Osteomyelitis

Imaging of MSK infections in the ER

Musculoskeletal infections in the ER are not an uncommon presentation. The clinical context is critical in determining the suspicion for infection and degree of tissue involvement which can involve all layers from the skin to bones. The location, extent, and severity of clinically suspected infection directly relate to the type of imaging performed. Uncomplicated cellulitis typically does not require any imaging. Localized and superficial infections can mostly be evaluated with ultrasound. If there is a diffuse site (an entire extremity) or suspected deeper involvement (muscle/deep fascia), then CT is accurate in diagnosing, widely available, and performed quickly. With potential osseous involvement, MRI is the gold standard for diagnosing acute osteomyelitis; however, it has the drawbacks of longer scan times, artifacts including patient motion, and limited availability.

A case of Winkia neuii (Actinomyces neuii) vertebral osteomyelitis and review of the literature

This case report presents an unusual occurrence of Winkia (Actinomyces) neuii vertebral osteomyelitis in a 55-year-old male patient with diabetes mellitus. W. neuii is a distinct species formerly placed within the Actinomyces genus, exhibiting unique morphological and clinical characteristics. Vertebral osteomyelitis caused by Actinomyces species is rare, with only one prior case reported in the literature. The patient was successfully managed with a combination of intravenous ceftriaxone during hospitalization and an oral antibiotic regimen for an extended period. This case report contributes to the limited body of knowledge surrounding W. neuii, as well as actinomycotic vertebral osteomyelitis.

Osteomyelitis in the Nonunion of a Patellar Fracture

Osteomyelitis is by definition any infection of the bone. It can have a hematogenous or non-hematogenous mechanism of infection, but comorbidities such as cardiovascular disease, diabetes mellitus, and the presence of orthopedic hardware can increase the risk of osteomyelitis. Our case focuses on a 64-year-old Caucasian female with multiple comorbidities who presented with a fractured right patella that was not healing four months after the occurrence of the fracture. The patient reported cramping, fasciculations, and severe pain that was worsening. She also reported that she received nine X-rays from different orthopedists before receiving an MRI, ordered by internal medicine. The MRI showed a small knee effusion with mild generalized edema of the nearby subcutaneous tissues and evidence of nonunion of the fracture as evidenced by fracture fragments of the right patella. The MRI additionally showed increased signal in the bone fragments of the right patella, as well as the anterior and posterior superior rims of the right tibial plateau, concerning for potential osteomyelitis. Referral to infectious disease confirmed the diagnosis of patellar osteomyelitis, a rather rare diagnosis. The patient was promptly started on cefdinir and doxycycline, and within days of starting antibiotic therapy, her right knee pain was reduced to zero. Surgical debridement was not necessary, and the patient was able to resume her daily activities with the pain resolved. The possibility of patients only having to undergo antibiotic treatment for patellar osteomyelitis improves their chances of a full recovery and reduces the risks associated with undergoing surgical debridement.

Serratia Sacroiliitis Secondary to Intravenous Drug Use: A Case Report

Serratia spp. are ubiquitous, opportunistic, and infectious organisms that have historically been known to infect the upper respiratory, urinary, and circulatory systems. This manuscript presents the case of a 35-year-old White female with a past medical history of polysubstance abuse, intravenous drug use (IVDU), and poor dentition who was admitted to a community hospital with complaints of lower back pain for 10 days following the recent completion of treatment for a suspected epidural abscess. Per her report, her last IVDU with fentanyl was 11 days prior, and she admitted to using various sources of water to inject her drugs. Magnetic resonance imaging with contrast was significant for possible infectious sacroiliitis, and blood cultures grew Serratia marcescens. Due to this patient's extensive IVDU history, in-patient ceftriaxone was chosen over discharging the patient with a peripherally inserted central catheter line. Serratia spp.bacteremia with concomitant septic sacroiliitis in the setting of IVDU is an extremely rare presentation. Due to the nonspecific presentation of sacroiliitis, multidrug resistance profile of Serratia spp., and high mortality rate associated with S. marcescens sepsis, early detection and diagnosis is paramount in similar patients with extensive risk factors.

Clinical characteristics and outcomes associated with culture-negative status in limb osteomyelitis patients

Aims

This study aimed to investigate the clinical characteristics and outcomes associated with culture-negative limb osteomyelitis patients.

Methods

A total of 1,047 limb osteomyelitis patients aged 18 years or older who underwent debridement and intraoperative culture at our clinic centre from 1 January 2011 to 31 December 2020 were included. Patient characteristics, infection eradication, and complications were analyzed between culture-negative and culture-positive cohorts.

Results

Of these patients, 264 (25.2%) had negative cultures. Patients with a culture-negative compared with a culture-positive status were more likely to have the following characteristics: younger age (≤ 40 years) (113/264 (42.8%) vs 257/783 (32.8%); p = 0.004), a haematogenous aetiology (75/264 (28.4%) vs 150/783 (19.2%); p = 0.002), Cierny-Mader host A (79/264 (29.9%) vs 142/783 (18.1%); p < 0.001), antibiotic use before sampling (34/264 (12.9%) vs 41/783 (5.2%); p＜0.001), fewer taken samples (n＜3) (48/264 (18.2%) vs 60/783 (7.7%); p＜0.001), and less frequent presentation with a sinus (156/264 (59.1%) vs 665/783 (84.9%); p < 0.001). After initial treatments of first-debridement and antimicrobial, infection eradication was inferior in culture-positive osteomyelitis patients, with a 2.24-fold increase (odds ratio 2.24 (95% confidence interval 1.42 to 3.52)) in the redebridement rate following multivariate analysis. No statistically significant differences were found in long-term recurrence and complications within the two-year follow-up.

Conclusion

We identified several factors being associated with the culture-negative result in osteomyelitis patients. In addition, the data also indicate that culture negativity is a positive prognostic factor in early infection eradication. These results constitute the basis of optimizing clinical management and patient consultations.

Alternatives for the Detection and Diagnosis of Osteoarticular Infections: An Exploratory Review

The precise diagnosis of osteomyelitis, a bone infection, remains a significant challenge for healthcare professionals. This difficulty stems from the highly variable nature of its clinical presentation and disease course. Patients can exhibit a wide range of symptoms, making it easy to misdiagnose the condition. In turn, inaccurate diagnoses lead to inappropriate treatment regimens, potentially hindering a patient's recovery and causing unnecessary complications. Nuclear medicine offers a ray of hope in this fight against diagnostic ambiguity. It provides valuable tools, such as radiopharmaceutical imaging, that can significantly improve the accuracy of osteomyelitis diagnosis. However, limitations exist. This article explores the need for alternative diagnostic approaches within the specific context of Costa Rica. This exploration is particularly relevant due to the current regional shortage of gallium-67 (⁶⁷Ga), a radiopharmaceutical commonly used in osteomyelitis diagnosis. The article delves into the nature, function, and limitations of various nuclear medicine techniques, encompassing both independent radiopharmaceuticals like ⁶⁷Ga and those conjugated with specific targeting molecules to pinpoint areas of infection within the body. Given the scarcity of ⁶⁷Ga in Costa Rica, it becomes crucial to explore and implement viable alternative diagnostic techniques within the healthcare system. This article emphasizes the need for further investigation into these alternatives, with the goal of improving diagnostic accuracy and ensuring optimal patient care. By implementing these alternatives, healthcare professionals in Costa Rica can effectively combat the challenges posed by osteomyelitis and pave the way for better patient outcomes.

Dual release of daptomycin and BMP-2 from a composite of β-TCP ceramic and ADA gelatin

BACKGROUND

Antibiotic-containing carrier systems are one option that offers the advantage of releasing active ingredients over a longer period of time. In vitro sustained drug release from a carrier system consisting of microporous β-TCP ceramic and alginate has been reported in previous works. Alginate dialdehyde (ADA) gelatin gel showed both better mechanical properties when loaded into a β-TCP ceramic and higher biodegradability than pure alginate.

METHODS

Dual release of daptomycin and BMP-2 was measured on days 1, 2, 3, 6, 9, 14, 21, and 28 by HPLC and ELISA. After release, the microbial efficacy of the daptomycin was verified and the biocompatibility of the composite was tested in cell culture.

RESULTS

Daptomycin and the model compound FITC protein A (n = 30) were released from the composite over 28 days. A Daptomycin release above the minimum inhibitory concentration (MIC) by day 9 and a burst release of 71.7 ± 5.9% were observed in the loaded ceramics. Low concentrations of BMP-2 were released from the loaded ceramics over 28 days.

The Septic Elbow Joint: Treatment Approaches for Improved Patient Outcomes

Septic arthritis of the elbow is a serious problem requiring prompt, accurate diagnosis and urgent surgical intervention. Achieving successful patient outcomes depends heavily on early diagnosis and efficient streamlined surgical treatment. Essential tactics for treating the septic elbow joint include immediate joint irrigation and debridement in addition to administration of appropriate antibiotics. This comprehensive review delves into the cause of the septic elbow joint, identifies associated risk factors, and provides a comprehensive approach encompassing the diagnosis and treatment of the septic elbow. The aim of this review is to optimize patient care and outcomes.

An Unusual Case of Proteus mirabilis-Induced Severe Contiguous Bacterial Osteomyelitis in an Elderly Nursing Home Resident: A Case Report

Contiguous bacterial osteomyelitis results from the spread of a variety of pyogenic bacteria from nearby skin, soft tissue, or joint infections into the underlying bone. This report describes a case of severe contiguous bacterial osteomyelitis in an 82-year-old female nursing home resident with newly diagnosed and comorbid peripheral arterial disease, along with a history of decubitus ulcers as a result of presumed neglect at her residence. The patient initially presented with multiple ulcerative lesions overlying the left foot and ankle with associated severe pain and chronic vascular insufficiency. The patient was empirically started on broad-spectrum antibiotics, with a subsequent wound culture demonstrating heavy growth of Proteus mirabilis. Multiple imaging modalities irrefutably demonstrated destructive bony changes characteristic of osteomyelitis. Left below-the-knee amputation was thereafter agreed upon as the most beneficial treatment method, with concomitant prolonged antibiotic therapy. This case emphasizes the importance of providing adequate medical and preventative care for elderly nursing home residents in an effort to reduce the incidence of contiguous bacterial osteomyelitis, a topic rarely discussed in current literature.

Oritavancin Versus Daptomycin for Osteomyelitis Treatment After Surgical Debridement

INTRODUCTION

Weekly intravenous (IV) oritavancin and daily daptomycin were compared in an outpatient setting following extensive surgical debridement for treating patients with osteomyelitis.

METHODS

This was a retrospective, observational study of patients diagnosed with acute osteomyelitis. Exclusion criteria were the use of Gram-negative antibiotic therapy, use of antibiotics for more than 48 h prior to oritavancin or daptomycin or prior use of > 2 doses of oritavancin or more than 4 weeks of daptomycin. Clinical success was resolution or improvement of symptoms and no further treatment. Data were analyzed with Chi-square test or Fisher's exact test.

RESULTS

Consecutive outpatients (n = 150) with acute osteomyelitis who were treated with oritavancin or daptomycin (1:1) following extensive surgical debridement were identified. Staphylococcus aureus was the most common pathogen (n = 117). No patient in either group received prior antibiotic therapy (previous 30 days) or was hospitalized within 90 days prior to surgical debridement. Twenty-one (28%) patients prescribed oritavancin had chronic kidney disease, seven of whom were receiving hemodialysis or peritoneal dialysis. Compared to oritavancin, patients prescribed daptomycin had higher rates of all-cause readmission [odds ratio (OR) 2.89; p < 0.001], more infection-related readmission (OR 3.19; p < 0.001), and greater likelihood of receiving antibiotics post-discontinuation of initial therapy (OR 2.13; p < 0.001). Repeat surgical debridement was required for 68.0% with daptomycin vs. 23.1% with oritavancin (p < 0.001).

CONCLUSIONS

Oritavancin demonstrated a significantly higher rate of clinical success compared to daptomycin, with lower all-cause and infection-related readmissions, reduced need for repeat surgical debridement, and fewer additional antibiotic requirements.

Osteomyelitis by Microsporum canis and Staphylococcus spp. in cat (Felis catus) - case report

BACKGROUND

Staphylococcus spp and Microsporum canis are zoonotic microorganisms which can cause infections and systemic diseases. The bone infection is usually caused by invasion of pathogen through the hematologic route. Mixed osteomyelitis caused by bacteria and fungi is rare, and to date, there have been no reports of mixed osteomyelitis with Staphylococcus spp. and Microsporum canis.

CASE PRESENTATION

This essay reports an atypical presentation of mixed osteomyelitis (Staphylococcus spp. and Microsporum canis) in a domestic cat. A 15-month-old female Persian cat was presented to a veterinary service; the main complaint was the appearance of a nodule in the mandibular ventral rostral region. A radiographic exam performed on the animal showed proliferative and osteolytic bone lesions. The patient was submitted to a biopsy for histopathological evaluation, along with bacterial and fungal cultures. Results showed mixed osteomyelitis by Staphylococcus spp. and Microsporum canis. Microbial Sensitivity Test was performed to choose a more suitable treatment. Two surgical procedures were executed to resect and curette the lesion, and treatments with anti-inflammatory, antibiotic, and antifungal drugs were established, showing a positive clinical evolution. After 8 months of treatment, the patient's owner moved to a different city, and the animal was seen by other veterinarians, who followed along with the same treatment. However, due to complications and a diminishing quality of life over 4 years of diagnosis, the patient was euthanized.

CONCLUSION

Given the above, mixed osteomyelitis is difficult to treat and can cause losses of life quality resulting death, especially in infections where M. canis is the agent causing the disease. Bacterial osteomyelitis is more frequently reported. But the lack of investigation of microorganisms other than bacteria, such as fungal cases, may imply in underdiagnosed cases. Treatment of osteomyelitis can be difficult considering the difficulties in isolating the pathological agent, resistance to the drug used, prolonged treatment time, and cost.

Injectable systems of chitosan in situ forming composite gel incorporating linezolid-loaded biodegradable nanoparticles for long-term treatment of bone infections

The objective of the current study was to create an efficient, minimally invasive combined system comprising in situ forming hydrogel loaded with both spray-dried polymeric nanoparticles encapsulating linezolid and nanohydroxyapatite for local injection to bones or their close vicinity. The developed system was designed for a dual function namely releasing the drug in a sustained manner for long-term treatment of bone infections and supporting bone proliferation and new tissues generation. To achieve these objectives, two release sustainment systems for linezolid were optimized namely a composite in situ forming chitosan hydrogel and spray-dried PLGA/PLA solid nanoparticles. The composite, in situ forming hydrogel of chitosan was prepared using two different gelling agents namely glycerophosphate (GP) and sodium bicarbonate (NaHCO3) at 3 different concentrations each. The spray-dried linezolid-loaded PLGA/PLA nanoparticles were developed using a water-soluble carrier (PVP K30) and a lipid soluble one (cetyl alcohol) along with 3 types of DL-lactide and/or DL-lactide-co-glycolide copolymer using nano-spray-drying technique. Finally, the optimized spray-dried linezolid nanoparticles were incorporated into the optimized composite hydrogel containing nanohydroxy apatite (nHA). The combined hydrogel/nanoparticle systems displayed reasonable injectability with excellent gelation time at 37 °C. The optimum formulae sustained the release of linezolid for 7-10 days, which reveals its ability to reduce the frequency of injection during the course of treatment of bones infections and increase the patients' compliance. They succeeded to alleviate the bone infections and the associated clinical, biochemical, radiological, and histopathological changes within 2-4 weeks of injection. As to the state of art in this study and to the best of our knowledge, no such complete and systematic study on this type of combined in situ forming hydrogel loaded with spray-dried nanoparticles of linezolid is available yet in literatures.

Evaluating the efficacy of combined flap coverage, antibiotic-loaded bone cement and negative pressure irrigation in traumatic osteomyelitis management

Traumatic osteomyelitis with accompanying soft tissue defects presents a significant therapeutic challenge. This prospective, randomised controlled trial aims to evaluate the efficacy of antibiotic-impregnated bone cement, flap coverage and negative pressure sealed irrigation in the management of traumatic osteomyelitis complicated by soft tissue defects. A total of 46 patients with clinically diagnosed traumatic osteomyelitis and soft tissue defects were randomised into a control group (n = 23) and an observation group (n = 23). The control group underwent standard flap coverage and negative-pressure lavage, while the observation group received an additional treatment with antibiotic-loaded bone cement. Efficacy was measured based on clinical criteria, surgical metrics and morphometric assessment of bone and soft tissue defects. Statistical analyses were performed using SPSS version 27.0. The observation group, treated with an integrated approach of flap coverage, negative pressure wound therapy (NPWT) and antibiotic-impregnated bone cement, demonstrated significantly higher overall treatment efficacy (91.3%) compared to the control group, which received only flap coverage and NPWT (65.2%) (p < 0.01). This enhanced efficacy was evidenced through various outcomes: the observation group experienced reduced surgical times, shorter hospital stays, fewer dressing changes and accelerated wound healing, all statistically significant (p < 0.001). Additionally, a quantitative analysis at 6-month post-treatment revealed that the observation group showed more substantial reductions in both bone and soft tissue defect sizes compared to the control group (p < 0.001). The multi-modal treatment strategy, combining skin flap coverage, antibiotic bone cement and negative-pressure irrigation, showed marked efficacy in treating traumatic osteomyelitis and associated soft tissue defects. This approach accelerated postoperative recovery and lowered costs.

Pathologic Femur Fracture in an Immunocompetent Healthy Young Adult due to Acute Osteomyelitis

An immunocompetent 33-year-old woman presented with a pathologic femur fracture after one month of progressively worsening right thigh pain. Open biopsy demonstrated acute suppurative osteomyelitis despite the lack of clinical risk factors. The polymicrobial infection was successfully treated with three operative procedures and culture-specific antibiotic agents. Acute osteomyelitis, while an uncommon cause of pathologic fracture, must always be on the differential diagnosis, even when no obvious predisposing factors are present. When investigating for an infectious etiology in cases such as our own, considering immunodeficiency syndromes alongside the more typical causes of osteomyelitis is encouraged.

Metal nanoparticles as inhibitors of enzymes and toxins of multidrug-resistant Staphylococcus aureus

Staphylococcus aureus is an aerobic Gram-positive spherical bacterium known to cause a broad range of infections worldwide. It is a major cause of infective skin and soft infections and severe and life-threatening conditions, such as pneumonia, bloodstream infections, and endocarditis. The emergence of drug-resistant strains of S aureus, particularly methicillin-resistant S aureus (MRSA), has become a significant concern in the healthcare community. Antibiotic-resistant S aureus is commonly acquired in hospitals and long-term care facilities. It often affects patients with weakened immune systems, those undergoing invasive medical procedures, or those who have been hospitalized for extended periods. In the US, S aureus is known to cause potentially fatal illnesses, such as toxic shock syndrome (TSS) and acute-onset toxic shock syndrome (TSS), which are characterized by fever and hypotension. It develops resistance to antibiotics through several mechanisms, such as the production of enzymes that inactivate antibiotics, target site modification, efflux pumps, and plasmid-mediated resistance. Therefore, preventing the spread of drug-resistant S aureus is needed, and there is an urgent need to explore novel approaches in the development of anti-staphylococcal agents. This article reviews the principal infections caused by S aureus, major virulence factors, mechanisms of resistance development, and nanotechnology-based solutions for the control of drug-resistant S aureus.

Diabetes mellitus-related musculoskeletal disorders: Unveiling the cluster of diseases

The current study ushers in a comprehensive review in clinical research to demonstrate the prevalence of musculoskeletal (MSK) complications in diabetes mellitus and the most relevant clinical aspects. In particular, revealing the early symptoms of the disorders, the pathology lurking behind the complications and their optimal management. In diabetes mellitus, MSK complications are common and are largely due to similar pathogenetic factors responsible for the internal organ complications associated with diabetes leading to chronic low-intensity inflammatory processes. MSK disorders develop by vasculopathy, neuropathy, arthropathy or combinations of the above, which are not specific to diabetes. However, their prevalence is significantly increased in diabetes and contributes to the disability impairing patients' quality of life. Locomotor disease affects approximately 34.4-83.5 % of patients suffering from type-2 diabetes mellitus. Several musculoskeletal abnormalities (cheiroarthropathy, Dupuytren's contracture, trigger finger, ect.) can be diagnosed upon physical examination, although certain symptoms (frozen shoulder, neurogenic arthropathy, septic arthritis, etc.) require differential diagnostic considerations. Early identification regarding characteristic symptoms in the treatment reducing inflammation and pain, followed with increasingly strenuous exercise therapy, aligned with optimal management of carbohydrate metabolism, proves essential in alleviating MSK complications.

A potential hybrid nanocomposite of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and fullerene for bone tissue regeneration and sustained drug release against bone infections

Developing a multifunctional biomaterial for bone filling and local antibiotic therapy is a complex challenge for bone tissue engineering. Hybrid nanocomposites of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) with nanohydroxyapatite (nHA), fullerene (C60), and vancomycin (VC) were produced by injection. Fullerene was successfully impregnated with VC, as seen in FTIR. The crystallinity degree of PHBHV was slightly reduced in the presence of C60 and VC (64.3 versus 60.8 %), due to the plasticizing effect of these particles. It also resulted in a decrease in the glass transition temperature (Tg), observed by differential scanning calorimetry (DSC). Dense PHBHV/nHA/C60/VC had a flexural elastic modulus 29 % higher than PHBHV, as a result of the good interface between PHBHV, C60, and nHA - particles of high elastic modulus. Dense disks released 25.03 ± 4.27 % of VC for 14 days, which demonstrated its potential to be an alternative treatment to bone infections. Porous scaffolds of PHBHV/nHA/C60/VC were 3D printed with a porosity of 50 % and porous size of 467 ± 70 μm, and had compression elastic modulus of 0.022 GPa, being a promising material to trabecular bone replacement. The plasticizing effect of C60 improved the printability of the material. The hybrid nanocomposite was non-cytotoxic and showed good ability in adhering macrophage cells.

Abscess pulsatility: a sonographic sign of osteomyelitis

INTRODUCTION

Early diagnosis and aggressive treatment of acute osteomyelitis may improve prognosis and prevent further complications. Sonography is useful in the evaluation of osteomyelitis. It can demonstrate early signs of inflammation, such as soft tissue changes near the affected bone, periosteal thickening, periosteal elevation, and subperiosteal abscess.

CASE PRESENTATION

A 68-year-old female presented to the emergency department with 3 weeks of worsening left lower extremity pain. She was initially seen by urgent care for left shin erythema and swelling and treated for cellulitis with intramuscular ceftriaxone without improvement. On presentation, she was afebrile and hemodynamically stable with erythema, swelling, and tenderness of the left pretibial soft tissues. Her labs revealed leukocytosis and elevated inflammatory markers. Point-of-care ultrasound demonstrated a bidirectional flow of fluid through a disruption in the bone cortex visualized on greyscale imaging and confirmed with color and spectral Doppler. The patient was diagnosed with osteomyelitis and treated with antibiotics and incision and drainage by orthopedic surgery.

DISCUSSION

The unique sonographic finding of pulsatile flow of fluid within an abscess near bone has not been previously described in the literature. The presence of Doppler signal in any fluid other than blood is known as pseudoflow. The presence of pulsatility in this case, which could represent either blood or pseudoflow, drew the ultrasound operator's eye to the cortical defect and lead to the diagnosis of osteomyelitis.

CONCLUSIONS

The sonographic finding of pulsatility in an abscess near bone should raise the concern for communication with the medullary cavity.

Comparison of the Therapeutic Efficacy of Antibiotic-Loaded Polymeric Tissue Scaffold and Bone Cement in the Regeneration of Infected Bone Tissue

Background Local antibiotic applications have been used in chronic osteomyelitis and have been defined as an adjunctive treatment method. Biodegradable materials are also used for the same purpose by adding antibiotics. The fact that it does not require additional surgery to be removed is an important advantage. In this study, we intended to develop a new biodegradable drug-loaded polymeric scaffold with good antibiotic release and compare the microbiological results with antibiotic-impregnated bone cement. Methodology A tissue scaffold containing poly(2-hydroxyethyl methacrylate) (PHEMA) was prepared in our laboratory and loaded with ertapenem and daptomycin antibiotics. The surface morphology and pore geometries of drug-loaded and unloaded scaffolds were analyzed by a scanning electron microscope under vacuum. The dose-dependent antiproliferative effects of PHEMA scaffold, drug-loaded scaffold, cement, and drug-loaded cement on osteoblast cells were investigated. To evaluate drug release kinetics, the absorbance values of the scaffold loaded with ertapenem and daptomycin were measured with the spectrometer. For microbiological tests, ertapenem and daptomycin-impregnated cement and scaffold, as well as the control scaffold and cement samples, were investigated for their antibacterial activities on Staphylococcus aureus and Klebsiella pneumoniae strains using the disc diffusion method. These microorganisms are one of the most common microorganisms in osteomyelitis. Results The efficacy of antibiotic-impregnated scaffold and cement on both gram-negative and gram-positive microorganisms was investigated. The daptomycin zone diameter in S. aureus ATCC 29233 strain was 17 mm, whereas it was 24 mm for scaffold and 22 mm for cement. Scaffold was found to be more effective than cement against S. aureus strain. The K. pneumoniae ATCC BAA-2814 strain was found to be resistant to ertapenem, but the zone diameter was 21 mm for scaffold and 20 mm for cement. Ertapenem-loaded scaffold was found to be more effective than cement. It was found that the antimicrobial activity of the scaffold was higher than cement. When we evaluated the release profiles, for the daptomycin-loaded cement group, 98% of daptomycin was cumulatively released within 30 minutes, and for the daptomycin-loaded scaffold group, 100% of daptomycin was cumulatively released in six days. To compare ertapenem-loaded cement and scaffold, 98% of ertapenem was cumulatively released within 10 minutes in the cement group. For the scaffold group, 100% of ertapenem was cumulatively released in 17 days. We found that the scaffold released the antibiotic more slowly and for a longer duration. Therefore, it was thought that the scaffold would be more effective on biofilm and the treatment of osteomyelitis would be more successful. Conclusions The produced scaffold was compared with cement, and it was concluded that the scaffold had better release and antimicrobial efficacy. Scaffold is more advantageous than cement because it is bioeliminable. Thus, there is no need for a second surgical intervention with the likely prevention of mortality and morbidity. Because of all these features, the scaffold seems promising in the local treatment of osteomyelitis.

Epidemiological updates of post-traumatic related limb osteomyelitis in china: a 10 years multicentre cohort study

BACKGROUND

Post-traumatic related limb osteomyelitis (PTRLO) is a complex bone infection. Currently, there are no available microbial data on a national scale that can guide appropriate antibiotic selection, and explore the dynamic changes in dominant pathogens over time. This study aimed to conduct a comprehensive epidemiological analysis of PTRLO in China.

METHODS

The study was approved by the Institutional Research Board (IRB), and 3526 PTRLO patients were identified from 212 394 traumatic limb fracture patients at 21 hospitals between 1 January 2008 and 31 December 2017. A retrospective analysis was conducted to investigate the epidemiology of PTRLO, including changes in infection rate (IR), pathogens, infection risk factors and antibiotic resistance and sensitivity.

RESULTS

The IR of PTRLO increased gradually from 0.93 to 2.16% (Z=14.392, P <0.001). Monomicrobial infection (82.6%) was significantly higher than polymicrobial infection (17.4%) ( P <0.001). The IR of Gram-positive (GP) and Gram-negative (GN) pathogens showed a significant increase from the lowest 0.41% to the highest 1.15% (GP) or 1.62% (GN), respectively. However, the longitudinal trend of GP vs. GN's composition did not show any significance (Z=±1.1918, P >0.05). The most prevalent GP strains were Methicillin-sensitive Staphylococcus aureus (MSSA) (17.03%), Methicillin-resistant Staphylococcus aureus (MRSA) (10.46%), E. faecalis (5.19%) and S. epidermidis (4.87%). In contrast, the dominant strains GN strains were Pseudomonas Aeruginosa (10.92%), E. cloacae (10.34%), E. coli (9.47%), Acinetobacter Baumannii (7.92%) and Klebsiella Pneumoniae (3.33%). In general, the high-risk factors for polymicrobial infection include opened-fracture (odds ratio, 2.223), hypoproteinemia (odds ratio, 2.328), and multiple fractures (odds ratio, 1.465). It is important to note that the antibiotics resistance and sensitivity analysis of the pathogens may be influenced by complications or comorbidities.

CONCLUSIONS

This study provides the latest data of PTRLO in China and offers trustworthy guidelines for clinical practice. (China Clinical Trials.gov number, ChiCTR1800017597).

Enterobacter cloacae as sole organism responsible for vertebral osteomyelitis/discitis and vertebral collapse in a patient with intravenous drug abuse

Staphylococcus aureus is the most commonly isolated organism in osteomyelitis, while gram-negative bacteria (GNB) comprises only a minor portion. GNB osteomyelitis is usually seen in patients with bacteraemia, recent genitourinary infection, open fractures or trauma and is rarely seen in the spines. Our case is a man in his 30s with no significant risk factors except an extended history of intravenous drug use (IVDU), who presented with back pain and subsequently developed vertebral collapse. Bone culture grew Enterobacter cloacae, yet blood cultures were negative. To date, there are limited data on the prevalence of GNB osteomyelitis in IVDU and its association. Due to rising rates of IVDU, further research must be done into associated medical complications to provide comprehensive care. Moreover, the emergence of multidrug-resistant GNB strains limits the number of effective antibiotics and is expected to pose more serious public concerns in the future.

Injectable rBMSCs-laden hydrogel microspheres loaded with naringin for osteomyelitis treatment

Osteomyelitis, caused by purulent bacteria invading bone tissue, often occurs in long bones and seriously affects the physical and mental health and working ability of patients; it can even endanger life. However, due to bone cavity structure, osteomyelitis tends to occur inside the bone and thus lacks an effective treatment; anti-inflammatory treatment and repair of bone defects are necessary. Here, we developed injectable hydrogel microspheres loaded with naringin and bone marrow mesenchymal stem cells, which have anti-inflammatory and osteogenic properties. These homogeneous microspheres, ranging from 200 to 1000μm, can be rapidly fabricated using an electro-assisted bio-fabrication method. Interestingly, it was found that microspheres with relatively small diameters (200μm) were more conducive to the initial cell attachment, growth, spread, and later osteogenic differentiation. The developed microspheres can effectively treat tibial osteomyelitis in rats within six weeks, proving their prospects for clinical application.

Sinogram: A Valuable Diagnostic Tool for an Adult Male With Discharging Heel Ulcer and Suspected Calcaneal Osteomyelitis

This report highlights the clinical significance of a sinogram in diagnosing osteomyelitis in resource-poor areas. We report a case in which a sinogram was used successfully for the diagnosis of calcaneal osteomyelitis. A 25-year-old male patient sought medical attention for persistent pain in the right ankle joint and heel, accompanied by a discharging ulcer over the right heel. He had a history of foot trauma involving vegetative matter sustained during a farming injury one month prior to the onset of symptoms. An ankle radiograph revealed an osteolytic lesion involving the calcaneum, prompting further investigation with a sinogram, which indicated a subcutaneous sinus tract with intramedullary extension into the calcaneum. Despite the clinical necessity for a magnetic resonance imaging (MRI) or computed tomography (CT) evaluation to precisely assess the lesion's extent and aid in formulating an appropriate treatment plan, the patient faced significant financial constraints that hindered him from undergoing the essential imaging procedure.

Adjunctive Plasma Rich in Growth Factors in the Treatment of Osteomyelitis and Large Odontogenic Cysts Prior to Successful Implant Rehabilitation: Case Report

Osteomyelitis of the jaws presents a clinical challenge to conventional treatment, often requiring multiple surgical interventions resulting in significant deformity and presenting significant problems to satisfactory rehabilitation. While benign odontogenic cysts, such as the radicular cyst, are generally predictably treated, they can cause significant localized bone destruction and thus can present significant problems in satisfactory rehabilitation. In this case report, patients were treated combining conventionally appropriate surgical debridement and oral antibiotics with adjunctive plasma rich in growth factors (PRGF). Patients showed a complete soft tissue and osseous regeneration to their pre-pathologic state, with successful implant rehabilitation. PRGF appears to be highly successful in minimizing or eliminating osseous deformities normally associated with conventional treatment of osteomyelitis of the jaw and treatment of large odontogenic cysts. Future trials must be performed to confirm these results in comparison to controls using conventional treatment alone.

Composite material consisting of microporous beta-TCP ceramic and alginate-dialdehyde-gelatin for controlled dual release of clindamycin and bone morphogenetic protein 2

The aim of this study was to produce a composite of microporous β-TCP filled with alginate-gelatin crosslinked hydrogel, clindamycin and bone morphogenetic protein (BMP-2) to prolong the drug-release behaviour for up to 28 days. The most promising alginate-di-aldehyde(ADA)-gelatin gel for drug release from microcapsules was used to fill microporous β-TCP ceramics under directional flow in a special loading chamber. Dual release of clindamycin and BMP-2 was measured on days 1, 2, 3, 6, 9, 14, 21 and 28 by high performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA). After release, the microbial efficacy of the clindamycin was checked and the biocompatibility of the composite was tested in cell culture. Clindamycin and the model substance FITC-protein A were released from microcapsules over 28 days. The clindamycin burst release was 43 ± 1%. For the loaded ceramics, a clindamycin release above the minimal inhibitory concentration (MIC) until day 9 and a burst release of 90.56 ± 2.96% were detected. BMP-2 was released from the loaded ceramics in low concentrations over 28 days. The release of active substances from β-TCP and hydrogel have already been extensively studied. Directional flow loading is a special procedure in which the ceramic could act as a stabilizer in the bone and, as a biodegradable system, enables a single-stage surgical procedure. Whether ADA-gelatin gel is suitable for this procedure as a more biodegradable alternative to pure alginate or whether a dual release is possible in this composite has not yet been investigated.

Dalbavancin in Bone and Joint Infections: A Systematic Review

BACKGROUND

Approved for acute bacterial skin and skin structure infections, dalbavancin (DBV) has gradually acquired over the years a role as an off-label treatment for several infections caused by Gram-positive bacteria even in other anatomical sites. Osteoarticular (OA) infections are one of the most difficult-to-treat infections and, since the absence of recommendations, clinicians use different and heterogenic DBV dosing schedule regimens for the off-label treatment of osteomyelitis, spondylodiscitis, and septic arthritis. Our aim is to systematically review the current literature to describe DBV administration schedules and their outcome in OA infections.

METHODS

According to the 2020 updated PRISMA guidelines, all peer-reviewed articles regarding the use of DBV in OA infections were included. We conducted a literature search on PubMed and Cochrane Controlled Trials.

RESULTS

A total of 23 studies and 450 patients were included, prevalently male (144/195, 73.8%) and diabetic (53/163, 32.5%). Overall, 280 (280/388, 72.2%) osteomyelitis, 79 (79/388, 20.4%) spondylodiscitis, and 29 (29/388, 7.5%) septic arthritis were considered. Staphylococcus aureus (164/243, 67.5%) was the most common pathogen isolated. A previous treatment failure (45/96, 46.9%) was the main reason for a switch to a long-acting antibiotic. Most patients were successfully cured with DBV (318/401, 79.3%). A source control was performed in most patients with a favourable outcome (80.4%), while MRSA was prevalently isolated in people with an unfavourable outcome (57%). While a higher percentage of success was found in people who received three doses of DBV 1 week apart (92.3%), a higher rate of treatment failure was recorded in cases of when the DBV cycle was composed of less than two or more than four doses (27.8%).

CONCLUSIONS

DBV has shown to be effective as a treatment for OA infections. The most favourable outcome was found in patients receiving three doses of DBV and with an adequate surgical management prior to antibiotic treatment. Although a rigorous administration schedule does not exist, DBV is a viable treatment option in the management of OA infections.

Insights into S. aureus-Induced Bone Deformation in a Mouse Model of Chronic Osteomyelitis Using Fluorescence and Raman Imaging

Osteomyelitis is an infection of the bone that is often difficult to treat and causes a significant healthcare burden. Staphylococcus aureus is the most common pathogen causing osteomyelitis. Osteomyelitis mouse models have been established to gain further insights into the pathogenesis and host response. Here, we use an established S. aureus hematogenous osteomyelitis mouse model to investigate morphological tissue changes and bacterial localization in chronic osteomyelitis with a focus on the pelvis. X-ray imaging was performed to follow the disease progression. Six weeks post infection, when osteomyelitis had manifested itself with a macroscopically visible bone deformation in the pelvis, we used two orthogonal methods, namely fluorescence imaging and label-free Raman spectroscopy, to characterise tissue changes on a microscopic scale and to localise bacteria in different tissue regions. Hematoxylin and eosin as well as Gram staining were performed as a reference method. We could detect all signs of a chronically florid tissue infection with osseous and soft tissue changes as well as with different inflammatory infiltrate patterns. Large lesions dominated in the investigated tissue samples. Bacteria were found to form abscesses and were distributed in high numbers in the lesion, where they could occasionally also be detected intracellularly. In addition, bacteria were found in lower numbers in surrounding muscle tissue and even in lower numbers in trabecular bone tissue. The Raman spectroscopic imaging revealed a metabolic state of the bacteria with reduced activity in agreement with small cell variants found in other studies. In conclusion, we present novel optical methods to characterise bone infections, including inflammatory host tissue reactions and bacterial adaptation.

Prolonged liver transplantation survival and aging successfully

The traditional definition of successful aging as the absence of disease, disability, and cognitive impairment is not always applicable to patients with long survival despite complex multimorbidity. This case report details the situation of an 87-year-old man, currently partially self-sufficient and partially autonomous, without cognitive impairment, who has been affected with recurrent right knee osteomyelitis since the age of 6. A diagnosis of hepatitis C virus (HCV)-related liver cirrhosis at 41 led to liver transplantation at 56. The immunosuppressive anti-rejection therapy caused a relapse of chronic osteomyelitis and HCV infection, a major cause of graft loss and shortened survival in HCV liver transplant recipients. Other pathologies were also diagnosed during his lifetime. This patient is an example of aging successfully despite complex multimorbidity and disproves the traditional concept of successful aging formerly described in the literature.

Diabetic Pedal Osteomyelitis and Its Treatment

Diabetes is a fast-growing chronic metabolic disorder that is widely associated with foot ulcers. The major challenge among these ulcers is wound infections, altered inflammatory responses, and a lack of angiogenesis that can complicate limb amputation. The foot, because of its architecture, becomes the part most prone to complications and the infection rate is higher mainly between the toes due to the humid nature. Therefore, the infection rate is significantly higher. Wound healing in diabetes is a dynamic process usually delayed due to poor immune function. Diabetes-related pedal neuropathy and perfusion disturbances can lead to a loss of sensation in the foot. This neuropathy can further be a risk factor for ulcer development due to repetitive mechanical stress that later might get infected by the invasion of microorganisms extending to the bone and causing an infection called pedal osteomyelitis. This review details the pathophysiology, the biomaterials aiding in the infection cure and regeneration of bone along with their limitations, as well as their future prospects.

Incidence and Risk Factors for Extremity Osteoradionecrosis after Limb-Sparing Surgery and Adjuvant Radiotherapy

Osteoradionecrosis (ORN) is a major complication after radiotherapy. Most studies on ORN have focused on patients with mandibular lesions, with few studies including patients with extremity soft tissue sarcoma (STS). We included 198 patients with extremity STS who underwent limb-sparing surgery and adjuvant radiotherapy between 2004 and 2017. The incidence rate of extremity ORN was 3.5% (7/198), with most lesions (6/7) located in the lower extremities. The mean follow-up time was 62 months. Clinical presentations included chronic ulcers, soft tissue necrosis, sinus discharge, bone nonunion, and pathological fractures. Compared with the non-ORN group, the ORN group had a significantly higher total radiation dose (68 Gy vs. 64 Gy, p = 0.048) and greater use of intraoperative periosteal stripping (p = 0.008). Repeat surgeries and subsequent soft tissue reconstruction or limb amputation were performed as treatments. The risk and management of ORN in patients with extremity STS was ignored previously. Because the disease is complex and affects both clinicians and patients, careful surveillance should be undertaken.

Escherichia Coli Vertebral Osteomyelitis: A Case Report

Diagnosis of spondylodiscitis is often challenging, delayed, or even missed due to the uncommonness of the disease, and it can lead to devastating consequences. Therefore, a high index of suspicion is needed for prompt diagnosis and improved long-term outcomes. Vertebral osteomyelitis, or spondylodiscitis, is a rare disease with increasing prevalence due to advanced spinal surgical procedures, nosocomial bacteremia, increased life expectancy, and intravenous drug use. Hematogenous infection is the most common cause of spondylodiscitis. We report a case of a 63-year-old man with a history of liver cirrhosis who initially presented due to abdominal distension. During his hospital stay, he complained of uncontrolled back pain due to Escherichia coli spondylodiscitis.

Thermosensitive Nanotherapeutics for Localized Photothermal Ablation of MRSA-Infected Osteomyelitis Combined with Chemotherapy

Chronic osteomyelitis is an inflammatory skeletal disease caused by a bacterial infection that affects the periosteum, bone, and bone marrow. Methicillin-resistant Staphylococcus aureus (MRSA) is the most common causative agent. The bacterial biofilm formed on the necrotic bone is a considerable challenge to treating MRSA-infected osteomyelitis. Here, we developed an all-in-one cationic thermosensitive nanotherapeutic (TLCA) for treating MRSA-infected osteomyelitis. The prepared TLCA particles were positively charged and <230 nm in size, which allowed them to diffuse effectively into the biofilm. The positive charges of the nanotherapeutic accurately targeted the biofilm, and it subsequently regulated the drug release under near-infrared (NIR) light irradiation, thereby efficiently exerting the synergistic effect of NIR light-driven photothermal sterilization and chemotherapy. More than 80% of the antibiotics were abruptly released at 50 °C, which dispersed the biofilm by up to 90%. When applied to MRSA-infected osteomyelitis, with a localized temperature of 50 °C induced by 808 nm laser irradiation, it not only eliminated the bacteria and controlled infection but also inhibited the bone tissue inflammatory response, significantly reducing TNF-α, IL-1β, and IL-6 levels. In conclusion, we constructed an all-in-one antimicrobial treatment modality that provides a new and effective strategy for the topical treatment of chronic osteomyelitis.

Osteomyelitis of the Lower Limb: Diagnostic Accuracy of Dual-Energy CT versus MRI

BACKGROUND

MRI is the preferred imaging technique for the identification of osteomyelitis. The key element for diagnosis is the presence of bone marrow edema (BME). Dual-energy CT (DECT) is an alternative tool which is able to identify BME in the lower limb.

PURPOSE

To compare the diagnostic performance of DECT and MRI for osteomyelitis, using clinical, microbiological, and imaging data as reference standards.

MATERIALS AND METHODS

This prospective single-center study enrolled consecutive patients with suspected bone infections undergoing DECT and MRI imaging from December 2020 to June 2022. Four blinded radiologists with various experience levels (range of 3-21 years) evaluated the imaging findings. Osteomyelitis was diagnosed in the presence of BMEs, abscesses, sinus tracts, bone reabsorption, or gaseous elements. The sensitivity, specificity, and AUC values of each method were determined and compared using a multi-reader multi-case analysis. A p value < 0.05 was considered significant.

RESULTS

In total, 44 study participants (mean age 62.5 years ± 16.5 [SD], 32 men) were evaluated. Osteomyelitis was diagnosed in 32 participants. For the MRI, the mean sensitivity and specificity were 89.1% and 87.5%, while for the DECT they were 89.0% and 72.9%, respectively. The DECT demonstrated a good diagnostic performance (AUC = 0.88), compared with the MRI (AUC = 0.92) (p = 0.12). When considering each imaging finding alone, the best accuracy was achieved by considering BME (AUC for DECT 0.85 versus AUC of MRI of 0.93, with p = 0.07), followed by the presence of bone erosions (AUC 0.77 for DECT and 0.53 for MRI, with p = 0.02). The inter-reader agreement of the DECT (k = 88) was similar to that of the MRI (k = 90).

CONCLUSION

Dual-energy CT demonstrated a good diagnostic performance in detecting osteomyelitis.

Imaging Osteomyelitis: An Update

BACKGROUND

 Hematogenous osteomyelitis has increased over the past quarter century in frequency, virulence, and degree of soft-tissue involvement, bringing about changes in clinical manifestations and management of the disease especially in children that should be reflected in the current imaging approach. Likewise, the global disease burden of diabetes has increased greatly in the same period, compounding the problem of ascertaining osteomyelitis in diabetic foot.

METHOD

 This article provides an updated overview of imaging findings in hematogenous and contiguous osteomyelitis based on the literature and our institutional experience, along with salient features of recent recommendations from expert groups on the diagnostic algorithms and reporting terminology.

RESULTS AND CONCLUSION

 Findings on radiography and especially magnetic resonance imaging (MRI) closely reflect pathophysiology in osteomyelitis, whereby the characteristic involvement of the metaphysis or metaphyseal-equivalents, the formation and subperiosteal extension of intramedullary pus collection, and the development of cloaca, sequestrum, and involucrum are all diagnostic clues. Non-enhancing foci within the medullary bone, the penumbra sign, intra- or extramedullary fat globules, and surrounding soft tissue inflammation or abscesses are among key MRI findings. Diabetic foot is a special condition with characteristic pathophysiologic and imaging features that suggest the likelihood of osteomyelitis and the main differential diagnostic consideration of acute on chronic neuropathic osteoarthropathy with or without osteomyelitis.

KEY POINTS

  · Imaging closely reflects pathophysiology in hematogenous osteomyelitis.. · Acute hematogenous osteomyelitis predominantly involves metaphyses and metaphyseal equivalent sites.. · MRI clues for hematogenous osteomyelitis include central marrow non-enhancement, intra- or extramedullary fat globules, and the "penumbra" sign.. · An increased fluid-sensitive MRI bone signal abutting a soft tissue ulcer, abscess, or sinus tract suggests a high probability of contact osteomyelitis..

CITATION FORMAT

· Aydingoz U, Imaging Osteomyelitis: An Update. Fortschr Röntgenstr 2023; DOI: 10.1055/a-1949-7641.

A Combination of Ilizarov Frame, Externalized Locking Plate and Tibia Bridging for an Adult with Large Tibial Defect and Severe Varus Deformity Due to Chronic Osteomyelitis in Childhood: A Case Report

Background: Various techniques have been reported to treat large, segmental tibial defects, such as autogenous bone graft, vascularized free fibula transfer and bone transport. We present a case of a 24-year-old male with a 17-year history of chronic osteomyelitis with obvious lower limb length discrepancy and severe varus deformity of the tibia secondary to osteomyelitis in childhood. Aim: The aim of this work is to provide an alternative choice for treating patients in developing countries with severe lower limb deformity caused by chronic osteomyelitis. Case Presentations: Without surgical intervention for a prolonged period of time, the patient was admitted in our institute for corrective surgery. Corrective surgery consisted of three stages: lengthening with Ilizarov frame, removal of Ilizarov frame and fixation with externalized locking plate, and removal of externalized locking plate. Tibia bridging was achieved at the distal and proximal junction. The range of motion (ROM) of the knee joint was nearly normal, but the stiffness of the ankle joint was noticeable. The remaining leg discrepancy of 0.1 cm required no application of a shoe lift. Moreover, the patient could engage in daily activities without noted limping. Conclusions: Distraction-compression osteogenesis using the Ilizarov apparatus is a powerful tool to lengthen the shortened long bone and adjust the deformity of the lower limbs. Externalized locking plates provide an alternative to the traditional bulky external fixator, as its low profile makes it more acceptable to patients without compromising axial and torsional stiffness. In all, a combination of Ilizarov frame, externalized locking plate and tibia bridging is an alternative for patients in similar conditions.

Identification of Ferroptosis-Related Biomarkers for Diagnosis and Molecular Classification of Staphylococcus aureus-Induced Osteomyelitis

Objective

Staphylococcus aureus (SA)-induced osteomyelitis (OM) is one of the most common refractory diseases in orthopedics. Early diagnosis is beneficial to improve the prognosis of patients. Ferroptosis plays a key role in inflammation and immune response, while the mechanism of ferroptosis-related genes (FRGs) in SA-induced OM is still unclear. The purpose of this study was to determine the role of ferroptosis-related genes in the diagnosis, molecular classification and immune infiltration of SA-induced OM by bioinformatics.

Methods

Datasets related to SA-induced OM and ferroptosis were collected from the Gene Expression Omnibus (GEO) and ferroptosis databases, respectively. The least absolute shrinkage and selection operator (LASSO) and support vector machine-recursive feature elimination (SVM-RFE) algorithms were combined to screen out differentially expressed-FRGs (DE-FRGs) with diagnostic characteristics, and gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) were used to explore specific biological functions and pathways. Based on these key DE-FRGs, a diagnostic model was established, and molecular subtypes were divided to explore the changes in the immune microenvironment between molecular subtypes.

Results

A total of 41 DE-FRGs were identified. After screening and intersecting with LASSO and SVM-RFE algorithms, 8 key DE-FRGs with diagnostic characteristics were obtained, which may regulate the pathogenesis of OM through the immune response and amino acid metabolism. The ROC curve indicated that the 8 DE-FRGs had excellent diagnostic ability for SA-induced OM (AUC=0.993). Two different molecular subtypes (subtype 1 and subtype 2) were identified by unsupervised cluster analysis. The CIBERSORT analysis revealed that the subtype 1 OM had higher immune cell infiltration rates, mainly in T cells CD4 memory resting, macrophages M0, macrophages M2, dendritic cells resting, and dendritic cells activated.

Conclusion

We developed a diagnostic model related to ferroptosis and molecular subtypes significantly related to immune infiltration, which may provide a novel insight for exploring the pathogenesis and immunotherapy of SA-induced OM.

Nanoparticular and other carriers to deliver lactoferrin for antimicrobial, antibiofilm and bone-regenerating effects: a review

Bone and joint infections are a rare but serious problem worldwide. Lactoferrin’s antimicrobial and antibiofilm activity coupled with its bone-regenerating effects may make it suitable for improving bone and joint infection treatment. However, free lactoferrin (LF) has highly variable oral bioavailability in humans due to potential for degradation in the stomach and small intestine. It also has a short half-life in blood plasma. Therefore, encapsulating LF in nanocarriers may slow degradation in the gastrointestinal tract and enhance LF absorption, stability, permeability and oral bioavailability. This review will summarize the literature on the encapsulation of LF into liposomes, solid lipid nanoparticles, nanostructured lipid carriers, polymeric micro and nanoparticles and hydroxyapatite nanocrystals. The fabrication, characterization, advantages, disadvantages and applications of each system will be discussed and compared.

ACR Appropriateness Criteria® Suspected Osteomyelitis, Septic Arthritis, or Soft Tissue Infection (Excluding Spine and Diabetic Foot): 2022 Update

Musculoskeletal infections involve bones, joints, and soft tissues. These infections are a common clinical scenario in both outpatient and emergent settings. Although radiography provides baseline findings, a multimodality approach is often implemented to provide more detailed information on the extent of infection involvement and complications. MRI with intravenous contrast is excellent for the evaluation of musculoskeletal infections and is the most sensitive for diagnosing osteomyelitis. MRI, CT, and ultrasound can be useful for joint and soft tissue infections. When MRI or CT is contraindicated, bone scans and the appropriate utilization of other nuclear medicine scans can be implemented for aiding in the diagnostic imaging of infection, especially with metal hardware and arthroplasty artifacts on MRI and CT. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Bone regeneration after marginal bone resection in two-stage treatment of chronic long bone infection - a combined histopathological and clinical pilot study

INTRODUCTION

In chronic bone infection, marginal bone resection avoids large and difficult to reconstruct bone defects. However, there is still a lack of knowledge on bone regeneration during chronic bone infection and bone healing capability after marginal bone resection. Therefore, the purpose of this study was to investigate the clinical and histopathological outcomes after marginal bone resection in chronic long bone infection. We hypothesized that there is a regenerative bone healing potential after marginal bone resection that results in an acceptable clinical outcome and improved pathohistological bone healing parameters during treatment.

MATERIALS AND METHODS

Nine patients were treated for chronic bone infections in a two-stage manner with marginal bone resection of the infected area and the placement of an antibiotic-loaded polymethyl methacrylate (PMMA) spacer at stage one followed by bone reconstruction at stage two combined with systemic antibiotic therapy. Comparable bone samples were harvested at the border region between vital and necrotic bone area during stage one and the identical location during stage two. Control bone samples were harvested from five healthy patients without bone infection. Clinical outcome in terms of infection eradication and bone consolidation were assessed. The phenotypic changes of osteocyte and morphological changes of lacunar-canalicular network were investigated by histological and immunohistochemical staining between the two observation periods. Furthermore, expression levels of major bone formation and resorption markers were investigated by immunohistochemical and tartrate-resistant acid phosphatase (TRAP) staining.

RESULTS

The clinical results with a follow-up of 12.9 months showed that eight of nine patients (88.9%) achieved bone consolidation after a planned two-stage procedure of marginal resection of necrotic bone and consecutive reconstruction. In four of the nine patients (44.4%), additional marginal debridements after stage two had to be performed. After marginal resection at stage one, the improved bone formation ability at stage two was demonstrated by significantly lower percentage of empty lacunae, significantly more mature osteocytes and higher BMP-2 positive cell density, whereas decreased resorption was indicated by significantly lower osteoclast density and RANKL/OPG ratio. In patients requiring additional debridement compared to patients without additional debridements, a significantly higher percentage of empty lacunae was found at stage one.

CONCLUSION

Marginal bone resection combined with local and systemic antibiotic therapy is a feasible treatment option to avoid large bone defects as bone from the marginal resection area seems to have good regenerative potential. Despite a high revision rate of 44.4%, this technique avoids large bone resection and revisions can be done by further marginal debridements.

Identifying Clinically Relevant Bacteria Directly from Culture and Clinical Samples with a Handheld Mass Spectrometry Probe

Background

Rapid identification of bacteria is critical to prevent antimicrobial resistance and ensure positive patient outcomes. We have developed the MasSpec Pen, a handheld mass spectrometry-based device that enables rapid analysis of biological samples. Here, we evaluated the MasSpec Pen for identification of bacteria from culture and clinical samples.

Methods

A total of 247 molecular profiles were obtained from 43 well-characterized strains of 8 bacteria species that are clinically relevant to osteoarticular infections, including Staphylococcus aureus, Group A and B Streptococcus, and Kingella kingae, using the MasSpec Pen coupled to a high-resolution mass spectrometer. The molecular profiles were used to generate statistical classifiers based on metabolites that were predictive of Gram stain category, genus, and species. Then, we directly analyzed samples from 4 patients, including surgical specimens and clinical isolates, and used the classifiers to predict the etiologic agent.

Results

High accuracies were achieved for all levels of classification with a mean accuracy of 93.3% considering training and validation sets. Several biomolecules were detected at varied abundances between classes, many of which were selected as predictive features in the classifiers including glycerophospholipids and quorum-sensing molecules. The classifiers also enabled correct identification of Gram stain type and genus of the etiologic agent from 3 surgical specimens and all classification levels for clinical specimen isolates.

Conclusions

The MasSpec Pen enables identification of several bacteria at different taxonomic levels in seconds from cultured samples and has potential for culture-independent identification of bacteria directly from clinical samples based on the detection of metabolic species.

Nanotechnology in the Diagnosis and Treatment of Osteomyelitis

Infection remains one of the largest threats to global health. Among those infections that are especially troublesome, osteomyelitis, or inflammation of the bone, typically due to infection, is a particularly difficult condition to diagnose and treat. This difficulty stems not only from the biological complexities of opportunistic infections designed to avoid the onslaught of both the host immune system as well as exogenous antibiotics, but also from changes in the host vasculature and the heterogeneity of infectious presentations. While several groups have attempted to classify and stage osteomyelitis, controversy remains, often delaying diagnosis and treatment. Despite a host of preclinical treatment advances being incubated in academic and company research and development labs worldwide, clinical treatment strategies remain relatively stagnant, including surgical debridement and lengthy courses of intravenous antibiotics, both of which may compromise the overall health of the bone and the patient. This manuscript reviews the current methods for diagnosing and treating osteomyelitis and then contemplates the role that nanotechnology might play in the advancement of osteomyelitis treatment.

Bacteriophage Therapy for Staphylococcus Aureus Infections: A Review of Animal Models, Treatments, and Clinical Trials

Staphylococcus aureus (S. aureus) is a common and virulent human pathogen causing several serious illnesses including skin abscesses, wound infections, endocarditis, osteomyelitis, pneumonia, and toxic shock syndrome. Antibiotics were first introduced in the 1940s, leading to the belief that bacterial illnesses would be eradicated. However, microorganisms, including S. aureus, began to develop antibiotic resistance from the increased use and abuse of antibiotics. Antibiotic resistance is now one of the most serious threats to global public health. Bacteria like methicillin-resistant Staphylococcus aureus (MRSA) remain a major problem despite several efforts to find new antibiotics. New treatment approaches are required, with bacteriophage treatment, a non-antibiotic strategy to treat bacterial infections, showing particular promise. The ability of S. aureus to resist a wide range of antibiotics makes it an ideal candidate for phage therapy studies. Bacteriophages have a relatively restricted range of action, enabling them to target pathogenic bacteria. Their usage, usually in the form of a cocktail of bacteriophages, allows for more focused treatment while also overcoming the emergence of resistance. However, many obstacles remain, particularly in terms of their effects in vivo, necessitating the development of animal models to assess the bacteriophage efficiency. Here, we provide a review of the animal models, the various clinical case treatments, and clinical trials for S. aureus phage therapy.

Mini Review Therapeutic Strategies Targeting for Biofilm and Bone Infections

Bone infection results in a complex inflammatory response and bone destruction. A broad spectrum of bacterial species has been involved for jaw osteomyelitis, hematogenous osteomyelitis, vertebral osteomyelitis or diabetes mellitus, such as Staphylococcus aureus (S. aureus), coagulase-negative Staphylococcus species, and aerobic gram-negative bacilli. S. aureus is the major pathogenic bacterium for osteomyelitis, which results in a complex inflammatory response and bone destruction. Although various antibiotics have been applied for bone infection, the emergence of drug resistance and biofilm formation significantly decrease the effectiveness of those agents. In combination with gram-positive aerobes, gram-negative aerobes and anaerobes functionally equivalent pathogroups interact synergistically, developing as pathogenic biofilms and causing recurrent infections. The adhesion of biofilms to bone promotes bone destruction and protects bacteria from antimicrobial agent stress and host immune system infiltration. Moreover, bone is characterized by low permeability and reduced blood flow, further hindering the therapeutic effect for bone infections. To minimize systemic toxicity and enhance antibacterial effectiveness, therapeutic strategies targeting on biofilm and bone infection can serve as a promising modality. Herein, we focus on biofilm and bone infection eradication with targeting therapeutic strategies. We summarize recent targeting moieties on biofilm and bone infection with peptide-, nucleic acid-, bacteriophage-, CaP- and turnover homeostasis-based strategies. The antibacterial and antibiofilm mechanisms of those therapeutic strategies include increasing antibacterial agents’ accumulation by bone specific affinity, specific recognition of phage-bacteria, inhibition biofilm formation in transcription level. As chronic inflammation induced by infection can trigger osteoclast activation and inhibit osteoblast functioning, we additionally expand the potential applications of turnover homeostasis-based therapeutic strategies on biofilm or infection related immunity homeostasis for host-bacteria. Based on this review, we expect to provide useful insights of targeting therapeutic efficacy for biofilm and bone infection eradication.

Linear programming based gene expression model (LPM-GEM) predicts the carbon source for Bacillus subtilis

BACKGROUND

Elucidating cellular metabolism led to many breakthroughs in biotechnology, synthetic biology, and health sciences. To date, deriving metabolic fluxes by ¹³C tracer experiments is the most prominent approach for studying metabolic fluxes quantitatively, often with high accuracy and precision. However, the technique has a high demand for experimental resources. Alternatively, flux balance analysis (FBA) has been employed to estimate metabolic fluxes without labeling experiments. It is less informative but can benefit from the low costs and low experimental efforts and gain flux estimates in experimentally difficult conditions. Methods to integrate relevant experimental data have been emerged to improve FBA flux estimations. Data from transcription profiling is often selected since it is easy to generate at the genome scale, typically embedded by a discretization of differential and non-differential expressed genes coding for the respective enzymes.

RESULT

We established the novel method Linear Programming based Gene Expression Model (LPM-GEM). LPM-GEM linearly embeds gene expression into FBA constraints. We implemented three strategies to reduce thermodynamically infeasible loops, which is a necessary prerequisite for such an omics-based model building. As a case study, we built a model of B. subtilis grown in eight different carbon sources. We obtained good flux predictions based on the respective transcription profiles when validating with ¹³C tracer based metabolic flux data of the same conditions. We could well predict the specific carbon sources. When testing the model on another, unseen dataset that was not used during training, good prediction performance was also observed. Furthermore, LPM-GEM outperformed a well-established model building methods.

CONCLUSION

Employing LPM-GEM integrates gene expression data efficiently. The method supports gene expression-based FBA models and can be applied as an alternative to estimate metabolic fluxes when tracer experiments are inappropriate.

Bone Involvement in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a wide variability of clinical manifestations due to the potential involvement of several tissues and internal organs, with a relapsing and remitting course. Dysregulation of innate and adaptive immune systems, due to genetic, hormonal and environmental factors, may be responsible for a broad spectrum of clinical manifestations, affecting quality of life, morbidity and mortality. Bone involvement represents one of the most common cause of morbidity and disability in SLE. Particularly, an increased incidence of osteoporosis, avascular necrosis of bone and osteomyelitis has been observed in SLE patients compared to the general population. Moreover, due to the improvement in diagnosis and therapy, the survival of SLE patient has improved, increasing long-term morbidities, including osteoporosis and related fractures. This review aims to highlight bone manifestations in SLE patients, deepening underlying etiopathogenetic mechanisms, diagnostic tools and available treatment.

Exercise‐induced thoracic outlet syndrome and concomitant osteomyelitis in cervical rib with a possible familial origin: A case report

Cervical ribs are rare and usually asymptomatic. Occasionally, they can cause nerve impingements and compressive symptoms. In cervical ribs, osteomyelitis secondary to trauma is unheard of. We report such a case made more interesting by the familial presence of bilateral cervical ribs in two generations, indicating a familial origin.

Structural Analysis of Mitochondrial Dynamics-From Cardiomyocytes to Osteoblasts: A Critical Review

Mitochondria play a crucial role in cell physiology and pathophysiology. In this context, mitochondrial dynamics and, subsequently, mitochondrial ultrastructure have increasingly become hot topics in modern research, with a focus on mitochondrial fission and fusion. Thus, the dynamics of mitochondria in several diseases have been intensively investigated, especially with a view to developing new promising treatment options. However, the majority of recent studies are performed in highly energy-dependent tissues, such as cardiac, hepatic, and neuronal tissues. In contrast, publications on mitochondrial dynamics from the orthopedic or trauma fields are quite rare, even if there are common cellular mechanisms in cardiovascular and bone tissue, especially regarding bone infection. The present report summarizes the spectrum of mitochondrial alterations in the cardiovascular system and compares it to the state of knowledge in the musculoskeletal system. The present paper summarizes recent knowledge regarding mitochondrial dynamics and gives a short, but not exhaustive, overview of its regulation via fission and fusion. Furthermore, the article highlights hypoxia and its accompanying increased mitochondrial fission as a possible link between cardiac ischemia and inflammatory diseases of the bone, such as osteomyelitis. This opens new innovative perspectives not only for the understanding of cellular pathomechanisms in osteomyelitis but also for potential new treatment options.

Clinical Characteristics of Patients with Pyogenic Vertebral Osteomyelitis and Concurrent Infections and Their Clinical Outcomes

Patients with pyogenic vertebral osteomyelitis (PVO) often develop concurrent infections, and a significant number of these patients show rapid deterioration in their medical condition, leading to mortality without PVO-related structural instability or neurological deficits. To improve clinical outcomes, we investigated the clinical presentation and treatment outcomes of patients with PVO and concurrent infections. This study included 695 patients with PVO, of which 175 (25%) had concurrent infections and 520 (75%) did not. The clinical characteristics of the two groups were compared, and multivariable analysis was performed to identify the association between concurrent infections and clinical outcomes. Patients with concurrent infections were older and had more comorbidities than those without. Moreover, there were significant intergroup differences in the anatomical involvement of PVO, and patients with concurrent infections had a higher number of regions involved more frequently than those without concurrent infections (15% vs. 6%). In contrast, patients with concurrent infections showed a lower degree of focal invasiveness, including a lower incidence of posterior abscess (47% vs. 59%; p = 0.008) and fewer neurological impairments according to the American Spinal Injury Association grade (p < 0.001) than those without concurrent infections. The causative organisms also differed significantly between the two groups, and patients with concurrent infections had a greater proportion of Gram-negative infections (31% vs. 16%, respectively) and a smaller proportion of methicillin-resistant S. aureus infections than those without concurrent infections (6% vs. 24%). Consequently, their clinical outcomes were significantly different, and patients with concurrent infections showed lower recurrence and higher mortality rates. We investigated the 1-year recurrence and mortality rates and their 95% confidence intervals according to the types of concurrent infections and their time of diagnosis and found variations in these parameters. Our results, based on a large number of patients, can be practically used as a reasonable reference to warn clinicians of the clinical risks of concurrent infections in patients with PVO and to help predict their clinical outcomes.