Faizatul Izza Rozalli

Objectives: This study explores the correlation between volunteer demographics with enthesis stiffness and intra- and interobserver agreements using shear wave elastography (SWE). Methods: Ninety-eight healthy volunteers were recruited. SWE was performed on quadriceps, suprapatellar, infrapatellar, and Achilles entheses. The stiffness measurements were measured in shear wave velocity (SWV). Results: Mann-Whitney test revealed insignificant difference in SWV among gender. Wilcoxon signed-rank test showed significant difference in SWV between left and right Achilles entheses. Spearman correlation test revealed moderate negative correlation between SWV and age group in quadriceps (ρ, −0.45, P < .01), and weak negative correlation in suprapatellar (ρ, −0.31, P < .01), and left Achilles (ρ, −0.29, P < .01). Multiple linear regression analysis showed subjects’ demographic significantly predicted quadriceps, suprapatellar, and left Achilles entheses stiffness with only age statistically significantly to the prediction (P < .05). Kruskal-Wallis showed significant differences in SWV for quadriceps (P = .01), suprapatellar (P = .03), and left Achilles (P = .01) among different age groups. Good interobserver [0.79-0.86 (95% CI, 0.32-0.94)] and interobserver agreement [0.78-0.89 (95% CI, 0.62-0.95)] were found in all the entheses. Conclusion: SWE emerges as a reproducible method for entheses stiffness quantification, with the study highlighting age as a significant factor impacting SWV in quadriceps, suprapatellar, and left Achilles entheses. Among the studied entheses, SWV for Achilles enthesis is the highest in all age groups. Advances in knowledge: The study significantly contributes to the understanding of enthesis stiffness by exploring the influence of gender, BMI, and age.

Objective To establish the scanning protocol for 2-dimensional shear wave elastography (SWE) on normal entheses by investigating the possible confounding factors that may increase the variability of measured elasticity. Material and methods 30 normal quadriceps entheses were scanned using SWE to compare the stiffness and coefficient variation by changing the ultrasonic coupling gel thickness, knee position, region of interest size, and scanning plane. Results No significant difference in median shear wave velocity (SWV) was observed in different coupling gel thicknesses. The median SWV was higher in the knee flexion position than in the extended position (p < 0.001). Increased knee flexion led to stiffer quadriceps enthesis and higher SWV (ρ = 0.8, p < 0.001). The median SWV was higher when the diameter region of interest was 4.0 mm than 2.0 mm (p = 0.001). The median SWV was higher in the transverse plane than in the longitudinal plane (p < 0.001). Strong correlation was found between SWV and the degree of the shear wave to muscle fiber direction (ρ = 0.8, p < 0.001). The coefficient variation was lower in a gel thickness of 2.5 cm, with an extended knee, a region of interest of 2.0 mm, and a longitudinal plane (p > 0.05). For interobserver reliability for the proposed protocol, the intraclass correlation coefficients was 0.763. Conclusion In this study, we determined supine position with the knee extended; using 2.0 mm diameter region of interest and image acquisition at the longitudinal plane with thicker layer coupling gel seems most appropriate to reliably image healthy quadriceps entheses with SWE.

The purpose of this study was to investigate the role of fear of falling (FoF) and psychological symptoms in explaining the relationship between osteoarthritis (OA) symptom severity and falls. Individuals aged ≥65 years with ≥2 falls or ≥1 injurious fall over the past 12 months were included in the falls group, while volunteers aged ≥65 years with no history of falls over 12 months were recruited as controls. The presence of lower extremity OA was determined radiologically and clinically. Severity of symptoms was assessed using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire. FoF and psychological status were measured with the shortened version of the Falls Efficacy Scale-International and the 21-item Depression, Anxiety and Stress Scale (DASS-21), respectively. Of 389 (229 fallers, 160 non-fallers) potential participants, mean (SD) age: 73.74 (6.60) years, 141 had clinical OA and 171 had radiological OA. Fallers with both radiological OA and clinical OA had significantly higher FoF and DASS-21 scores than non-fallers. FoF was significantly positively correlated with symptom severity in fallers and non-fallers with radiological and clinical OA. Depression, anxiety, and stress scores were only significantly correlated with symptom severity among fallers but not non-fallers in both clinical and radiological OA. The relationship between mild symptoms and reduced risk of falls compared to no symptoms in those with radiological OA was attenuated by increased anxiety. The increased falls risk associated with severe symptoms compared to mild symptoms in clinical OA was attenuated by FoF. FoF may, therefore, be a potentially modifiable risk factor for OA-associated falls which could be considered in future intervention studies.