Clinical Outcomes of Focused Shockwave Therapy in Moderate-to-Severe Knee Osteoarthritis: A Review of Key Trials

Knee osteoarthritis (OA) is one of the leading causes of chronic pain and mobility loss in adults over 50. As the condition progresses, the protective cartilage that cushions the knee joint wears away, leading to stiffness, inflammation, and persistent discomfort. Traditional conservative treatments—such as nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroid injections, and physical therapy—often provide only temporary relief.

In recent years, focused shockwave therapy (FSWT) has emerged as a promising non-invasive treatment that targets the underlying biological processes of osteoarthritis rather than simply masking symptoms.

What Is Focused Shockwave Therapy?

Focused shockwave therapy uses high-energy acoustic pulses that penetrate deep into the tissues of the knee joint. These sound waves are precisely targeted to areas of degeneration, where they stimulate healing and regeneration at the cellular level.

Unlike radial shockwave therapy, which delivers broader, more superficial waves, focused shockwaves reach deeper structures such as cartilage, subchondral bone, and the synovial membrane—making them particularly suited for osteoarthritic joints.

Mechanisms of Action

Research has shown that FSWT works through several key biological mechanisms:

• Angiogenesis: It promotes the formation of new blood vessels, improving circulation and nutrient delivery to damaged tissues.

• Chondrocyte stimulation: It enhances the activity of cartilage-producing cells, supporting repair and maintenance of joint surfaces.

• Anti-inflammatory effects: Shockwaves reduce the expression of inflammatory cytokines such as IL-1β and TNF-α.

• Pain modulation: The therapy desensitises nerve endings and alters pain signalling pathways, resulting in long-term relief.

• Subchondral bone remodelling: It supports regeneration of the bone beneath the cartilage, improving joint stability and load distribution.

Evidence from Key Clinical Trials

Wang et al., 2011 – American Journal of Sports Medicine

One of the earliest randomised controlled trials to evaluate FSWT for knee OA involved 40 patients with moderate osteoarthritis. Participants received either focused shockwave therapy or a placebo treatment.

After three and six months, those who underwent FSWT experienced significant improvements in both pain and function, measured by the WOMAC and VAS pain scales. MRI imaging also revealed increases in cartilage thickness and improved subchondral bone quality. Importantly, there were no major side effects reported.

Conclusion: FSWT improved symptoms and delayed degenerative progression in moderate OA cases.

Zhao et al., 2020 – Clinical Rehabilitation

In this randomised controlled study of 80 participants with grade II–III knee OA, one group received FSWT alongside standard physical therapy, while the control group underwent physical therapy alone.

After 12 weeks, the FSWT group showed a 45% reduction in pain scores compared to 18% in the control group. They also demonstrated greater improvements in knee range of motion and walking distance. The benefits remained significant at six-month follow-up.

Conclusion: FSWT provided meaningful, sustained pain relief and functional recovery beyond standard therapy alone.

Kim et al., 2022 – Journal of Orthopaedic Science

This prospective cohort study focused on patients with severe OA (grades III–IV). Participants received five sessions of FSWT over five weeks.

At the end of treatment, 70% of patients reported clinically meaningful pain reduction—defined as a decrease of more than 30% in VAS scores. Strength testing showed increased quadriceps activation, and ultrasound imaging suggested improved synovial fluid quality and cartilage health.

Conclusion: FSWT demonstrated real-world benefits for severe OA patients, even when conventional options were limited.

Li et al., 2023 – BMC Musculoskeletal Disorders (Meta-Analysis)

A comprehensive meta-analysis reviewing nine randomized controlled trials involving 460 participants found that FSWT significantly outperformed placebo and radial shockwave therapy in improving WOMAC, Lequesne, and VAS scores.

The authors identified optimal treatment parameters as 0.20–0.25 mJ/mm² energy density, 1,000–2,000 pulses per session, administered weekly for 3–5 sessions. The incidence of side effects was low and transient, typically mild redness or soreness at the treatment site.

Conclusion: FSWT offers consistent, clinically meaningful improvements in pain and function across multiple studies.

Safety and Tolerability

Focused shockwave therapy is generally well tolerated. Most patients experience only mild, temporary discomfort during or after treatment. Unlike injections or surgery, there is no risk of infection, bleeding, or structural joint damage.

Contraindications include active joint infection, malignancy near the treatment area, severe vascular disease, or the presence of a pacemaker close to the target site. When administered by trained professionals, FSWT is considered a safe and effective option for many patients with knee OA.

Clinical Implications

The accumulating body of evidence suggests that FSWT can play a meaningful role in managing moderate-to-severe knee osteoarthritis—particularly for individuals who have not responded to conventional care but wish to avoid or delay surgery.

• Ideal candidates: Patients with chronic pain and functional limitation, but with retained joint mobility.

• Treatment integration: Combining FSWT with physiotherapy, weight management, and joint-strengthening exercises yields the best outcomes.

• Duration of benefit: Clinical improvements typically last six to twelve months, and booster sessions may be used to maintain results.

• Cost-effectiveness: FSWT can reduce dependence on medication and invasive interventions, offering long-term value in knee OA management.

Limitations and Future Research

While the results to date are highly encouraging, some limitations remain. Many clinical trials have small sample sizes and short follow-up periods. Differences in treatment parameters—such as energy intensity, frequency, and number of sessions—make it difficult to standardise protocols across studies.

Future research should focus on larger, multicentre trials and include advanced imaging and biomarker studies to further clarify the regenerative mechanisms of FSWT and its long-term impact on joint structure.

Conclusion

Focused shockwave therapy represents an evidence-based advancement in the non-surgical treatment of knee osteoarthritis. Clinical studies consistently demonstrate reductions in pain, improvements in function, and possible cartilage and bone regeneration.

For patients with moderate-to-severe OA who are not yet ready for joint replacement, FSWT offers a safe, effective, and biologically active alternative that goes beyond symptom management—supporting true tissue healing and better long-term outcomes.