In March 2020, the World Health Organisation declared the COVID-19 outbreak a pandemic. Multiple new guidelines were proposed and existing models of social, domestic and hospital care altered. Most healthcare systems were largely unprepared for this and this pandemic has tested their adaptability. This study is aimed at assessing the impact of covid-19 on the demographics, presentation and clinical management of patients with proximal femoral (hip) fractures.

This retrospective multi-centre cohort study compared all patients admitted with hip fractures, between 1^st March and 30th May 2019 (Group PC: Pre-Covid) with hip fracture patients admitted over the same time period during the pandemic in 2020 (Group C: Covid). The data was obtained from the hospitals' local and National Hip Fracture Databases. Mortality data was checked with the Office for National Statistics (ONS). Primary outcomes were time to theatre, in-patient length of stay and 30-day mortality.

580 patients were included (304 PC, 276 C). Patient Charlson comorbidity index and Nottingham Hip Fracture scores were broadly similar across the two cohorts. There was a significant reduction in percentage of total hip replacements in Group C (11% to 5%, p=0.006). There was an increase in conservative management in group C (1% to 5%, p=0.002). The time to theatre was significantly delayed in Group C (43.7 hours C versus 34.6 hours PC, p<0.001). Overall length of hospital stay was similar in both groups (16.6 days PC versus 15 days C, p=0.089). 30-day mortality rate in Group C was 9.8% compared to 8.2% in Group PC (p=0.431), but for covid (+) patients it was significantly higher at 38.2% versus 5.8% in covid (−) patients (p<0.001).

This is one of the largest multi-centre comparative cohort study in the literature to date, examining the impact of the covid-19 pandemic on the management of hip fracture patients. Whilst mortality rates were similar in both groups, covid patients were almost seven times more likely to die, reflecting the seriousness of the covid-19 infection and its sequelae in such elderly, vulnerable patients.

Prosthetic joint infections (PJI) occur infrequently, but they represent the most devastating complication with high morbidity and substantial cost. Staphylococcus aureus are the most common infecting agents associated with acute PJI, and also appear in some cases of delayed PJI¹. S. aureus biofilm development can be divided in two stages: adhesion and proliferation². To avoid PJI bacterial adhesion has to be decreased.

Hybrid organo-inorganic sol-gel coatings are proposed as a promising biomaterial improvement³. One of these compounds is a mixture of two organopolisiloxanes: 3-methacryloxypropyltrimethoxysilane (MAPTMS) and tetramethylorthosilicate (TMOS). The aim of this work was to evaluate bacterial adhesion on MAPTMS-TMOS coating compared to titanium parts made by powder metallurgy.

MAPTMS-TMOS sol-gel coating was produced using a molar ratio of 1:2 (MAPTMS:TMOS) and dispersed in ethanol. The sol-gel was deposited by dip-coating on titanium parts made by powder metallurgy followed by a thermal treatment at 120 ºC for 30 minutes⁴. Titanium parts without sol-gel coating were used as control.

S. aureus 15981 strain adherence study was performed using the protocol described by Kinnari et al.⁵ with 90 min incubation. After incubation, the samples were stained with LIVE/DEAD BacLight Bacterial Viability Kit. Proportion of total adhered, live and dead bacteria was calculated and studied by using ImageJ software. The experiments were performed in triplicate.

The statistical data were analyzed by pairwise comparisons using the nonparametric Mann-Whitney test with a level of statistical significance of p<0.05. Values are cited and represented as medians.

S. aureus 15981 adherence was 942-fold lower on MAPTMS-TMOS coating than on uncoated titanium.

According with our results, MAPTMS-TMOS sol-gel coating is a promising antiadherent surface for S. aureus. More studies are necessary in order to evaluate this property with other species and strains.