Age- and Osteoarthritis-Related Stiffness Alterations in Major Knee Ligaments: A Shear Wave Sonoelastography Study

Background and/or Objectives: Knee osteoarthritis (OA) affects approximately 7.6% of the general population and is commonly associated with degeneration of cartilage and subchondral bone. However, periarticular soft tissue structures, including ligaments, may also be compromised. This study aimed to investigate the impact of aging and osteoarthritis on the stiffness of major knee ligaments using shear wave sonoelastography.

Design: A cross-sectional observational study.

Setting : Ultrasound evaluations were conducted in a clinical musculoskeletal imaging setting with participants positioned in the supine posture.

Participants : A total of 147 participants were enrolled, comprising 59 asymptomatic controls and 88 patients diagnosed with knee osteoarthritis. Healthy controls were stratified into three age groups: 20–40 years, >40–60 years, and >60 years.

Interventions: No therapeutic intervention was applied. Shear wave sonoelastography was used to quantitatively assess the stiffness of the medial collateral ligament, lateral collateral ligament, anterior cruciate ligament, and posterior cruciate ligament.

Main Outcome Measures: Primary outcomes included shear wave elastography measurements of ligament stiffness. Statistical analyses were performed using the Kruskal-Wallis test to assess differences across age groups and between OA and non-OA knees.

Results: Ligament stiffness significantly differed among the three age groups for all four ligaments. In comparisons between osteoarthritic and non-osteoarthritic knees, no significant differences were found in the medial and lateral collateral ligaments. However, in osteoarthritic knees, the lateral collateral ligament was stiffer and the posterior cruciate ligament was softer.

Conclusions: Shear wave sonoelastography provides an effective, non-invasive means to evaluate the biomechanical properties of knee ligaments. Ligament stiffness is influenced by both age and the presence of osteoarthritis, particularly affecting the lateral collateral and posterior cruciate ligaments. These findings suggest that specific ligaments may serve as potential therapeutic targets in the management of knee osteoarthritis.