Acupuncture is an ancient practice originating in traditional Chinese medicine, involving the precise insertion of very thin needles into specific body points. It is commonly sought as a complementary therapy for various pain conditions, particularly chronic knee discomfort, often caused by osteoarthritis. This article examines the scientific evidence supporting the use of acupuncture for managing knee pain, focusing on clinical outcomes, biological processes, treatment commitment, and safety profile.
Clinical Evidence for Knee Pain Relief
Clinical trials and systematic reviews consistently show that acupuncture offers meaningful pain relief and functional improvement for people suffering from chronic knee osteoarthritis. When compared to a control group receiving usual care or placed on a waiting list, patients undergoing acupuncture report clinically relevant short- and long-term reductions in pain scores. Studies have shown that the pain-relieving effect of acupuncture can be comparable to non-steroidal anti-inflammatory drugs (NSAIDs), but with fewer systemic side effects.
Acupuncture is often superior to sham or placebo acupuncture, which involves needling non-acupuncture points or using non-penetrating needles, indicating a specific therapeutic benefit beyond the expectation effect. The positive effects are not just short-lived, as the benefits regarding pain and function have been observed to persist for several months after the initial course of treatment is completed. Researchers also suggest that the type of stimulation matters, with electroacupuncture—where a mild electrical current is passed through the needles—potentially yielding greater pain reduction compared to manual needle manipulation alone.
Explaining the Mechanism of Action
The analgesic effect of acupuncture is not solely attributed to the needling sensation but involves a complex series of neurological and biochemical changes within the body. When needles stimulate specific points, they activate sensory nerves, which then transmit signals to the spinal cord and brain, initiating a process called neuromodulation. This stimulation triggers the release of the body’s natural pain-relieving chemicals, known as endogenous opioids, such as beta-endorphin and enkephalins.
These opioids activate receptors in the central nervous system, effectively blocking the transmission of pain signals to the brain. Acupuncture has also been shown to modulate the activity in brain regions associated with pain processing, such as the periaqueductal gray. The treatment exhibits anti-inflammatory properties by influencing the hypothalamic-pituitary-adrenal (HPA) axis, leading to a reduction in inflammatory mediators like cyclooxygenase-2 (COX-2) and prostaglandins. Locally, the insertion of needles can promote the release of adenosine, a molecule that acts as a potent analgesic near the site of stimulation.
The Typical Treatment Course
A course of acupuncture treatment for chronic knee pain is typically structured over several weeks to achieve sustained relief and functional improvement. Following an initial consultation and assessment, a standard treatment protocol often involves a minimum of 6 to 12 sessions. The frequency of these sessions is usually one to three times per week, with evidence suggesting that a higher frequency, such as three times weekly, may be more effective for symptomatic relief in knee osteoarthritis.
A single session generally lasts between 20 and 40 minutes, which is the time the fine needles are retained in the skin. The acupuncturist selects specific points, which commonly include local sites around the knee joint itself, such as Stomach 35 (Dubi) and Spleen 9. The treatment also frequently incorporates distal points located on the lower leg, hand, or torso, which are believed to influence the knee area via neurological pathways. After the initial intensive phase, patients may transition to a maintenance schedule of treatments every few weeks or monthly, depending on the persistence of their symptoms.
Safety Profile and Side Effects
Acupuncture is recognized as a generally safe procedure when performed by a licensed and properly trained practitioner using sterile, single-use needles. Serious adverse events (SAEs) are extremely uncommon, with multinational registry data suggesting they occur in less than 0.12% of cases. The most frequently reported side effects are minor and temporary, occurring locally at the needle insertion site.
These minor reactions can include slight bruising, minor bleeding upon needle removal, or temporary soreness. A small percentage of patients may also experience vasovagal syncope, or temporary fainting, which is usually related to anxiety about the needles. Caution is advised for individuals with bleeding disorders or those taking anticoagulants, and electroacupuncture is contraindicated for patients with pacemakers due to the electrical stimulation.