Knee Ligament Stiffness Across Ethnicities Before and After Osteoarthritis Treatment

Knee osteoarthritis is increasingly recognized as a whole-joint disease involving not only articular cartilage but also periarticular soft tissues, including the cruciate and collateral ligaments. Although ultrasound elastography has been widely applied to musculoskeletal tissues, normative biomechanical data for knee ligaments remain limited, and the influence of osteoarthritis on ligament stiffness has not been fully characterized.

The primary objective of this study is to establish normative shear wave elastography values for the ACL, PCL, MCL, and LCL across different age groups and ethnic populations and to determine their associations with demographic characteristics, body composition, and limb dominance. A secondary objective is to compare ligament stiffness between healthy individuals and patients with radiographic knee osteoarthritis. Participants will undergo standardized ultrasound examinations, SWE measurements, physical examinations, pain assessment using the Visual Analog Scale (VAS), and functional assessment using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).

Patients with symptomatic knee osteoarthritis will initially receive conservative treatment according to routine clinical practice. Those who subsequently undergo clinically indicated ultrasound-guided injection therapy, including corticosteroid, hypertonic dextrose prolotherapy, or platelet-rich plasma (PRP), will receive repeat clinical and SWE evaluations after completion of treatment to investigate longitudinal changes in ligament biomechanical properties. The study will also assess measurement reliability through intra- and inter-rater analyses.

Inclusion criteria

• Healthy volunteers:
• Adults aged 20 years or older.
• Able to understand the study procedures and provide written informed consent.
• Able to ambulate independently without walking aids.
• No pain in either knee during the previous 6 months.
• Patients with symptomatic knee osteoarthritis:
• Adults aged 20 years or older.
• Able to understand the study procedures and provide written informed consent.
• Pain in at least one knee during the previous year.
• Knee pain, soreness, or stiffness documented within the previous month.
• Radiographic knee osteoarthritis defined by at least one of the following:
• Kellgren-Lawrence grade ≥2 on anteroposterior radiographs.
• Kellgren-Lawrence grade ≥2 on skyline radiographs.
• Superior or inferior patellar osteophytes or posterior tibial osteophytes on lateral radiographs.

Exclusion criteria

• Healthy volunteers:
• Previous knee surgery.
• Rupture of any cruciate or collateral ligament.
• Major knee or periarticular trauma.
• Rheumatic or autoimmune disease.
• Diagnosis of knee osteoarthritis within the previous 6 months.
• Patients with symptomatic knee osteoarthritis:
• Rheumatic or autoimmune disease.
• Malignancy.
• Previous major knee trauma or knee surgery.
• Corticosteroid injection into the affected knee within the previous 3 months.