The Value of Ortho-ID Teams in Treating Bone and Joint Infections

Pharmacokinetic and pharmacodynamic considerations for optimizing antimicrobial therapy used to treat bone and joint infections: an evidence-based algorithmic approach

INTRODUCTION

Bone and joint infections (BJIs) are a major health concern causing remarkable morbidity and mortality. However, which antimicrobial treatment could be the best according to specific clinical scenarios and/or to the pharmacokinetic/pharmacodynamic (PK/PD) features remains an unmet clinical need. This multidisciplinary opinion article aims to develop evidence-based algorithms for empirical and targeted antibiotic therapy of patients affected by BJIs.

AREAS COVERED

A multidisciplinary team of four experts had several rounds of assessment for developing algorithms devoted to empirical and targeted antimicrobial therapy of BJIs. A literature search was performed on PubMed-MEDLINE (until April 2023) to provide evidence for supporting therapeutic choices. Four different clinical scenarios were structured according to specific infection types (i.e. vertebral osteomyelitis, prosthetic joint infections, infected non-unions and other chronic osteomyelitis, and infectious arthritis), need or not of surgical intervention or revision, isolation or not of clinically relevant bacterial pathogens from blood and/or tissue cultures, and PK/PD features of antibiotics.

EXPERT OPINION

The proposed therapeutic algorithms were based on a multifaceted approach considering the peculiar features of each antibiotic (spectrum of activity, PK/PD properties, bone penetration rate, and anti-biofilm activity), and could be hopefully helpful in improving clinical outcome of BJIs.

W. Simpson AH, Sutherland RK, McNally MA. A Survey of Orthopedic Surgical Management of Pressure Ulcer-Related Pelvic Osteomyelitis

Pressure-ulcer related pelvic osteomyelitis is managed with little high-quality evidence. We undertook an international survey of orthopedic surgical management, covering diagnostic parameters, multidisciplinary input, and surgical approaches (indications, timing, wound closure, and adjunctive therapies). This identified areas of consensus and disagreement, representing a starting point for future discussion and research.

Pre-Referral Microbiology in Long Bone Infection: What Can It Tell Us?

Background: It remains unclear how accurately patients’ previous microbiology correlates with that ascertained from deep sampling in long bone infection. This study assessed the quality of microbiology referral information and compared it to the gold standard of intra-operative deep tissue sampling. Methods: All patients referred to a single specialist centre within the UK between January 2019 and March 2020 who received surgery for long bone infection were eligible for inclusion. Data on microbiological testing that was performed prior to referral was collected prospectively at the time of clinic appointment and prior to surgery. Pre-referral microbiology was compared to microbiology from deep tissue samples taken during surgery. Results: 141 patients met the diagnostic criteria for long bone infection and were included for analysis. Of these, 72 patients had microbiological information available at referral from 88 samples, obtained from either sinus swab (n = 40), previous surgical sampling (n = 25), biopsy (n = 19) or blood cultures (n = 4). In 65.9% of samples, pre-referral microbiology was deemed to be a non-match when compared to intra-operative samples. Factors that increased risk of a non-match included presence of a sinus (odd’s ratio (OR) 11.3 [95% CI 2.84−56.6], p = 0.001), increased duration of time from sampling (OR 2.29, [95% CI 1.23−5.90], p = 0.030) and results from prior surgical sampling (OR 23.0 [95% CI 2.80−525.6], p = 0.011). Furthermore, previous surgical debridement gave an increased risk of multi-, extensively or pan-resistant isolates cultured from intra-operative sampling (OR 3.6 [95% CI 1.5−8.7], p < 0.01). Conclusions: We have demonstrated that presence of a sinus, a long time from the sample being taken and results from prior surgical sampling are more likely to give inaccurate representation of current microbiology. Importantly, in cases with previous debridement surgery, there was an increased risk of multi drug resistant isolates which should be planned for in future treatments.

Perioperative myocardial injury and mortality after revision surgery for orthopaedic device-related infection

AIMS

Periprosthetic joint infections (PJIs) and fracture-related infections (FRIs) are associated with a significant risk of adverse events. However, there is a paucity of data on cardiac complications following revision surgery for PJI and FRI and how they impact overall mortality. Therefore, this study aimed to investigate the risk of perioperative myocardial injury (PMI) and mortality in this patient cohort.

METHODS

We prospectively included consecutive patients at high cardiovascular risk (defined as age ≥ 45 years with pre-existing coronary, peripheral, or cerebrovascular artery disease, or any patient aged ≥ 65 years, plus a postoperative hospital stay of > 24 hours) undergoing septic or aseptic major orthopaedic surgery between July 2014 and October 2016. All patients received a systematic screening to reliably detect PMI, using serial measurements of high-sensitivity cardiac troponin T. All-cause mortality was assessed at one year. Multivariable logistic regression models were applied to compare incidence of PMI and mortality between patients undergoing septic revision surgery for PJI or FRI, and patients receiving aseptic major bone and joint surgery.

RESULTS

In total, 911 consecutive patients were included. The overall perioperative myocardial injury (PMI) rate was 15.4% (n = 140). Septic revision surgery for PJI was associated with a significantly higher PMI rate (43.8% (14/32) vs 14.5% (57/393); p = 0.001) and one-year mortality rate (18.6% (6/32) vs 7.4% (29/393); p = 0.038) compared to aseptic revision or primary arthroplasty. The association with PMI persisted in multivariable analysis with an adjusted odds ratio (aOR) of 4.7 (95% confidence interval (CI) 2.1 to 10.7; p < 0.001), but was not statistically significant for one-year mortality (aOR 1.9 (95% CI 0.7 to 5.4; p = 0.240). PMI rate (15.2% (5/33) vs 14.1% (64/453)) and one-year mortality (15.2% (5/33) vs 9.1% (41/453)) after FRI revision surgery were comparable to aseptic long-bone fracture surgery.

CONCLUSION

Patients undergoing revision surgery for PJI were at a risk of PMI and death compared to those undergoing aseptic arthroplasty surgery. Screening for PMI and treatment in specialized multidisciplinary units should be considered in major bone and joint infections. Cite this article: Bone Joint J 2022;104-B(6):696-702.

Soft-tissue reconstruction in lower-leg fracture-related infections: An orthoplastic outcome and risk factor analysis

Introduction Fracture-related infection (FRI) is a severe post-traumatic complication which is occasionally accompanied by a deficient or even avital soft-tissue envelope. In these cases, a thoroughly planned orthoplastic approach is imperative as a vital and intact soft-tissue envelope is mandatory to achieve fracture union and infection eradication. The aim of this study was, to analyse if soft-tissue reconstruction (STR) without complications is associated with a better long-term outcome compared to FRI patients with STR complications. In particular, it was investigated if primary flap failure represented a risk factor for compromised fracture union and recurrence of infection. Patients and Methods Patients with a lower leg FRI requiring STR (local, pedicled and free flaps) who were treated from 2010-18 at the University Hospital Basel were included in this retrospective analysis. The main outcome measure was the success rate of STR, further outcome measures were fracture nonunion and recurrence of infection. Results Overall, 145 patients with lower leg FRI were identified, of whom 58 (40%) received STR (muscle flaps: n = 38, fascio-cutaneous flaps: n=19; composite osteo-cutaneous flap: n = 1). In total seven patients required secondary STR due to primary flap failure. All failures and flap-related complications occurred within the first three weeks after surgery. Secondary STR was successful in all cases. A high Charlson Comorbidity Index Score was a significant risk factor for flap failure (p = 0.011). Out of the 43 patients who completed the 9-month follow-up, 11 patients presented with fracture nonunion and 12 patients with a recurrent infection. Polymicrobial infection was a significant risk factor for fracture nonunion (p = 0.002). Primary flap failure was neither a risk factor for compromised fracture consolidation (p = 0.590) nor for recurrence of infection (p = 0.508). Conclusion: A considerable number of patients with lower-leg FRI required STR. This patient subgroup is complex and rich in complications and the long-term composite outcome demonstrated a high rate of compromised fracture consolidation and recurrent infections. It appears that secondary STR should be performed, as primary flap failure was neither a risk factor for compromised fracture consolidation nor for recurrence of infection. We propose to monitor these patients closely for three weeks after STR.

Candida fracture-related infection: a systematic review

Background: The aim of this study is to summarize and improve knowledge regarding a Candida fracture-related infection (CFRI) through a systematic review on the topic, accompanied by a case report. Methods: A systematic review and meta-analysis based on PRISMA statement were conducted on the CFRI topic. The following combined search terms were used to explore PubMed, Cochrane, and the Embase database: "fungal infection", "candida", "fracture related infection", "bone infection", "orthopedic infection", "internal fixation", "post-traumatic infection", and "osteomyelitis". Results: Out of 1514 records, only 5 case reports matched the selection criteria and were included. Moreover, a new case of CFRI, not previously described, was reported in this paper and reviewed. The main risk factors for CFRI were open wounds (three cases) and immunodeficiency (three cases). Initial improvement of clinical and laboratory signs of infection was noted in all cases. In the available short-term follow-up (mean 12.1 months; range 3-42), the reoperation rate was 33.3 %. Using a strategy based on extensive debridement/resection methods and prolonged systemic antifungal therapy (mean 8.8 weeks; range 6-18), four of six cases (66.6 %) were cured. Bone union occurred in three out of six cases. Conclusion: There is very low-quality evidence available regarding CFRI. Candida infections in surgically treated fractures are rare but difficult-to-treat events, with a slow onset, unspecific symptoms or signs, and a significant relapse risk; therefore, they still represent a current diagnostic challenge. The existing fracture-related infection treatment algorithm combined with long-term systemic antifungal therapy has an anecdotal value and needs more extensive studies to be validated.

Implementation of a multidisciplinary infections conference improves the treatment of spondylodiscitis

Establishing a multidisciplinary approach regarding the treatment of spondylodiscitis and analyzing its effect compared to a single discipline approach. 361 patients diagnosed with spondylodiscitis were included in this retrospective pre-post intervention study. The treatment strategy was either established by a single discipline approach (n = 149, year 2003–2011) or by a weekly multidisciplinary infections conference (n = 212, year 2013–2018) consisting of at least an orthopedic surgeon, medical microbiologist, infectious disease specialist and pathologist. Recorded data included the surgical and antibiotic strategy, complications leading to operative revision, recovered microorganisms, as well as the total length of hospital and intensive care unit stay. Compared to a single discipline approach, performing the multidisciplinary infections conference led to significant changes in anti-infective and surgical treatment strategies. Patients discussed in the conference showed significantly reduced days of total antibiotic treatment (66 ± 31 vs 104 ± 31, p < 0.001). Moreover, one stage procedures and open transpedicular screw placement were more frequently performed following multidisciplinary discussions, while there were less involved spinal segments in terms of internal fixation as well as an increased use of intervertebral cages instead of autologous bone graft (p < 0.001). Staphylococcus aureus and Staphylococcus epidermidis were the most frequently recovered organisms in both patient groups. No significant difference was found comparing inpatient complications between the two groups or the total in-hospital stay. Implementation of a weekly infections conference is an effective approach to introduce multidisciplinarity into spondylodiscitis management. These conferences significantly altered the treatment plan compared to a single discipline approach. Therefore, we highly recommend the implementation to optimize treatment modalities for patients.

A retrospective cohort study comparing clinical outcomes and healthcare resource utilisation in patients undergoing surgery for osteomyelitis in England: a case for reorganising orthopaedic infection services

Aims: An investigation of the impact of a multidisciplinary bone infection unit (BIU) undertaking osteomyelitis surgery with a single-stage protocol on clinical outcomes and healthcare utilisation compared to national outcomes in England. Patients and Methods: A tertiary referral multidisciplinary BIU was compared to the rest of England (ROE) and a subset of the 10 next busiest centres based on osteomyelitis treatment episode volume (Top Ten), using the Hospital Episodes Statistics database (HES). A total of 25 006 patients undergoing osteomyelitis surgery between April 2013 and March 2017 were included. Data on secondary healthcare resource utilisation and clinical indicators were extracted for 24 months before and after surgery. Results: Patients treated at the BIU had higher orthopaedic healthcare utilisation in the 2 years prior to their index procedure, with more admissions (p< 0.001) and a mean length of stay (LOS) over 4 times longer than other groups (10.99 d, compared to 2.79 d for Top Ten and 2.46 d for the ROE, p< 0.001). During the index inpatient period, the BIU had fewer mean theatre visits (1.25) compared to the TT (1.98, p< 0.001) and the ROE (1.64, p= 0.001). The index inpatient period was shorter in the BIU (11.84 d), 33.6 % less than the Top Ten (17.83 d, p< 0.001) and 29.9 % shorter than the ROE (16.88 d, p< 0.001). During follow-up, BIU patients underwent fewer osteomyelitis-related reoperations than Top Ten centres (p= 0.0139) and the ROE (p= 0.0137). Mortality was lower (4.71 %) compared to the Top Ten (20.06 %, p< 0.001) and the ROE (22.63 %, p< 0.001). The cumulative BIU total amputation rate was lower (6.47 %) compared to the Top Ten (15.96 %, p< 0.001) and the ROE (12.71 %, p< 0.001). Overall healthcare utilisation was lower in the BIU for all inpatient admissions, LOS, and Accident and Emergency (A&E) attendances. Conclusion: The benefits of managing osteomyelitis in a multi-disciplinary team (MDT) specialist setting included reduced hospital stays, lower reoperation rates for infection recurrence, improved survival, lower amputation rates, and lower overall healthcare utilisation. These results support the establishment of centrally funded multidisciplinary bone infection units that will improve patient outcomes and reduce healthcare utilisation.

Controversy about the Role of Rifampin in Biofilm Infections: Is It Justified?

Rifampin is a potent antibiotic against staphylococcal implant-associated infections. In the absence of implants, current data suggest against the use of rifampin combinations. In the past decades, abundant preclinical and clinical evidence has accumulated supporting its role in biofilm-related infections.In the present article, experimental data from animal models of foreign-body infections and clinical trials are reviewed. The risk for emergence of rifampin resistance and multiple drug interactions are emphasized. A recent randomized controlled trial (RCT) showing no beneficial effect of rifampin in patients with acute staphylococcal periprosthetic joint infection treated with prosthesis retention is critically reviewed and data interpreted. Given the existing strong evidence demonstrating the benefit of rifampin, the conduction of an adequately powered RCT with appropriate definitions and interventions would probably not comply with ethical standards.

Orthoplastics in Periprosthetic Joint Infection of the Knee: Treatment Concept for Composite Soft-tissue Defect with Extensor Apparatus Deficiency

Introduction: Reconstruction of composite soft-tissue defects with extensor apparatus deficiency in patients with periprosthetic joint infection (PJI) of the knee is challenging. We present a single-centre multidisciplinary orthoplastic treatment concept based on a retrospective outcome analysis over 20 years. Methods and Results: One-hundred sixty patients had PJI after total knee arthroplasty. Plastic surgical reconstruction of a concomitant perigenicular soft-tissue defect was indicated in 47 patients. Of these, six presented with extensor apparatus deficiency. One patient underwent primary arthrodesis and five patients underwent reconstruction of the extensor apparatus. The principle to reconstruct missing tissue 'like with like' was thereby favoured: Two patients with a wide soft-tissue defect received a free anterolateral thigh flap with fascia lata; one patient with a smaller soft-tissue defect received a free sensate, extended lateral arm flap with triceps tendon; and two patients who did not qualify for free flap surgery received a pedicled medial sural artery perforator gastrocnemius flap. Despite good functional results 1 year later, long-term follow-up revealed that two patients had to undergo arthrodesis because of recurrent infection and one patient was lost to follow-up. Conclusion: These results show that PJI of the knee and extensor apparatus deficiency is a dreaded combination with a poor long-term outcome. Standardization of surgical techniques for a defined PJI problem and consensus on study variables may facilitate interinstitutional comparisons of outcome data, and hence, improvement of treatment concepts.

Bone and joint infections of the hand

BACKGROUND

Little guidance is currently available for standardized diagnostic protocols and therapeutic recommendations for bone and joint infections (BJIs) of the hand.

OBJECTIVES

To summarize the available data in the scientific English-language literature on the diagnosis and treatment of native BJIs of the hand. To illustrate these concepts from a narrative point of view in areas where there is lack of evidence.

SOURCES

We performed a systematic PubMed and Internet search of studies that investigated hand BJIs in adult patients.

CONTENT

Few studies have systematically investigated and validated diagnostic concepts, classifications or surgical treatment protocols. Most concepts derive from traditional intra-institutional experience, expert opinions and extrapolations from infections in large joints and long bones. Similarly, there is no uniformly accepted infection definition of BJIs of the hand. The best-documented literature is available for microbiological findings and antibiotic treatment duration in uncomplicated native joint arthritis of the fingers. Retrospective studies and one prospective randomized trial suggest that post-surgical targeted antibiotic therapy of 2 weeks results in a microbiological cure rate of ≥88%.

IMPLICATIONS

Studies on diagnostic workup and infection definition and classification are urgently needed to compare inter-institutional outcome results and generate guidelines for the best patient care. For uncomplicated pyogenic arthritis of native joints, current evidence suggests that a 2-week course of antibiotic therapy following surgery cures the infection.