Title: Shear Wave Elastography (SWE) of Hamstring Muscles and Outcome Measures in Rheumatology (OMERACT) Knee Osteoarthritis Ultrasound Scores in Patients With Knee Osteoarthritis With MRI Association: A Cross Sectional Observational Study.

Background: The Outcome Measures in Rheumatology (OMERACT) and MRI Osteoarthritis Knee Score (MOAKS) scores are semi-quantitative scores used in the evaluation knee osteoarthritis (KOA) by ultrasonography (US) and MRI. Assessment of hamstring muscle function, which is very important for the prognosis and rehabilitation of KOA patients, can be attempted by shear wave elastography (SWE).

Aim: To study the SWE of hamstring muscles and OMERACT US scores in patients with KOA and compare them with MOAKS scores.

Method: This prospective, observational study was done on 80 patients with KOA who underwent MRI, US, and SWE examinations with calculation of MOAKS and OMERACT scores, as well as VTI and VTIQ assessment of hamstrings. Comparison of the findings of these was done, and appropriate statistical tests were applied.

Result: Statistically significant associations were found between OMERACT and MOAKS using Spearman Rho correlation for osteophytes (0.816 with p value 0.001), meniscal extrusion (0.514 with p value 0.001), cartilage abnormalities (0.442 with p value 0.001), joint effusion (0.397 with p value 0.001) and synovitis (0.34 with p value 0.002). The stiffness of hamstring muscles on SWE were also significantly correlated with MOAKS and OMERACT scores with p value of < 0.05 and 0.014, respectively. Color coding and stiffness on VTIQ of hamstring muscles were also significantly associated with BML size (p value 0.001), cartilage abnormalities (p value 0.001), osteophytes (p value 0.001), synovitis (p value 0.05), and meniscal extrusion (p value 0.001) found on MRI.

Conclusion: US of knee with SWE of hamstrings can be used not only as a primary screening modality for KOA but also for proper rehabilitation and management of these patients.