Therapeutic Ultrasound Applications in Knee Osteoarthritis

Therapeutic ultrasound has emerged as a non-invasive modality to address pain, inflammation and structural degeneration in knee osteoarthritis. By delivering acoustic energy to periarticular tissues and synovial joints, ultrasound stimulates cellular mechanotransduction pathways in chondrocytes, enhances local blood flow and modulates inflammatory mediators. Variants of this technology include focused low-intensity pulsed ultrasound (FLIPUS), which concentrates energy on the joint space with minimal thermal effect, and wearable long-duration low-intensity ultrasound devices, enabling daily home-based therapy. Preclinical studies reveal that ultrasound promotes cartilage matrix synthesis, attenuates chondrocyte apoptosis and rebalances cytokine profiles, while clinical trials demonstrate reductions in pain scores, improvements in mobility and enhanced quality of life. Recent advances elucidate mechanistic underpinnings such as ion channel activation, autophagy regulation and modulation of intracellular signalling axes. Together, these findings underscore the global significance of therapeutic ultrasound as a safe, cost-effective and patient-centred intervention for knee osteoarthritis.

Research from Nature Portfolio

Focused low-intensity pulsed ultrasound has been shown to augment standard pharmacological therapy in patients with bilateral knee osteoarthritis, yielding significant reductions in visual analogue pain scores and Western Ontario and McMaster Universities Osteoarthritis Index measures over a 12-week follow-up. Treated subjects exhibited improvements in ambulation speed and overall physical function without adverse events. The study highlighted sustained benefits in both pain relief and joint mobility, supporting the integration of ultrasound therapy into multidisciplinary management plans.

Therapeutic Ultrasound Applications in Knee Osteoarthritis publication trend

The graph below shows the total number of articles in therapeutic ultrasound applications in knee osteoarthritis across all publications each year (not limited to Nature Index journals).

Technical terms

Low-intensity pulsed ultrasound (LIPUS): A form of ultrasound delivered in short pulses at low energy density to stimulate tissue repair without heating.

Focused low-intensity pulsed ultrasound (FLIPUS): A variant of LIPUS that concentrates acoustic energy on targeted joint regions to maximise efficacy.

Chondrocyte: A specialised cell responsible for maintaining cartilage extracellular matrix in joints.

Primary cilium: A solitary, antenna-like projection on the cell surface that senses mechanical and chemical signals.

Transient receptor potential vanilloid 4 (TRPV4): A mechanosensitive ion channel mediating calcium influx in chondrocytes.

Autophagy: A cellular self-degradation process that removes damaged organelles and proteins to maintain homeostasis.

Nuclear factor-κB (NF-κB): A transcription factor regulating genes involved in inflammation and immune responses.

Yes-associated protein (YAP): A mechanotransducer that interacts with signalling pathways to influence cell proliferation and survival.

Receptor-interacting protein kinase 1 (RIPK1): A kinase involved in cell death and inflammatory signalling networks.

References

1. LIPUS regulates the progression of knee osteoarthritis in mice through primary cilia-mediated TRPV4 channels. Apoptosis (2024).
2. Low-intensity pulsed ultrasound delays the progression of osteoarthritis by regulating the YAP–RIPK1–NF-κB axis and influencing autophagy. Journal of Translational Medicine (2024).
3. Efficacy of focused low-intensity pulsed ultrasound therapy for the management of knee osteoarthritis: a randomized, double blind, placebo-controlled trial. Scientific Reports (2016).
4. Effect of low-intensity long-duration ultrasound on the symptomatic relief of knee osteoarthritis: a randomized, placebo-controlled double-blind study. Journal of Orthopaedic Surgery and Research (2018).