Several causes contribute to the high infection rate in tumor prostheses, including extensive tissue dissection and patients’ immunosuppression due to the neoplastic disease. Most of these infections develop within the first 2 years following surgery with 70% of them occurring during the first year, while they are often associated with a low pathogen burden. The pathogenesis of infections in tumor prostheses is linked to bacteria developing in biofilms. Approximately half of them are caused by Staphylococcus spp., followed by Streptococcus spp., Enterococcus spp., and Enterobacteriaceae spp., while multiple pathogens may be isolated in up to 25% of the cases, with coagulase-negative Staphylococci (CoNS) and Enterococccus spp. being the most frequent pair. Although early detection and timely management are essential for complete resolution of these challenging infections, prompt diagnosis is problematic due to the highly varying clinical symptoms and the lack of specific preoperative and intraoperative diagnostic tests. Surgical management with one- or two-stage revision surgery is the mainstay for successful eradication of these infections. The recent advances in laboratory diagnostics and the development of biofilm-resistant prostheses over the past years have been areas of great interest, as research is now focused on prevention strategies. The aim of this study is to review and consolidate the current knowledge regarding the epidemiology, risk factors, microbiology, and diagnosis of infections of tumor prostheses, and to review the current concepts for their treatment and outcomes.

Biopsy is a pivotal component in the diagnostic process of bone and soft tissue tumors. The objective is to obtain adequate tissue without compromising local tumor dissemination and the patient’s survival. This review explores contemporary principles and practices in musculoskeletal biopsies, emphasizing the critical role of diagnostic accuracy while also delving into the evolving landscape of liquid biopsies as a promising alternative in the field. A thorough literature search was done in PubMed and Google Scholar as well as in physical books in libraries to summarize the available biopsy techniques for musculoskeletal tumors, discuss the available methods, risk factors, and complications, and to emphasize the challenges related to biopsies in oncology. Research articles that studied the basic principles and specialized techniques of biopsy techniques in tumor patients were deemed eligible. Their advantages and disadvantages, technical and pathophysiological mechanisms, and possible risks and complications were reviewed, summarized, and discussed. An inadequately executed biopsy may hinder diagnosis and subsequently impact treatment outcomes. All lesions should be approached with a presumption of malignancy until proven otherwise. Liquid biopsies have emerged as a potent non-invasive tool for analyzing tumor phenotype, progression, and drug resistance and guiding treatment decisions in bone sarcomas and metastases. Despite advancements, several barriers remain in biopsies, including challenges related to costs, scalability, reproducibility, and isolation methods. It is paramount that orthopedic oncologists work together with radiologists and pathologists to enhance diagnosis, patient outcomes, and healthcare costs.

Water polo is a competitive team sport played in the water between two teams of seven players each. Water polo players must have swimming speed, strong abdominal and back muscles, and strong shoulder muscles to cope with this sport's special conditions. In this study, we investigate the possible association of shoulder and trunk muscle systems in adolescent water polo athletes of high demands. The research included 42 water polo players aged 14-16, who train regularly for at least five years, six times a week, and participate in national championships and national teams. The athletes were evaluated on the strength and torque of these muscular systems using the isokinetic dynamometer Biodex System 4 Pro (Biodex Medical Systems, Inc, Shirley, NY). The correlation of the results was done using the statistical package SPSS 21. The correlations revealed statistically significant differences in trunk extension in combination with the shoulder external/internal rotation ratio. Also, most of the correlations occurred between the trunk and non-dominant limb of the athletes and, more often, in the female athletes. Furthermore, for the hand grip, the male athletes showed a greater difference in strength between the dominant and the non-dominant member than female athletes. Finally, the evaluation of the trunk extension/flexion ratio and external/internal rotation ratio for the shoulder joint showed that many athletes are outside the normal range and need targeted strengthening. The negative correlation coefficient between trunk extension/flexion and shoulder external/internal rotation indicates that the trunk extension mechanism helps for better internal rotation of the shoulder. Therefore, water polo players should focus on the training of the stretching mechanism of the trunk and also give weight to achieving a balance between the competing muscular systems of the trunk and the shoulder. Thus, athletes can maximize their skills and, at the same time, protect themselves from injuries.

Approximately 50–70% of patients with advanced cancer will experience bone metastases. The link between metastatic lesions and pathological bones is especially troubling since more metastases mean a higher chance of painful fractures, which can reduce mobility and often require surgery. Therefore, fracture risk predictions are essential for managing patients with bone metastases. However, the current methods for evaluating the risk of fractures are subjective, with low predictive value. This paper highlights how there being no effective comprehensive models for grouping patients by fracture risk due to skeletal metastases makes it harder to create personalized treatment plans; presents the methods currently used for objective evaluations of the pathological fracture risk in bone metastases; and discusses their pros and cons.

Background/Objectives: Diagnosing periprosthetic joint infection (PJI) after megaprosthetic reconstruction may be difficult due to altered inflammatory responses, extensive prior surgery, and the limited performance of conventional criteria such as the 2018 ICM score. Synovial calprotectin is a rapid neutrophil-derived biomarker that may improve diagnostic accuracy in this challenging setting. The primary aim of this study was to evaluate the diagnostic performance of synovial calprotectin in detecting periprosthetic infection in patients treated with tumor megaprostheses; secondary aims included comparison with ICM classification, assessment in infection classification-inconclusive cases, and exploratory performance in patients with low CRP. Methods: This prospective study included 20 consecutive megaprosthesis patients evaluated for suspected PJI at ATTIKON University Hospital, Athens, with a minimum follow-up of 1 year after biomarker testing. Synovial calprotectin was measured using a lateral-flow assay (positive ≥ 50 mg/L) and compared with a predefined infection reference standard. ICM final status (0 = aseptic, 1 = inconclusive, 2 = infected) was recorded for all cases. Other synovial biomarkers (α-defensin, leukocyte esterase, synovial D-dimer) were not routinely available. The cohort had a mean age of 52.9 ± 22.5 years, 70% were male, and reconstructions involved the knee (80%), hip (15%), and humerus (5%). Preoperative cultures were positive in 40%, the median systemic WBC was 7100/μL, and the median time from last surgery to testing was 1.0 years (IQR 0.46–2.0). Among infected cases, the most common microorganisms were coagulase-negative staphylococci (61.5%) and Staphylococcus aureus (23.1%), with 30.8% demonstrating polymicrobial infection. Results: Thirteen of 20 patients (65%) were classified as infected. Using the ≥50 mg/L threshold, synovial calprotectin demonstrated high apparent diagnostic accuracy in this exploratory cohort, and no false positives, yielding a sensitivity of 92.3%, specificity of 100%, PPV of 100%, NPV of 87.5%, LR+ = ∞, and LR− = 0.08. The AUC for continuous values was 1.00. Agreement with the ICM final classification was substantial (κ = 0.76), with no directional discordance (McNemar p = 1.00). Among the three ICM-inconclusive cases, calprotectin correctly reclassified two (66.7%). In patients with low CRP (<10 mg/L), a clinically difficult subgroup, calprotectin maintained strong performance (sensitivity 75%, specificity 100%, NPV 85.7%). Conclusion: Synovial calprotectin demonstrated promising diagnostic performance for PJI in megaprosthesis patients, with high sensitivity and specificity, and substantial agreement with the 2018 ICM criteria. It successfully clarified most ICM-inconclusive cases and remained reliable even in patients with low CRP. These findings support calprotectin as a valuable adjunctive biomarker in the complex diagnostic environment of megaprosthetic reconstruction and justify further validation in larger cohorts.

Background/Objectives: Diagnosing periprosthetic joint infection (PJI) after megaprosthetic reconstruction may be difficult due to altered inflammatory responses, extensive prior surgery, and the limited performance of conventional criteria such as the 2018 ICM score. Synovial calprotectin is a rapid neutrophil-derived biomarker that may improve diagnostic accuracy in this challenging setting. The primary aim of this study was to evaluate the diagnostic performance of synovial calprotectin in detecting periprosthetic infection in patients treated with tumor megaprostheses; secondary aims included comparison with ICM classification, assessment in infection classification-inconclusive cases, and exploratory performance in patients with low CRP. Methods: This prospective study included 20 consecutive megaprosthesis patients evaluated for suspected PJI at ATTIKON University Hospital, Athens, with a minimum follow-up of 1 year after biomarker testing. Synovial calprotectin was measured using a lateral-flow assay (positive ≥ 50 mg/L) and compared with a predefined infection reference standard. ICM final status (0 = aseptic, 1 = inconclusive, 2 = infected) was recorded for all cases. Other synovial biomarkers (α-defensin, leukocyte esterase, synovial D-dimer) were not routinely available. The cohort had a mean age of 52.9 ± 22.5 years, 70% were male, and reconstructions involved the knee (80%), hip (15%), and humerus (5%). Preoperative cultures were positive in 40%, systemic WBC was elevated in 55%, and the median time from last surgery to testing was 1.0 years (IQR 0.46–2.0). Among infected cases, the most common microorganisms were coagulase-negative staphylococci (61.5%) and Staphylococcus aureus (23.1%), with 30.8% demonstrating polymicrobial infection. Results: Thirteen of 20 patients (65%) were classified as infected. Using the ≥ 50 mg/L threshold, synovial calprotectin demonstrated high diagnostic accuracy, and no false positives, yielding a sensitivity of 92.3%, specificity of 100%, PPV of 100%, NPV of 87.5%, LR+ = ∞, and LR− = 0.08. The AUC for continuous values was 1.00. Agreement with the Parvizi final classification was substantial (κ = 0.76), with no directional discordance (McNemar p = 1.00). Among the three ICM-inconclusive cases, calprotectin correctly reclassified two (66.7%). In patients with low CRP (< 10 mg/L), a clinically difficult subgroup, calprotectin maintained strong performance (sensitivity 75%, specificity 100%, NPV 85.7%). Conclusion: Synovial calprotectin demonstrated excellent diagnostic accuracy for PJI in megaprosthesis patients, with high sensitivity, perfect specificity, and substantial agreement with the 2018 ICM criteria. It successfully clarified most ICM-inconclusive cases and remained reliable even in patients with low CRP. These findings support calprotectin as a valuable adjunctive biomarker in the complex diagnostic environment of megaprosthetic reconstruction and justify further validation in larger cohorts.