Max van der Velden
Learn to critically appraise a trial
Learn about contextual effects
Current guidelines concerning chronic neck pain promote manual therapy in combination with exercise therapy. Different guidelines provide conflicting recommendations regarding dry needling for neck pain. This study aimed to determine the benefit of adding dry needling (DN) to guideline-based physical therapy.
A two-arm randomized controlled trial was set up with concealed allocation and a blind outcome assessment. The study was preregistered at clinicaltrials.gov. Participants between 18-65 years old with at least three months of neck pain without major structural pathology were included. A neck pain intensity of at least 3 out of 10 and a disability of at least 15 out of 100 points on the Neck Disability Index (NDI) was needed. Patients with any contraindications were excluded. Three physical therapists provided the therapy in separate locations and were trained by the lead investigator to standardize treatment.
Participants were randomized to either guideline-based physical therapy (PT) or guideline-based physical therapy plus dry needling (PT+DN). Both groups received 4-6 consultations over 4 weeks with a mean duration of 40 minutes.
The aims of the interventions were to reduce neck pain, strengthen the neck and upper back, increase ROM and educate the patients about their condition. Participants in the PT+DN group received DN on the upper and middle trapezius, cervical multifidi, splenius cervicis, and levator scapulae muscles at the end of each session when hyperalgesic and hyperirritable nodules were detected.
The primary outcomes were average pain intensity in the previous 24h, the previous week, and the NDI. These were measured one month post-randomization. Additional secondary outcomes were recorded at the 3 and 6 months time-point.
The sample size was estimated a priori ensuring 90% power to detect a mean difference of 2 points on the NRPS at one month.
Most participants were women (72%) and reported a moderate level of neck pain in the previous 24h (6.6/10 NRPS). Significant reductions for average pain intensity in the previous 24h and the previous week were apparent in both groups after one month. At this month, PT+DN was slightly superior – yet not clinically meaningful — for average pain intensity in the previous 24h compared with PT (3.72 ±1.11 vs 2.16 ±0.95) and the average pain intensity in the previous week (3.37 ±1.22 vs 2.17 ±0.84). No between-group differences were found between all other outcome measures and time-points.
Group-by-time interaction for disability was insignificant at one month and no differences were noted between PT and PT+DN.
Exploratory secondary outcome measures resulted in no differences between groups.
No serious or significant adverse events were reported.
This is the first pragmatic (high quality) RCT where patients received guideline-based physical therapy for chronic neck pain.
No clinically meaningful effects were found by adding dry needling to the treatment. This is a rather surprising result — since most trials comparing treatment A to treatment A+B result in greater effects for the latter. This is explained by increased attention, contextual effects, or possibly other (non-)specific treatment effects.
One could ask if dry needling could be effective for chronic pain in general. Subjects had an average neck pain duration of 36 and 41 months for the PT group and PT+DN respectively. The authors mention ‘booster session’ could facilitate long-term maintenance of beneficial effects. However, the noted effects were too small to be deemed important. Let’s say there is a meaningful effect of adding dry needling, is it worth your time? Most of us are busy clinicians. Do you have time to spare after addressing guideline-based recommendations such as education, manual therapy, and exercise?
Let’s get into the strengths of the trial: the trial was preregistered, assessors and statisticians were blinded, the researchers calculated the statistical power a priori (90%), clinical practice guideline recommendations were used for treatment (increasing the external validity), they had predetermined clinically important differences for the primary outcome measures, subjects were analyzed using ‘intention to treat analysis’, and participants were randomized.
Of course, this trial has some limitations too. Participants were not blinded meaning the PT+DN group was well aware that they received dry needling. Some studies use sham-needling however there are a few concerns regarding the ‘believability’ of it. Lack of blinding would possibly result in superior results in the DN group; however, this was not the case. The interventions were given by three trained physical therapists, one cannot confidently say results would be equal if treatments were delivered by their own healthcare providers.
Looking at the outcome measures, it is clear there were multiple secondary outcome measures. This could be a problem, since the risk of false negatives and false positives increases quite steeply when adding measures. The study wasn’t powered for outcome measures other than one primary outcome measure (pain intensity) at one-time point (1 month).