The effectiveness of superficial versus deep dry needling or acupuncture for reducing pain and disability in individuals with spine-related painful conditions: a systematic review with meta-analysis

Abstract

Objective: The purpose of this systematic review was to evaluate the effects of deep versus superficial dry needling or acupuncture on pain and disability for spine-related painful conditions. A secondary purpose was to account for the differences of needling location in relation to the painful area. Methods: This PROSPERO (#CRD42018106237) registered review found 691 titles through a multi-database search. Following a comprehensive search, 12 manuscripts were included in the systematic review and 10 in the meta-analysis. Standardized mean differences (SMD) with 95% confidence intervals were calculated for pain and disability. Results: The included studies demonstrated an unclear to high risk of bias recommending a cautious interpretation of the results. A consistent effect supporting deep needling over superficial with an SMD of 0.585 [0.335, 0.835], p < 0.001 from 10 articles for pain but a non-significant effect of 0.197 [-0.066, 0.461], p = 0.14 from 2 studies for disability. A temporal examination was similar for effects on pain with an SMD of 0.450 [0.104, 0.796] immediately, 0.711 [0.375, 1.048] short-term (1 to 11 weeks), and 0.470 [0.135, 0.805] for time-points ≥12 weeks. Regionally, there was a greater effect needling the area of pain locally (SMD = 0.754) compared to remotely (SMD = 0.501). Discussion: Statistically significant between-group differences were observed favoring deep needling over superficial. Both superficial and deep needling resulted in clinically meaningful changes in pain scores over time. However, differences between groups may not be clinically meaningful. More high-quality trials are needed to better estimate the effect size of deep versus superficial needling while controlling for location and depth of the lesion. Level of evidence: 1a.

Keywords: Deep; acupuncture; dry needling; pain; superficial.

Figures

Figure 1.

PRISMA Flow diagram of search strategy and results.

Figure 1.

PRISMA Flow diagram of search strategy and results.

Figure 2.

Forest plots illustrating the treatment effects of deep versus superficial needle insertion on overall pain (2a), immediately (2b), 12 weeks (2d).  Treatment effects ranged from small to moderate. Within the plots, squares represent estimates of treatment effect with larger squares representing larger sample sizes.  Diamond represents pooled treatment effect, horizontal lines represent 95% confidence intervals, and vertical line at 0 represents no difference.

Figure 3.

Forest plots illustrating the effect of deep versus superficial needle insertion on overall disability. Small treatment effects were observed. Within the plots, squares represent estimates of treatment effect with larger squares representing larger sample sizes.  Diamond represents pooled treatment effect, horizontal lines represent 95% confidence intervals, and vertical line at 0 represents no difference.

Figure 4.

Forest plots illustrating the treatment effects of needling depth on pain when inserted local (4a), mixed local and remote (4b) or remote only (4c).  Moderate treatment effects were observed for local and mixed with small effects observed for remote only. Within the plots, squares represent estimates of treatment effect with larger squares representing larger sample sizes.  Diamond represents pooled treatment effect, horizontal lines represent 95% confidence intervals, and vertical line at 0 represents no difference.

Figure 5.

Forest plots illustrating the treatment effects on disability for mixed local and remote to the painful area. Small treatment effects were observed. Within the plots, squares represent estimates of treatment effect with larger squares representing larger sample sizes.  Diamond represents pooled treatment effect, horizontal lines represent 95% confidence intervals, and vertical line at 0 represents no difference.