Antibiotic utilisation in primary and revision total hip replacement patients: A registry linkage cohort study of 106 253 patients using the Australian Orthopaedic Association National Joint Replacement Registry

Zinc phosphate glass microspheres promoted mineralization and expression of BMP2 in MC3T3-E1 cells

Degradable phosphate glasses have shown favorable properties for tissue engineering. By changing the composition of the glasses, the degradation rate, and ion release are controllable. Zinc oxide can function as a glass network modifier and has been shown to play a positive role in bone formation. Also, phosphate glasses can easily be processed into microspheres, which can be used as microcarriers. This study aims to develop zinc phosphate glasses microspheres and explore the optimized size and composition for applications in bone tissue engineering. Zinc-titanium-calcium-sodium phosphate glasses with 0, 1, 3, 5, or 10 mol % zinc oxide were prepared and processed into microspheres. The smaller microspheres ranged in size from 50 to 106 μm, while the larger ones ranged from 106 to 150 μm. The characteristics of glasses were examined. The osteoblastic cell line MC3T3-E1 was cultured on the surface of microspheres and the cell viability was examined. To evaluate osteogenic differentiation, Alizarin Red S staining, quantitative reverse transcription polymerase chain reaction, and western blot analysis were performed after 14 days. Different sizes of zinc phosphate glass microspheres were successfully made. The glass microspheres with <10 mol % zinc oxide were able to support the adhesion and proliferation of MC3T3-E1 cell lines. The relative gene expression of BMP2 was significantly upregulated in the smaller glass microspheres containing 3 mol % zinc oxide (26-fold, p < .001) and both sizes of microspheres containing 5 mol % zinc oxide (smaller: 27-fold, p < .001; larger: 35-fold, p < .001). Additionally, cluster formation was observed in glass microspheres after 14 days, and the mineralization of MC3T3-E1 cell lines was promoted. Based on these findings, the glass microspheres containing 3-5 mol % of zinc oxide can promote osteogenic differentiation for MC3T3-E1 cells.

Temporal trends in revision rate due to knee periprosthetic joint infection: a study of 115,120 cases from the Danish Knee Arthroplasty Register

BACKGROUND AND PURPOSE

We aimed to examine the temporal trends in periprosthetic joint infection (PJI) revision incidence after knee arthroplasty (KA) from 1997 through 2019.

PATIENTS AND METHODS

115,120 primary KA cases from the Danish Knee Arthroplasty Register were followed until the first PJI revision. We computed cumulative incidences and adjusted hazard ratios (aHRs) of PJI revision by calendar periods and several patient- and surgical-related risk factors. Results were analyzed from 0-3 months and from 3-12 months after KA.

RESULTS

The overall 1-year PJI revision incidence was 0.7%, increasing from 0.5% to 0.7% (1997 through 2019). The incidence of PJI revision within 3 months increased from 0.1% to 0.5% (1997 through 2019). The adjusted hazard ratio (aHR) within 1 year of primary KA was 5.1 comparing 2017-2019 with 2001-2004. The PJI revision incidence from 3-12 months of KA decreased from 0.4% to 0.2%, with an aHR of 0.5 for 2017-2019 vs. 2001-2004. Male sex, age 75-84 (vs. 65-74), and extreme obesity (vs. normal weight) were positively associated with the risk of PJI revision within 3 months, whereas only male sex was associated from 3-12 months. Partial knee arthroplasty (PKA) vs. total KA was associated with a lower risk of PJI revision both within 3 months and 3-12 months of KA.

CONCLUSION

We observed an increase in PJI revision within 3 months of KA, and a decrease in PJI revision incidence from 3-12 months from 1997 through 2019. The reasons for this observed time-trend are thought to be multifactorial. PKA was associated with a lower risk of PJI revision.