Acupuncture for Chronic Knee Pain
Among patients with chronic knee pain, does the use of acupuncture in addition to standard therapy reduce pain or improve functional capacity?
Among patients with chronic knee pain, neither laser nor needle acupuncture reduced pain or improved of functional capacity when compared to a sham treatment.
Chronic knee pain is often the result of osteoarthritis and leads to decreased physical function. It is associated with increasing age (especially over the age of 50) and is the most frequent pain concern for the elderly population. Many nonpharmacological methods are used to alleviate pain; however, acupuncture is becoming more prevalent. Currently, there is a lack of scientific data supporting which form of acupuncture (needle or laser) causes the greatest decrease in chronic knee pain. Meta-analyses have been previously conducted, however, recruitment bias associated with traditional clinical trials has influenced patients’ preconceptions and positive attitudes toward better treatment outcomes of acupuncture.
To determine the efficacy of needle acupuncture versus laser acupuncture, a Zelen-design clinical trial was conducted with 282 people from Melbourne and Victoria, Australia, over the age of 50 who suffer from chronic knee pain. This study design randomized participants before informed consent was obtained in order to reduce the chance of bias associated with the knowledge of the specific intervention. Participants were divided into 4 treatment groups that consisted of no treatment, laser, needle, or sham laser acupuncture. The treatments were performed by 8 family physicians over 12 weeks with 8-12 possible treatments. Follow-up was performed at 12 weeks and 1 year from the start of treatment. Primary outcomes included pain reduction (11 points numeric rating scale (NRS) and physical function (Western and McMaster Universities Osteoarthritis Index). Secondary outcomes evaluated average knee pain with walking and standing (NRS), daily activity restriction (NRS), quality of life (Assessment of Quality of Life instrument), physical and mental health (Short Form Health Survey), and global changes in overall pain and function (5 point ordinal scale). There were essentially no differences in the primary and secondary outcomes between the groups.
The following trial analyzes an additional treatment option for patients with chronic knee pain. Due to the inclusion and exclusion criteria, the diversity amongst the participants is fairly narrow and results may not accurately be portrayed to other populations. Also, participants who were on additional therapies which could have influenced the pain relief results amongst the experimental groups. Although there are some concerns regarding the validity of this trial, acupuncture may be beneficial as an adjunct to therapy rather than a primary treatment modality for patients.
ACR Osteoarthritis (2012, adapted)
- Use of traditional Chinese acupuncture in select patients with moderate to severe pain due to osteoarthritis, only if the patient is unwilling to undergo total knee arthroplasty, having comorbid medical conditions, or taking concomitant medications that lead to a relative or absolute contraindication to surgery.
- Trial Type: Zelen-Design Randomized Clinical Trial
- N= 282 participants (returned questionnaire and were randomized)
- Experimental arm 1: Received needle acupuncture, n= 70
- Experimental arm 2: Received laser acupuncture, n=71
- Experimental arm 3: Received sham laser acupuncture, n=70
- Control: Receive no acupuncture, n=71
- Setting: 8 Family Physician Offices from Melbourne and regional Victoria (Australia)
- Enrollment: February 2010- December 2011
- Mean Follow-up: 12 weeks and 1 year
- Analysis: Intention-to-treat
- Primary Outcome: average knee pain and physical function
- Aged 50 years or older
- Knee pain of longer than 3 months’ duration
- Knee pain most days with average severity of 4 or more out of 10 on a numeric rating scale (NRS)
- Morning stiffness lasting less than 30 minutes
- Note: These criteria are consistent with clinical guidelines advocating a clinical diagnosis of osteoarthritis
- History of any systemic arthritic condition
- History of knee arthroplasty on the most painful knee
- Wait-listed for any knee surgery for either knee
- History of any knee surgery in previous 6 months
- Any other condition affecting lower limb function (ex: trauma, malignancy, neurological condition)
- History of any knee injection in past 6 months (ex: cortisone, hyaluronic acid)
- Current use of oral or injectable anticoagulant medication
- Use of acupuncture in past 12 months
- Any bleeding disorder
- Allergy to light
- Referral to pain clinic or use of morphine or pethidine within past 6 months
- Any other medical condition precluding participation in the trial (ex: kidney or liver disease, deep vein thrombosis)
- Knee pain subject to compensation claim
- Unable to give written informed consent
- Note: For bilaterally eligible knees, only the most symptomatic knee was evaluated
From the control group.
- Demographics: Age 63 years, female sex 56%
- Anthromorphics: Height 1.7 m, weight 86 kg, BMI 29.3 kg/m2
- Pain data:
- Duration of symptoms: <1 year 8%, 1-5 years 35%, 5-10 years 25%, ≥10 years 27%
- Unilateral: 49%
- Medications: Analgesia 48%, NSAIDs 20%, COX-2 inhibitors 4%, opioids 1%, glucosamine 28%, fish oil 28%
- Prior therapies: PT 41%, surgery 32%, injections 8%, acupuncture 7%, exercise 52%, hydrotherapy 11%
The control groups did not receive acupuncture while experimental groups were treated with needle, laser, or sham laser acupuncture. Sham laser acupuncture mimics standard laser acupuncture but does not target known effective areas. Family physicians registered as acupuncturists provided acupuncture therapy. Treatment was received for 12 weeks. Participants and therapists were blinded in the laser acupuncture groups. The control group was unaware of the acupuncture trial.
Presented as control vs. needle acupuncture vs. laser acupuncture vs. sham laser acupuncture.
- Overall pain
- Out of 10, higher being worse pain. Neither needle nor laser acupuncture significantly improved pain or function compared with sham at 12 weeks. Compared with control, needle and laser acupuncture resulted in modest improvements in pain (−1.1; 95% CI, −1.8 to −0.4 p-value 0.002, and −0.8; 95% CI, −1.5 to −0.1 p-value 0.03, respectively) at 12 weeks, but not at 1 year.
- Baseline: 5.1 vs. 5.3 vs. 4.9 vs. 5.0
- 12 weeks: 4.4 vs. 3.3. vs. 3.4 vs. 3.4
- 1 year: 4.6 vs. 4.9 v.s 4.0 vs. 3.9
- WOMAC function
- Out of 60, higher being worse physical function. Needle acupuncture resulted in modest improvement in function compared with control at 12 weeks (−3.9; 95% CI, −7.7 to −0.2 p-value 0.04) but was not significantly different from sham and was not maintained at 1 year. Laser acupuncture did not result in significant improvement of function.
- Baseline: 26.1 vs. 31.3 vs. 27.9 vs. 27.5
- 12 weeks: 23.0 vs. 22.5 vs. 21.9 vs. 21.7
- 1 year: 23.6 vs. 22.4 vs. 22.6 vs. 21.6
Secondary outcomes included other pain and function measurements, quality of life, global change and one year follow-up. The study concluded that there were no differences for secondary outcomes.
- Previous treatments for knee pain and concurrent medication use, especially analgesics, by participants may have influenced the outcomes of pain relief.
- The trial did not show a significant difference in the reduction of chronic knee pain or improvement of function in patients who received acupuncture treatment. Therefore, the NNT can not be calculated.
- Small sample size
- The participants included were all from Australia and over the age of 50.
- Chronic knee pain is most common in the elderly; however, other factors can contribute to the cause. These factors include athletics, congenital deformities, and trauma can also subject a person to this condition. We determined the results from this trial cannot be applied to the previous stated populations due to the lack of diversity amongst the group.
The National Health and Medical Research Council was the source of funding for this trial. The funders for this study had no role in the design and conduction.