Extracorporeal Shockwave Therapy for Knee Osteoarthritis

Knee osteoarthritis is a common disease that causes joint pain, stiffness, and movement limitation. Nearly 50% in those 75 years and above are affected. In Taiwan, the reported prevalence was more than 6000 per year. The cause of pain is joint instability and structure changed, including hyaline articular cartilage lost, bony remodeling, capsular stretching and periartcular muscle weakness. Current guidelines for treatment of symptomatic knee osteoarthritis include exercise, anti-inflammatory drugs, transcutaneous electrical stimulation(TENS) and magnetic fields(MF) which reduce pain and improve the patient's quality of life.

However, conservative therapies and oral supplements have been evaluated but are without clear efficacy. Prolotherapy is an injection therapy for chronic musculoskeletal pain. One of the hypotheses is stimulating local healing and current study demonstrated clinical benefit for pain and improvement of function. The effects of multi-point injections were more pronounced in several studies than single-point injection.

Extracorporeal shock wave is common treatment for kidney stones, has been widely used in soft tissue diseases, such as calcified tendon lesions and plantar fasciitis. The theory of extracorporeal shock wave is energy of high-frequency vibration caused destruction of stones and other hard material and by increasing the rate of vascular regeneration in the injured area and increasing the rate of autologous tissue repair, possible biological processes include increased mesenchymal stem cell proliferation and differentiation, slowing the inflammatory response and antimicrobial efficacy. Current studies have shown equivalent clinical outcomes on calcific rotator cuff tendinopathy among extracorporeal shock wave therapy, sono-guided acupuncture and arthroscopic surgery and the extracorporeal shock wave has the advantage of non-invasive treatment.

Taking the advantages of non-invasive treatment of extracorporeal shockwave. We want to design a randomized control trial by multi-point shockwave therapy and physical therapy compared with placebo shockwave therapy and physical therapy. Two randomized controlled trial (RCT) reported improvement in outcomes in response to shockwave therapy but were not methodologically rigorous. The investigators therefore conducted a two-arm RCT to assess the hypothesis that adults with symptomatic knee pain receiving shockwave therapy will report greater improvement in knee-related quality-of-life than sham shockwave therapy.