Metallic biomaterials are widely used in implants to strengthen, repair, or replace damaged bone tissue, and their material characteristics have direct influences on short- and long-term implant performance. Of these, titanium and its alloys are the most widely applied due to their superior corrosion resistance, biocompatibility, and mechanical properties, such as in joint replacements, dental implants, and spinal fusion cages. However, Ti and Ti alloys are bioinert materials that have difficulty in binding directly to bone tissue after implantation, due to a lack of osteoconductive and osteoinductive properties. Bacterial adhesion and colonisation at the implantation site may also lead to infection-associated complications. The surface of the titanium implant directly interfaces with blood, cells, and tissues in vivo, and the surface properties can have profound influences on protein- and cell-based interactions that then promote or impede osseointegration. Therefore, the material surface morphology, chemistry and antibacterial function are key parameters in implant design, and contribute to determining the long-term success of the implant. In this review, we systematically present the latest advances in surface modification techniques for orthopaedic implants, including mechanical, physical, chemical, and biological modification. We also analyse and compare different surface modification approaches, including drug loading, metallic element doping, and bionic coatings, as well as topographical modifications such as nanotubes, nanopores and nanowires. Finally, we present a critical analysis and future perspectives on the use of surface modifications to improve the osseointegration and antibacterial properties of orthopaedic implants.

Carbon dots (CDs) with excellent cytocompatibility, tunable optical properties, and simple synthesis routes are highly desirable for use in optical bioimaging. However, the majority of existing CDs are triggered by ultraviolet/blue light, presenting emissions in the visible/first near‐infrared (NIR‐I) regions, which do not allow deep tissue penetration. Emerging research into CDs with NIR‐II emission in the red region has generated limited designs with poor quantum yield, restricting their in vivo imaging applications due to low penetration depth. Developing novel CDs with NIR‐II emissions and high quantum yield has significant and far‐reaching applications in bioimaging and photodynamic therapy. Here, it is developed for the first time Fe‐doped CDs (Fe‐CDs) exhibiting the excellent linear relationship between 900–1200 nm fluorescence‐emission and pH values, and high quantum yield (QY‐1.27%), which can be used as effective probes for in vivo NIR‐II bioimaging. These findings demonstrate reliable imaging accuracy in tissue as deep as 4 mm, reflecting real‐time pH changes comparable to a standard pH electrode. As an important example application, the Fe‐CDs probe can non‐invasively monitor in vivo gastric pH changes during the digestion process in mice, illustrating its potential applications in aiding imaging‐guided diagnosis of gastric diseases or therapeutic delivery.

Objective: To estimate the global prevalence of hip osteoarthritis (HOA) through a systematic review and meta-analysis, and to determine by regression analysis the respective relationships between age and sex, and sex and prevalence.Methods: EMBASE, PubMed, Web of science, CINAHL, and SCOPUS were searched from inception until August 2022. Two authors independently extracted data and assessed the quality of the retrieved literature. Random-effects meta-analysis was performed to derive the pooled prevalence. Variations in the prevalence estimate in different subgroups, including diagnostic methods, region, and patient sex, were examined by subgroup meta-analysis. Meta-regression was used to construct the age-specific prevalence of HOA.Results: A total of 31 studies were included in our analysis, involving 326,463 participants. Quality evaluation showed that all studies included in the analysis had a Quality Score of at least 4. The most frequently used method for diagnosing HOA was the Kellgren–Lawrence (K-L) grade classification, accounting for 19/31 (61.3%) studies. The pooled prevalence of HOA diagnosed based on the K-L grade ≥ 2 criterion was 8.55% (95% CI 4.85–13.18) worldwide. The prevalence of HOA was lowest in Africa at 1.20% (95% CI: 0.40–2.38), followed by Asia at 4.26% (95% CI 0.02–14.93) and North America at 7.95% (95% CI 1.98–17.36), and highest in Europe at 12.59% (95% CI 7.17–19.25). There was no statistically significant difference in HOA prevalence between men (9.42%, 95% CI:4.81–15.34) and women at (7.94%, 95% CI: 3.57–13.81). The regression model showed a correlation between age and the prevalence of HOA.Conclusion: HOA has high prevalence worldwide and increases with age. The prevalence varies significantly by region but not by patient sex. High-quality epidemiological studies are warranted to more accurately estimate the prevalence of HOA.

Scaffold-based tissue engineering strategies are being explored for the management and reconstruction of damaged or diseased skeletal tissues, the effective treatment of which has remained a significant global healthcare challenge.

Doped calcium silicate ceramics (DCSCs) have recently gained immense interest as a new class of candidates for the treatment of bone defects. Although calcium phosphates and bioactive glasses have remained the mainstream of ceramic bone substitutes, their clinical use is limited by suboptimal mechanical properties. DCSCs are a class of calcium silicate ceramics which are developed through the ionic substitution of calcium ions, the incorporation of metal oxides into the base binary xCaO–ySiO₂ system, or a combination of both. Due to their unique compositions and ability to release bioactive ions, DCSCs exhibit enhanced mechanical and biological properties. Such characteristics offer significant advantages over existing ceramic bone substitutes, and underline the future potential of adopting DCSCs for clinical use in bone reconstruction to produce improved outcomes. This review will discuss the effects of different dopant elements and oxides on the characteristics of DCSCs for applications in bone repair, including mechanical properties, degradation and ion release characteristics, radiopacity, and biological activity (in vitro and in vivo). Recent advances in the development of DCSCs for broader clinical applications will also be discussed, including DCSC composites, coated DCSC scaffolds and DCSC-coated metal implants.