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Background It has recently been found that some metal-on-metal (m-o-m) friction arthroplasties may produce a variety of clinical alterations because of the presence of metal ions, especially chromium (Cr) and cobalt (Co), in blood and urine. These complications may cause general or local damage known as ALVALs (aseptic lymphocyte-dominant vasculitis-associated lesions). Patient monitoring involves several analytical and imaging tests that increase the patient’s follow up costs. Purpose To draw attention to the possibility of detecting metal ions in patients’ hair by ICP-MS (Inductively Coupled Plasma Mass Spectrometry) as a cheaper method of screening versus double analysis of blood and urine. Materials and methods Cr and Co levels in serum and urine, and Cr, Co, and Mo levels in hair were analysed in 45 patients who had metal-on-metal hip resurfacing arthroplasties (DePuy ASR). Metal quantification was performed with a high-resolution and double-focus ICP-MS. Samples were taken 3 times (months 0–6–12). Hair samples were taken by trained non-specialised personnel. Results The mean ion metal levels were: Cr 163.27 (SD 300.62), Co 61.98 (SD 126.48) in hair; Cr 8.29 (SD 17.97), Co 8.38 (SD 21.97) ppb in serum; and Cr 16.20 (SD 190.86), Co 75.40 (SD 190.86) ppb in urine. The total analyses in hair involve a cost of 2,997 € whilst the double analysis in blood and urine increases the cost to 5,994 €. The cost per element and sample was 7.4€. Conclusions We have demonstrated that metal ions in hair are a biomarker that allows the detection of ion levels in higher amounts (ppm), versus serum or urine (ppb). In addition, it is an interesting screening method in patients with ASR devices (since several agency alerts have warned against the use of these prostheses) because it is an easier, safer technique. Hair collection does not require highly trained personnel and is therefore cost effective. No conflict of interest.

Background The use of metal on metal prostheses (m-o-m) emerged in the last decade because the problem of polyethylene wear was avoided and they were supposed to have better survival rates. A meta-analysis reported survival rates of 95% for m-o-m prosthesis versus 92% for metal on polyethylene (m-o-p) and 88.9% for metal on ceramic. Several studies reported that wear rate in young, active patients was lower with m-o-m prosthesis. Purpose The main endpoint of this study was to assess the survival rate of m-o-m DePuy ASR devices and to analyse the principle causes of hip prosthesis failure. Another point of interest was to estimate the economic impact of revision surgery. Materials and methods Patients with DePuy ASR systems were recruited to analyse the incidence of failure. The global economic impact of revision surgery was estimated on the basis of the average costs of this kind of procedures, including indirect costs (10,000 € peri-surgical intervention). Results Eleven out of forty-five patients (two women) with DePuy ASR devices underwent revision surgery. Their average age was 57.5 years (35–76) and their BMI was 29.42 (19.48–43.58). The prosthesis failure was caused by: femur fracture (n = 2, 18.2%), relapsing luxation (n = 1, 9.1%), metallosis (n = 5, 45.4%) and unexplained pain (n = 3, 27.3%). The estimated cost of revision surgery in these eleven cases was up to 110,000 €. Conclusions The survival rate of DePuy ASR devices is significantly lower in m-o-m ASR prostheses compared to other m-o-m models, even lower than in m-o-p systems. It would be necessary to follow up the appearance of adverse reactions to health products in order to know their real performance. The sooner we detect these failures the better we can choose better alternatives. No conflict of interest.

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