Clinical and radiologic diagnosis of primary knee osteoarthritis (Kellgren & Lawrence I, II or III); 
Capability to understand the Informed Consent Form; 
Chronic pain for at least 3 months prior to inclusion, measured by VAS. (VAS 4 or above); 
Absence of skin injures, infections or tumor in the target knee; 
Availability to comply with the visits. 

NCT02904785_inc_T1
Condition
primary knee osteoarthritis
NCT02904785_inc_T2
Measurement
Kellgren & Lawrence
NCT02904785_inc_T3
Value
I, II or III
NCT02904785_inc_T4
Qualifier
Clinical diagnosis
NCT02904785_inc_T5
Qualifier
radiologic diagnosis
NCT02904785_inc_T8
Condition
Chronic pain
NCT02904785_inc_T9
Temporal
at least 3 months prior
NCT02904785_inc_T10
Reference_point
inclusion
NCT02904785_inc_T11
Procedure
VAS
NCT02904785_inc_T12
Qualifier
measured by VAS
NCT02904785_inc_T13
Measurement
VAS
NCT02904785_inc_T14
Value
4 or above
NCT02904785_inc_T16
Condition
skin injures
NCT02904785_inc_T17
Negation
Absence
NCT02904785_inc_T18
Condition
infections
NCT02904785_inc_T19
Condition
tumor
NCT02904785_inc_T20
Reference_point
target knee