Introduction: Lower limb malalignment is a major risk factor for knee osteoarthritis (OA) and is mainly diagnosed using the Hip Knee Ankle Angle (HKA). Therefore, accurate HKA measurements are indispensable. Objectives: This study aimed to research the effects of knee flexion, leg rotation, and X-ray beam height on the accuracy of the HKA measurement. To convert our findings into a guideline for obtaining whole leg radiographs (WLR) in favor of accuracy and reproducibility. Methods: An in vitro experiment was designed using sawbones (in 5°varus) of the whole lower limb, fixated in different leg rotation angles, knee flexion angles, and three different X-ray beam heights. Results: The HKA measurement error was 1°per 20°of leg rotation without flexion ( P < .01). When 5°of flexion was added, the HKA measurement error was 0.8°per 20°rotation ( P < .01 ). With 15°knee flexion, the HKA measurement error became 4°per 20°rotation ( P < .01 ). Varying X-ray beam heights of 5cm ( P = .959) and 10 cm ( P = .967) did not cause any significant measurement errors. Conclusion:This study showed that leg rotation alone (without knee flexion) can lead to clinically relevant measurement errors when exceeding 9°. When there is 15°of knee flexion and 10°leg rotation the error becomes approximately 2°. Varying X-ray beam heights within a range of 10 cm does not affect the accuracy. Based on these findings, we propose guidelines for system setup and patient positioning during a WLR that is easy to apply and aims at minimizing errors when measuring the HKA.

<b><i>Background:</i></b> When infected with the chikungunya virus (CHIKV), 3% to 28% of CHIKV-infected individuals remain asymptomatic, necessitating the development of improved high-throughput screening methods to overcome the limitations of molecular diagnostics or enzyme-linked immunosorbent assays (ELISAs). <b><i>Objective:</i></b> In this study, two novel monoclonal antibodies (mAbs) targeting envelope 1 (E1) of CHIKV were developed and applied in a fluorescence-linked immunosorbent assay (FLISA) using coumarin-derived dendrimer as the fluorophore. <b><i>Methods:</i></b> The performance of the FLISA was compared with that of ELISA. <b><i>Results:</i></b> Using the two novel mAbs (2B5 and 2C8), FLISA could detect 1 × 10⁵ PFU/mL of CHIKV, exhibiting a 2-fold lower limit of detection (LOD) compared to ELISA. The LOD of FICT corresponded to a comparative threshold value of 23.95 and 4  ×  10⁶ of RNA copy number/µL. In the presence of human sera and blood, virus detection by FLISA was 3-fold better than ELISA, with an LOD of 2 × 10⁵ PFU/mL. Sera and blood interfered with the ELISA, resulting in 6 × 10⁵ PFU/mL as the LOD. <b><i>Conclusions:</i></b> FLISA using two novel mAbs and coumarin-derived dendrimer is a superior diagnostic assay for detecting CHIKV in human sera and blood, compared to conventional ELISA.

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