The finite element method (FEM) represents a computer simulation method, originally used in civil engineering, which dates back to the early 1940s. Applications of FEM have also been used in numerous medical areas and in orthopedic surgery. Computing technology has improved over the years and as a result, more complex problems, such as those involving the spine, can be analyzed. The spine is a complex anatomical structure that maintains the erect posture and supports considerable loads. Applications of FEM in the spine have contributed to the understanding of bone biomechanics, both in healthy and abnormal conditions, such as scoliosis, fractures (trauma), degenerative disc disease and osteoporosis. However, since FEM is only a digital simulation of the real condition, it will never exactly simulate in vivo results. In particular, when it concerns biomechanics, there are many features that are difficult to represent in a FEM. More FEM studies and spine research are required in order to examine interpersonal spine stiffness, young spine biomechanics and model accuracy. In the future, patient-specific models will be used for better patient evaluations as well as for better pre- and inter-operative planning.

Introduction: Fungal hip prosthetic joint infections (PJIs) are rare but severe infections. Their incidence has increased in the last decades due to the aging population, as well as due to the increased number of immunosuppressed hosts. The present review of all published fungal PJIs in hip arthroplasties aims to present as much data as possible for both medical and surgical treatment options, so that the best applicable management may be concluded. Methods: A meticulous review of all published fungal hip PJIs was conducted. Information regarding demographics, causative fungus, antifungal treatment (AFT), surgical management as well as the infection outcome was recorded. Results : A total of 89 patients suffering fungal hip PJI were identified. The patients’ mean age was 66.9 years. The mean time from initial arthroplasty to onset of symptoms was 69.3 months, while 40.4% of the patients were immunocompromised. The most common imaging method indicating diagnosis was plain X-ray or CT scan (20.2%), while definite diagnosis had become possible through cultures in most cases (98.9%), and/or histology (44.9%). The most frequently isolated fungus was C. albicans (49.4%), followed by C. parapsilosis (18%) and C. glabrata (12.4%), while bacterial co-infection was present in 32 cases (36%). Two-stage revision arthroplasty (TSRA) was the most commonly performed procedure (52.8%), with mean time between the two stages = 7.9 months. Regarding antifungal treatment (AFT), fluconazole was the preferred agent (62.9%), followed by amphotericin B (36%), while the mean duration of AFT was 5.1 months. Outcome was successful in 68 cases (76.4%). Conclusions: Both diagnosis and management of fungal PJIs in patients having undergone total hip arthroplasty are quite demanding. A multidisciplinary approach is of utmost importance, since the combination of AFT and TSRA appears to be the proper treatment method.

Background: Spondylodiscitis caused by Aspergillus spp. is a rare but life-threatening clinical entity. However, a consensus on diagnostic criteria and most effective medical management is still missing. The present study is a review of all published cases of spondylodiscitis caused by Aspergillus spp., in an effort to elucidate epidemiology, patients’ characteristics, andand the medical and surgical treatment options and their effectiveness. Methods: A thorough review of all existing spondylodiscitis cases caused by Aspergillus was performed. Data regarding demographics, responsible fungus, time between symptoms’ onset and firm diagnosis, antifungal treatment (AFT), surgical intervention, andand the infection’s outcome were investigated. Results: A total of 118 Aspergillus spondylodiscitis cases, yielding 119 Aspergillus spp. isolates, were identified in the literature. The patients’ mean age was 40.6 years. Magnetic resonance imaging (MRI) (after its introduction) indicated the diagnosis in most cases (66.7%), while definite diagnosis was established through cultures in the majority of cases (73.7%). Aspergillus fumigatus was isolated in most cases (73; 61.3%), followed by Aspergillus flavus (15; 12.6%) andand Aspergillus nidulans and terreus (7; 5.9%, each). The mean time between symptoms’ onset and diagnosis was 5.7 months. Amphotericin B was the preferred antifungal regiment (84 cases; 71.2%), followed by voriconazole (31; 26.3%), and the mean AFT duration was 6.1 months. The final outcome was successful in 93 cases (78.8%). Furthermore, 77 patients (65.3%) underwent surgery. Conclusions: Spondylodiscitis caused by Aspergillus spp. represents a clinical challenge, requiring a multidisciplinary approach. The present review has shown that prolonged AFT has been the standard of care of the studied cases, while surgical treatment seems to play an important role in selected patents.

Background: Septic arthritis due to Aspergillus spp. represents a rare, but severe disease. Nevertheless, clear guidelines regarding most effective medical treatment have not yet been established. The present study is a literature review of all reported cases of fungal septic arthritis due to Aspergillus spp, in order to clarify epidemiology, as well as the medical and operative management and their outcome. Methods: A meticulous review of all published septic arthritis infections due to Aspergillus has been conducted. Information regarding demographics, causative fungus, antifungal treatment (AFT), surgical intervention, as well as the infection’s outcome were recorded and evaluated. Results: A total of 30 Aspergillus spp. strains from 29 hosts have been studied. The patients’ mean age was 45.8 years. The most commonly affected joint was the knee (45.7%), while the predominant symptom was joint pain (62%). Most patients were immunocompromised (72.4%). Diagnosis was established through cultures and/or histopathology. Aspergillus fumigatus was the most common responsible fungi (63.3%), followed by A. flavus (16.6%) and A. terreus (10%). Regarding AFT, the preferred agent proved to be Amphotericin B (14 cases; 48.3%), followed by voriconazole (11; 37.9%), while the mean AFT duration was 5.6 months. In most cases surgical treatment was also performed (in 4 cases no surgery was reported). Treatment was effective in 20 cases (69%). Conclusions: Septic arthritis caused by Aspergillus spp. represents a severe clinical entity. It seems that, with the available data, prolonged AFT along with surgical intervention is the preferred management of this infection, while identification of the responsible fungus is of utmost importance.

Background: Coccidioidomycosis represents an endemic and challenging disease, with rare extrapulmonary manifestations. The present review of all published cases of core and extremities osseous coccidioidomycosis aims to describe epidemiology, patients’ characteristics, symptoms as well as medical and surgical treatment options and their effectiveness. Methods: A thorough review of all published skeletal core and extremity infections due to Coccidioides species was conducted. Information regarding demographics, causative fungus, antifungal treatment (AFT), surgical management as well as the infection outcome was recorded. Results: A total of 92 cases of Coccidioides spp. skeletal infections were recorded in 87 patients. The patients’ mean age was 35.3 years. The most common site of infection was the spine (82.6%), followed by the foot (6.5%), while the predominant symptom upon presentation was pain (29.9%). Immunosuppressive conditions and/or medications were observed in 21 patients (24.1%). Regarding imaging methods, indicating diagnosis, plain X-rays or CT scans were performed in most patients (50.6%), followed by magnetic resonance imaging (MRI) (47.1%). Most cases were diagnosed through histopathology (62; 71.3%), followed by serology testing (36; 42.4%) and by cultures (35; 40.2%). In 32 cases (36.8%), Coccidioides immitis was cultured, while in the remaining 55 cases (63.2%) the fungus was not further characterized. Regarding AFT, amphotericin B was the preferred agent (52.9%), followed by fluconazole (43.3%). In most cases (78.2%) surgical treatment was also performed. Treatment was successful in 80.5% of cases. Conclusions: Skeletal core and extremity infections due to Coccidioides spp. represent a severe disease. With the available data, the combination of prolonged proper AFT with surgical intervention seems to be the optimal current therapeutic approach.

Extrapulmonary infections by Coccidioides spp., though rare, can occur via dissemination, affecting singular or multiple sites, including the skin and musculoskeletal system. Skeletal involvement often manifests as osteomyelitis, particularly in the axial skeleton. The present systematic review evaluates all documented cases of skeletal coccidioidomycosis to assess the diagnostic and treatment strategies alongside the outcomes, drawing insights from an analysis of 163 verified cases. A systematic review following PRISMA guidelines identified all studies reporting skeletal infections by Coccidioides spp. up to 2023 from the PubMed and Scopus databases. Eligible studies evaluated osteoarticular infections from Coccidioides spp. Data extraction included demographics, microbiological data, diagnostic methods, and treatment outcomes. Of the 501 initially identified records, a total of 163 patients from 69 studies met the inclusion criteria. Most cases were from the USA, predominantly males, while the median age of the population was 36 years. Diabetes mellitus was the common comorbidity (14.7%). C. immitis was the most prevalent pathogen. The spine and hand were common sites of infection (17.5% and 15.1%, respectively). Osteomyelitis by Coccidioides spp. was diagnosed, in most cases, by positive cultures (n = 68; 41.7%), while, in 49 (30.9%), both the histological examination and cultures yielded the fungus. Surgical debridement was performed in 80.9% of cases. A total of 118 (72.3%) patients were treated with monotherapy, while combination therapy with two or more antifungal agents was reported in 45 (17.7%). Amphotericin B (either liposomal or deoxycholate) was the most commonly given agent as monotherapy in 51 (31.2%) patients, while 30 (18.4%) patients received itraconazole as monotherapy. The rate of infection’s resolution was higher in patients undergoing surgical debridement (79.5%), compared to those treated only with antifungal agents (51.6%, p = 0.003). Treatment outcomes showed complete resolution in 74.2% of patients, with a mortality rate of 9.2%. Coccidioidal osseous infections present diagnostic and therapeutic challenges. Surgical intervention is often necessary, complementing antifungal therapy. Vigilance for Coccidioides spp. infections, especially in regions with endemicity, is crucial, particularly when bacterial cultures yield negative results.