The Paradox of Prosthetic Joint Infection and the Microbiome: Are Some Bacteria Actually Helpful?

Antibiotic-Loaded Calcium Sulphate Beads for Treatment of Acute Periprosthetic Joint Infection in Total Knee Arthroplasty: Results Based on Risk Stratification

Background: A post-operative or late acute periprosthetic joint infection (PJI) after Total Knee Arthroplasty (TKA) requires a protocol of aggressive joint Debridement, modular implant Exchange, Component Retention, and post-operative Antimicrobial therapy (DECRA). Recently, the novel addition of intra-articular Antimicrobial Loaded Calcium Sulphate (AL-CaSO4) beads during DECRA has been utilized to improve microbial eradication. This study reviews a consecutive series of DECRA TKA procedures with AL-CaSO4 beads with a standardized antimicrobial regimen. We hypothesize AL-CaSO4 beads will not improve infection-free implant survival in compromised hosts and limbs. Methods: This consecutive series included DECRA procedures for acute post-operative or late hematogenous PJI-TKA (primary and revision) detected within 4 weeks. One gram of vancomycin powder and 240 mg of liquid tobramycin were added to 10 cc of CaSO4 powder to create 3.0 and 4.8 mm beads delivered into the joint at closure. All patients were risk stratified according to McPherson Staging and followed for a minimum of 1 year. Results: Forty-two patients were studied. The infection-free success rate of DECRA with AL-CaSO4 was 62% (26/42) at 1 year. Average bead volume per case was 18.6 cc (range = 10-40 cc). McPherson Host stage and Limb Score were found to be significantly correlated with the success of the DECRA (p < 0.05). The success rate was highest in A-hosts (87.5%), declining to 50% in B-hosts, and 25% in C-hosts. Similarly, the success rate was highest for patients with Limb score 1 (100%), declining to 58.6% with Limb score 2, and 20% with Limb score 3. Importantly, a previous episode of infection in the affected joint was associated with significantly increased failure (p = 0.000025). Conclusions: This study reports an overall higher infection-free success rate of DECRA using AL-CaSO4 beads compared to the current literature. Antibiotic beads provide an advantage in selected groups that include A or B hosts and Limb scores of 1 or 2. In C-hosts, where the immune system is weak, or Limb score 3, where the wound is compromised and leaks, antibiotic beads do not improve success. Importantly, DECRAs should not be considered curative with a prior history of joint infection. In these difficult circumstances, one should consider an exchange protocol.

Clostridium difficile Infection Prior to Total Hip Arthroplasty Independently Increases the Risk of Periprosthetic Joint Infection

BACKGROUND

Periprosthetic joint infection (PJI) following total hip arthroplasty (THA) is associated with major morbidity. There may be a link between the gut microbiome and an individual's overall immune system. A Clostridium difficile (C. difficile) infection portends poor gut microbiome health and has been previously associated with increased 90-day complication rates in total joint arthroplasty (TJA). The purpose of this study was to determine the effect of a previous history of C. difficile infection within 2 years of undergoing THA on PJI within 2 years postoperatively.

METHODS

Patients undergoing THA from 2010 to 2021 were identified in a patient claims database (n = 770,075). Patients who had active records 2 years before and after THA as well as a history of C. difficile infection within 2 years prior to THA (n = 1,836) were included and propensity matched to a control group using age, sex, and Elixhauser comorbidity index. The primary outcome was the 2-year incidence of postoperative PJI. The exposed C. difficile infection cohort was stratified into 4 groups based on the time proximity of the C. difficile infection. Chi-square tests and logistic regressions were used to compare the groups.

RESULTS

A C. difficile infection anytime within 2 years prior to total hip arthroplasty was independently associated with higher odds of PJI (OR [odds ratio]: 1.49 [95% CI (confidence interval) 1.09 to 2.02, P = .014]). Proximity of C. difficile infection to arthroplasty was associated with increased risk of PJI (infection 0 to 3 months before THA: OR 2.01 [95% CI 1.23 to 3.20], infection 3 to 6 months before THA: OR 1.84 [95% CI 1.06 to 3.04], infection 6 to 12 months before THA: OR 1.10 [95% CI 0.65 to 1.77], infection 1 to 2 years before THA: OR 1.40 [95% CI 0.94 to 2.06]).

CONCLUSIONS

A C. difficile infection prior to THA is an independent risk factor for PJI. Proximity of C. difficile infection is associated with increased risk of PJI. Future investigations should evaluate how to adequately optimize patients prior to THA and pursue strategies to determine appropriate timing for proceeding with THA.

The influence of gut microbiome on periprosthetic joint infections: State-of-the art

Early periprosthetic joint infection constitutes one of the most frightening complications of joint replacement. Recently, some evidence has highlighted the potential link between dysregulation of the gut microbiota and degenerative diseases of joints. It has been hypothesized that microbiome dysbiosis may increase the risk of periprosthetic joint infection by facilitating bacterial translocation from these sites to the bloodstream or by impairing local or systemic immune responses. Although the processes tying the gut microbiome to infection susceptibility are still unknown, new research suggests that the presurgical gut microbiota-a previously unconsidered component-may influence the patient's ability to resist infection. Exploring the potential impact of the microbiome on periprosthetic joint infections may therefore bring new insights into the pathogenesis and therapy of these disorders. For a successful therapy, a proper surgical procedure in conjunction with an antibacterial concept is essential. As per the surgical approach, different treatment strategies include surgical irrigation, debridement, antibiotic therapy, and implant retention with or without polyethylene exchange. Other alternatives could be one-stage or two-stage revisions surgery. Interventions that either directly target gut microbes as well as interventions that modify the composition and/or function of the commensal microbes represent an innovative and potentially successful field to be explored. In recent times, innovative therapeutic methods have arisen in the realm of microbiome restoration and the management of gut-related ailments. These progressive approaches offer fresh perspectives on tackling intricate microbial imbalances in the gastrointestinal tract. These emerging therapies signify a shift towards more precise and individualized approaches to microbiome restoration and the management of gut-related disorders. Once a more advanced knowledge of the pathways linking the gut microbiota to musculoskeletal tissues is gained, relevant microbiome-based therapies can be developed. If dysbiosis is proven to be a significant contributor, developing treatments for dysbiosis may represent a new frontier in the prevention of periprosthetic joint infections.

A Proposal for a Multidisciplinary Integrated Oral Health Network for Patients Undergoing Major Orthopaedic Surgery (IOHN-OS)

The passing of the years of life physiologically leads to the accumulation of changes in tissues in the oral cavity, influencing dentition, chewing and swallowing mechanisms, and the oral microbiota. Some diseases and medications can aggravate oral symptoms and negatively influence eating behaviours, increasing the likelihood of becoming malnourished. This could make older individuals more vulnerable to complications when undergoing major orthopaedic surgery. Hidden infection foci in the oral cavity are a recognised cause of post-operative periprosthetic joint infections. Dysfunctional oral problems might also compromise feeding after surgery when good nutrition represents a fundamental aspect of a proper recovery. To manage these shortcomings, in this article, the authors hypothesise a multidisciplinary path of care named the Integrated Oral Health Network applied to major Orthopaedic Surgery (IOHN-OS). This peri-operative initiative would include pre-operative oral health screening and risk management by a dental team, patient education programmes before and after surgery, and bedside gerodontology actions like oral care and meal and eating support for fragile individuals. The IOHN-OS has the potential to reshape the concept of suitability for major orthopaedic surgery and generate momentum for designing community-based surveillance programmes that can keep the mouths of older subjects healthy for a long time.