Antibiotic cement-coated rigid locked nails in infected femoral and tibial nonunion. Reoperation rates of commercial versus custom-made nails.

INTRODUCTION: The objective of this study is to assess bone union, infection control, and reoperation rates in a series of patients with infected femoral or tibial nonunion treated with antibiotic-cement-coated rigid nails and to compare the results obtained with custom-made nails versus commercial nails. METHODS: We retrospectively analyzed a series of consecutive patients with infected nonunion of the femur or the tibia treated with antibiotic-cement-coated rigid nails between January 2010 and 2020. We assessed patients' distinctive characteristics, initial injury, type of nail used (custom-made nail with vancomycin or commercial nail with gentamicin), success rate (bone union + infection control), reoperation rate, and failure rate. Comparative analyses were conducted between reoperated and non-reoperated patients regarding the type of nail used. A multivariate regression analysis was performed to assess the risk variables that impacted reoperation rates. RESULTS: We included 54 patients with 22 (40.74%) infected femoral nonunions and 32 (59.25%) tibial nonunions, who were treated with 38 (70.37%) custom-made antibiotic-cement coated nails and 16 (29.62%) commercial nails. Bone union and infection control were achieved in 51 (94.44%) cases. The reoperation rate was 40.74% (n = 22), and the failure rate was 5.55% (n = 3). The use of custom-made nails was associated with a higher risk of reoperation (Odds Ratio 4.71; 95% Confidence Interval 1.10 - 20.17; p = 0.036). CONCLUSION: Antibiotic-cement-coated nails reached a 94.44% success rate. Nails manufactured in the OR coated with vancomycin cement were associated with a higher risk of reoperation than commercial nails loaded with gentamicin cement. LEVEL OF EVIDENCE: III comparative, observational, non-randomized.

Osteomielite: perfil epidemiológico e desfechos verificados em pacientes internados em um hospital público de Curitiba / Osteomyelitis: epidemiologic profile and outcomes of inpatients of a public hospital in Curitiba

Introdução: Osteomielite é inflamação aguda ou crônica de ossos trabeculares ou corticais, periósteo, medula óssea e tecidos moles próximos. É classificada pela localização dentro do osso, extensão da dispersão e fonte de infecção. Objetivo: Avaliar os aspectos epidemiológicos dos pacientes internados com osteomielite e analisar relação entre o tempo de internamento e fatores correlatos.Métodos: Estudados dados de 33 pacientes de uma seleção inicial de 42 prontuários. Resultados: O grupo de 0 a 20 anos com 8 (24,4%) pacientes ficou 18 ± 24 dias, 13 (39,4%) adultos jovens (21 a 40 anos): 12,3 ± 12,4 d; 6 (18,1%) adultos (41 a 60 anos) e 6 (18,1%) >60 anos receberam cuidados hospitalares por 31,8 ± 36 e 19,6 ± 15,8 dias respectivamente. O periodo maior de permanência foi de 91 dias. O etilismo (6%), o tabagismo (6%) e o diabetes (6%) foram as comorbidades mais encontradas. A mortalidade foi de 15%, sendo que 60% eram usuários de álcool. O perfil epidemiológico também mostrou o predomínio do sexo masculino na faixa de 21 a 40 anos e o principal agente infeccioso encontrado foi S. aureus. Conclusão: A alta taxa de mortalidade em indivíduos maiores de 50 anos, com maior permanência hospitalar e presença de comorbidades como o etilismo e diabetes mellitus alerta para a necessidade de planejamento estratégico visando intervenções que diminuam prejuízos tanto para o paciente quanto para o sistema de saúde.

Introduction: Osteomyelitis is an acute or chronic inflammation of trabecular or cortical bones, periosteum, bone marrow, and nearby soft tissue. It is classified by location within the bone, extent and source of infection. Objective: Assess the epidemiological aspects of hospitalized patients with osteomyelitis and analyze the relationship between length of stay and correlated factors. Methods: Data were collected from 33 patients from an initial selection of 42. Results: The groups were arranged as follows: 8 (24.4%) individuals from 0-20 yo and with a hospital stay of 18 ± 24 d; 13 (39.4%) young adults (21-40 yo) and 12.3 ± 12.4 d; 6 (18.1%) adults (41-60 yo) and 31.8 ± 36 d; and 6 (18.1%) over 60 yo who were under hospital care for 19.6 ± 15.8 d. The longest period of hospital stay was 91 days. Alcoholism (6%), smoking habits (6%) and diabetes (6%) were the most common comorbidities. Mortality rate was 15%, among which 60% were alcohol users. The epidemiologic profile also showed that the majority of the hospitalized were males between the ages 21-40 yo and the most common infective agent was S. aureus. Conclusion: the high mortality rate in individuals over 50, with comorbidities and longer hospital stays highlights the need for strategic planning yielding interventions that diminish harm to the patients and the health system.

[Infected nonunion: diagnostic and therapeutic work-up]. / Infizierte Pseudarthrose: diagnostischer und therapeutischer Ablauf.

BACKGROUND: Septic nonunion is one of the major complications in fracture healing. The challenge is to identify the infection as the cause of nonunion first and then to achieve healing of the infection and the bone. OBJECTIVE: Because of the more heterogeneous appearance of an infected nonunion, the prevalence of germ detection in surgical nonunion revision is often underestimated. MATERIAL AND METHODS: In a retrospective study between 2010 and 2017, 86 patients with radiologically confirmed femoral shaft nonunion without clinical evidence and unremarkable medical history of a florid infection as the cause of nonunion, who had undergone primary single-stage surgical nonunion revision were analyzed. At least four intraoperatively obtained samples were evaluated for microbiological diagnosis. A distinction was made between tissue samples with subsequent 48­h short-term incubation and tissue samples with 14-day long-term cultivation. The finding "germ detection" was made if at least two of the samples demonstrated bacterial growth. RESULTS: In 18 of 86 patients with a nonunion preoperatively judged to be aseptic, positive bacterial evidence was obtained after short-term incubation. After long-term cultivation, positive bacterial detection was possible in 38 of 86 patients with a femoral shaft nonunion initially classified as aseptic. Regarding potential risk factors, the two groups demonstrated no relevant differences. In 29 patients, 1 pathogen was isolated from the obtained samples, whereas in the remaining 9 patients, a mixed culture with an average of 2.9 ± 0.5 different bacteria was detected. Identification revealed mainly low-virulence bacteria, most commonly Staphylococcus epidermidis. CONCLUSION: If the preoperative diagnostics including clinical, laboratory and radiological examination as well as a careful anamnesis reveal indications of a possible infectious event, the surgical nonunion revision should be performed in two stages with specimen collection before definitive nonunion revision. For microbiological diagnosis, several representative tissue samples should independently be obtained from the nonunion site and incubated for 14 days. Only in the absence of evidence of septic nonunion is a single-stage procedure suggested.

Chronic recurrent multifocal osteomyelitis in pediatrics in a tertiary center / Osteomielitis crónica multifocal recurrente en pediatría en un hospital terciario

ABSTRACT Introduction: Chronic recurrent multifocal osteomyelitis (CRMO), also called chronic non-bacterial osteomyelitis, is an autoinflammatory disease characterized by bone involvement, recurrent flare-ups, and the lack of microbiological isolation. It is a diagnosis of exclusion, and the fundamental basis of treatment is non-steroidal anti-inflammatory drugs. The objective of the study is to describe our experience as a result of three girls diagnosed with CRMO, highlighting the clinical presentation, the findings in the complementary tests, the treatment, and the evolution of the disease. Patients and methods: Retrospective chart review of children with CRMO in the last 5 years, being followed-up in a pediatric rheumatology clinic in a tertiary center. Results: The cases are presented of 3 patients diagnosed with CRMO, all of them young girls, with a mean age of 11 years, who consulted due to pain and functional impotence. It was in single location in two cases, and the other with several sources of pain, at cervical and lumbar level, associated with weakness of the upper and lower limbs. Two of the cases received antibiotic treatment. One girl responded to treatment with anti-inflammatory drugs and another required combining corticosteroids. The remaining case, in addition to anti-inflammatory drugs and corticosteroids, required intravenous pamidronate. Conclusions: With this study, and despite the small sample size, the aim was to highlight the importance of this, in many cases unknown and underdiagnosed, pathology, and to stress the importance of establishing a diagnostic and therapeutic protocol for the correct approach to this disease.

RESUMEN Introducción: La osteomielitis crónica multifocal recurrente (OCMR), también conocida como osteomielitis crónica no bacteriana, es una enfermedad autoinflamatoria caracterizada por afectación ósea, de curso en brotes y en ausencia de aislamiento microbiológico. El diagnóstico es de exclusión y el pilar fundamental del tratamiento son los antiinflamatorios no esteroideos (AINES). El objetivo del estudio es describir nuestra experiencia de tres niñas diagnosticadas de OCMR, destacando la presentación clínica, los hallazgos en las pruebas complementarias, el tratamiento y la evolución de la enfermedad. Pacientes y métodos: Revisión retrospectiva de historias clínicas de niños diagnosticados de OCMR en los últimos cinco años, en seguimiento en consulta de reumatología pediátrica de un hospital terciario. Resultados: Presentamos tres pacientes diagnosticadas de OCMR, todas ellas mujeres adolescentes, con media de edad de 11 años. Consultaron por dolor e impotencia funcional, dos en una única localización y la otra por varios focos de dolor, a nivel cervical y lumbar, asociando debilidad de miembros superiores e inferiores. Con respecto al tratamiento, dos recibieron tratamiento antibiótico. Una niña respondió a antiinflamatorios; otra precisó asociar corticoides, y la restante, además de antiinflamatorios y corticoides, necesitó pamidronato intravenoso. Conclusiones: Con este estudio y a pesar del pequeño tamaño muestral, se pretende resaltar la importancia de esta patología, en muchos casos desconocida e infradiagnosticada, e insistir en la importancia de establecer un protocolo diagnóstico y terapéutico para su correcto abordaje.

Brucellosis and sacroiliitis: A differential diagnosis to keep in mind / Sacroiliitis por brucelosis: Un diagnóstico diferencial para tener presente

ABSTRACT Brucellosis is a zoonosis that causes a multi-organ granulomatous infection. It has diverse and non-specific clinic features that can make diagnosis difficult. Medical personnel often do not recognize it early. Delayed treatment is associated with high morbidity and even mortality. Its timely diagnosis requires a high index of suspicion. The case is presented of a 35-year-old male zootechnologist, previously healthy, with a progressive picture of two months of evolution of irradiated low back pain to the left hip, nocturnal diaphoresis, and unintentional weight loss. Elevation of acute phase reactants was documented and magnetic resonance imaging found signs of iliopsoas tendonitis and inflammatory changes in the left sacroiliac joint. The IgG and IgM antibodies using an immunoassay forbrucella were positive. After establishing antibiotic treatment, a marked clinical improvement, with resolution of the inflammatory process was evident.

RESUMEN La brucelosis es una zoonosis que genera una infección granulomatosa multiorgánica. Tiene una clínica diversa e inespecífica que puede hacer difícil el diagnóstico. Con frecuencia, el personal médico no la reconoce de forma temprana. El retraso en el tratamiento se asocia con una gran morbilidad e incluso mortalidad. Su diagnóstico oportuno requiere un alto índice de sospecha. Se presenta el caso de un hombre de 35 arios, zootecnista, previamente sano, con un cuadro progresivo de dos meses de evolución de dolor lumbar irradiado a cadera izquierda, diaforesis nocturna y pérdida no intencional de peso. Se documentó elevación de reactantes de fase aguda y en la resonancia magnética se encontraron signos de tendinitis del psoas y cambios inflamatorios en la articulación sacroilíaca izquierda. Los anticuerpos IgG e IgM por inmunoensayo para Brucella fueron positivos, y luego de instaurar tratamiento antibiótico se evidenció marcada mejoría clínica con resolución del proceso inflamatorio.

Paediatric osteoarticular infections caused by staphylococcus aureus producing panton-valentine leucocidin in morocco: Risk factors and clinical features.

OBJECTIVE: We aimed to estimate the prevalence of Staphylococcus aureus producing Panton-Valentine leucocidin (PVL) isolated from children diagnosed with osteoarticular infections (OAIs), and to examine risk factors and clinical features. METHODS: This prospective study was conducted from January 2017 to December 2018. All hospitalised children diagnosed with S. aureus OAI are included. Blood cultures, articular fluids, synovial tissues and/or bone fragments were collected for bacteriological culture. Antimicrobial susceptibility tests were determined by disk diffusion method. Genes encoding methicillin resistance (mecA) and PVL virulence factors (luk-S-PV and luk-F-PV) were detected by multiplex polymerase chain reaction. The demographic, clinical, laboratory, radiographic and clinical features were reviewed prospectively from medical records. RESULTS: A total of 37 children with S. aureus OAIs were included, 46% of them have PVL-positive infection and 70.6% were male. The mean age was 8.12 years (±4.57), and almost were from rural settings (76.5%). Children with Staphylococcus aureus producing Panton-Valentine leucocidin (SA-PVL) were significantly associated with type of infection (P = 0.005), location of infection (P = 0.037) and abnormal X-ray (P = 0.029). All strains SA-PVL+ are sensitive to methicillin, but one strain SA-PVL negative was methicillin-resistant S. aureus, confirmed by gene mecA positive. CONCLUSION: The prevalence of S. aureus infections producing PVL toxin was high in OAIs amongst Moroccan children, mainly due to methicillin-susceptible S. aureus. Type and location of infections and abnormal X-ray were significantly associated with SA-PVL. Routine diagnostic testing of PVL-SA, continuous epidemiological surveillance and multidisciplinary management of OAI is essential to prevent serious complications.

An injectable gellan gum-based hydrogel that inhibits Staphylococcus aureus for infected bone defect repair.

The treatment of infected bone defects in complex anatomical structures, such as oral and maxillofacial structures, remains an intractable clinical challenge. Therefore, advanced biomaterials that have excellent anti-infection activity and allow convenient delivery are needed. We fabricated an innovative injectable gellan gum (GG)-based hydrogel loaded with nanohydroxyapatite particles and chlorhexidine (nHA/CHX). The hydrogel has a porous morphology, suitable swelling ratio, and good biocompatibility. It exerts strong antibacterial activity against Staphylococcus aureus growth and biofilm formation in vitro. We successfully established an infected calvarial defect rat model. Bacterial colony numbers were significantly lower in tissues surrounding the bone in rats of the GG/nHA/CHX group after debride surgery and hydrogel implantation in the defect regions than in rats of the blank group. Rats in the GG/nHA/CHX group exhibited significantly increased new bone formation compared to those in the blank group at 4 and 8 weeks. These findings indicate that gellan gum-based hydrogel with nHA/CHX can accelerate the repair of infected bone defects.

Past and Future of Phage Therapy and Phage-Derived Proteins in Patients with Bone and Joint Infection.

Phage-derived therapies comprise phage therapy and the use of phage-derived proteins as anti-bacterial therapy. Bacteriophages are natural viruses that target specific bacteria. They were proposed to be used to treat bacterial infections in the 1920s, before the discovery and widespread over-commercialized use of antibiotics. Phage therapy was totally abandoned in Western countries, whereas it is still used in Poland, Georgia and Russia. We review here the history of phage therapy by focusing on bone and joint infection, and on the development of phage therapy in France in this indication. We discuss the rationale of its use in bacterial infection and show the feasibility of phage therapy in the 2020s, based on several patients with complex bone and joint infection who recently received phages as compassionate therapy. Although the status of phage therapy remains to be clarified by health care authorities, obtaining pharmaceutical-grade therapeutic phages (i.e., following good manufacturing practice guidelines or being "GMP-like") targeting bacterial species of concern is essential. Moreover, multidisciplinary clinical expertise has to determine what could be the relevant indications to perform clinical trials. Finally "phage therapy 2.0" has to integrate the following steps: (i) follow the status of phage therapy, that is not settled and defined; (ii) develop in each country a close relationship with the national health care authority; (iii) develop industrial-academic partnerships; (iv) create academic reference centers; (v) identify relevant clinical indications; (vi) use GMP/GMP-like phages with guaranteed quality bioproduction; (vii) start as salvage therapy; (vii) combine with antibiotics and adequate surgery; and (viii) perform clinical trials, to finally (ix) demonstrate in which clinical settings phage therapy provides benefit. Phage-derived proteins such as peptidoglycan hydrolases, polysaccharide depolymerases or lysins are enzymes that also have anti-biofilm activity. In contrast to phages, their development has to follow the classical process of medicinal products. Phage therapy and phage-derived products also have a huge potential to treat biofilm-associated bacterial diseases, and this is of crucial importance in the worldwide spread of antimicrobial resistance.

Anaerobio osteomyelitis. A rare condition in children / Osteomielitis por anaerobios. Una entidad poco frecuente en pediatría

ABSTRACT Osteoarticular infections due to anaerobes are very rare in children, with the Fusobacterium genus being the most frequently isolated. The course is usually subacute and, although there are predisposing factors described, most patients do not present with them. Generally, joint fluid cultures are sterile since these microorganisms are very sensitive to contact with oxygen, so they require specific culture media. All of the above causes the diagnosis to be delayed, increasing the risk of long-term sequelae. However, the prognosis improves when treatment is started early. The case is presented of a 10-year-old patient who was admitted for 30 days due septic arthritis of the right hip caused by Fusobacterium nucleatum During the admission, he required three surgical interventions, and completed 6 weeks of effective antibiotic therapy, with a good outcome and remaining asymptomatic at the current time.

RESUMEN Las infecciones osteoarticulares por anaerobios son muy raras en los niños, siendo el género Fusobacterium el que se aisla con más frecuencia. El curso suele ser subagudo y, aunque hay factores predisponentes descritos, la mayoría de los pacientes no los presenta. Generalmente, los cultivos de liquido articular son estériles ya que estos microorganismos son muy sensibles al contacto con el oxigeno, por lo que precisan medios de cultivo específicos. Todo lo anterior hace que el diagnóstico se retrase y que el riesgo de secuelas a largo plazo aumente. Sin embargo, el pronóstico mejora cuando el tratamiento se inicia de modo precoz. Por todo ello, presentamos el caso de un paciente de 10 anos con una artritis séptica de cadera derecha por Fusobacterium nucleatum que permaneció ingresado 30 dias. Durante el ingreso precisó 3 intervenciones quirúrgicas y cumplió 6 semanas de antibioterapia efectiva, con buena evolución; permanece asintomático en el momento actual.

Antibiotic cement plate composite structure internal fixation after debridement of bone infection.

An internal fixation composite structure of antibiotic cement plates was created. The aim of this study was to analyse the infection control effect of this structure when applied to treat a bone infection. We retrospectively analysed patients with bone infection admitted to our hospital between January 2013 and June 2019. After debridement, an antibiotic cement plate composite structure was used to fill and stabilize the defects. The treatment effect was evaluated at six months after surgery, and the infection control rate, factors associated with the recurrence of infection, and complications were analysed. If the patients had bone defects, the defect was repaired after infection control, and the infection control rate of all of the patients was re-evaluated at 12 months after surgery. A total of 548 patients were treated with this technique, including 418 men and 130 women. The infection sites included 309 tibias, 207 femurs, 16 radii and ulnae, 13 humeri, and 3 clavicles. After at least 6 months of follow-up, 92 patients (16.79%) had an infection recurrence and needed further treatment. The recurrence rate of the tibia was higher than that of the femur (P = 0.025). Eighty-nine out of 92 patients who relapsed underwent a second debridement with the same method, and the infection control rate after the second debridement was 94.71%. Complications included 8 cases of epidermal necrosis around the incision, 6 cases of internal fixation failure, and 30 cases of lower limb swelling. By the follow-up time of 12 months, another 6 patients had experienced recurrence of infection, and 4 cases were controlled after debridement. Finally, among all 548 cases, 7 patients remained persistently infected, and 6 underwent amputation. The infection control rate was 97.6% at the 1-year follow-up. The clinical efficacy of this new antibiotic cement plate composite structure for internal fixation after debridement of bone infection is stable and reliable.

Antibacterial, conductive, and osteocompatible polyorganophosphazene microscaffolds for the repair of infectious calvarial defect.

Many osteoconductive and osteoinductive scaffolds have been developed for promoting bone regeneration; however, failures would occur in osteogenesis when the defect area is significantly infected while the biomaterials have no antibacterial performances. Herein, a kind of multipurpose PATGP@PDA + Ag microspheres was prepared via emulsion method by using a conductive aniline tetramer (AT) substituted polyphosphazene (PATGP), followed by polydopamine (PDA) modification and silver nanoparticles (AgNPs) loading. The PATGP@PDA + Ag microspheres demonstrated a strong antibacterial activity against Staphylococcus aureus both in vitro and in vivo, while showing no cytotoxicity at an optimized AgNPs loading amount. Due to the electron-donor structure of the AT moieties, the PATGP@PDA + Ag microspheres displayed antioxidant capacities to scavenge reactive oxygen species (ROS). Due to their phosphorus-rich feature, the PATGP@PDA + Ag microspheres favored the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). As controls, nonconductive microspheres (PAGP@PDA, PAGP@PDA + Ag) were prepared similarly by using poly[(ethylalanine)(ethylglycyl)]phosphazene (PAGP). By co-implanting these microspheres with S. aureus into rat calvarial defects, among them, it was determined that the PATGP@PDA + Ag microspheres achieved the most abundant neo-bone formation, benefiting from their antibacterial, antioxidant and osteogenic activities. These results revealed that AgNPs loaded scaffolds made of conductive polyphosphazenes were promising for the regeneration of infected bone defects.

Adherence to oral antibiotic therapy in patients with bone and joint infection: A pilot study.

OBJECTIVES: The management of bone and joint infections (BJI) is complex and requires prolonged antimicrobial therapy. Few data exist on adherence to anti-infectious treatment other than HIV, and none on BJI, even though compliance is considered as a major determinant of clinical outcome. This work aimed at evaluating adherence to oral antimicrobial treatment in patients with BJI. PATIENTS AND METHODS: This is a prospective observational blinded pilot study evaluating adherence by a 6-item questionnaire at 6 weeks (W6) and 3 months (M3) post-surgery. The primary endpoint was the proportion of patients with high, moderate and poor adherence at W6. Secondary endpoints included change in adherence between W6 and M3, and the exploration of potential variables influencing adherence. RESULTS: Analysis was performed on 65 questionnaires obtained from 43 patients including 35 with device-associated BJI. At W6, 11 out of 34 patients were highly adherent to oral antibiotic therapy, 22 moderately adherent and 1 poorly adherent. There was no significant change in adherence to antibiotic therapy between W6 and M3. The only variable significantly associated with the level of adherence at W6 and M3 was the number of daily doses of antibiotic (P=0.04 and 0.02 at W6 and M3, respectively). CONCLUSIONS: This study provided a snapshot of patients' adherence in BJI. Adherence to antibiotic therapy appeared to be stable up to 3 months and a higher number of daily doses of antibiotic was associated with poorer adherence. These observations need to be confirmed in future large-scale studies using electronic pill monitoring systems.

Actinomicosis ósea del antepié izquierdo. Presentación de un caso / Bone actinomycosis of the left forefoot. Presentation of a case

RESUMEN Se presentó el caso de una actinomicosis ósea, que se manifestó como una lesión de la piel en la zona correspondiente al segundo metatarsiano izquierdo. Por el antecedente de ser la paciente operada de un tumor de células gigantes, se pensó en una recidiva tumoral. Fue intervenida quirúrgicamente y se realizó exéresis del segundo metatarsiano y de la piel afectada. La biopsia informó actinomicosis. Se trató a la paciente con amoxicilina; evolucionando satisfactoriamente, y dando seguimiento en consulta (AU).

ABSTRACT The authors presented the case of a bone actinomycosis expressed as a skin lesion in the area of the second left metatarsals. Due to the antecedent of having undergone a surgery of a giant cell tumor, a tumor recurrence was thought. Surgical intervention was performed and the excision of the second metatarsals and affected skin was performed. The biopsy reported Actinomycosis. The patient was treated with amoxicillin. She had a satisfactory evolution and is still followed up in consultation (AU).

Bacteriophage therapy for bone and joint infections.

Antibiotic resistance represents a threat to human health. It has been suggested that by 2050, antibiotic-resistant infections could cause ten million deaths each year. In orthopaedics, many patients undergoing surgery suffer from complications resulting from implant-associated infection. In these circumstances secondary surgery is usually required and chronic and/or relapsing disease may ensue. The development of effective treatments for antibiotic-resistant infections is needed. Recent evidence shows that bacteriophage (phages; viruses that infect bacteria) therapy may represent a viable and successful solution. In this review, a brief description of bone and joint infection and the nature of bacteriophages is presented, as well as a summary of our current knowledge on the use of bacteriophages in the treatment of bacterial infections. We present contemporary published in vitro and in vivo data as well as data from clinical trials, as they relate to bone and joint infections. We discuss the potential use of bacteriophage therapy in orthopaedic infections. This area of research is beginning to reveal successful results, but mostly in nonorthopaedic fields. We believe that bacteriophage therapy has potential therapeutic value for implant-associated infections in orthopaedics. Cite this article: Bone Joint J 2021;103-B(2):234-244.

Evaluation of imaging features of pelvic echinococcosis based on multimodal images.

BACKGROUND: Hydatid disease (HD) is a zoonotic parasitic disease caused by the larvae of Echinococcus, It is mainly prevalent in pastoral areas. Bone echinococcosis is rare, accounting for 0.5 to 4.0% of all echinococcosis. It is likely to miss the diagnosis and misdiagnose due to non-specific early symptoms and the clinical manifestations and imaging features. The clinical data of 15 patients with pelvic cystic echinococcosis were analyzed retrospectively, and the X-ray, CT, and MRI imaging features of the disease were discussed, which are reported below. METHODS: All 15 patients underwent CT scan evaluation. A total of 8 patients underwent coronal, sagittal, and three-dimensional reconstruction with 3-mm-slice thickness, and 4 patients underwent X-ray plain film examination. Five cases underwent MRI scan. Eight cases underwent MRI or CT enhanced scan. RESULTS: X-ray plain film is characterized by continuous cystic bone destruction, irregular low-density shadow when invading soft tissue, and sometimes calcification which can be seen on the wall or inside the cyst. The involved sacroiliac joint or hip joint may narrow or disappear. The involvement of pelvic cystic echinococcosis is relatively wide, and 80% of patients with pelvic cysts in this group had multiple lesions in the same period. Cystic expansive bone destruction was the most common. Pelvic CT revealed a lobulated hypodense lesion of varying size with internal septae, causing cortical thinning and destruction. Most of them had no periosteal reaction. The iliopsoas muscle is most easily invaded. Single cystic echinococcosis of pelvis showed intermediate or low signal intensity on T1-weighted images and hyperintensity on T2-weighted images in the involved bone and surrounding soft tissue on MRI, and the cyst wall showed linear low signal in T1WI, T2WI, and STIR sequences. The polycystic type is characterized by multiple cysts of varying signal intensity (daughter cysts) within a larger cyst is the typical MRI finding, forming "small vesicles" high signal daughter cysts. Osteosclerosis or calcification showed low signal in T1WI and T2WI. CONCLUSIONS: The results of this study suggest that the lesions of pelvic cystic echinococcosis are mostly cystic expansive and osteolytic bone destruction, which is easy to invade the surrounding soft tissue, often accompanied with calcification; among them, multiple cystic lesions are characteristic.

Lytic lesion of skull: a rare presentation of chronic granulomatous disease.

An 18-month-old boy presented with lytic lesion of skull and recurrent abscesses with Serratia marcescens The extensive work up revealed a gene mutation confirming the diagnosis of chronic granulomatous disease (CGD). This case scenario underscores the importance of exploring the possibility of immunodeficiency if there is a history of recurrent abscesses with atypical organism. The case also demonstrates that CGD can present as lytic lesion of skull.

Two-stage treatment with sliding fibular flap technique for chronic infected nonunion of the tibia.

PURPOSE: To assess the effectiveness of two-stage treatment with the fibular sliding technique in chronic infected nonunion of the tibia. METHODS: The study included patients who were diagnosed with long-term chronic infected tibial nonunion following trauma and treated with the two-stage technique between January 2010 and November 2017. Patients with (1) intra-articular fractures of the distal third of the tibia and fibula, (2) pathological fracture resulting in bone loss or (3) neurological and vascular pathologies of the limbs were excluded. The operation consisted of two stages and the main goal in the first stage was to control the infection and in the second stage to control the healing of the bone. Functional & radiographic results and complications were evaluated according to Paley's criteria. RESULTS: The patients comprised 14 males and 5 females with a mean age of 37.4 years (range, 21-52 years). Patients were followed up for an average of 27 months (range, 15-38 months). The microorganisms produced from these patients were Staphylococcus aureus in 13 patients, Pseudomonas aeruginosa in 4 patients and no bacteria in 2 patients. After the first stage operation, superficial skin necrosis developed in 1 patient. In another patient, there was a persistent infection, although union was achieved. For the entire patient group, union was observed at the end of 7.44 months (range, 7-11 months). Based on Paley's criteria, there were 16 (84.2%) patients with excellent scores, 2 (10.5%) good scores and 1 (5.3%) fair scores radiologically; while regarding the tibial function, 15 (78.9%) patients had excellent scores, 3 (15.8%) good scores, and 1 (5.3%) fair scores. No patients had poor radiological or functional score. CONCLUSION: Two-stage treatment can be considered as an alternative for fractures in regions that are susceptible to many and persistent complications, such as the tibia. This technique has the advantages of short operation time, minimal blood loss, no excessive tissue damage and not very technique-demanding (a short learning curve with no requirement for an experienced team).

Does Training Innate Immunity Confer Broad-spectrum Protection Against Bone and Joint Infection in a Mouse Model?

BACKGROUND: The innate immune system can recall previous immunologic challenges and thus respond more effectively to subsequent unrelated challenges, a phenomenon called trained immunity. Training the innate immune system before surgery might be a potential option to prevent bone and joint infection. QUESTIONS/PURPOSES: (1) Does the training process cause adverse effects such as fever or organ injury? (2) Does training the innate immune system confer broad-spectrum protection against bone and joint infection in a mouse model? (3) Does trained immunity remain effective for up to 8 weeks in this mouse model? METHODS: After randomization and group information blinding, we trained the innate immune system of C57BL/6 mice (n = 20 for each group) by intravenously injecting them with either 0.1 mg of zymosan (a toll-like receptor 2 agonist), 0.1 mg of lipopolysaccharide (a toll-like receptor 4 agonist), or normal saline (control). For assessing the host response and possible organ injury after training and infection challenge, we monitored rectal temperature, collected blood to determine leukocyte counts, and performed biochemical and proinflammatory cytokine analyses. After 2 weeks, we then assessed whether trained immunity could prevent infections in an intraarticular implant model subjected to a local or systemic challenge with a broad spectrum of bacterial species (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Streptococcus pyogenes, or Pseudomonas aeruginosa) in terms of culture-positive rate and colony counts. The proportion of culture-positive joint samples from trained and control groups were compared after 4 weeks. Finally, we increased the interval between training and bacterial challenge up to 8 weeks to assess the durability of training efficacies. RESULTS: Training with zymosan and lipopolysaccharide caused mild and transient stress in host animals in terms of elevated rectal temperature and higher blood urea nitrogen, creatinine, alanine aminotransferase, and aspartate aminotransferase levels. Trained mice had fewer culture-positive joint samples after local inoculation with S. aureus (control: 100% [20 of 20]; zymosan: 55% [11 of 20], relative risk 0.55 [95% CI 0.37 to 0.82]; p = 0.001; lipopolysaccharide: 60% [12 of 20], RR 0.60 [95% CI 0.42 to 0.86]; p = 0.003) and systemic challenge with S. aureus (control: 70% [14 of 20]; zymosan: 15% [3 of 20], RR 0.21 [95% CI 0.07 to 0.63]; p = 0.001; lipopolysaccharide: 15% [3 of 20], RR 0.21 [95% CI 0.07 to 0.63]; p = 0.001) than controls. We observed similar patterns of enhanced protection against local and systemic challenge of E. coli, E. faecalis, S. pyogenes, and P. aeruginosa. Zymosan-trained mice were more effectively protected against both local (control: 20 of 20 [100%], zymosan: 14 of 20 [70%], RR 0.70 [95% CI 0.53 to 0.93]; p = 0.02) and systemic (control: 70% [14 of 20]; zymosan: 30% [6 of 20], RR 0.43 [95% CI 0.21 to 0.89]; p = 0.03) challenge with S. aureus for up to 8 weeks than controls. CONCLUSIONS: Trained immunity confers mild stress and broad-spectrum protection against bone and joint infection in a mouse model. The protection conferred by immunity training lasted up to 8 weeks in this mouse model. The results of the current research support further study of this presurgical strategy to mitigate bone and joint infection in other large animal models. CLINICAL RELEVANCE: If large animal models substantiate the efficacy and safety of presurgical immunity training-based strategies, clinical trials would be then warranted to translate this strategy into clinical practice.

An innovative strategy to treat large metaphyseal segmental femoral bone defect using customized design and 3D printed micro-porous prosthesis: a prospective clinical study.

Five patients with segmental irregular-shaped bone defect of the femur were recruited in this study from 2017.12 to 2018.11. All patients were treated by customized design and 3D printed micro-porous prosthesis. And the procedure was divided into stages: radical debridement and temporary fixation (the first stage); the membrane formation and virtual surgery (intervening period for 6-8 weeks); definite reconstruction the defects (the second stage). Routine clinical follow-up and radiographic evaluation were done to assess bone incorporation and complications of internal fixation. The weight-bearing time and the joint function of the patients were recorded. The patients were followed up for an average of 16.4 months. The average length of bone defect and the distal residual bone was 12 cm and 6.5 cm. The average time of partial weight-bearing and full weight-bearing was 12.7 days and 2.6 months. X-ray demonstrated good osseous integration of the implant/bone interface. No complications occurred such as implant loosening, subsidence, loss of correction and infection. At the last follow-up, Harris score of hip joint was excellent in 2 cases, good in 2 cases, fair in 1 case; HSS score of knee joint was good in 4 cases, middle in 1 case. From our study, we concluded that meticulous customized design 3D printed micro-porous prosthesis combined with intramedullary nail may be a promising and an alternative strategy to treat metaphyseal segmental irregular-shaped femoral bone defect, especially for cases with massive juxta-articular bone loss.

[Masquelet technique combined with flap transplantation for infectious bone and soft tissue defects of lower leg].

OBJECTIVE: To investigate the effectiveness of Masquelet technique combined with flap transplantation in treatment of infectious bone and soft tissue defects of the lower leg. METHODS: Between January 2013 and January 2017, 35 cases of infectious bone and soft tissue defects of lower leg were treated with Masquelet technique combined with flap transplantation. There were 21 males and 14 females, with an average of 31.5 years (mean, 25-55 years). All patients were tibial fractures caused by trauma and the infections occurred after debridement or internal fixation. The time from injury to admission was 1 to 6 months, with an average of 3.2 months. Defect located at the proximal leg in 11 cases, the middle leg in 11 cases, and the distal leg in 13 cases. The length of tibia defect after debridement ranged from 5.6 to 11.2 cm, with an average of 7.1 cm. The size of soft tissue defect ranged from 14.2 cm×6.9 cm to 17.3 cm×8.7 cm. Bacterial culture of purulent secretion of wound was positive in 18 cases. After debridement, the bone cement was used to fill the bone defect and the flap transplantation was used to repair the wound. The bone cement was taken out at 8 to 12 weeks after the one-stage operation, and the bone defect was repaired with autogenous iliac bone or combined with artificial bone. RESULTS: Three cases had necrosis at the distal edge of the flap after one-stage operation, and survived after dressing change. The other flaps survived successfully, and the wounds healed by first intention. All incisions healed by first intention after two-stage operation. All patients were followed up 24-32 months, with an average of 27 months. The color of the flap was similar to that of the surrounding normal tissue, and its texture was good. X-ray reexamination showed that all bone defects healed after 6-8 months, with an average of 6.7 months. At 9 months after two-stage operation, according to the revised Edwards tibial fracture evaluation standard, 19 cases were excellent, 14 cases were good, and 2 cases were poor, the excellent and good rate was 94.3%. The American Orthopedic Ankle Association (AOFAS) score was 60-98, with an average of 81.3. And 21 cases were excellent, 11 were good, and 3 were fair, with an excellent and good rate of 91.4%. CONCLUSION: Masquelet technique combined with flap transplantation is an effective treatment for infectious bone and soft tissue defects of lower leg.