Is there a role for suppression of infection in managing fracture-related infection following intra-medullary nailing?

BACKGROUND: The management of fracture-related infection has undergone radical progress following the development of international guidelines. However, there is limited consideration to the realities of healthcare in low-resource environments due to a lack of available evidence in the literature from these settings. Initial antimicrobial suppression to support fracture union is frequently used in low- and middle-income countries despite the lack of published clinical evidence to support its practice. This study aimed to evaluate the outcomes following initial antimicrobial suppression to support fracture union in the management of fracture-related infection. METHODS: A retrospective review of consecutive patients treated with initial antimicrobial suppression to support fracture healing followed by definitive eradication surgery to manage fracture-related infections following intramedullary fixation was performed. Indications for this approach were; a soft tissue envelope not requiring reconstructive surgery, radiographic evidence of stable fixation with adequate alignment, and progression towards fracture union. RESULTS: This approach was associated with successful treatment in 51/55 (93 %) patients. Fracture union was achieved in 52/55 (95 %) patients with antimicrobial suppression alone. Remission of infection was achieved in 54/55 (98 %) patients following definitive infection eradication surgery. Following antibiotic suppression, 6/46 (13 %) pathogens isolated from intra-operative samples demonstrated multi-drug resistance. CONCLUSION: Initial antimicrobial suppression to support fracture healing followed by definitive infection eradication surgery was associated with successful treatment in 93 % of patients. The likelihood of remission of infection increases when eradication surgery is performed in a healed bone. This approach was not associated with an increased risk of developing multi-drug-resistant infections compared to contemporary bone infection cohorts in the published literature. LEVEL OF EVIDENCE: IV.

The role of implant retention and conservative management in the management of fracture-related infection.

Fracture-related infection (FRI) management has advanced considerably in recent years, offering new possibilities for predictable rates of infection eradication. Debridement, antibiotics, and implant retention (DAIR) procedures have shown promise in the treatment of early FRI. This article provides an overview of the principles and indications of DAIR, including the importance of meticulous debridement and the management of dead space. The outcomes of DAIR are discussed, highlighting the range of fracture union rates reported in the literature. The role of antimicrobial suppression in optimizing host biology and facilitating surgical intervention is also explored. While further research is needed to establish optimal treatment strategies, DAIR offers a valuable treatment approach for FRI when specific criteria are met. Level of evidence: IV.

The 2023 Orthopedic Research Society's international consensus meeting on musculoskeletal infection: Summary from the in vitro section.

Antimicrobial strategies for musculoskeletal infections are typically first developed with in vitro models. The In Vitro Section of the 2023 Orthopedic Research Society Musculoskeletal Infection international consensus meeting (ICM) probed our state of knowledge of in vitro systems with respect to bacteria and biofilm phenotype, standards, in vitro activity, and the ability to predict in vivo efficacy. A subset of ICM delegates performed systematic reviews on 15 questions and made recommendations and assessment of the level of evidence that were then voted on by 72 ICM delegates. Here, we report recommendations and rationale from the reviews and the results of the internet vote. Only two questions received a ≥90% consensus vote, emphasizing the disparate approaches and lack of established consensus for in vitro modeling and interpretation of results. Comments on knowledge gaps and the need for further research on these critical MSKI questions are included.

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.

Outcomes, Microbiology and Antimicrobial Usage in Pressure Ulcer-Related Pelvic Osteomyelitis: Messages for Clinical Practice.

Introduction: Pressure ulcer-related pelvic osteomyelitis is a relatively under-studied entity in the field of bone infection. We sought to add to the limited evidence base for managing this challenging syndrome. Methods: Cases were identified retrospectively from a surgical database and hospital discharge codes at a U.K. tertiary centre (2009-2018). Risk factors associated with outcomes were analysed by logistic regression. Results: We identified 35 patients (mean age 57.4 years), 69% managed with a combined medical and surgical approach, with mean follow-up of 3.7 years from index admission. Treatment failure (requiring further surgery or intravenous antimicrobials) occurred in 71% and eventual ulcer healing in 36%. One-year mortality was 23%. Lack of formal care support on discharge, post-traumatic (asensate) neurological deficit and index CRP (>184mg/L) were associated with treatment failure (p=0.001). Age (>59.5 years), lack of attempted soft tissue coverage, haemoglobin (<111g/L) and albumin (<25g/L) were associated with non-healing ulcers (p=0.003). Superficial wound swabs had low sensitivity and specificity compared to deep bone microbiology. Infection (based on deep bone microbiology from 46 infection episodes) was usually polymicrobial (87%), commonly involving S. aureus, Enterococci, GNB and anaerobes. Antimicrobial duration ranged from 0-103 days (mean 54) and was not associated with subsequent treatment failure. Conclusions: Attempted soft tissue coverage after surgical debridement, ensuring appropriate support for personal care after discharge and nutritional optimisation could improve outcomes. Superficial wound swabs are uninformative and deep bone sampling should be pursued. Long antimicrobial courses do not improve outcomes. Clinicians should engage patients in anticipatory care planning.

Human monoclonal antibody GNX-8 directed to extended type 1 chain: Specific binding to human colorectal cancer.

We observed previously that two carbohydrate epitopes, extended type 1 chain Le(a)-Le(a) and Le(b)-Le(a), are expressed strongly in human gastric or colorectal cancer and cell lines derived therefrom, but their expression in human normal colorectal cells is highly limited. A monoclonal antibody, termed GNX-8, was established through immunization of "KM mice" with colonic cancer cell line Colo205, and with purified Le(b)-Le(a) glycosphingolipid, followed by screening human IgG directed to this antigen. KM mice possess human chromosome fragments and are capable of producing human immunoglobulin. GNX-8 reacted specifically with extended type 1 chain epitope Le(b)-Le(a), bound to all five colonic cancer cell lines so far tested, and displayed strong complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC). The antigens defined by GNX-8, expressed in Colo205 cells, were: (i) glycosphingolipids with epitope Le(b)-Le(a), whose reactivity was abolished upon defucosylation; (ii) glycoproteins with molecular mass range from 32 to >175 kDa, which were depleted in cells cultured in the presence of benzyl-alpha-GalNAc, indicating that these epitopes are O-linked glycans.Immunohistological reactivity of GNX-8 at 1 mug/ml, applied on tissue sections from colorectal and various other types of cancer, was much stronger than that with various normal cells and tissues. GNX-8 reactivity with normal cells required a much higher concentration (150 mug/ml), and this reactivity was based on cross-reaction with non-extended, normal blood group Le(b) antigen. Growth of subcutaneous xenograft of human colonic cancer cells, Colo205 or DLD-1, in nude mice or SCID mice, was strongly inhibited by administration of GNX-8. These observations, taken together, indicate that antibody GNX-8, directed specifically to Le(b)-Le(a) antigen, provides a novel direction of immunotherapy for human colorectal cancer. (c) 2009 UICC.