The purpose of this study is verify the efficacy and safety of Cettum (Electric moxibustion) for patients with knee osteoarthritis.

The investigator targets the patients with knee osteoarthritis. After treatment in 3 groups - Cettum treatment, traditional indirect moxibustion treatment, and usual care groups - the investigators will compare the effects of pain relieving and daily performing improvement. So the investigators will confirm the efficacy of Cettum, and further the best treatment method. In addition, the investigators are going to evaluate the safety of abnormal reaction during the treatment.

Inclusion Criteria:

1. At least 40 years of age, but below 70 years of age

2. Presence of knee osteoarthritis diagnosed according to American College of Rheumatology classification criteria and satisfying the following 2 conditions

   • Knee pain when weight load in one or both knees in the last 6 months

     • Knee pain rated >4cm on a 10cm Visual Analog Scale (VAS)

3. Feeling temperature sense to distinguish temperature differences

4. An understanding of the objectives and methods of the clinical trial, and willingness in completing the consent form

5. Those who are reliable and willing to cooperate in this test, and obey the restrictions for the next 3 months

Exclusion Criteria:

1. Trauma to the knee(s) within 6 months prior to enrollment, causing pain or functional problems
2. Surgery on the knee(s) within 6 months prior to enrollment, causing pain or functional problems
3. A history of intra-articular injection within the last 3 months
4. A physical or laboratory finding indicating presence of an inflammatory arthritis (e.g. rheumatoid arthritis, autoimmune disease)
5. Presence of physical or psychiatric disorder that may affect moxibustion treatment
6. Presence of neurological disorder including paralysis symptoms on local or general sensation
7. A female who is pregnant or is lactating
8. Being afraid of moxibustion treatment or expected to cause side effects
9. When researchers evaluate that it is not appropriate to participate in this clinical test