SMT for Acute Neck Pain – Systematic Review & Meta-Analysis +MP3
Research Review By Dr. Michael Haneline©
Audio:
Date Posted:
February 2022
Study Title:
Spinal Manipulative Therapy for Acute Neck Pain: A Systematic Review and Meta-Analysis of Randomised Controlled Trials
Authors:
Chaibi A, Stavem K & Russell M
Author's Affiliations:
Head and Neck Research Group, Division for Research and Innovation, Akershus University Hospital, Oslo, Norway
Publication Information:
Journal of Clinical Medicine 2021; 10(21): 5011. doi: 10.3390/jcm10215011.
Background Information:
Acute neck pain is very common, and relapses of this condition are frequent. Musculoskeletal neck pain together with low back pain have been reported as the leading global cause of disability in almost all age groups (1, 2). Annual spending for the management of lower back and neck pain combined in the United States alone has been estimated to be $87.6 billion (USD).
About 1/3 of patients seeking care from a general practitioner (GP) do so because of musculoskeletal pain, mostly for neck and lower back pain. Such care generally involves analgesic and/or muscle relaxant medications and possible referral to a physiotherapist. However, only about 8% of GPs refer patients with neck pain for manual therapy, which often includes spinal manipulative therapy (SMT). Reasons given by GPs for not referring more patients for manual therapy/SMT include concern about associated complications and inadequate support in practice guidelines regarding the effectiveness of SMT (3).
About 1/3 of patients seeking care from a general practitioner (GP) do so because of musculoskeletal pain, mostly for neck and lower back pain. Such care generally involves analgesic and/or muscle relaxant medications and possible referral to a physiotherapist. However, only about 8% of GPs refer patients with neck pain for manual therapy, which often includes spinal manipulative therapy (SMT). Reasons given by GPs for not referring more patients for manual therapy/SMT include concern about associated complications and inadequate support in practice guidelines regarding the effectiveness of SMT (3).
The objectives of this systematic review were:
- to determine the effect of SMT on acute neck pain of less than 6 weeks duration;
- to determine the pooled effect size using unimodal SMT intervention vs. control/placebo and multimodal interventions vs. control/placebo;
- to descriptively present the effect of SMT on disability and quality of life measures; and
- to descriptively report adverse effects (AEs).
Pertinent Results:
The literature search and screening of retrieved articles ultimately yielded 6 RCTs on acute neck pain in which participants were treated with SMT. A total of 446 participants were included in the 6 RCTs which were conducted in Australia, Spain and USA and published from 2005 to 2013. Physiotherapists or osteopaths provided the intervention in 5 studies, whereas 1 study recruited participants through 12 private physiotherapy, chiropractic, and osteopathy clinics. Only 2 of the studies evaluated SMT alone, whereas multimodal interventions were utilized in the other 4 studies.
The methodological quality of 5 of the RCTs was rated as good (4-8) and the sixth was rated as low quality (9). None of the RCTs blinded patients or published their research protocol and only one study concealed the outcomes for the assessor.
Regarding pain outcomes, 5 of the 6 studies showed a statistically significant reduction in neck pain intensity favoring SMT compared to other treatments. Average reduction in pain intensity was 66% at 1 day to 1 week follow-up, 74% at > 1 week to 4 weeks follow-up, and 86% at > 4 weeks follow-up.
Participants in the combined unimodal and multimodal studies who received SMT had lower neck pain intensity at the time of the first assessment than other treatments (standardized mean difference of -1.37). These studies were also highly heterogeneous, regardless of modality, duration of end-point assessment or pain measurement scale that was used. The level of evidence found in the combined studies was rated as very low, providing very little confidence in the overall estimate of effect.
One of the unimodal RCTs (6) found no statistically significant differences between the cervical SMT and the cervical spinal mobilization group for the neck disability index (NDI), patient-specific functional scale or health-related quality of life at 4- and 12-week follow-ups. Though not statistically significant, the cervical SMT group’s percentage improvement scores were somewhat higher than for the cervical mobilization group.
Three of the multimodal RCTs presented results for disability. One of them (5) reported a statistically significant before-and-after intervention reduction in the Neck Pain Questionnaire (NPQ), and statistically significant improvement between groups in favor of the group that received electro- and thermotherapy plus thoracic SMT at posttreatment over the electro/thermal only group. Another multimodal RCT (7) reported significantly lower NDI scores for the cervical SMT group as compared to the thoracic SMT group at all follow-up time points. The third RCT (8) reported a statistically significant difference for NDI in favor of cervical SMT plus thoracic SMT versus cervical mobilization at 1-week follow-up.
The methodological quality of 5 of the RCTs was rated as good (4-8) and the sixth was rated as low quality (9). None of the RCTs blinded patients or published their research protocol and only one study concealed the outcomes for the assessor.
Regarding pain outcomes, 5 of the 6 studies showed a statistically significant reduction in neck pain intensity favoring SMT compared to other treatments. Average reduction in pain intensity was 66% at 1 day to 1 week follow-up, 74% at > 1 week to 4 weeks follow-up, and 86% at > 4 weeks follow-up.
Participants in the combined unimodal and multimodal studies who received SMT had lower neck pain intensity at the time of the first assessment than other treatments (standardized mean difference of -1.37). These studies were also highly heterogeneous, regardless of modality, duration of end-point assessment or pain measurement scale that was used. The level of evidence found in the combined studies was rated as very low, providing very little confidence in the overall estimate of effect.
One of the unimodal RCTs (6) found no statistically significant differences between the cervical SMT and the cervical spinal mobilization group for the neck disability index (NDI), patient-specific functional scale or health-related quality of life at 4- and 12-week follow-ups. Though not statistically significant, the cervical SMT group’s percentage improvement scores were somewhat higher than for the cervical mobilization group.
Three of the multimodal RCTs presented results for disability. One of them (5) reported a statistically significant before-and-after intervention reduction in the Neck Pain Questionnaire (NPQ), and statistically significant improvement between groups in favor of the group that received electro- and thermotherapy plus thoracic SMT at posttreatment over the electro/thermal only group. Another multimodal RCT (7) reported significantly lower NDI scores for the cervical SMT group as compared to the thoracic SMT group at all follow-up time points. The third RCT (8) reported a statistically significant difference for NDI in favor of cervical SMT plus thoracic SMT versus cervical mobilization at 1-week follow-up.
Adverse events were reported in the included trials as follows:
- In the study by McReynolds and Sheridan (9), 28% of participants who were administered medicine (ketorolac injection) reported AEs, including arm soreness, bad taste in mouth, dizziness, drowsiness, dyspepsia, heart palpitations, light headedness, nausea or vomiting, whereas only 1 participant (3%) in the SMT group reported a temporary feeling of a “funny” arm.
- AEs were reported in the study by Leaver et al. (6) which were approximately evenly distributed between those in the SMT versus spinal mobilization group. AEs included increased neck pain, headache, dizziness/vertigo, nausea, paresthesia, and “others” (upper limb pain, neck stiffness, fatigue, mild lower back pain and unpleasant change in spinal posture).
- In the study by Puentedura et al. (7), minor transient AEs (increased neck pain, fatigue, headache, and upper back pain) were reported by 80% of participants in the thoracic SMT group. Similarly, minor transient increased neck pain was reported post-treatment in 1 participant in the cervical SMT group.
- No severe/serious AEs were reported.
Clinical Application & Conclusions:
This systematic review reported that SMT – alone or in combination with another modality – is likely to be effective in the treatment of acute neck pain. Few AEs and no serious AEs were reported in the RCTs. These conclusions are weakened, however, by presence of heterogeneity of the included RCTs, small sample sizes, lack of blinding, and unanswered placebo effects.
Clinicians can use the results of this review to support the use of SMT in the treatment of acute neck pain patients and to defend its use before medical providers, payors and in court proceedings.
Clinicians can use the results of this review to support the use of SMT in the treatment of acute neck pain patients and to defend its use before medical providers, payors and in court proceedings.
EDITOR’S NOTE: from a chiropractic perspective, we as a profession need to conduct some studies in this area! As noted here, the studies included featured treatment delivered mainly by physiotherapists and osteopaths, which may have surprised you? I’m not saying their treatment would be inferior to ours; rather, I feel we should be major contributors to this literature as the profession that utilizes SMT with the highest frequency. As with many other areas in the MSK realm, we have an important role to play and a critical part of that responsibility is contributing to the body of evidence.
Study Methods:
This was a systematic review and meta-analysis of RCTs that measured the effectiveness of SMT for patients with acute neck pain. The literature search was broad, encompassing seven biomedical databases. In addition, the reference lists of selected RCTs and previous systematic reviews were cross-checked to identify any additional relevant studies.
Study selection criteria were as follows:
- Study participants must have had acute neck pain of < 6 weeks duration as the primary complaint
- The intervention had to include SMT alone (unimodal intervention) or in combination with any other interventions (multimodal intervention). Advice, reassurance, and encouragement to continue normal activities were not considered as multimodal interventions.
- The SMT intervention could be conducted by any type of clinician, i.e., physiotherapist, chiropractor, osteopath
- Any comparison group was included
The following types of studies were excluded:
- Pilot or feasibility studies
- Studies that included sub-acute (6–11 weeks duration) and/or chronic neck pain (12 weeks duration) participants unless individual results were presented for the acute neck pain population
- Studies in which the duration of pain was unclear
- Studies that did not include pain intensity as an outcome measure
Data were extracted from the included studies independently by two of the authors with discrepancies resolved through consensus. The Cochrane Back and Neck (CBN) Risk of Bias tool was used by the same two authors to assess the methodological quality and internal validity of the included articles. Studies were thus classified as being of higher quality or lower quality. The evidence in the included articles was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria to rate the evidence in the included articles as “high”, “moderate”, “low” or “very low”.
The primary outcome measure was pain intensity as measured by either a visual analogue scale (VAS) or numeric rating scale (NRS). Secondary outcome measures included disability, quality of life measures and AEs.
The RCTs were grouped together and the pooled effect sizes of SMT alone vs. control/placebo and multimodal approach vs. control/placebo were calculated. An effect size of > 0.2 was considered to be small, > 0.5 medium, > 0.8 large, and > 1.3 very large.
The primary outcome measure was pain intensity as measured by either a visual analogue scale (VAS) or numeric rating scale (NRS). Secondary outcome measures included disability, quality of life measures and AEs.
The RCTs were grouped together and the pooled effect sizes of SMT alone vs. control/placebo and multimodal approach vs. control/placebo were calculated. An effect size of > 0.2 was considered to be small, > 0.5 medium, > 0.8 large, and > 1.3 very large.
Study Strengths / Weaknesses
This was a well-conducted systematic review, although several methodological deficiencies were present in the included RCTs which negatively affect the strength of the review’s conclusions. Therefore, its results should be interpreted with caution (as appropriately noted by the authors themselves).
The authors listed several study limitations, as follows:
- the quantity and quality of the included RCTs were limited,
- there was heterogeneity regarding the RCTs study design and results,
- none of the studies blinded patients,
- non-English RCTs were not included,
- reporting bias have existed, and
- publication bias was most likely present.
Additional References:
- GBD 2015 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990–2015: A systematic analysis for the Global Burden of Disease Study 2015. Lancet 2016; 388: 1545-1602.
- Kamper S, Henschke N, Hestbaek L et al. Musculoskeletal pain in children and adolescents. Braz. J Phys Ther 2016; 20: 275-84.
- Dikkers M, Westerman M, Rubinstein S et al. Why Neck Pain Patients are Not Referred to Manual Therapy: A Qualitative Study among Dutch Primary Care Stakeholders. PLoS ONE 2016; 11: e0157465.
- Martínez-Segura R, Fernández-de-las-Peñas C, Ruiz-Sáez M et al. Immediate effects on neck pain and active range of motion after a single cervical high-velocity low-amplitude manipulation in subjects presenting with mechanical neck pain: A randomized controlled trial. J Manip Physiol Ther 2006; 29: 511-17.
- González-Iglesias J, Fernández-de-las-Peñas C, Cleland J et al. Thoracic spine manipulation for the management of patients with neck pain: A randomized clinical trial. J Orthop Sports Phys Ther 2009; 39: 20-7.
- Leaver A, Maher C, Herbert R et al. A randomized controlled trial comparing manipulation with mobilization for recent onset neck pain. Arch Phys Med Rehabil 2010; 91: 1313–18.
- Puentedura E, Landers M, Cleland J et al. Thoracic spine thrust manipulation versus cervical spine thrust manipulation in patients with acute neck pain: A randomized clinical trial. J Orthop Sports Phys Ther 2011; 41: 208-20.
- Masaracchio M, Cleland J, Hellman M, Hagins M. Short-term combined effects of thoracic spine thrust manipulation and cervical spine nonthrust manipulation in individuals with mechanical neck pain: A randomized clinical trial. J Orthop Sports Phys Ther 2013; 43: 118-27.
- McReynolds T, Sheridan B. Intramuscular ketorolac versus osteopathic manipulative treatment in the management of acute neck pain in the emergency department: A randomized clinical trial. J Am Osteopath Assoc 2005; 105: 57-68.
