In a randomized, placebo-controlled, double-blinded study described in Pain Medicine, researchers from the University Medical Center Hamburg-Eppendorf in Germany found that acupuncture was effective in alleviating pain associated with primary adhesive capsulitis (AC).1
It is estimated that primary AC affects 3% to 5% of the general population, with rates as high as 20% among individuals with diabetes.2 AC is a self-limiting condition, also known as “frozen shoulder,” with idiopathic etiology. It is initially treated with non-invasive methods such as corticosteroids or physiotherapy.Surgical approaches such as arthroscopic capsular release performed under anesthesia represent an alternative option, although this technique can damage the labrum and humeral head.3
Acupuncture is a pain management technique that “causes a peripheral effect through the release of local tissue substances and transmitters,” according to the current study researchers.4 However, conducting placebo-controlled trials assessing the efficacy of acupuncture have proven challenging, as needle use may cause pain.
Press tack needles are shallow and are thought to be safer and to cause minimal sensation or skin alteration.5 Press tack placebos can be used in controlled trials, as they have similar appearance as treatment needles, but do not include the needle element in the shaft.
The current investigation used press tack needles and press tack placebos to assess the efficacy of distal needling acupuncture as a pain management approach in adults with primary AC lasting more than 1 month. A total of 60 participants with a Constant-Murley Shoulder Score pain subscore of 10 (indicating mild pain) or lower (indicating more severe pain) were randomly assigned to either the treatment or placebo condition.
In addition, in an open follow-up study lasting 10 weeks, 34 of the participants received conservative therapy that included 10 sessions of classical needle acupuncture, whereas 13 received conservative therapy without acupuncture. Follow-up assessments occurred at 1 year.
The press tack needle group showed immediate improvement in the Constant-Murley Shoulder Score pain subscore of 3.3 ± 3.2, compared with 1.6 ± 2.8 in the placebo group (P <.001). In the follow-up study, significant improvements were observed at 14.9 ± 15.9 weeks in the group that received conservative therapy with classical needle acupuncture compared with 30.9 ± 15.8 weeks in the group receiving only conservative therapy (P <.001). No adverse effects were observed in any of the participants.
These results provide “evidence that acupuncture has a specific impact on AC beyond the placebo effects that may not only be beneficial in reducing short-term pain perception, but may also have a positive long-term influence on the time course of recovery,” the researchers wrote.
Summary and Clinical Applicability
Acupuncture was found to be more effective than placebo in reducing pain in patients with primary adhesive capsulitis.
The current study focused solely on acupuncture at distant points, which has been shown to provide immediate pain relief compared with local needling. Future research could explore the potential for improved results with a combination of local and distal points.
- Schröder S, Meyer-Hamme G, Friedemann T, et al. Immediate pain relief in adhesive capsulitis by acupuncture-a randomized controlled double-blinded study [published online March 20, 2017]. Pain Med. 2017. doi:10.1093/pm/pnx052
- Manke RC, Prohaska D. Diagnosis and management of adhesive capsulitis. Curr Rev Musculoskelet Med. 2008; 1(3-4):180–189 doi:10.1007/s12178-008-9031-9036
- Sasanuma H, Sugimoto H, Kanaya Y, et al. Magnetic resonance imaging and short-term clinical results of severe frozen shoulder treated with manipulation under ultrasound-guided cervical nerve root block. J Shoulder Elbow Surg. 2016; 25(1):e13–20. doi:10.1016/j.jse.2015.06.019
- Goldman N, Chen M, Fujita T, et al. Adenosine A1 receptors mediate local anti-nociceptive effects of acupuncture. Nat Neurosci. 2010; 13(7):883–888. doi:10.1038/nn.2562
- Yamashita H, Tsukayama H. Minimal acupuncture may not always minimize specific effects of needling. Clin J Pain. 2001; 17(3):277.