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Porous tantalum has been extensively used in orthopaedic surgery, including uncemented total knee arthroplasty (TKA). Favourable results were reported with earlier monobloc tibial components and the design evolved to modular implants. We aimed to analyse possible causes for extensive medial tibia bone loss, resulting in modular porous tantalum tibia baseplate fracture after primary TKA. Retrieved tissue samples were scanned with 3 MeV focused proton beam for Proton-Induced X-ray Emission (micro-PIXE) elemental analysis. Fractographic and microstructural analysis were performed by stereomicroscopy. A full 3D finite-element model was made for numerical analysis of stress–strain conditions of the tibial baseplate. Histological examination of tissue underneath the broken part of the tibial baseplate revealed dark-stained metal debris, which was confirmed by micro-PIXE to consist of tantalum and titanium. Fractographic analysis and tensile testing showed that the failure of the tibial baseplate fulfilled the criteria of a typical fatigue fracture. Microstructural analysis of the contact surface revealed signs of bone ingrowth in 22.5% of the surface only and was even less pronounced in the medial half of the tibial baseplate. Further studies are needed to confirm the responsibility of metal debris for an increased bone absorption leading to catastrophic tibial tray failure.

Hip prosthesis replacement is one of the most frequent and costly treatments in developed countries. The increased number of patients and the insufficient understanding of physiological processes leading to prosthesis failure make necessary the use of complementary techniques to better understand the degradation of implants [1]. We present two cases of prosthesis failure: Patient 2, with a modular hip prosthesis made of TiAlV alloy (Profemur®), presents a broken neck; and Patient 7, with a Ceramic on Ceramic articulation made of zirconia toughtened alumina (Biolox® Delta), presents a broken acetabular inlay. The presence of metallic debris coming from the prosthesis has been studied by using Particle-Induced X-ray Emission (PIXE). This technique combines high elemental sensitivity (detection limit 0,1 ppm) with high lateral resolution (600 nm) [2]. The analysis was performed with the 2 MV tandem accelerator available at Jožef Stefan Institute (JSI) [3]. [1] Fokter SK, et al., Acta Orthopaedica, 87(2), p.197-202, 2016. [2] P. Vavpetič et al., Nuclear Instruments and Methods in Physics Research B, vol. 306, pp. 140-143, 2013. [3] Primoz Pelicon et al., Nuclear Instruments and Methods in Physics Research B, vol. 332, pp. 229-233, 2014, This project, TISSUEMAPS, has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 799182.

Hip prosthesis replacement is one of the most frequent and costly treatments in developed countries. The increased number of patients and the insufficient understanding of physiological processes leading to prosthesis failure make necessary the use of complementary techniques to better understand the degradation of implants [1]. We present two cases of prosthesis failure: Patient 2, with a modular hip prosthesis made of TiAlV alloy (Profemur®), presents a broken neck; and Patient 7, with a Ceramic on Ceramic articulation made of zirconia toughtened alumina (Biolox® Delta), presents a broken acetabular inlay. The presence of metallic debris coming from the prosthesis has been studied by using Particle-Induced X-ray Emission (PIXE). This technique combines high elemental sensitivity (detection limit 0,1 ppm) with high lateral resolution (600 nm) [2]. The analysis was performed with the 2 MV tandem accelerator available at Jožef Stefan Institute (JSI) [3]. [1] Fokter SK, et al., Acta Orthopaedica, 87(2), p.197-202, 2016. [2] P. Vavpetič et al., Nuclear Instruments and Methods in Physics Research B, vol. 306, pp. 140-143, 2013. [3] Primoz Pelicon et al., Nuclear Instruments and Methods in Physics Research B, vol. 332, pp. 229-233, 2014

Hip prosthesis replacement is one of the most frequent and costly treatments in developed countries. The increased number of patients and the insufficient understanding of physiological processes leading to prosthesis failure make necessary the use of complementary techniques to better understand the degradation of implants [1]. We present two cases of prosthesis failure: Patient 2, with a modular hip prosthesis made of TiAlV alloy (Profemur®), presents a broken neck; and Patient 7, with a Ceramic on Ceramic articulation made of zirconia toughtened alumina (Biolox® Delta), presents a broken acetabular inlay. The presence of metallic debris coming from the prosthesis has been studied by using Particle-Induced X-ray Emission (PIXE). This technique combines high elemental sensitivity (detection limit 0,1 ppm) with high lateral resolution (600 nm) [2]. The analysis was performed with the 2 MV tandem accelerator available at Jožef Stefan Institute (JSI) [3]. [1] Fokter SK, et al., Acta Orthopaedica, 87(2), p.197-202, 2016. [2] P. Vavpetič et al., Nuclear Instruments and Methods in Physics Research B, vol. 306, pp. 140-143, 2013. [3] Primoz Pelicon et al., Nuclear Instruments and Methods in Physics Research B, vol. 332, pp. 229-233, 2014, This project, TISSUEMAPS, has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 799182.

Hip prosthesis replacement is one of the most frequent and costly treatments in developed countries. The increased number of patients and the insufficient understanding of physiological processes leading to prosthesis failure make necessary the use of complementary techniques to better understand the degradation of implants [1]. We present two cases of prosthesis failure: Patient 2, with a modular hip prosthesis made of TiAlV alloy (Profemur®), presents a broken neck; and Patient 7, with a Ceramic on Ceramic articulation made of zirconia toughtened alumina (Biolox® Delta), presents a broken acetabular inlay. The presence of metallic debris coming from the prosthesis has been studied by using Particle-Induced X-ray Emission (PIXE). This technique combines high elemental sensitivity (detection limit 0,1 ppm) with high lateral resolution (600 nm) [2]. The analysis was performed with the 2 MV tandem accelerator available at Jožef Stefan Institute (JSI) [3]. [1] Fokter SK, et al., Acta Orthopaedica, 87(2), p.197-202, 2016. [2] P. Vavpetič et al., Nuclear Instruments and Methods in Physics Research B, vol. 306, pp. 140-143, 2013. [3] Primoz Pelicon et al., Nuclear Instruments and Methods in Physics Research B, vol. 332, pp. 229-233, 2014

The metallic-associated adverse local tissue reactions (ALTR) and events accompanying worn-broken implant materials are still poorly understood on the subcellular and molecular level. Current immunohistochemical techniques lack spatial resolution and chemical sensitivity to investigate causal relations between material and biological response on submicron and even nanoscale. In our study, new insights of titanium alloy debris-tissue interaction were revealed by the implementation of label-free high-resolution correlative microscopy approaches. We have successfully characterized its chemical and biological impact on the periprosthetic tissue obtained at revision surgery of a fractured titanium-alloy modular neck of a patient with hip osteoarthritis. We applied a combination of photon, electron and ion beam micro-spectroscopy techniques, including hybrid optical fluorescence and reflectance micro-spectroscopy, scanning electron microscopy (SEM), Energy dispersive X-ray Spectroscopy (EDS), helium ion microscopy (HIM) and micro-particle-induced X-ray emission (micro-PIXE). Micron-sized wear debris were found as the main cause of the tissue oxidative stress exhibited through lipopigments accumulation in the nearby lysosome. This may explain the indications of chronic inflammation from prior histologic examination. Furthermore, insights on extensive fretting and corrosion of the debris on nm scale and a quantitative measure of significant Al and V release into the tissue together with hydroxyapatite-like layer formation particularly bound to the regions with the highest Al content were revealed. The functional and structural information obtained at molecular and subcellular level contributes to a better understanding of the macroscopic inflammatory processes observed in the tissue level. The established label-free correlative microscopy approach can efficiently be adopted to study any other clinical cases related to ALTR.