Socioeconomic Status May Not Be a Risk Factor for Periprosthetic Joint Infection

Socioeconomic Disadvantage Predicts Decreased Likelihood of Maintaining a Functional Knee Arthroplasty Following Treatment for Prosthetic Joint Infection

BACKGROUND

Prosthetic joint infection (PJI) carries major morbidity and mortality as well as a complicated and lengthy treatment course. In patients who have high degrees of socioeconomic disadvantage, this may be a particularly devastating complication. Our study sought to evaluate the impact of socioeconomic deprivation on outcomes following treatment for PJI of the knee.

METHODS

We conducted a retrospective review of revision total knee arthroplasty (TKA) procedures performed for the treatment of initial PJI between 2008 and 2020 at a single tertiary care center in the United States. The Area Deprivation Index (ADI) was used to quantify socioeconomic deprivation. The primary outcome measure was presence of a functional knee joint at the time of most recent follow-up defined as TKA components or an articulating spacer. A total of 96 patients were included for analysis. The median follow-up duration was 26.5 months.

RESULTS

There was no significant difference in the rate of treatment failure (P = .63). However, the proportion of patients who had a functional knee arthroplasty (in contrast to having undergone arthrodesis, amputation, or retention of a static spacer) declined significantly with increasing ADI index (81.8% for the least disadvantaged group, 58.7% for the middle group, 42.9% for the most disadvantaged group, P = .021).

CONCLUSIONS

Patients who have a higher socioeconomic disadvantage as measured by ADI are less likely to maintain a functional knee arthroplasty following treatment for TKA PJI. These findings support continued efforts to improve access to care and optimize treatment plans for patients who have socioeconomic disadvantage.

Sex-related differences in periprosthetic joint infection research

Introduction: Periprosthetic joint infections (PJIs) have emerged as a focal point in the realm of orthopedics, garnering widespread attention owing to the escalating incidence rates and the profound impact they impose on patients undergoing total joint arthroplasties (TJAs). Year after year, there has been a growing trend in the analysis of multiple risk factors, complication rates, and surgical treatments in the field. This study aims to illuminate the status of the sex-related differences in periprosthetic joint infections and advance research in this field. Methods: A systematic review was carried out following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The final reference list comprised longitudinal studies (both retrospective and prospective) and randomized controlled trials. A sex-based analysis was conducted to assess differences between males and females. Results: A total of 312 studies were initially identified through online database searches and reference investigations. Nine studies were subsequently included in the review. Eight out of nine studies examined the risk of developing PJI after total joint replacement. Notably, only half of these studies demonstrated a statistically significant value, with a p  value  < 0.05 , indicating a higher risk of infectious complications in males compared to females. Conclusion: According to the current literature, there appears to be a propensity for males to develop periprosthetic joint infection after total joint arthroplasty at a higher rate than the female population. Enhancing sex-related analysis in this field is imperative for gathering more robust evidence and insights.

Differences in In Vitro Bacterial Adherence between Ti6Al4V and CoCrMo Alloys

Prosthetic joint infection is an uncommon entity, but it supposes high costs, both from the economic side to the health systems and from the emotional side of the patient. The evaluation of the bacterial adherence to different materials frequently involved in joint prostheses allows us to better understand the mechanisms underlying this and provide information for the future development of prevention strategies. This study evaluated the bacterial adherence of four different species (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa) on Ti6Al4V and CoCrMo. The topography, surface contact angles, and linear average roughness were measured in the samples from both alloys. The interaction with the surface of both alloys was significantly different, with the CoCrMo showing an aggregating effect on all the species, with additional anti-adherent activity in the case of Pseudomonas aeruginosa. The viability also changes, with a significant decrease (p < 0.05) in the CoCrMo alloy. In the case of S. epidermidis, the viability in the supernatant from the samples was different, too, with a decrease in the colony-forming units in the Ti6Al4V, which could be related to cation release from the surface. Beyond adhesion is a multifactorial and complex process, and considering that topography and wettability were similar, the chemical composition could play a main role in the different properties observed.

Is Social Deprivation Associated With Usage, Adverse Events, and Patient-reported Outcome Measures in Total Joint Arthroplasty? A Systematic Review

BACKGROUND

To capture various social determinants of health, recent analyses have used comprehensive measures of socioeconomic disadvantage such as deprivation and vulnerability indices. Given that studies evaluating the effects of social deprivation on total joint arthroplasty (TJA) have yielded mixed results, a systematic review of this relationship might help answer questions about usage, complications, and results after surgery among patients in different socioeconomic groups and help guide targeted approaches to ensure health equity.

QUESTIONS/PURPOSES

We asked: How is social deprivation associated with TJA (1) usage, (2) adverse events including discharge deposition and length of stay, and (3) patient-reported outcome measures (PROMs)?

METHODS

A comprehensive review of the PubMed, EBSCO host, Medline, and Google Scholar electronic databases was conducted to identify all studies that evaluated social deprivation and TJA between January 1, 2000, and March 1, 2022. Studies were included if they evaluated comprehensive measures of socioeconomic deprivation rather than individual social determinants of health. Nineteen articles were included in our final analysis with a total of 757,522 patients. In addition to characteristics of included studies (such as patient population, procedure evaluated, and utilized social deprivation metric), we recorded TJA usage, adverse events, and PROM values as reported by each article. Two reviewers independently evaluated the quality of included studies using the Methodological Index for Nonrandomized Studies (MINORS) tool. The mean ± SD MINORS score was 13 ± 1 of 16, with higher scores representing better study quality. All the articles included are noncomparative studies. Given the heterogeneity of the included studies, a meta-analysis was not performed and results were instead presented descriptively.

RESULTS

Although there were inconsistencies among the included articles, higher levels of social deprivation were associated with lower TJA usage even after controlling for various confounding variables. Similarly, there was agreement among studies regarding higher proportion of nonhome discharge for patients with more social deprivation. Although there was limited agreement across studies regarding whether patients with more social deprivation had differences in their baseline and postoperative PROMs scores, patients with more social deprivation had lower improvements from baseline for most of the included articles.

CONCLUSION

These findings encourage continued efforts focusing on appropriate patient education regarding expectations related to functional improvement and the postoperative recovery process, as well as resources available for further information and social support. We suggest linking patient data to deprivation measures such as the Area Deprivation Index to help encourage shared decision-making strategies that focus on health literacy and common barriers related to access. Given the potential influence social deprivation may have on the outcome and utilization of TJA, hospitals should identify methods to determine patients who are more socially deprived and provide targeted interventions to help patients overcome any social deprivation they are facing. We encourage physicians to maintain close communication with patients whose circumstances include more severe levels of social deprivation to ensure they have access to the appropriate resources. Additionally, as multiple social deprivation metrics are being used in research, future studies should identify a consistent metric to ensure all patients that are socially deprived are reliably identified to receive appropriate treatment.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The association between socioeconomic status and the 30- and 90-day risk of infection after total hip arthroplasty : a registry-based cohort study of 103,901 patients with osteoarthritis

AIMS

The aim of this study was to examine whether socioeconomic status (SES) is associated with a higher risk of infections following total hip arthroplasty (THA) at 30 and 90 days.

METHODS

We obtained individual-based information on SES markers (cohabitation, education, income, and savings) on 103,901 THA patients from Danish health registries between 1 January 1995 and 31 December 2017. The primary outcome measure was any hospital-treated infection (i.e. all infections). The secondary outcomes were further specified to specific hospital-treated infections (pneumonia, urinary tract infection, and periprosthetic joint infection). The primary timepoint was within 90 days. In addition, the outcomes were further evaluated within 30 days. We calculated the cumulative incidence, and used the pseudo-observation method and generalized linear regression to estimate adjusted risk ratios (RRs) with 95% confidence intervals (CIs) for each marker.

RESULTS

The cumulative incidence of any infection at 90 days was highest in patients who lived alone (1.5% (95% CI 1.3 to 1.6)) versus cohabitant (0.7% (95% CI 0.7 to 0.8)), had the lowest educational achievement (1.1% (95% CI 1.0 to 1.2)) versus highest (0.7% (95% CI 0.5 to 0.8)), had the lowest income (1.6% (95% CI 1.5 to 1.70)) versus highest (0.4% (95% CI 0.3 to 0.5)), or had lowest savings (1.3% (95% CI 1.2 to 1.4)) versus highest (0.7% (95% CI 0.6 to 0.8)). Within 90 days, the RRs for any infection were 1.3 (95% CI 1.2 to 1.4) for patients living alone versus cohabiting, 1.2 (95% CI 1.0 to 1.3) for low education achievement versus high, 1.7 (95% CI 1.4 to 2.1) for low income versus high income, and 1.5 (95% CI 1.4 to 1.8) for low savings versus high savings. The same trends were also seen for any infections within the first 30 days.

CONCLUSION

Our study provides evidence that socioeconomic inequality adversely influences the risk of infection after THA, thus contributing to healthcare disparities and inequalities. We found that living alone, low educational achievement, low income, or low savings were associated with higher risks of infections within the first 30 and 90 days after THA. Therefore, the development of targeted intervention strategies with the aim of increasing awareness of patients identified as being at greatest risk is needed to mitigate the impact of SES on the risk of infections following THA. Cite this article: Bone Joint J 2022;104-B(2):221-226.

Antibiotics- and Heavy Metals-Based Titanium Alloy Surface Modifications for Local Prosthetic Joint Infections

Prosthetic joint infection (PJI) is the second most common cause of arthroplasty failure. Though infrequent, it is one of the most devastating complications since it is associated with great personal cost for the patient and a high economic burden for health systems. Due to the high number of patients that will eventually receive a prosthesis, PJI incidence is increasing exponentially. As these infections are provoked by microorganisms, mainly bacteria, and as such can develop a biofilm, which is in turn resistant to both antibiotics and the immune system, prevention is the ideal approach. However, conventional preventative strategies seem to have reached their limit. Novel prevention strategies fall within two broad categories: (1) antibiotic- and (2) heavy metal-based surface modifications of titanium alloy prostheses. This review examines research on the most relevant titanium alloy surface modifications that use antibiotics to locally prevent primary PJI.

Increasing Reoperations and Failures With Increasing BMI in Patients Undergoing 2-Stage Exchange for Infected Total Hip Arthroplasty

BACKGROUND

While morbid obesity is associated with increased infection after total hip arthroplasty, little is known on the outcomes after 2-stage reimplantation for prosthetic joint infection (PJI) in this population. The purpose of this study is to evaluate the impact of morbid obesity (body mass index>40 kg/m2) on reinfection, postoperative complications, readmissions, and reoperations.

METHODS

We conducted a retrospective review of 107 patients undergoing first time 2-stage reimplantation for PJI from 2013 to 2019. 18 patients (50% women) with body mass index>40 kg/m2 were identified. To minimize confounders, three propensity score matched cohorts were created, yielding 16 nonobese (<30 kg/m2), 16 obese (30-39.9 kg/m2), and 18 morbidly obese (>40 kg/m2) patients. Outcomes were compared using chi-square or Fisher's exact tests. All patients had minimum 12-month follow-up, with mean follow-up of 36.3, 30.1, and 40.0 months in the nonobese, obese, and morbidly obese cohorts, respectively.

RESULTS

Compared with nonobese patients, morbidly obese patients had a higher rate of reinfection (0% vs 33%, P = .020 and higher likelihood of length of stay>4 days (19% vs 61%, P = .012). In addition, compared with nonobese and obese patients, morbidly obese patients had higher rate of return to the operating room for any reason (13% vs 19% vs 50%, respectively, P = .020). No differences between cohorts were found regarding complications, death, or revision surgery.

CONCLUSION

Morbidly obese patients have significantly increased risk of reinfection and reoperation after 2-stage reimplantation for PJI when compared with obese and nonobese patients. These data can be used to counsel morbidly obese patients contemplating total hip arthroplasty and supports the notion of deferring arthroplasty in this population pending optimization.