This cross-sectional study investigated the association between knee synovial effusion, body composition, and serum glutamate levels in middle-aged women with knee osteoarthritis. Female participants (n = 241) from a health promotion project were classified into control (n = 165), early (n = 34), and definitive (n = 42) knee osteoarthritis groups. Synovial effusion was assessed based on the ultrasonographic effusion area, body composition via bioelectrical impedance, and serum glutamate from fasting blood samples. Muscle mass was higher in the definitive group than in the control (p = 0.009). Fat mass increased from normal to definitive, showing a significant difference between the control and definitive groups (p = 0.047). The effusion area correlated with muscle mass (r = -0.122, p < 0.05) and glutamate levels (r = 0.154, p < 0.001). Logistic regression identified fat mass as an associated factor of early (OR = 1.089, p = 0.004) and definitive (odds ratio = 1.063, p = 0.005) knee osteoarthritis, suggesting a potential association between adiposity and knee osteoarthritis. A weak correlation was observed between serum glutamate and synovial effusion. These findings underscore the importance of body composition optimization as a potential approach in the context of knee osteoarthritis management.

Chronic osteomyelitis in the setting of recent soft tissue cancers, also known as sarcoma, and radiation therapy presents a clinical challenge due to poor wound healing and impaired vascularity. We present the case of a 64-year-old female patient with a history of sarcoma treated with proton beam therapy who developed chronic osteomyelitis, abscess formation, and pathologic fractures of the tibia and fibula. The course was further complicated by recurrent knee effusion and concerns for septic arthritis. Despite repeated surgical recommendations for above-knee amputation and antibiotic therapy, the patient elected to pursue conservative management. This case highlights the interplay between cancer, tissue damage from radiation therapy, and chronic infection, as well as challenges in achieving adequate treatment.

Infrapatellar fat pad (IPFP) is considered a marker for disease progression in knee osteoarthritis (KOA), but currently no ultrasound parameters effectively quantify abnormal changes in IPFP. To investigate the correlation between clinical symptoms of KOA and semi-quantitative ultrasound scores as well as the echo intensity (EI) of the IPFP, and investigate the correlation between the IPFP EI and knee joint effusion and synovium. This study included 75 patients with primary KOA. Ultrasound semi-quantitative scoring of the knee joint and measurement of IPFP EI were performed. Patients' Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores and Visual Analog Scale (VAS) scores were assessed. Spearman correlation analysis was used to compare the correlations between these two symptom scores and the ultrasound semi-quantitative score and IPFP EI. The correlation between IPFP EI and joint effusion and synovium was also compared. Ordered logistic regression analysis was performed to determine the factors influencing clinical symptoms of KOA. Correlation analysis reveals that VAS scores, WOMAC pain scores, stiffness scores, and functional scores all show a positive correlation with IPFP EI. Synovial thickening also exhibits a positive correlation with IPFP EI. Ordered logistic regression analysis demonstrates that IPFP EI is an independent and significant predictor of KOA symptom severity. In summary, synovial thickening shows a significant correlation with IPFP's EI. The stronger the echo of the IPFP, the more severe the clinical symptoms of KOA. This may offer a new perspective for ultrasound in assessing the severity of KOA patients.

Scrub typhus is a common cause of acute febrile illness in endemic regions; however, musculoskeletal involvement is usually limited to myalgia, and true inflammatory arthritis is rarely reported. We describe a 19-year-old previously healthy male military recruit who presented with a two-month history of progressive bilateral knee swelling and left ankle pain, accompanied by fever, weight loss, and lymphadenopathy. Clinical evaluation revealed inflammatory oligoarthritis with culture-negative synovial fluid. Given the chronicity of symptoms and systemic features, tubercular and septic arthritis were initially considered. Imaging showed preserved joint architecture, and synovial fluid analysis demonstrated inflammatory features without microbial growth. Investigations for tuberculosis, autoimmune disorders, and other tropical infections were negative. Serological testing was positive for scrub typhus immunoglobulin M using a rapid immunochromatographic assay. Following the initiation of doxycycline therapy, the patient showed rapid clinical improvement with resolution of fever and marked reduction in joint symptoms. This case highlights an uncommon presentation of scrub typhus-associated inflammatory oligoarthritis mimicking tubercular arthritis in endemic regions. Clinicians should consider scrub typhus in patients presenting with febrile oligoarthritis and culture-negative joint effusion, as early recognition and appropriate treatment can result in excellent outcomes.

Charcot neuroarthropathy (CN) of the knee in adolescents with congenital insensitivity to pain with anhidrosis (CIPA) is exceptionally rare and presents unique diagnostic and therapeutic challenges. We present the case of a 13-year-old girl with genetically confirmed CIPA and a two-year history of recurrent knee swelling, effusion, and functional limitation. Imaging revealed intra-articular loose bodies and osteochondral defects in the left knee. The patient was treated with arthroscopic synovectomy and removal of a large loose body via standard anteromedial, anterolateral, and posteromedial portals. Intraoperative findings included extensive synovial proliferation and a 3 × 4 cm mobile loose body. Postoperatively, the patient followed a function-based rehabilitation protocol. At 30 days, she ambulated without assistive devices. At 1-year and 17-month follow-up, she demonstrated sustained clinical improvement with increased Lysholm score (from 50 to 82) and enhanced range of motion (from 10°-110° to 0°-140°). Magnetic resonance imaging (MRI) confirmed joint stability and absence of recurrent loose bodies. This case illustrates that arthroscopic management may offer a joint-preserving option in carefully selected adolescents with CIPA-associated Charcot knee and persistent mechanical symptoms. The approach may function as a temporizing measure to delay more invasive reconstructions. Adherence to protective joint education and close follow-up are essential in this population. This report highlights the clinical presentation, technical considerations, and mid-term outcomes of arthroscopic intervention in a rare neuropathic knee condition.