The goal of this study is to use single photon emission computed tomography (SPECT) and functional magnetic resonance imaging (f-MRI) of the brain to study the response of both normal participants and participants with Osteoarthritis (OA) of the knee to acupuncture.

Recent experimental studies in both animal and humans have begun to demonstrate some measurable physiologic effects that are associated with acupuncture, suggesting the possibility of a neurophysiologic explanation. In addition, brain research continues to uncover a complex set of endogenous neurologic control systems, such that it has become clear that the brain plays a major role in the modulation of pain perception and control. If acupuncture can be demonstrated to have a consistent effect on specific areas of the brain, it will become possible to explore the potential efficacy of acupuncture based on measurable neurophysiologic responses.

Inclusion criteria:

• Seen in an outpatient clinical setting
• Have active knee OA of >6 months including Kellgren x-ray changes >2 from an x-ray report <12 months old or new x-ray interpretation
• Moderate unilateral only pain (average >4/10 on a 0-10 likert scale) for more than 5 out of 7 days
• Have the capacity to understand the requirements of the study and complete the baseline studies in a reasonable time frame, as determined by the interviewer

Exclusion criteria:

• Having had acupuncture before (must be acupuncture naïve)
• Any history of claustrophobia that could affect the subject's ability to tolerate the f-MRI study
• Hip or ankle disease by history or exam severe enough to cause pain >2/10 daily
• Bleeding disorder or current use of warfarin or heparin by patient history
• Other primary causes of chronic knee pain, per the referring physician, including chondromalacia patella, torn meniscus or ligament injury.