birmingham Hip Resurfacing or a 28mm Metasul THR. Whole blood levels (at 1year) and urinary
Introduction. The advantages of metal on metal (MOM) hip replacement are decreased wear rate, preservation of bone stock, anatomical restoration and enhanced stability. Large amounts of metal wear particles and
A randomised prospective study of 4 bearing surfaces in hip replacements is being conducted. The primary objective is to identify the best long term bearing surface clinically and radiographically, and
Bone related adverse events including failure of implant osseo-integration, periprosthetic fracture, femoral neck narrowing, and unexplained pain occur more frequently following metal-on-metal hip resurfacing (MoMHR) versus total hip arthroplasty (THA). The exact mechanism for the adverse effects is still unclear and may be due to the direct effect on bone cells of
Total knee arthroplasty is a well-established treatment for degenerative joint disease, on the other hand
Introduction. Little is known about variations in blood
It has been suggested that
Aims. We investigated whether blood
Introduction. The aim of this study was to analyze the results of our series of female patients treated with <48 mm MOMHR devices at a minimum follow-up of 5 years, to understand which is the most important aspects affecting the results and to define if the
A retrospective study was conducted to investigate
the changes in
Metal-on-metal hip bearings are being implanted into younger patients. The consequence of elevated levels of potentially carcinogenic
Blood
Introduction: Local problems of metal on metal (MOM) hip arthroplasty such as pseudotumours, neck thinning and osteolysis maybe related to concentrations of cobalt and chromium ions in the synovial fluid. There is little reported on these values. Our aim was to determine the range of
Metal on metal (MoM) bearings in hip surgery may result in increased blood levels of
The combination of a ceramic head articulating against a metal acetabular liner (CoM) has shown reduced
Introduction. A
The aim of this study is to investigate whether MoM implants result in more chromosome aberrations and increased blood
Background: There is a paucity of published literature with regard to
Introduction: Despite the satisfactory short-term implant survivorship of MoM hip resurfacing arthroplasty, symptomatic abnormal periprosthetic soft-tissue masses relating to the hip joint, ‘pseudotumours’, are being increasingly reported. These were found be locally destructive, requiring revision surgery in 75% of patients. Asymptomatic pseudotumours have not been previously investigated. Methods: The aims were: (1) to investigate the prevalence of asymptomatic pseudotumours; and (2) to investigate their potential association with the level of
Introduction: Potential problems resulting from metal-on-metal hip wear debris are well known. Previous studies have shown an association between high cup angles and raised
Comparisons of blood
The search for the ideal bearing surfaces to be used in Total Hip Replacement continues. The current “best” materials are felt to be various combinations of metal, ceramics and cross linked polyethylene. This study aims to identify the best combination with the lowest side effect profile. In February 2004 a prospective randomised trial on different bearing surfaces was started. The combinations selected were ceramic on cross linked polyethylene, ceramic on ceramic, metal on metal and ceramic on metal. Institutional ethics clearance was obtained. In all patients uncemented femoral stems are used, and an uncemented porocoated acetabular shell. 28mm Head size was selected. Blood samples have been taken to measure the
Wear debris associated with CoCr bearings has been implicated in the development of adverse soft tissue reactions and pseudotumors following THA with large metal heads and following hip resurfacing. Additional concerns have been raised regarding trunion fretting and corrosion. Most recently, the neck-stem junction of some modular femoral stem designs have come under additional scrutiny. We undertook a review of patients who had undergone THA with a proximal modular junction stem design in order to ascertain the state of the junction in early follow up. We examined the records of all patients in our practice who had undergone uncomplicated, unilateral THA with the ARC stem (OmniLife Science, East Taunton, MA, USA) between April 2010 and April 2012. Office records, radiographs and laboratory data were included. Serum or blood cobalt and chromium ion levels were obtained at the one-year post-op visit or later or if the patient had unexpected pain. The test obtained (serum or blood) was dependent on the lab performing the study. In the study period 100 patients met the inclusion criteria and had
Total knee arthroplasty is a well established treatment for degenerative joint disease with good clinical results. However, complications may occur due to a biological response to polyethylene wear particles, leading to osteolysis and aseptic loosening, as well as local and systemic hypersensitivity reactions triggered by
Introduction:. Whole blood
The search for the ideal bearing surface in Total Hip Replacements continues. The current ‘best’ materials are felt to be combinations of metal, ceramics and cross-linked polyethylene. Laboratory studies suggest that ceramic-on-metal articulations may provide distinct advantages. This study aims to identify the best bearing surface combination with the lowest adverse side effect profile. Between February 2004 and September 2007, 164 hips were replaced in 142 patients. 39% were male and 69% were female. The average age at surgery was 53 years (17-72 years). Follow-up assessment included radiographs, the Harris Hip Score and whole blood samples for
Background: Definitive cup position for the reduction of blood
The search for the ideal bearing surfaces to be used in Total Hip Replacement continues. The current “best” materials are felt to be various combinations of metal, ceramics and cross-linked polyethylene. Laboratory studies suggest that ceramic-on-metal articulations may provide distinct advantages. This study aims to identify the best combination with the lowest side effect profile. In February 2004 a prospective randomised trial on different bearing surfaces was started. The combinations selected were ceramic-on-cross-linked polyethylene, ceramic-on-ceramic, metal-on-metal and ceramic-on-metal. Institutional ethics clearance was obtained. In all patients uncemented femoral stems are used, with an uncemented porocoated acetabular shell. A uniform 28mm femoral head size was selected. Blood samples have been taken to measure the
Plasma levels of cobalt and chromium ions and
Metal Artefact Reduction Sequence (MARS)-MRI scans were performed
on patients with 209 consecutive, unilateral, symptomatic metal-on-metal
(MoM) hip arthroplasties. There was wide variation in plasma cobalt
and chromium levels, and MARS-MRI scans were positive for adverse reaction
to metal debris (ARMD) in 84 hips (40%). There was a significant
difference in the median plasma cobalt and chromium levels between
those with positive and negative MARS-MRI scans (p <
0.001).
Compared with MARS-MRI as the potential reference standard for the
diagnosis of ARMD, the sensitivity of
Introduction: In vitro simulation experiments and in vivo
Introduction: Pain and mass lesions around hip resurfacing are reported with increasing frequency. The aetiology is unknown but reaction to metal wear debris and mechanical impingement have both been suggested. We are aware of a group of our patients with significant pain following resurfacing. We sought to correlate
We have studied the relationship between
Metal-on-metal (MOM) bearings for hip arthroplasty are increasing in popularity. Concern remains, however, regarding the potential toxicological effects of the
Purpose: Metal-on-metal articulations are an increasingly popular choice as an alternate bearing surface in total hip arthroplasty (THA) and Resurfacing implants. One advantage of a metal-on-metal bearing is the use of larger diameter femoral heads with hip simulator data demonstrating reduced wear. We performed a prospective, multicentre, randomized, blinded clinical trial comparing 28mm to 36mm metal-on-metal bearings assessing multiple validated outcome measures and serum, erythrocyte and urine
Introduction.
Introduction: Metal-on-metal arthroplasties are being used for their increased durability and reduced requirement for revision. Previous data reports that metal-on-metal bearing surfaces release three times more cobolt and chromium ions than metal-on-polyethelene hip replacements. Data also suggests that these
INTRODUCTION. Metallic ion release may be related to bearing surface wear and thus serve as an indicator of in-vivo performance of metal on metal (MOM) articulations. OBJECTIVES. Compare large head MOM hip components with modular MOM and metal on polyethylene (MOP) to determine their relative effects on serum
Introduction. Large diameter metal-on-metal hip arthroplasty (LDMMTHA) provides benefits of reduced dislocation rates and low wear. The use of modular systems allows better restoration of hip biomechanics. There have been reports of modular LDMMTHAs with tapered sleeves generating excessively high
Introduction:. The clinical significance of serum
Metal-on-metal (MOM) bearings after total hip arthroplasty are known to elevate the serum concentrations of
Background: Blood
Background. Modularity in total hip replacement(THR) enables precise recreation of native hip biomechanics. However, there have been concerns about raised
Introduction: Spinal arthrodesis with stainless steel implants is a common procedure to correct scoliosis however, the long-term consequences of retained implants is unclear. Raised serum
We investigated the role of ion release in the assessment of fixation of the implant after total knee replacement and hypothesised that ion monitoring could be a useful parameter in the diagnosis of prosthetic loosening. We enrolled 59 patients with unilateral procedures and measured their serum aluminium, titanium, chromium and cobalt ion levels, blinded to the clinical and radiological outcome which was considered to be the reference standard. The cut-off levels for detection of the ions were obtained by measuring the levels in 41 healthy blood donors who had no implants. Based on the clinical and radiological evaluation the patients were divided into two groups with either stable (n = 24) or loosened (n = 35) implants. A significant increase in the mean level of Cr ions was seen in the group with failed implants (p = 0.001). The diagnostic accuracy was 71% providing strong evidence of failure when the level of Cr ions exceeded the cut-off value. The possibility of distinguishing loosening from other causes of failure was demonstrated by the higher diagnostic accuracy of 83%, when considering only patients with failure attributable to loosening. Measurement of the serum level of Cr ions may be of value for detecting failure due to loosening when the diagnosis is in doubt. The other
Instrumented spinal arthrodesis is a common procedure to correct scoliosis. The long-term consequences of these retained implants is unclear. Concern of possible toxic effects of raised
Introduction: Systemic
We performed a prospective, randomised, blinded clinical trial comparing metal versus polyethylene bearing surfaces in patients receiving a THA. Forty-one patients were randomised to receive a metal (twenty-three) or a polyethylene (eighteen) insert with identical femoral and acetabular components. The metal bearing was a 28mm low carbon on high carbon couple. Patients were evaluated pre-operatively, at three, six, twelve months and annually thereafter, including an evaluation of erythrocyte and urine cobalt, chromium, and titanium, outcome measures (WOMAC, SF-12, Harris Hip Score) and radiographs. No patients were lost to follow-up. At an average 7.2 (range 6.1 – 7.8) years follow-up there were no differences in any outcome measures or radiographic findings. Patients receiving metal liners had significantly elevated
Despite a large body of literature the optimal choice of bearing surface for total hip arthoplasty (THA) remains controversial. To avoid the brittleness and squeaking noted with ceramic-on-ceramic and the
We present a series of 35 patients (19 men and
16 women) with a mean age of 64 years (36.7 to 75.9), who underwent
total hip replacement using the ESKA dual-modular short stem with
metal on-polyethylene bearing surfaces. This implant has a modular
neck section in addition to the modular head. Of these patients,
three presented with increasing post-operative pain due to pseudotumour
formation that resulted from corrosion at the modular neck-stem
junction. These patients underwent further surgery and aseptic lymphocytic
vaculitis associated lesions were demonstrated on histological analysis. Retrieval analysis of two modular necks showed corrosion at the
neck-stem taper. Blood cobalt and chromium levels were measured
at a mean of nine months (3 to 28) following surgery. These were
compared with the levels in seven control patients (three men and
four women) with a mean age of 53.4 years (32.1 to 64.1), who had
an identical prosthesis and articulation but with a prosthesis that
had no modularity at neck-stem junction. The mean blood levels of
cobalt in the study group were raised at 50.75 nmol/l (5 to 145)
compared with 5.6 nmol/l (2 to 13) in control patients. Corrosion at neck-stem tapers has been identified as an important
source of
Purpose: A ceramic head coupled to a metal liner is a proposed new alternate bearing in THA. The authors participated in an FDA approved multicentre prospective, randomized, blinded clinical trial comparing ceramic-on-metal (CoM) to metal-on-metal (MoM) in patients receiving a THA. Method: 390 patients received the same acetabular component and metal insert. 194 patients received a delta ceramic head (CoM) and 196 received a metal head (MoM).
As a result of the increased popularity of metal-on-metal bearings for total hip arthroplasty, concerns have been expressed about patient exposure to increased serum
Serum and blood cobalt (Co) and chromium (Cr) ion levels are used to monitor patients at risk for adverse reaction to metal debris (ARMD) following metal-on-metal (MoM) total hip arthroplasty (THA). However, these levels often do not correlate with the degree of local soft-tissue reaction and damage observed at the time of revision. The purpose of this study was to analyze synovial fluid
Introduction. Wear and corrosion of metal-on-metal (MM) bearings releases (a) soluble
Purpose of the study: Tribology studies of total hip arthroplasty (THA) have demonstrated that large diameter head in metal-on-metal bearings produce fewer wear particles than small diameter heads. The other advantages of this option are better stability, less dislocation, and optimal joint range of motion. The purpose of this work was to compare blood levels of chromium, cobalt and titanium six months and one year after implantation of different models of large diameter metal-on-metal THA. Material and methods: We conducted a retrospective comparative and randomised study including 110 patients who had been implanted with a larger diameter head THA/Zimmer? Smith and Nephez, Biomet or Depuy. The
This is a longitudinal study of the daily urinary output and the concentrations in whole blood of cobalt and chromium in patients with metal-on-metal resurfacings over a period of four years. Twelve-hour urine collections and whole blood specimens were collected before and periodically after a Birmingham hip resurfacing in 26 patients. All ion analyses were carried out using a high-resolution inductively-coupled plasma mass spectrometer. Clinical and radiological assessment, hip function scoring and activity level assessment revealed excellent hip function. There was a significant early increase in urinary metal output, reaching a peak at six months for cobalt and one year for chromium post-operatively. There was thereafter a steady decrease in the median urinary output of cobalt over the following three years, although the differences are not statistically significant. The mean whole blood levels of cobalt and chromium also showed a significant increase between the pre-operative and one-year post-operative periods. The blood levels then decreased to a lower level at four years, compared with the one-year levels. This late reduction was statistically significant for chromium but not for cobalt. The effects of systemic
Summary. Five year migration results of 49 large-head metal-metal (MoM) total hip arthroplasties show good implant stability and no association between implant migration and metal-ions levels, stem and cup position, or femoral bone mineral density. Introduction. The failure mechanism of metal-metal (MoM) total hip arthroplasty has been related to metal wear-debris and pseudotumor, but it is unknown whether implant fixation is affected by metal wear-debris. Patients and Methods. In July-August 2012 41 patients (10 women) at a mean age of 47 (23–63) years with a total of 49 MoM hip arthroplasties (ReCap Shell/M2a-Magnum head/Bi-Metric stem; Biomet Inc.) participated in a 5–7 year follow-up with blood tests (chrome and cobalt serum ions), questionnaires (Oxford Hip Score (OHS) and Harris Hip Score (HHS), measurement of cup and stem position and periprosthetic BMD. Further the patients had been followed with stereo-radiographs post-operative and at 1, 2 and 5 years for analysis of implant migration (Model-Based RSA 3.32). Results. 4 patients (6 hips) had elevated metal-ion levels (>7ug/l). The mean cup inclination was 45°(sd 6), the mean cup anteversion was 17°(sd7), and the mean stem anteversion was 19°(sd7). The difference between genders was statistically insignificant (p>0.09). At 5 years follow-up total translation (TT) for the stems (n=39 hips) was a mean 0.79mm (sd 0.53) and total rotation (TR) was a mean 1.99° (sd 1.53). Between 1–2 years there was no significant difference in mean TT (p=0.49)for the stems and between 2–5 years TT was mean 0.13 mm (sd 0.35) which was significant (p=0.03) but clinically very small and within the precision limits of the method. We found no significant migration along the 3 separate axes. There was no significant association between stem migration and
The aim of this study is to investigate whether Metal-on-Metal (MoM) implants result in more chromosome aberrations and increased blood
Summary. Management of metal on metal hip replacements can be accomplished with a simple algorithm including easily available
Bearing diameter and acetabular component orientation have been shown to be important variables effecting blood
The issues surrounding raised levels of metal
ions in the blood following large head metal-on-metal total hip replacement
(THR), such as cobalt and chromium, have been well documented. Despite
the national popularity of uncemented metal-on-polyethylene (MoP)
THR using a large-diameter femoral head, few papers have reported
the levels of