Bone and Joint Infections in Older Adults

Does Preoperative Glycemic Control Restore Immune Defense Against Implant-related Infection in Mice With Diabetes?

BACKGROUND

The presence of Type II diabetes is a well-established risk factor for bone and joint infection, especially in patients with poor glycemic control. However, few studies have investigated the effect of the duration of preoperative glycemic intervention. For patients with poor glycemic control, the effect of the duration of preoperative glycemic intervention remains unknown. Many glycemic biomarkers including hemoglobin A1c (HbA1c), fructosamine, and 1,5-anhydroglucitol have different response rates to glycemic change. It is unclear which biomarker is more closely related to the decrease in infection proportion after preoperative glycemic intervention.

QUESTIONS/PURPOSES

(1) Is there an effect of the duration of preoperative insulin therapy in mice with diabetes receiving an experimental intra-articular implant? (2) Of the three commonly used biomolecules for monitoring blood glucose levels (HbA1c, fructosamine, and 1,5-anhydroglucitol), is one more closely related to decrease in infection proportion after presurgical insulin therapy?

METHODS

With a well-established protocol, Type II diabetes was modeled in female 10-week-old C57BL/6 mice by maintaining them on a high-fat diet (60% fat) for 8 months; control mice without diabetes received a normal low-fat diet (10% fat). Mice with Type II diabetes were randomized into groups to receive preoperative glycemic intervention with insulin for 0, 1, 3, 5, 7, 14, or 28 days, and investigators were blinded to the randomization. Mice with and without diabetes then received a surgically inserted wire into the femoral canal in a retrograde fashion and received a local or systemic challenge with Staphylococcus aureus or Escherichia coli (n = 20 for each bacteria challenge [systemic or local]/timepoint). The proportion of culture-positive joint samples was calculated. An additional 10 mice with Type II diabetes were treated with insulin for 28 days and the HbA1c, fructosamine, and 1,5-anhydroglucitol levels were consecutively monitored. Fisher exact tests and nonparametric Wilcoxon rank sum tests were used to analyze the different between different groups, with p < 0.05 taken as significant.

RESULTS

When insulin therapy was administered, the proportion of bone and joint infections decreased in mice with Type II diabetes, reaching asymptotic levels after 3 days of treatment for the systemic (S. aureus: 7 of 20 mice with diabetes on 3-day therapy, p < 0.001; 8 of 20 on 5-day, p = 0.002; 10 of 20 on 7-day, p = 0.01; 9 of 20 on 14-day, p = 0.006; and 8 of 20 on 28-day, p = 0.002 versus 18 of 20 in the no insulin therapy group; E. coli: 6 of 20 on 3-day therapy, p = 0.004; 7 of 20 on 5-day, p = 0.01; 7 of 20 on 7-day, p = 0.01; 6 of 20 on 14-day, p = 0.004; and 7 of 20 on 28-day, p = 0.01 versus 16 of 20 in the no insulin therapy group) or local bacterial challenge (S. aureus: 11 of 20 on 3-day therapy, p = 0.001; 12 of 20 on 5-day, p = 0.003; 10 of 20 on 7-day, p < 0.001; 12 of 20 on 14-day, p = 0.003; and 13 of 20 on 28-day, p = 0.008 versus 20 of 20 in the no insulin therapy group; E. coli: 10 of 20 on 3-day therapy, p = 0.003; 10 of 20 on 5-day, p = 0.003; 9 of 20 on 7-day, p = 0.001; 11 of 20 on 14-day, p = 0.008; and 10 of 20 on 28-day, p = 0.003 versus 19 of 20 in no insulin therapy group). Even after 28 days of insulin therapy, the proportion of bone and joint infections was still higher (statistically insignificant with large absolute difference, except for one instance) in mice with diabetes than in control mice without diabetes after systemic (S. aureus: 8 of 10 mice with diabetes on 28-day therapy versus 4 of 20 mice without diabetes, p = 0.30; E. coli: 7 of 20 on 28-day therapy versus 1 of 20 mice without diabetes, p = 0.04) or local challenge (S. aureus: 13 of 20 mice on 28-day therapy versus 8 of 20 mice without diabetes, p = 0.21; E. coli: 10 of 20 on 28-day therapy versus 5 of 20 mice without diabetes, p = 0.19). HbA1c and fructosamine levels were lagging indicators of the decrease in infection proportion after insulin treatment. In contrast, the 1,5-anhydroglucitol level increased quickly (reflecting lower blood glucose levels) in response to short-term glycemic control. Moreover, the time required for changes in 1,5-anhydroglucitol levels to be detected was no more than 3 days (3 days insulin therapy 1.86 ± 0.20 [95% CI -1.27 to -0.45]; p˂0.001 versus no insulin therapy 1.00 ± 0.11).

CONCLUSION

In a model of mice with Type II diabetes, prolonged preoperative glycemic intervention did not further reduce the proportion of bone and joint infections compared with that achieved with short-term intervention of 3 days.

CLINICAL RELEVANCE

Compared with HbA1c and fructosamine, 1,5-anhydroglucitol might be a better indicator for risk stratification and guiding the timing for elective surgery. Comparative study of these three biomarkers based on patient samples is warranted to further confirm this conclusion.

Prevalence and correlates of bone and joint diseases and its association with falls among older adults in India: Evidence from LASI, 2017-18

This study explores the prevalence and correlates of bone and joint diseases and its association with falls among older adults in India. Data from the Longitudinal Aging Study in India (2017-18) were utilized for analysis (n = 31,464). Bivariate and logistic regression was used to fulfill the study objectives. The findings revealed that 19.71% of older adults had bone and joint disease, which was higher among women (22.79%) than men (16.25%). The strongest predictors of such diseases included being currently employed, physically inactive, having difficulties in performing functional activities and higher economic status. The fall in the last two years was reported by 12.63% of older adults, and bone and joints diseases were significantly associated with falls (AOR = 1.287; 95% CI: 1.117-1.483) after adjusting for several socio-demographic and health covariates. These findings imply that policymakers and providers must implement interventions designed to reduce the risk of those diseases and associated falls.

The application of ceragenins to orthopedic surgery and medicine

Osteomyelitis and infections associated with orthopedic implants represent a significant burden of disease worldwide. Ceragenins (CSAs) are a relatively new class of small-molecule antimicrobials that target a broad range of Gram-positive and Gram-negative bacteria as well as fungi, viruses, and parasites. This review sets the context of the need for new antimicrobial strategies by cataloging the common pathogens associated with orthopedic infection and highlighting the increasing challenges of managing antibiotic-resistant bacterial strains. It then comparatively describes the antimicrobial properties of CSAs with a focus on the CSA-13 family. More recently developed members of this family such as CSA-90 and CSA-131 may have a particular advantage in an orthopedic setting as they possess secondary pro-osteogenic properties. In this context, we consider several new preclinical studies that demonstrate the utility of CSAs in orthopedic models. Emerging evidence suggests that CSAs are effective against antibiotic-resistant Staphylococcus aureus strains and can prevent the formation of biofilms. There remains considerable scope for developing CSA-based treatments, either as coatings for orthopedic implants or as local or systemic antibiotics to prevent bone infection.

Pharmacotherapy options and drug development in managing periprosthetic joint infections in the elderly

INTRODUCTION

Prosthetic joint infections are an increasingly important problem among patients undergoing arthroplasty procedures, and are associated with significant morbidity, reduced quality of life, substantial healthcare costs, and even mortality. Arthroplasties are performed with increasing frequency in elderly patients, who present specific problems.

AREAS COVERED

Surgical therapy is clearly influenced by the clinical status of the patient, which in some case can contraindicate surgery. Antibiotic selection is also affected by comorbidities and underlying diseases, which in some cases reduce therapeutic options. The authors review this together with the changes in pharmacokinetics and pharmacodynamics in the elderly population and the prospects for future research on prevention and treatment.

EXPERT OPINION

The management of PJI in the elderly makes multidisciplinary teams even more mandatory than in other patients, because the complexity of these patients. A frequent scenario is that in which surgery is contraindicated with long-term suppressive treatment as the only available option. Treating physicians must consider the presence of multiple comorbidities, interactions with other treatments and secondary effects when choosing antibiotic treatment. An in-depth knowledge of the alterations in pharmacokinetics and pharmacodynamics in elderly patients is key for a proper treatment selection.

In vitro activity of tedizolid and comparator agents against Gram-positive pathogens responsible for bone and joint infections

Tedizolid, a second-generation oxazolidinone that displays a potent activity against Gram-positive pathogens, could be an interesting option for the treatment of bone and joint infections (BJIs). The aim of the study was to determine minimal inhibitory concentration (MIC) of tedizolid against a collection of 359 clinical isolates involved in clinically-documented BJIs and to compare them to those of comparator agents used in Gram-positive infections. Of the 104 Staphylococcusaureus and 102 coagulase-negative staphylococci (CoNS) isolates, 99 and 92 % were categorized as susceptible to tedizolid, respectively (MIC25=0.12/0.25 µg ml^-1 and MIC90=0.25/0.5 µg ml^-1), regardless of their methicillin resistance. MIC50 and MIC90 for the 51 enterococci, the 50 Corynebacterium spp. and the 52 Propionibacterium spp. were either equal or inferior to 0.5 µg ml^-1. Altogether, tedizolid possessed a potent in vitro activity against most of the BJI Gram-positive pathogens with 95 % of them exhibiting a MIC ≤0.5 µg ml^-1.