For the improvement of surface roughness, titanium joint arthroplasty (TJA) components are grit-blasted with Alsub.2Osub.3 (corundum) particles during manufacturing. There is an acute concern, ...particularly with uncemented implants, about polymeric, metallic, and corundum debris generation and accumulation in TJA, and its association with osteolysis and implant loosening. The surface morphology, chemistry, phase analysis, and surface chemistry of retrieved and new Alsub.2Osub.3 grit-blasted titanium alloy were determined with scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and confocal laser fluorescence microscopy, respectively. Peri-prosthetic soft tissue was studied with histopathology. Blasted retrieved and new stems were exposed to human mesenchymal stromal stem cells (BMSCs) for 7 days to test biocompatibility and cytotoxicity. We found metallic particles in the peri-prosthetic soft tissue. Ti6Al7Nb with the residual Alsub.2Osub.3 particles exhibited a low cytotoxic effect while polished titanium and ceramic disks exhibited no cytotoxic effect. None of the tested materials caused cell death or even a zone of inhibition. Our results indicate a possible biological effect of the blasting debris; however, we found no significant toxicity with these materials. Further studies on the optimal size and properties of the blasting particles are indicated for minimizing their adverse biological effects.
We investigated micro-threaded stem taper surface and its impact on premature failures, aseptic loosening, and infection in cementless hip endoprostheses. Our study focused on the fretting, and ...crevice corrosion of micro-threaded tapers, as well as the characterization of the microstructure and surface properties of two new and three retrieved Zweymüller stem tapers. The retrieved samples were selected and examined based on the head–stem taper interface being the sole source of modularity with a metallic component, specifically between the Ti alloy taper stem and the ceramic head. To determine the surface chemistry and microstructures of both new and retrieved hip endoprostheses stem taper titanium alloy, scanning -electron microscopy (SEM) was employed for morphological and microstructural analyses. Energy dispersive spectroscopy (EDS) was utilized for characterizing chemical element distribution, and electron backscattered diffraction (EBSD) was used for phase analysis. The roughness of the micro-threated stem tapers from different manufacturers was investigated using an optical profilometer, with standard roughness parameters Ra (average surface roughness) and Rz (mean peak to valley height of the roughness profile) being measured. Electrochemical studies revealed no fretting corrosion in retrieved stem tapers with ceramic heads. Consequently, three retrieved tapers and two new ones for comparison underwent potentiodynamic measurements in Hank’s solution to determine the corrosion rate of new and retrieved stem taper surfaces. The results showed a low corrosion rate for both new and prematurely failed retrieved samples due to aseptic loosening. However, the corrosion rate was higher in infected and low-grade infected tapers. In conclusion, our study suggests that using ceramic heads reduces taper corrosion and subsequently decreases the incidence of premature failures in total hip arthroplasty.
The preparation of autologous platelet and extracellular vesicle-rich plasma (PVRP) has been explored in many medical fields with the aim to benefit from its healing potential. In parallel, efforts ...are being invested to understand the function and dynamics of PVRP that is complex in its composition and interactions. Some clinical evidence reveals beneficial effects of PVRP, while some report that there were no effects. To optimize the preparation methods, functions and mechanisms of PVRP, its constituents should be better understood. With the intention to promote further studies of autologous therapeutic PVRP, we performed a review on some topics regarding PVRP composition, harvesting, assessment and preservation, and also on clinical experience following PVRP application in humans and animals. Besides the acknowledged actions of platelets, leukocytes and different molecules, we focus on extracellular vesicles that were found abundant in PVRP.
For the improvement of surface roughness, titanium joint arthroplasty (TJA) components are grit-blasted with Al2O3 (corundum) particles during manufacturing. There is an acute concern, particularly ...with uncemented implants, about polymeric, metallic, and corundum debris generation and accumulation in TJA, and its association with osteolysis and implant loosening. The surface morphology, chemistry, phase analysis, and surface chemistry of retrieved and new Al2O3 grit-blasted titanium alloy were determined with scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and confocal laser fluorescence microscopy, respectively. Peri-prosthetic soft tissue was studied with histopathology. Blasted retrieved and new stems were exposed to human mesenchymal stromal stem cells (BMSCs) for 7 days to test biocompatibility and cytotoxicity. We found metallic particles in the peri-prosthetic soft tissue. Ti6Al7Nb with the residual Al2O3 particles exhibited a low cytotoxic effect while polished titanium and ceramic disks exhibited no cytotoxic effect. None of the tested materials caused cell death or even a zone of inhibition. Our results indicate a possible biological effect of the blasting debris; however, we found no significant toxicity with these materials. Further studies on the optimal size and properties of the blasting particles are indicated for minimizing their adverse biological effects.
We studied inflammatory and oxidative stress-related parameters and cytotoxic response of human umbilical vein endothelial cells (HUVEC) to a 24 h treatment with milled particles simulating debris ...involved in sandblasting of orthopedic implants (OI). We used different abrasives (corundum-(Al
O
), used corundum retrieved from removed OI (u. Al
O
), and zirconia/silica composite (ZrO
/SiO
)). Morphological changes were observed by scanning electron microscopy (SEM). Concentration of Interleukins IL-6 and IL-1β and Tumor Necrosis Factor α (TNF)-α was assessed by enzyme-linked immunosorbent assay (ELISA). Activity of Cholinesterase (ChE) and Glutathione S-transferase (GST) was measured by spectrophotometry. Reactive oxygen species (ROS), lipid droplets (LD) and apoptosis were measured by flow cytometry (FCM). Detachment of the cells from glass and budding of the cell membrane did not differ in the treated and untreated control cells. Increased concentration of IL-1β and of IL-6 was found after treatment with all tested particle types, indicating inflammatory response of the treated cells. Increased ChE activity was found after treatment with u. Al
O
and ZrO
/SiO
. Increased GST activity was found after treatment with ZrO
/SiO
. Increased LD quantity but not ROS quantity was found after treatment with u. Al
O
. No cytotoxicity was detected after treatment with u. Al
O
. The tested materials in concentrations added to in vitro cell lines were found non-toxic but bioactive and therefore prone to induce a response of the human body to OI.
Cutibacterium acnes is a major etiologic agent of orthopaedic implant-associated infections (IAIs) and requires up to 14 days of incubation in an anaerobic atmosphere for growth detection. As blood ...culture (BC) systems are increasingly being used to monitor the growth of IAI specimens, we compared different BC media for growth detection of C. acnes. Non-duplicate C. acnes isolates (n = 99) obtained from sonicate-fluid cultures of orthopaedic IAIs from Slovenia (n = 54), conventional tissue samples of monomicrobial orthopaedic IAIs from France (n = 43) and two reference strains were inoculated to anaerobic BC bottles of two major BC systems and 3 conventional culture media types (thioglycolate broth, Schaedler and chocolate agar). Growth and time-to-detection (TTD) were recorded. Only Lytic (BACTEC) and SN (BacT/ALERT) bottles consistently detected growth of C. acnes within 14 days with 94% (n = 93) and 92% (n = 91) detection rates, respectively (p = 0.79). Lytic was superior to Plus BACTEC medium (p < 0.001), while SN was superior to all other BacT/ALERT media (p < 0.001). Mean TTD was 128 ± 43 h (61–336 h) for Lytic and 158 ± 65 h (77–336 h) for SN medium. Among the conventional media, 99% (n = 98) of the isolates grew on Schaedler agar, 96% (n = 95) in thioglycolate broth and 74% (n = 73) on chocolate agar. Inconsistent growth of C. acnes in different BC media can critically influence the detection of this major IAI pathogen. Only Lytic (BACTEC) and SN (BacT/ALERT) BC media types were consistently able to detect C. acnes within 14 days of incubation. However, visible growth was observed faster in thioglycolate broth and Schaedler agar media.
•C. acnes is a major orthopaedic implant-associated infection (IAI) pathogen.•Blood culture (BC) systems are increasingly used for culture of IAI specimens.•Inconsistent and slow detection of C. acnes by different BC systems was detected.•BACTEC Lytic/10 Anaerobic/F and BacT/ALERT SN detected C. acnes within 14 days.•Thioglycolate broth and Schaedler agar proved a more reliable and faster option.
The biomechanical parameters of the hip joint articular surface were analysed in 141 adult hips after Legg-Calve Perthes Disease, and 114 contralateral unaffected hips (controls), by using HIPSTRESS ...mathematical models. Geometrical parameters, assessed from anteroposterior and axial radiograms, were used as input to models for resultant hip force and contact hip stress. Results confirm previous indications that head enlargement after the Legg-Calve-Perthes Disease compensates the values of hip stress. Furthermore, it was found that an increased risk for coxarthritis development after the disease is secondary to concomitant hip dysplasia, with considerable and statistically significantly lower centre-edge angle and unfavourable distribution of stress.
![The Impact of Al[sub.2]O[su...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1996-1944/small "The Impact of Al[sub.2]O[sub.3] Particles from Grit-Blasted Ti6Al7Nb Implant Surfaces on Biocompatibility, Aseptic Loosening, and Infection")
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