Revision of fractured ceramic-on-ceramic total hip replacements with a cobalt-chromium (CoCr) alloy-on-polyethylene articulation can facilitate metallosis and require further expensive revision surgery [1–3]. In the present study, a fifty-two year old male patient suffered from fatal cardiomyopathy after undergoing revision total hip arthroplasty. The patient had received a polyethylene-ceramic acetabular liner and a ceramic femoral head as his primary total hip replacement. The polyethylene-ceramic sandwich acetabular liner fractured in vivo after 58 months and the patient underwent his first revision surgery where he received a Vitamin E stabilized acetabular Polyethylene (PE) liner and a CoCr alloy femoral head with documented synovectomy at that time. After 15 months, the patient was admitted to hospital in cardiogenic shock, with retrieval of the bearing components. Before the second revision surgery, peak serum cobalt levels measured 6,521 μg/L, 78-times greater than serum cobalt levels of 83μg/L associated with cobalt poisoning [4]. Serum titanium levels found in the patient measured 17.5 μg/L) normal, healthy range 0–1.4 μg/L). The retrieved CoCr alloy femoral head had lost a total of 28.3g (24% or an estimated amount of 102 × 10. −9. wear particles (∼2 μm diameter) [1]) within 16 months of in vivo service. Despite initiating a cobalt chelating therapy, the patients' cardiac left ventricular ejection fraction remained reduced at 6%. This was followed by multi-organ failure, and ultimately the patient passed away shortly after being taken off life support. Embedded ceramic particles were found on the backside and articular surfaces of the Vitamin E-stabilized PE acetabular liner. Evidence of fretting wear on the titanium (Ti) alloy acetabular shell was present, possibly explaining the increased serum Ti levels. Scanning electron microscopy and energy dispersive X-ray analyses confirmed Ti alloy transfer on the embedded ceramic particles on the backside PE liner surface and CoCr alloy transfer on the embedded ceramic particles on the articular PE liner surface. A fractured ceramic-on-ceramic total hip replacement should not be revised to a CoCr alloy-on-polyethylene articulation irrespective of concurrent synovectomy [5] as it can cause severe, third-body wear to the CoCr alloy femoral head that can lead to metallosis with fatal, systemic consequences

Spondylodiscitis rarely coexists with endocarditis (around 5% of patients with endocarditis). Furthermore, viridans streptococci are not common pathogens of spondylodiscitis and finally the combination of spondylodiscitis and right – sided endocarditis due to viridans streptococci is rare. We present a case of right-sided native valve endocarditis due to Streptococcus mutans presenting as cervical and lumbar spondylodiscitis in a patient with obstructive cardiomyopathy. A 52 year – old man with a history of hypertrophic obstructive cardiomyopathy was admitted with fever and back pain of ten days duration, followed by torticollis. He had undergone dental therapy some weeks before symptom appearance, due to bad oral hygiene, without receiving any chemoprophylaxis. Magnetic resonance imaging revealed L4-L5 and C4-C5 spondylodiscitides. Four blood cultures drawn were all positive for Streptococcus mutans, while fine needle aspiration of the lumbar lesion was unsuccessful. Transesophageal echocardiogram revealed tricuspid and possible pulmonary valve vegetations. The patient was treated with ceftriaxone plus gentamicin for 2 weeks and then ceftriaxone only, for a total of 3 months. He had an uneventful recovery and was referred for cardiosurgical consultation. Physicians managing cases of spondylodiscitides should bear in mind to rule out endocarditis, especially in cases with underlying cardiopathy. The possibility of coexistence is even greater when there is sustained bacteremia and the pathogen isolated from blood cultures is a common pathogen for endocarditis

Over the past 15 years metal on metal hip resurfacing (MOMHR) has seen a spectacular resurgence in utilization followed by near abandonment of the procedure. A select group of surgeons still offer the procedure to a select group of patients suggesting that there are benefits of MOMHR over total hip arthroplasty (THA). This is problematic for the following reasons:. 1). MOMHR does not lead to increased survivorship. The Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the England and Wales National Joint Registry, from countries with high rates of utilization of MOMHR, both report significantly worse survivorship with MOMHR compared to all types of conventional THA. Risk factors for revision of resurfacing were older patients, females, smaller femoral head size, patients with developmental dysplasia, and certain implant designs. 2). MOMHR is associated with the generation of metal ions that can have devastating effects in some patients. Cobalt and chromium ions generated from MOMHR can result in adverse local tissues reactions around the hip, sometimes with catastrophic consequences, as well as neurological deficits, skin rashes, and cardiomyopathy. It is unclear as to which patients are at risk for the generation of high ion levels and less clear with respect to the host response to these ions. The discriminative and predictive values of ion testing are still being determined. MOMHR subsequently require careful follow-up with limited tools to assess risk and pending problems. 3). MOMHR is not less invasive. In order to deliver the femoral head for safe preparation and to access the acetabulum with the femoral head and neck in situ, significant dissection and retraction are required. The exposure issue is compounded as the procedure is most often performed in younger, larger males. Difficulty with exposure has been associated with an insult to the femoral head's blood supply that may lead to fracture and/or neck narrowing. 4). Preservation of the femoral canal with MOMHR does not improve outcomes of revision. The perceived advantage of preserved femoral head and neck implies that a conversion of a MOMHR to total hip should convey survivorship similar to primary THA. However, this is not the case as confirmed by data from the AOANJRR demonstrating worse survivorship of revised resurfacings when compared to a primary total hip arthroplasty. 5). MOMHR does not result in superior functional outcomes. Advocates for MOMHR often claim that the large femoral head and intact femoral neck in resurfacing results in a better functional outcome and therefore, a better quality of life and satisfaction when compared to a conventional THA. This, however, was not the case when gait speed, postural balance evaluations and functional tests were used in a randomised study of 48 patients, which failed to show an advantage of MOMHR over THA. In conclusion, it is relatively straightforward to oppose and argue against the use of hip resurfacings as they have worse outcomes in all National Joint Registries, produce metal ions with significant clinical consequences, are more invasive, are difficult to revise with subsequent inferior outcomes when compared to a conventional primary THA, and do not provide better function. These adverse features come with a premium price when compared to a conventional THA

Introduction. The use of metal-on-metal (MOM) and modular total hip arthroplasty (THA) is associated with potentially serious complications including elevated serum metal ion levels, pseudotumor, cardiomyopathy and neurologic abnormalities. The primary aim of this analysis was to identify any associations between the presence of pseudotumor, serum metal ion levels, and specific dual modular implant components. Methods. We evaluated prospectively collected data from 49 patients, mean age 58.4 years, who underwent implantation of modular THA from 01/2004-01/2010. The collected data spanned a 5–11 year period from the time of index procedure. Serum metal ion levels, including titanium, cobalt and chromium, were collected in 2012 and 2015. Hip ultrasounds were performed on each patient by a trained musculoskeletal radiologist for evaluation of the presence of soft-tissue pseudotumor. Univariate nonparametric tests were used to compare the two groups: Fisher's exact tests for categorical variables, and Wilcoxon two-group tests for continuous variables. For the purposes of analysis, values that were below the level of detection (LOD) were set to half the LOD. All analyses were performed using SAS 9.4 (SAS Institute Inc, Cary, NC, USA). Statistical significance is set at p<0.05. Results. Eight of 49 patients (16.3%) had pseudotumors on ultrasound examination. The average size measured 35.05 cm3 (7.35 cm3 – 130.81 cm3). In patients without pseudotumor, the serum levels (ng/mL) of titanium, cobalt and chromium were 3.2 ± 2.7, 4.4 ± 5.7 and 3.4 ± 4.9 in 2012 and 3.6 ± 4.9, 11.3 ± 33.7 and 5.3 ± 10.8 in 2015, respectively. Patients with pseudotumor had titanium, cobalt and chromium levels of 3.5 ± 2.3, 8.4 ± 8.7 and 6.2 ± 9.4 in 2012 and 4.1 ± 3.4, 6.0 ± 4.5 and 5.1 ± 6.4 in 2015. The ratio of cobalt to chromium was 1.6 ± 1.3 in 2012 and 1.8 ± 1.2 in 2015 in patients without pseudotumor and 2.1 ± 1.2 and 1.9 ± 1.3 with patients with pseudotumor, respectively. There was no statistical correlation between the presence of pseudotumor and age, component pairings (stem, neck and cup) and any of the serum metal ion levels. Discussion/Conclusion. In this prospective cohort study the incidence of pseudotumor was 16.3% in asymptomatic patients with modular THA. The presence of pseudotumor did not correlate with component pairings, serum metal ion levels or cobalt to chromium ratios