Smart implants as a novel strategy to regenerate well-founded cartilage

Here we explore a new generation of smart, living implants, combining not only active therapeutics but also stem cells, as a novel strategy to regenerate stabilised cartilage and avoid prostheses. This process can regenerate the subchondral bone foundation, which is currently difficult in the clinic

Resuming hip and knee arthroplasty after COVID-19: ethical implications for wellbeing, safety and the economy

Reinstating elective hip and knee arthroplasty services presents significant challenges. We need to be honest about the scale of the obstacles ahead and realise that the health challenges and economic consequences of the COVID-19 pandemic are potentially devastating. We must also prepare to make difficult ethical decisions about restarting elective hip and knee arthroplasty. These decisions should be based on the existing evidence-base, reliable data, the recommendations of experts, and regional circumstance

Bacterial adhesion on biomedical surfaces covered by yttria stabilized zirconia

The aim of this study was to compare the bacterial adhesion of Staphylococcus spp. on Ti-6Al-4V with respect to Ti-6Al-V modified alloys with a set of Cubic yttria stabilized zirconia (YSZ) and Ag-YSZ nanocomposite films. Silver is well known to have a natural biocidal character and its presence in the surface predicted to enhance the antimicrobial properties of biomedical surfaces. Microbial adhesion tests were performed using collection strains and twelve clinical strains of Staphylococcus aureus and Staphylococcus epidermidis. The adherence study was performed using a previously published protocol by Kinnari et al. Both collection strains and clinical isolates have shown lower bacterial adhesion to materials modified with respect to the alloy Ti-6Al-4V and the modification with silver reduced the bacterial adhesion for most of all the strains studied. Moreover the percentage of dead bacteria have been evaluated, demonstrating increased proportion of dead bacteria for the modified surfaces. Nanocrystalline silver dissolves releasing both Ag+ and Ag-0 whereas other silver sources release only Ag+. We can conclude that YSZ with nanocrystalline silver coating may lead to diminished postoperative infections and to increased corrosion and scratch resistance of YSZ incorporating alloys Ti-6Al-4V.Peer reviewe

Polyethylene Oxidation in Total Hip Arthroplasty: Evolution and New Advances

Ultra-high molecular weight polyethylene (UHMWPE) remains the gold standard acetabular bearing material for hip arthroplasty. Its successful performance has shown consistent results and survivorship in total hip replacement (THR) above 85% after 15 years, with different patients, surgeons, or designs

Evaluation of Quantitative Analysis of Cultures from Sonicated Retrieved Orthopedic Implants in Diagnosis of Orthopedic Infection▿

To improve the microbiological diagnosis of device-related osteoarticular infections, we have developed a protocol based on the sonication of device samples, followed by concentration and inoculation of the sonicate in a broad variety of media in a quantitative manner. Sixty-six samples from 31 patients were included in the study (17 of them with clinical diagnosis of infection). The sonication procedure had a sensitivity of 94.1%, which is better than that of conventional cultures (88.2%). One case of contamination and six cases of unexpected positive cultures were detected (specificity of 42.8%): two of these were considered to represent true infection, while the other four were considered to be nonsignificant (corrected specificity of 50%), although the clinical importance of these isolates is questionable. When we analyzed the number of CFU, no breakpoint between significant and nonsignificant isolates could be established. Based on our results, the procedure of sonication of retrieved implants is better than conventional cultures for the diagnosis of device-related infections. The significance of some isolates in patients without clinical infection remains uncertain. However, they may become pathogens and cannot be routinely considered to be contamination

Osteostatin-coated porous titanium can improve early bone regeneration of cortical bone defects in rats

A promising bone graft substitute is porous titanium. Porous titanium, produced by selective laser melting (SLM), can be made as a completely open porous and load-bearing scaffold that facilitates bone regeneration through osteoconduction. In this study, the bone regenerative capacity of porous titanium is improved with a coating of osteostatin, an osteoinductive peptide that consists of the 107-111 domain of the parathyroid hormone-related protein (PTHrP) and the effects of this osteostatin-coating on bone regeneration were evaluated in vitro and in vivo. SLM-produced porous titanium received an alkali-acid-heat treatment and was coated with osteostatin through soaking in a 100nM solution for 24h or left uncoated. Osteostatin-coated scaffolds contained ~0.1µg peptide/g titanium, and in vitro 81% was released within 24h. Human periosteum-derived osteoprogenitor cells cultured on osteostatin coated scaffolds did not induce significant changes in osteogenic (ALP, Col1, OCN, Runx2) or angiogenic (VEGF) gene expression, however it resulted in an upregulation of OPG gene expression after 24h and a lower RankL:OPG mRNA ratio. In vivo, osteostatin-coated porous titanium implants increased bone regeneration critical-sized cortical bone defects (p=0.005). . Bone regeneration proceeded until 12 weeks and femurs grafted with osteostatin-coated implants and uncoated implants recovered respectively 66% and 53% of the original femur torque strength (97±31N.mm and 77±53N.mm, NS). In conclusion, the osteostatin-coating improved bone regeneration of porous titanium. This effect was initiated after a short burst-release, and might be related to the observed in vitro upregulation of OPG gene expression by osteostatin in osteoprogenitor cells. Long-term beneficial effects of osteostatin-coated porous titanium implants on bone regeneration or mechanical strength were not established here and may require optimization of the pace and dose of osteostatin release.status: publishe