Comparative evaluation of knee osteoarthritis: radiography vs. ultrasonography in Nepalese population: a cross-sectional study

Background and objectives: Osteoarthritis (OA) is a degenerative and long-term debilitating disease with rising prevalence, predominantly involving larger joints including the knee joint. While radiography has traditionally been the primary modality for joint evaluation, there is a growing trend towards using ultrasonography (USG) for musculoskeletal disorders, including joint assessment. This study aimed to find the role of USG in the evaluation of OA of knee joints with comparison to the radiographs. Methods: This was a cross-sectional study done on patients with signs and symptoms of OA of the knee who visited the radiology department for knee radiographs. Kellgren and Lawrence system was used for grading OA in radiographs. USG of knee joints was done with high-frequency probes and searched for joint space width, articular cartilage thickness, marginal osteophytes, meniscal extrusion, and other articular/ extra-articular abnormalities. The USG findings were correlated with findings in anteroposterior and lateral radiographs. Results: The mean number of osteophytes was higher in USG compared to the radiographs (P<0.001). Mean joint spaces were comparable in both modalities. Meniscal extrusion was seen with USG, which significantly correlated with joint space width and cartilage thickness (P<0.005). USG also detected synovial changes, effusion, and Baker's cyst. Conclusion: Although radiography is the standard first-line radiological investigation for the diagnosis of OA of the knee joint, USG can be an adjunct as it well correlates with the radiograph findings and can provide more useful information.