Table 1.

Eligibility criteria

Inclusion criteria
Age above 40 years
Member of a Health Insurance Company that participates in the "Model Project"
Signed informed consent
Chronic pain in at least one knee joint during the last six months as minimum according to the ACR-criteria [26]
Radiological signs of a gonarthrosis in the same knee (Kellgren 2 or 3) [27]
WOMAC ≥ 3 points (on a scale of 0–10)
Von Korff Chronic Pain Score ≥ 1
Exclusion criteria
A systemic disease of the musculosceletal system
Bone tumour, bone tumour like lesions or metastasis
Bone fracture in the lower extremities during the last three months
Acute infection or osteonecrosis in the knee joint
Surgery of the afflicted extremity during the last six months or planned surgery
Radiological signs of a severe gonarthrosis of a Kellgren grade 4
Other pain conditions which compels the patient to take analgesics for more than three days during the last four weeks
Addiction to analgesics, opiate or other drugs
Acupuncture treatment in the past 12 months
Acupuncture treatment of gonarthrosis.
Ongoing cortico-steroid therapy or cortisone injections in the past six weeks
Dermatological disease within the acupuncture area impairing acupuncture treatment
Medical diseases causing an impairment of physical capacity (NYHA > II)
Severe Coagulopathy
Ischialgia or other neurological diseases
History of epilepsy and psychiatric diseases
Pregnant or breast-feeding patients
Inability to follow instructions (insufficient command of language, dementia)
Participation in another clinical study
Ongoing legal proceedings concerning pension entitlement