Implant retention in a rabbit model of fracture-related infection.

Aims: Fracture-related infection (FRI) is commonly classified based on the time of onset of symptoms. Early infections (< two weeks) are treated with debridement, antibiotics, and implant retention (DAIR). For late infections (> ten weeks), guidelines recommend implant removal due to tolerant biofilms. For delayed infections (two to ten weeks), recommendations are unclear. In this study we compared infection clearance and bone healing in early and delayed FRI treated with DAIR in a rabbit model. Methods: Staphylococcus aureus was inoculated into a humeral osteotomy in 17 rabbits after plate osteosynthesis. Infection developed for one week (early group, n = 6) or four weeks (delayed group, n = 6) before DAIR (systemic antibiotics: two weeks, nafcillin + rifampin; four weeks, levofloxacin + rifampin). A control group (n = 5) received revision surgery after four weeks without antibiotics. Bacteriology of humerus, soft-tissue, and implants was performed seven weeks after revision surgery. Bone healing was assessed using a modified radiological union scale in tibial fractures (mRUST). Results: Greater bacterial burden in the early group compared to the delayed and control groups at revision surgery indicates a retraction of the infection from one to four weeks. Infection was cleared in all animals in the early and delayed groups at euthanasia, but not in the control group. Osteotomies healed in the early group, but bone healing was significantly compromised in the delayed and control groups. Conclusion: The duration of the infection from one to four weeks does not impact the success of infection clearance in this model. Bone healing, however, is impaired as the duration of the infection increases.

Fracture-related infection.

Musculoskeletal trauma leading to broken and damaged bones and soft tissues can be a life-threating event. Modern orthopaedic trauma surgery, combined with innovation in medical devices, allows many severe injuries to be rapidly repaired and to eventually heal. Unfortunately, one of the persisting complications is fracture-related infection (FRI). In these cases, pathogenic bacteria enter the wound and divert the host responses from a bone-healing course to an inflammatory and antibacterial course that can prevent the bone from healing. FRI can lead to permanent disability, or long courses of therapy lasting from months to years. In the past 5 years, international consensus on a definition of these infections has focused greater attention on FRI, and new guidelines are available for prevention, diagnosis and treatment. Further improvements in understanding the role of perioperative antibiotic prophylaxis and the optimal treatment approach would be transformative for the field. Basic science and engineering innovations will be required to reduce infection rates, with interventions such as more efficient delivery of antibiotics, new antimicrobials, and optimizing host defences among the most likely to improve the care of patients with FRI.

Local Application of a Gentamicin-Loaded Hydrogel Early After Injury Is Superior to Perioperative Systemic Prophylaxis in a Rabbit Open Fracture Model.

OBJECTIVES: Open fractures are at significant risk of developing a fracture-related infection, despite the routine administration of perioperative antibiotic prophylaxis. Early application of antibiotic prophylaxis is known to reduce infection rates; however, most international guidelines focus on postoperative duration rather than prehospital administration. We compared conventional perioperative prophylaxis against early prehospital prophylaxis either as a systemic single shot of cefuroxime or a locally applied gentamicin-loaded hydrogel in a laboratory animal model. METHODS: Thirty New Zealand white rabbits underwent a first surgical procedure to create an open wound, bone damage and contamination with Staphylococcus aureus. After a 4-hour observation period mimicking the time-to-treatment, the animals underwent a second procedure to irrigate the wound and apply a fracture fixation device. The 5 groups (n = 6 per group) received (1) no treatment; (2) conventional 24-hour cefuroxime; (3) an early single shot of cefuroxime 15 minutes after trauma; (4) a combined early and standard systemic prophylaxis; and (5) early application of a gentamicin-loaded hydrogel that was removed during irrigation. RESULTS: Untreated animals displayed high numbers of bacteria in irrigation fluid and were all highly culture positive at euthanasia. Three of 6 animals were culture positive at euthanasia after conventional prophylaxis. Early systemic prophylaxis reduced bacterial burden in irrigation fluid by up to 100-fold, but 5/6 animals were culture positive at euthanasia. The combined prophylaxis displayed greater efficacy with only 1/6 rabbits culture positive at euthanasia. Local application of the gentamicin-loaded hydrogel reduced bacteria recovered by irrigation to just above our detection limit, and at euthanasia, all animals were culture negative at euthanasia. CONCLUSIONS: Early systemic antibiotic administration can significantly reduce bacterial burden in the operative field and reduce culture positivity at euthanasia when continued for 24 hours after injury. The early application of a gentamicin-loaded hydrogel that was removed during irrigation displayed superior efficacy to early systemic therapy alone and postoperative conventional gold standard 24-hour systemic therapy alone. These experimental results highlight the importance of early antibiotic administration in fracture care.

Luxación acromioclavicular aguda: placa gancho vs. suturas coracoclaviculares / Comparison between hook plate and sutures reconstruction in acute acromial-clavicular dislocation

Introducción: aunque las luxaciones acromioclaviculares son lesiones traumáticas frecuentes, no existe un consenso sobre el tratamiento quirúrgico de elección para el manejo del escenario de una luxación aguda. Tanto la placa gancho como la reconstrucción coracoclavicular con suturas de anclaje son opciones terapéuticas en el arsenal quirúrgico para realizar reducción y cicatrización acromioclavicular. Este estudio busca comparar ambas técnicas para evaluar cuál es mejor en disminución de recidivas y recuperación de la función. Materiales y métodos: se realizó un ensayo clínico controlado con 36 pacientes que consultaron a la Clínica de Hombro y Codo del Hospital Pablo Tobón Uribe con diagnóstico de luxación acromioclavicular grado III a V según la clasificación de Rockwood entre septiembre de 2008 y febrero de 2011. Se asignaron de forma aleatoria a un grupo de tratamiento quirúrgico con placa gancho o a un grupo de tratamiento quirúrgico con suturas coracoclaviculares. Resultados: se incluyeron 36 pacientes que se aleatorizaron en un grupo de 19 (52,8 %) pacientes tratados con reconstrucción coracoclavicular con suturas de anclaje y otro grupo de 17 (47,2 %) pacientes tratados con reducción acromioclavicular directa con placa gancho. El grado de luxación más frecuente fue IV según la escala de Rockwood (47,2 %) seguido por el grado III (41,7 %). Al completar la mitad del reclutamiento de los pacientes se realizó un análisis de los resultados y se encontró una diferencia significativa en ambos grupos en cuanto a la incidencia de recidivas (52,6 % en el grupo de sutura y 23,5 % en el grupo de placa gancho), por lo que el estudio fue suspendido en este punto. Los promedios de funcionalidad de Constant total fueron similares para ambos grupos al igual que la percepción (análisis funcional del puntaje de Constant). Discusión: este estudio concluyó que la técnica de reparación con suturas coracoclaviculares tiene una recidiva mayor que la técnica con placa gancho acromioclavicular. Teniendo en cuenta las limitaciones del presente trabajo, es necesaria la realización de nuevos estudios encaminados a entender las causas de la recidiva con las suturas coracoclaviculares.