Stimulated by Lo et al 2019.
This paper caught my eye because I advocate the use of electroacupuncture (EA) in frozen shoulder, but I find it hard to know whether or not I am doing any good. There is little or no controlled trial data in this specific condition, whilst there is some good data in chronic shoulder pain. I had a conversation recently with a patient who was also an experienced GP. She was suffering from bilateral frozen shoulder and was keen to know whether acupuncture could speed the process of recovery. I had to say that I honestly did not know, and that I was not aware of any controlled or even cohort data in this condition.
So I was pleased to see this paper come out, although a little frustrated when I actually read the methods!
It claims to be a paper on frozen shoulder, but the key diagnostic inclusion criterion was unilateral pain restricted range of motion (RoM) of the shoulder for more than 3 months. On looking closer I noticed that the baseline average range of external rotation was 50-60 degrees! To my mind this is not frozen shoulder. In a true frozen shoulder or adhesive capsulitis the passive RoM in external rotation is less than 30 degrees, and often less than 10. I guess things may be a little different in Taiwan, where this study was based, and the 3-month minimum certainly would be consistent with frozen shoulder, or FSS – the authors had added a syndrome tag.
Let’s give them the benefit of the doubt for now and look a bit further into the study. It was a small study, and they only managed to recruit 21 patients over 18 months. The title of the paper refers to randomisation, but there is no further detail in the paper concerning the process of randomisation or allocation concealment. The subjects received 18 sessions (2-3 per week) over 6-9 weeks lasting 80 minutes each and including 20 minutes of EA followed by physiotherapy and assessment of passive RoM.
EA was low frequency (2-3Hz) with a reasonable pulse width (100-400ms) and an intensity just below discomfort. The points used were 4 around the affected shoulder (LI15, TE14, SI10, Jianqian) and 2 in each leg (GB34-ST38). Jianqian is an extra point (M-UE-48 in Deadman ) lying on the anterior aspect of the shoulder joint, midway between the anterior axillary crease and LI15 or the tip of the acromium.
All sounds good so far, doesn’t it?
Now I will relate what they did in the sham EA group!
Well the description in the paper is very short! They did exactly the same as in the true EA group apart from missing the ‘real’ points by about 2cm. In other words they performed the same stimulation to virtually the same tissues! From a WMA perspective we have a controlled trial of local segmental and general EA versus local segmental and general EA!
As this trial comes from the East no doubt you are expecting me to say that the true EA group had a miraculous recovery, and the sham EA group did not do so well. But no… there was no difference between the groups, and the authors concluded that both techniques appeared to work reasonably well and that TCM points clearly were not so important. This must be a first!
But sadly, we do not have any control, so it is really just a cohort study, and without an untreated control group it is difficult to gauge how successful the treatment actually was beyond natural history. The average pain dropped to a VAS of just below 1 out of 10 after about a month (9-12 sessions). That seems like quite a rapid recovery for a typical frozen shoulder, but we have to be relatively speculative about this of course.
I guess I will continue to use EA on my chronically painful and frozen shoulders and I can advise patients that 9-12 sessions might be needed to get the best results. But ultimately, I still don’t know for sure if I am really doing any better than nature alone – I just hope I am!
1 Lo M-Y, Wu C-H, Luh J-J, et al. The effect of electroacupuncture merged with rehabilitation for frozen shoulder syndrome: A single-blind randomized sham-acupuncture controlled study. J Formos Med Assoc Published Online First: 13 May 2019. doi:10.1016/j.jfma.2019.03.012
2 Vickers AJ, Vertosick EA, Lewith G, et al. Acupuncture for Chronic Pain: Update of an Individual Patient Data Meta-Analysis. J Pain 2017;19:455–74. doi:10.1016/j.jpain.2017.11.005
3 Deadman P, Al-Khafaji M, Baker P. A Manual of Acupuncture. 2nd ed. Journal of Chinese Medicine 2007.