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.

Inclusion Criteria:

1. Patient at Taoyuan general hospital rehabilitation outpatient department during 2017/01/01 ~ 2018/12/31
2. Diagnosis with knee osteoarthritis (ACR criteria or Kellgren and Lawrence grading II to IV)
3. Suitable for shockwave therapy and physical therapy with (TENS + MF + stretching + strengthening exercise)
4. Visual analog scale(VAS) ≧ 4

Exclusion Criteria:

1. Not suitable for shockwave therapy, including acute infection, osteomyelitis, coagulopathy, use of anticoagulants, pregnant women, patients with a pacemaker or implantable cardiac defibrillator
2. Patients who can't understand Chinese, including aphasia or dementia
3. Patient who can't receive 4 weeks of therapy
4. Patient who can't walk due to peripheral neuropathy or central nerve system diseases
5. Total knee arthroplasty
6. Shockwave therapy of knee for the prior 3 months
7. Skin defect or soft tissue infection over symptomatic knee
8. Other cause of knee pain which can't treat with physical therapy, including: rheumatoid arthritis, infection, fracture, ligament disruption

Participant, Investigator, Outcomes Assessor