Immunoglobulin A Nephropathy in a Patient With Bilateral Metal-on-Metal Hip Arthroplasty.

Immunoglobulin A (IgA) nephropathy in the presence of a metal-on-metal (MoM) hip arthroplasty is a rare condition that requires close monitoring. A 61-year-old male with bilateral hip osteoarthritis underwent resurfacing hip arthroplasty with MoM articulating surfaces. Prior to his four-year postoperative visit, the patient was diagnosed with IgA nephropathy. During this visit, the patient reported clicking in the left resurfacing hip arthroplasty, and serum metal ions were significantly elevated. Consequently, the patient underwent conversion to bilateral ceramic-on-cross-linked polyethylene total hip arthroplasty, which resulted in the restoration of metal ion levels to normal. This case highlights that IgA nephropathy played a critical role in impeding the clearance of metal ions. Routine metal ion counts are warranted in patients with MoM articulating interfaces and a newly diagnosed nephropathy.

Magnum metal-on-metal uncemented total hip replacement: 8- to 18-year outcomes of 211 cases.

BACKGROUND: Reports of adverse reactions to metal debris contributed in part to a decline in use of large-bearing metal-on-metal total hip devices. We hypothesize an optimal trunnion design may reduce risk of this failure mode in large-bearing total hip arthroplasty systems. The purpose of this study is to report mid- to long-term outcomes for a single-surgeon series of 211 total hip arthroplasties using the large-bearing Biomet Magnum metal-on-metal system. MATERIALS AND METHODS: Between December 2004 and January 2016, the primary surgeon performed 211 uncemented Magnum total hip arthroplasties in 181 patients. The average length of follow-up was 10.1 ± 3.5 years (range 8-18 years). RESULTS: Using failure of any component as the endpoint, the overall survivorship rate was 98.1% at 10 years and 97.4% at 18 years. These eight failures (3.8% of cohort) included one case of adverse wear-related failure (0.5%), two cases of acetabular ingrowth failure (0.9%), three cases of trunnion corrosion (1.4%), one failure of late infection (0.5%), and one inappropriate revision of components for trochanteric nonunion without instability (0.5%). Excluding failed cases, all components were radiographically stable with no radiolucencies. Except for the one wear failure, ion testing revealed that 97.2% of cases were within optimal whole blood metal ion levels with the remaining ion test results within acceptable levels. CONCLUSIONS: With the uncemented Magnum metal-on-metal total hip, we achieved 97.4% 18-year implant survivorship, exceeding the NICE criteria and registry benchmarks for implant survivorship. We observed a trunnion corrosion rate of 1.4% and no cases of instability. The single case of adverse wear-related failure was caused by acetabular component malposition.

Under-reporting by surgical pathologists in tissue removed during revision surgery for metal-on-metal arthroplasties.

Although adverse local tissue reactions (ALTR) have been reported for metal-on-metal implants (MoM) requiring early revision surgery, no study has looked at the accuracy of surgical pathologists in diagnosing ALTR. This study aims to investigate the accuracy of reporting adverse local tissue reactions in tissue samples following revision surgery from metal-on-metal implants. The authors reviewed histology glass slides as well as the original pathology reports of tissue processed in revision arthroplasties in 23 cases. These samples were microscopically analyzed for tissue necrosis and cystic degeneration, the presence of metal particles, corrosion byproducts, membrane formation, histiocytic cells, lymphocytic cells, and vascular pathology. The authors' findings were then compared to their corresponding original pathology reports. The authors found consistent under-reporting of the tissue findings. Most importantly, 18 samples showed evidence of metal present compared to 2 samples on original pathology reporting. The authors found that 15 samples showed evidence of pathological membranous tissue compared to just 6 on original pathology reporting. While just 3 of the original pathology reports indicated the presence of areas of predominantly lymphocytic inflammatory cells, the authors found 13 examples of such areas. Although ALTR reactions have been described as a sequala of failed MoM, the authors' data suggest that ALTR may occur more frequently than previously described. Under-reported findings of ALTR deprive both the patient and orthopaedic surgeon of important information that can help guide further follow-up.

Assessing the Effects and Challenges of Total Hip Arthroplasty before Pregnancy and Childbirth: A Systematic Review.

Total hip arthroplasty is indubitably one of the most performed operations worldwide. On the other hand, especially in the western world, the average age that women get pregnant has raised confoundedly. Consequently, a steadily increasing number of women become pregnant after they had hip arthroplasty surgery, with copious potential implications. The amount of knowledge on this particular field is considered inadequate in the existing literature. This paper aims to augment clinicians understanding surrounding this topic. A systematic literature review was conducted in accordance with the PRISMA guidelines. Papers from various computerized databases were scrutinized. Article selection was carried out by three authors independently employing specific pre-determined inclusion and exclusion criteria, while disagreements were elucidated with the contribution of other authors. A patently limited number of research articles were detected from our rigorous literature review, with only 12 papers meeting the inclusion criteria. The vast majority of studies were small-scale and examined confined population groups. Most studies had been performed in Finland, utilizing data from nationwide registries. Women with previous history of total hip arthroplasty feature increased rates of c-section delivery, although vaginal labor can be attempted with certain precautions. Hip implants' survival does not appear to be affected from gestation, which is predominately well-tolerated from these women. Metal ion circulation in mothers' blood has not been proven to trigger substantial complications concerning either mothers or offspring. It can be considered safe for women with such medical history to get pregnant; however, further multinational studies and pertinent research on this field are vital to attain more solid inferences.

Long-Term Outcome of Metal-on-Metal Total Hip Arthroplasty with Modular Neck Stem.

Background: This study aimed to report the long-term outcomes of total hip arthroplasty (THA) using a Conserve Plus (Wright Medical, Japan) metal-on-metal (MoM) acetabular prosthesis with a modular neck stem. Methods: This study enrolled 50 patients (10 men and 40 women; mean age, 65.8 (39-87) years) who underwent primary THA using a Conserve Plus MoM acetabular prosthesis with a modular neck stem. The preoperative diagnosis in most patients was osteoarthritis. Clinical function of hip joint outcomes was investigated using the Japanese Orthopedic Association (JOA) hip score preoperatively and at the final follow-up. The perfect JOA hip score was 100, while the worst score was 0. Radiological analyses were evaluated during the final follow-up visit. Magnetic resonance imaging (MRI) images were evaluated to screen for pseudotumors in 43 hips postoperatively. Results: Six patients did not visit before their 10-year follow-up for unknown reasons. Therefore, 44 patients were evaluated at a mean of 11-years of follow-up (10-12 years). The mean (±SD) preoperative JOA hip score of 44.2 (±15.5) improved significantly to 85.1 (±12.9) postoperatively at the final follow-up (n = 36 hips, excluding eight revision cases). One patient underwent femoral fixation for a periprosthetic fracture due to trauma that occurred 4 years postoperatively. Spot welds were identified in 93.2% (41/44 hips) of cases. Severe (third- and fourth-degree) stress shielding was identified in 40.9% (18/44 hips) of cases. Twenty-two patients (51.2%) had pseudotumors attributable to MoM articulation based on MRI results, 2 to 10 years after arthroplasty. Three hips showed cup osteolysis (7%) and three showed trochanteric region osteolysis (7%). There were seven cup and/or three stem revisions for aseptic loosening and/or osteolysis at 4 months (with trauma) and 3.3 to 11 years (with pseudotumor) postoperatively. The Kaplan-Meier survivorship for the THA construct in this group was constant at 93.0% and 75.9% at 10 and 12 years after arthroplasty, respectively. The rates of survivorship of revision and loss of follow-up at 10 and 12 years were 83.9% and 66.8%, respectively. Conclusions: In summary, we reported on the long-term treatment results of MoM THA, precautions based on our cohort's findings, and the measures taken to address these issues, such as revision replacement and its outcomes. Clinical scores revealed good outcomes during the mean 11-year follow-up period. However, the prevalence of pseudotumors (PTs) was 51.2%. Some cases required revisions even after the 10 years following surgery. This is because in MoM THA, PT occurrence increases over time, and as a result, there were cases in which revised THA was required even after 10 years.

Influence of Physical Activity and Cup Orientation on Metal Ion Release and Oxidative Stress in Metal-on-Metal and Ceramic-on-Metal Total Hip Arthroplasty.

BACKGROUND: Metal-on-metal (M-M) total hip arthroplasty (THA) has shown adverse reactions to metal debris, abnormal soft-tissue reactions, and high blood metal ion levels. This study aims to: (1) assess whether the toxicity of high levels of ions is related to altered oxidative stress and (2) evaluate tribological factors related to increased blood levels of chromium (Cr) and cobalt (Co) ions. METHODS: A cross-sectional analytical descriptive study was conducted on 75 patients. A total of 25 underwent M-M THA, 25 ceramic-on-metal (C-M) THA, and 25 were on the THA waiting list. Ion metallic levels in blood, oxidative stress, physical activity, and implant position were compared. RESULTS: In the M-M group, Co and Cr levels were significantly higher than those found in the C-M group and the control group (p < 0.01). We found no differences in terms of oxidative stress between the groups. Also, we did not find a correlation between metal blood levels and oxidative stress indicators, the physical activity of the patients or the position of the implants between groups. CONCLUSIONS: The use of M-M bearing surfaces in THA raises the levels of metals in the blood without modifying oxidative stress regardless of the physical activity levels of the patients. Therefore, although patients with M-M bearings require close monitoring, it does not seem necessary to recommend the restriction of physical activity in patients with M-M or C-M arthroplasties.

Quantification and severity grading of femoral vessel compression by adverse reactions to metal debris in metal-on-metal total hip arthroplasty.

INTRODUCTION: Metal-on-metal (MoM) total hip arthroplasty (THA) may cause adverse reactions to metal debris (ARMD). ARMD causing femoral vessel compression with serious complications has been described in case reports, but the rate of compression by ARMD is not known. This study aims to investigate the rate, and quantify the severity, of femoral vessel compression in MoM hips with ARMD lesions. METHODS: Patients under surveillance for MoM THA investigated with MRI were studied. In patients with confirmed ARMD, femoral artery (FA) and vein (FV) diameters were measured at the point of maximal compression and compared to contralateral vessels. The primary outcome measure was presence or absence of compression. Cases were then classified by compression ratios. Secondary outcome measures were rates of deep vein thrombosis, revision surgery and time to ARMD from index procedure. RESULTS: MRI scans for 436 patients with MoM THA were screened. Of these, 211/436 (48.4%) showed evidence of ARMD. Measurements were obtained on 133/211 (63.0%) patients. The FV was compressed in 102/133 (76.7%) and FA in 58/133 (43.6%), while 31/133 (23.3%) patients had no compression. In FVs, 42 demonstrated mild compression, 39 moderate and 21 severe. In FAs, none were severely compressed, 6 were moderate and 52 showed mild compression. There were 3 DVT cases, 2 in patients with moderate FV compression and 1 in patients without FV compression. Revision rates were highest in patients with severe FV compression (14/21, 66.7%). The mean time for MRI-diagnosed ARMD from index procedure was 8 years and 1 month (range 11 months-14.5 years). CONCLUSIONS: Extra-luminal compression of the femoral vessels was found in >75% of patients with ARMD. Although it is not clear whether revision for femoral vessel compression is required, quantification of FV compression may be useful for surgeons and radiologists considering revision for ARMD.

Hypersensitivity to metals in metal-on-metal hip arthroplasty: a prospective study of one hundred and thirty five lymphocyte transformation tests.

BACKGROUND: Metal allergy remains a controversial topic in the orthopaedic community. It is not known if or to what degree metal sensitivity contributes to inflammatory soft tissue failures, unexplained residual pain, or clinical complications after total joint replacement with metal prostheses. METHODS: We investigated the efficacy of the lymphocyte transformation test (LTT) in predicting adverse outcomes in patients after receiving a metal joint replacement. Our study cohort consists of 135 metal-on-metal hip resurfacing arthroplasty cases performed between 2013 and 2015. All study patients had an LTT preoperatively. We retrospectively analyzed clinical outcomes and failures for our cohort. RESULTS: There was no difference in LTT reactivity between men and women. Of the 135 patients tested, 46 (34.1% of cohort) tested positive to at least one of the materials comprising their implant, and 78 patients (57.8%) had at least one reactive score to any component of the LTT. After a minimum follow-up of two years, we did not observe an allergic response to the implant in any patients. There were no failures requiring revision. We observed a 2.2% rate of moderate residual pain; no patients with residual pain tested positive for metal sensitivity. When patients with moderate-high LTT reactivity (30.4% of cohort) were compared to the remainder of the study group, there was no difference in HHS or UCLA activity score. There was no correlation between blood metal ion levels and LTT reactivity. CONCLUSION: We were unable to prove any predictive value of the LTT. We failed to identify hypersensitivity to metals in patients with metal-on-metal hip resurfacing arthroplasty.

Metal-on-Metal Hip Arthroplasty: A Comprehensive Review of the Current Literature.

Metal-on-metal (MoM) total hip arthroplasty has been widely used since the end of the 20th century, although rates have now decreased due to concerns regarding adverse reactions and failure rates. The MoM implant has been replaced with other materials, such as ceramic-on-ceramic (CoC) and metal-on-polyethylene (MoP). This literature review looks at the past and present use of MoM prostheses to assess whether the turn away from MoM use is justified. Online literature searches were performed on PubMed, Ovid Medical Literature Analysis and Retrieval System Online (MEDLINE), and Web of Science online databases using the search terms "MoM and (ARMD and ALVAL)" (ARMD: adverse reaction to metal debris; ALVAL: aseptic lymphocyte-dominant vasculitis-associated lesion). A total of 64 relevant titles were included in the review. Although risk factors for adverse reactions and the causes of ARMD are generally agreed upon, more work is required to further understand the specific thresholds of blood metal ion levels that can be used to consistently identify ARMD and excessive metal wear-debris in patients who have not had their MoM implants revised. Metal-on-metal devices are not an acceptable option for total hip arthroplasties (THAs) in their current formulation due to the high rate and risk of ARMD. Some MoM hip resurfacing operations are appropriate for very carefully selected patients who are fully aware of the risks posed by the implant. It is recommended that device-specific thresholds for metal ion levels be developed to identify patients at risk of ARMD locally and systemically while using auxiliary tools to assist diagnosis, such as metal artefact reduction sequences (MARS)-MRI and hip scoring tools. Further work should investigate device-specific blood metal ion levels, the systemic effects of raised metal ion concentrations secondary to MoM arthroprosthetic wear, and the potential risks of ARMD caused by wear from tapered stems (including the implications this has for patients with CoC and MoP prostheses).

Reactive Peri-Arthroplasty Pseudotumors: A Rare Cause of Hip Pain and Iatrogenic Sciatica.

Total hip arthroplasty (THA) is the preferred treatment for patients with hip joint disorders refractory to conservative management. While original implants were designed to articulate a metallic femoral head onto a polyethylene liner, the popularity of "metal-on-metal" (MoM) hip implants surged in the early 21st century due to their perceived superior long-term durability and lower revision rates. However, subsequent follow-up studies showed high failure rates due to inflammatory responses to periprosthetic metallic debris leading to lymphocytic proliferation, soft tissue necrosis or fibrosis, systemic metal toxicity, and/or the development of cystic pseudotumors. Although these discoveries resulted in a significant decrease in MoM THA and revision procedures, the majority of MoM hip implants persist in the adult population. In this case report and review, we report the presentation, diagnostic work-up, and management of an 84-year-old status-post MoM THA who presented with unilateral leg tenderness and poor ambulation secondary to pseudotumor-induced sciatica.

Revision Arthroplasty for Bilateral McKee-Farrar Hip Prostheses 48 Years Following Implantation.

The McKee-Farrar hip prosthesis gained popularity in the 1960s and was one of the first widely used prostheses to employ a metal-on-metal design. Eventually, it laid the framework for the development of second and third-generation hip replacement prostheses. In time, the McKee-Farrar prosthesis was found to have high rates of early aseptic loosening and fell out of favor, especially with the development of the Charnley low-friction metal-on-polyethylene design. We present an interesting case of a patient who underwent bilateral total hip arthroplasty with a McKee-Farrar hip prostheses at the young age of 28 years, in view of secondary hip osteoarthritis resulting from ankylosing spondylitis. The implants lasted approximately 48 years after initial implantation in this case, which is an unusually long survival of this prosthesis. He presented to us at the age of 76 years with groin pain and difficulty to weight-bear, worse on the right side. Significant osteolysis around the acetabular component was noted, greater on the right side. Infection was excluded, and the patient underwent staged revision bilateral hip replacements one year apart. Extraction of the femoral components on both sides was done with the aid of extended trochanteric osteotomies. For both revisions, uncemented acetabular revision shells (TMARS, Zimmer Biomet, Warsaw, Indiana) were used for the acetabulum and long uncemented diaphyseal engaging interlocked stems (Arcos ILS, Zimmer Biomet) were used for the femoral side. No complications were encountered during the procedures. The patient made excellent progress following the procedures with immediate weight-bearing, as tolerated, and physiotherapy input. No subsequent postoperative complications occurred till the time of the patient's death five years later from unrelated medical causes. It is rare to encounter and revise the McKee-Farrar prosthesis in modern orthopaedic practice. This, to the best of our knowledge, is the longest-described survival of this prosthesis in literature.

Metal-on-metal (MoM) hip implants and pregnancy: are MoM implants good for mom?-a systematic review.

Metal-on-metal (MoM) bearing surfaces were historically used for young patients undergoing total hip arthroplasty (THA), and remain commonplace in modern hip resurfacing. A substantial number of female patients with MoM bearings subsequently gave birth following implantation of the bearings before a full understanding of metal ions exposure in these patients was established. In theory, it has been postulated that metal ions released from such implants may cross the placental barrier and cause harm to the fetus. In light of this potential risk, recommendations against the use of MoM components in women of child-bearing age have been advocated. The purpose of this systematic review was to evaluate: (I) the MoM bearing types and ion levels found; (II) the concentrations of metals in maternal circulation and the umbilical cord; and (III) the presence of abnormalities in the fetus or delivered child. A comprehensive literature review was conducted of studies published between January 1st, 1975 and April 1st, 2019 using specific keywords. We defined the inclusion criteria for qualifying studies for this review as follows: (I) studies that reported on the women who experienced pregnancy and who had a MoM hip implant; (II) studies that reported on maternal metal ions blood and umbilical cord levels; and (III) studies that reported on the occurrence of fetal complications. Data on cobalt and chromium ion levels in the maternal blood and umbilical cord blood, as well as the presence of adverse effects in the infant were collected. Age at parturition and time from MoM implant to parturition were also collected. A total of six studies were included in the final analysis that reported on a total of 21 females and 21 infants born. The mean age at parturition was 31 years (range, 24 to 41 years), and the mean time from MoM implantation to parturition was 47 months (range, 11 to 119 months). Maternal blood cobalt levels were found as a weighted average of 34.09 µg/L (0.425 to 138 µg/L), while umbilical cord blood cobalt levels were found to be 22.61 µg/L (0.52 to 51.11 µg/L). Cobalt levels were reduced by an average of 34% between maternal and umbilical cord blood. Maternal cord blood chromium levels were found as a weighted average of 18.18 µg/L (0.225 to 75 µg/L), while umbilical cord chromium levels were found to be 3.96 µg/L (0.14 to 11.96 µg/L). Chromium levels were reduced by an average of 78% between maternal and umbilical cord blood. No cobalt or chromium was detected in the umbilical cord blood of three patients. Out of the 21 infants born to women with MoM implants, 20 were born healthy with no adverse effects or complications. Only one complication was recorded in single infant that did not appear to be related to the maternal MoM implant. To date, there is a lack of consensus as to whether MoM hip arthroplasty implants are to be avoided in the child-bearing female population and whether they constitute a hazard to the fetus in utero. Both chromium and cobalt ions were markedly reduced in levels when transitioning from maternal to cord blood. In particular, chromium showed a greater reduction on average than cobalt (78% vs. 34%). Based on the current evidence, there appears to be no correlation between the presence of metal ions in umbilical cord blood and complications, as none of the infants experienced abnormalities uniquely attributable to the presence of metal ions.

How to Manage Metallosis: A Retrospective Cohort Analysis after Revision Hip Surgery.

BACKGROUND: Adverse local tissue reactions to metal debris are due to a metal-on-metal bearing complication caused by micromotions at modular interfaces that induce corrosion of the protective oxide layer. This process could lead to wear, fretting, and abrasion with the release of metal ions locally and systemically, which may cause adverse local reactions in nearby tissues. The aim of this study is to describe a series of patients with painful local adverse tissue reactions secondary to corrosion at the modular neck-body interface, to document the clinical presentation, diagnostic workup, and surgical findings of our research, and to search for a possible correlation between metallosis and infection. METHODS: A retrospective study of patients with adverse local tissue reactions due to metal surface corrosion was performed. Blood samples were collected to identify erythrocyte sedimentation rate, C reactive protein, and procalcitonin, and a magnetic resonance imaging protocol was performed. RESULTS: Serum cobalt and chromium levels of the 43 patients tested were significantly higher on average. However, both erythrocyte sedimentation rate and C-reactive protein were significantly elevated. Magnetic resonance imaging showed adverse reactions to metal debris with large soft tissue masses and surrounding tissue damage. CONCLUSIONS: Corrosion in hip prosthesis can lead to the release of metal ions and debris locally and systemically, resulting in local soft tissue changes. A "tumor-like" debridement can reduce this complication.

Hip Resurfacing Arthroplasty: Past, Present and Future.

The history of hip resurfacing arthroplasty (HRA) has faced numerous challenges and undergone decades of evolution in materials and methods. These innovations have been translated to the successes of current prostheses and represent a surgical and mechanical achievement. Modern HRAs now have long term outcomes with excellent results in specific patient groups as demonstrated in national joint registries. This article reviews the key moments in the history of HRAs with specific emphasis on the lessons learnt, current outcomes and future prospects.

Long-term Follow-up on Revisions of a Recalled Large Head Metal-on-metal Hip Prosthesis: A Single Surgeon Series.

Background: In 2010, a recall was issued for a specific monoblock large head metal-on-metal (MoM) hip prosthesis due to short-term revision rates of 12%-13% (articular surface replacement, DePuy Orthopaedics, Inc., Warsaw, IN). High complication, infection, and rerevision rates for revised MoM implants have been reported. The purpose of the study is to report long-term outcomes and trend metal ion levels of this recalled MoM prosthesis from a single surgeon series. Methods: Retrospective chart review was performed on all patients that underwent revision of large MoM hip replacements between 2010 and 2015. Pre- and post-revision Harris Hip Score (HHS), cup abduction angles, anteversion angles, and cup sizes were compared. Survivorship and HHS were the primary outcomes measured; serum cobalt and chromium levels were secondary outcomes. Multivariate linear regression was used to examine the correlation between prerevision serum metal ion levels and HHS. Results: A total of 24 hips (21 patients) met inclusion criteria. Mean time to revision was 4.12 years ± 1.1. Mean follow-up was 10.0 years (7-11.9 years). Mean HHS increased significantly after revision from 48.5 to 89.5 (P < .001). Higher prerevision cobalt levels were correlated with lower prerevision HHS (cobalt R = 0.25; chromium R = 0.3160). There was no correlation with prerevision cobalt (P = .2671) or chromium (P = .3160) with postrevision HHS. Most recent metal ion testing revealed a significant decrease in both cobalt (P = .0084) and chromium (P = .0115). Survival rate is 100%. Conclusions: Our study showed excellent survivorship and outcomes at 10 years. There were no failures for any reason including infection. This differs from previous studies and confirms excellent long-term results are possible with revision of this recalled MoM implant.

Mid-term clinical and radiographic outcome of metal-on-metal hip resurfacing through an anterolateral approach.

PURPOSE: The aim of this retrospective study was to evaluate the medium-term clinical and radiographic results of current generation metal-on-metal resurfacing prostheses performed through anterolateral approach. MATERIALS AND METHODS: Fifty-seven hips in 52 patients underwent resurfacing arthroplasty. Two patients died from unrelated causes, leaving 55 hips in 35 males (3 bilateral) and 15 females (2 bilateral), with a mean age at surgery of 56.2 years (range, 27-70 years). Clinical and radiographic assessment was carried out preoperatively and at follow-up in all the survived cases. The cumulative survival rate was determined according to the method of Kaplan-Meier. RESULTS: At a mean follow-up of 5.2 years (range, 1.8-9.1 years), 2 HRs of the same female patient were revised because of early loosening of the acetabular component. Deep venous thrombosis and transient femoral nerve palsy occurred both in 1 case. No specific complications of HR were observed. Average Harris hip score improved significantly from 59.8 points (range, 30.4-90.6) preoperatively to 93.7 points (range, 53-100) at the latest examination. Neck narrowing showed an average of 3.27%, but it never exceeded 10%. Nonprogressive acetabular radiolucencies and osteolysis were detected both in 2 hips. A high rate of patients (32, 60.4%) developed heterotopic ossifications, although low-grade in most cases (27, 84.4%). The cumulative survival rate at 9.1 years with revision for any reason as the end point was 93.0%. CONCLUSIONS: The early clinical and radiographic results of modern metal-on-metal hip resurfacing performed through an anterolateral approach are promising, but longer-term follow-up studies are necessary.

From embodiment to evidence: The harmful intersection of poor regulation of medical implants and obstructed narratives in embodied experiences of failed metal-on-metal hips.

This research presents the results of a study about people with failed metal-on-metal hip implants, and draws on the STS concept of the technological imperative alongside research on the value of patient knowledge in clinical settings and the legitimacy of embodied stories. Popularly understood as positive and life changing, hip replacement surgery was hailed as 'the operation of the century', until a series of widespread failures of hundreds of thousands of hip implants, known collectively as metal-on-metal (MoM) hips, drew attention to the poor regulation of medical implants. This paper argues that poor regulation intersects with narratives of patients' pain, which are obstructed by surgeons and the UK regulatory body, with the effect of denying both patients' embodied experiences of implant failure, and their restitution to good health. Patient narratives about problems with their hip implant are the wellspring from which scientific evidence emerges which can indicate widespread implant failure. By obstructing these narratives the regulatory system undermines the very evidence it needs to operate effectively.

Strategies for fixation of periprosthetic fragility fractures of the neck of femur below a well-functioning hip resurfacing arthroplasty: A case-series.

Introduction: Metal-on-metal Hip Resurfacing (HR) was performed in many young individuals as it conserved bone stock and had low wear rates, before it became less popular due to the detection of Adverse Reactions to Metal Debris. As such, many patients in the community have well-functioning HRs and as they age, the incidence of fragility fractures of the neck of femur around the existing implant is expected to increase. These fractures are amenable to surgical fixation as adequate bone stock remains in the head of the femur and the implants are well fixed. Case-series: We present a series of six cases which were treated by fixation using locked plates (3), dynamic hip screws (2) and cephalo-medullary nail (1). Four cases achieved clinical and radiographic union with good function. One case had a delayed union, though union was finally achieved at 23 months. One case had an early failure necessitating revision to a Total Hip Replacement after 6 weeks. Discussion: We highlight the geometrical principles of placing fixation devices under an HR femoral component. We have also conducted a literature search and present details of all case reports to date. Conclusion: Fragility per-trochanteric fractures under a well-fixed HR with good baseline function are amenable to fixation using a variety of methods including large screw devices that are commonly used in this location. Locked plates including variable angle locking designs should be kept available if needed.

Metal-on-metal metaphyseal and ceramic-on-ceramic femoral neck arthroplasty: the impact on clinical results, oxidative stress and concentration of metal ions in serum and blood.

PURPOSE: Growing number of hip arthroplasty in Poland performed with the use of metaphyseal stems results from the decreasing age of patients qualified for procedures and is consistent with the corresponding trends in European countries. To this day, a significant population functions after undergoing hip replacement using metal-on-metal implant. This study was aimed at the assessment of the variability of the oxidative system, as well as the concentrations of chromium and cobalt ions in serum and blood and their potential impact on postoperative clinical status. MATERIAL AND METHODS: The analysis included 58 men. The first group-operated using J&J DePuy ASR metal-on-metal implant with metaphyseal stem ProximaTm. Second group-operated using K-Implant SPIRON® femoral neck prosthesis in full ceramic articulation. Selected parameters of oxidative stress and the antioxidant system as well as the concentration of metal ions in blood were determined twice. Each patient underwent two clinical evaluations using acclaimed physical examination scale systems. RESULTS: In the first group, significantly higher concentrations of Cr (p = 0.028) and Co (p = 0.002) were demonstrated compared to the group of femoral neck arthroplasty. The mean concentrations of Cr and Co, 10.45 and 9.26 µg/l, respectively, were higher in patients operated bilaterally. In the ASR group, greater pain intensity in the operated hip and higher indicators of oxidative stress were found. CONCLUSIONS: Metal-on-metal articulation of the hip significantly increases the concentration of Cr and Co in blood, induces oxidative stress and modifies function of the antioxidant system and generates greater pain in the operated hip.