Effectiveness and safety of manual therapy compared with oral pain medications in patients with neck pain

This systematic review and meta-analysis investigated the effectiveness and safety of manual therapy (MT) interventions compared to oral or topical pain medications in the management of neck pain.
The investigators searched from inception to March 2023, in Cochrane Central Register of Controller Trials (CENTRAL), MEDLINE, EMBASE, Allied and Complementary Medicine (AMED) and Cumulative Index to Nursing and Allied Health Literature (CINAHL; EBSCO) for randomized controlled trials that examined the effect of manual therapy interventions for neck pain when compared to oral or topical medication in adults with self-reported neck pain, irrespective of radicular findings, specific cause, and associated cervicogenic headaches. Trials with usual care arms were also included if they prescribed medication as part of the usual care and they did not include a manual therapy component. The authors used the Cochrane Risk of Bias 2 tool to assess the potential risk of bias in the included studies, and the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach to grade the quality of the evidence.

Nine trials  with a total of 779 participants were included in the meta-analysis.

• low certainty of evidence was found that MT interventions may be more effective than oral pain medication in pain reduction in the short-term (Standardized Mean Difference: -0.39; 95% CI -0.66 to -0.11; 8 trials, 676 participants),
• moderate certainty of evidence was found that MT interventions may be more effective than oral pain medication in pain reduction in the long-term (Standardized Mean Difference: −0.36; 95% CI −0.55 to −0.17; 6 trials, 567 participants),
• low certainty evidence that the risk of adverse events may be lower for patients who received MT compared to the ones that received oral pain medication (Risk Ratio: 0.59; 95% CI 0.43 to 0.79; 5 trials, 426 participants).

The authors conluded that MT may be more effective for people with neck pain in both short and long-term with a better safety profile regarding adverse events when compared to patients receiving oral pain medications. However, we advise caution when interpreting our safety results due to the different level of reporting strategies in place for MT and medication-induced adverse events. Future MT trials should create and adhere to strict reporting strategies with regards to adverse events to help gain a better understanding on the nature of potential MT-induced adverse events and to ensure patient safety.

Let’s have a look at the primary studies. Here they are with their conclusions (and, where appropriate, my comments in capital letters):

1. For participants with acute and subacute neck pain, spinal manipulative therapy (SMT) was more effective than medication in both the short and long term. However, a few instructional sessions of home exercise with (HEA) resulted in similar outcomes at most time points. EXERCISE WAS AS EFFECTIVE AS SMT
2.  Oral ibuprofen (OI) pharmacologic treatment may reduce pain intensity and disability with respect to neural mobilization (MNNM and CLG) in patients with CP during six weeks. Nevertheless, the non-existence of between-groups ROM differences and possible OI adverse effects should be considered. MEDICATION WAS BETTER THAN MT
3. It appears that both treatment strategies (usual care + MT vs usual care) can have equivalent positive influences on headache complaints. Additional studies with larger study populations are needed to draw firm conclusions. Recommendations to increase patient inflow in primary care trials, such as the use of an extended network of participating physicians and of clinical alert software applications, are discussed. MT DOES NOT IMPROVE OUTCOMES
4. The consistency of the results provides, in spite of several discussed shortcomings of this pilot study, evidence that in patients with chronic spinal pain syndromes spinal manipulation, if not contraindicated, results in greater improvement than acupuncture and medicine. THIS IS A PILOT STUDY, A TRIAL TESTING FEASIBILITY, NOT EFFECTIVENESS
5. The consistency of the results provides, despite some discussed shortcomings of this study, evidence that in patients with chronic spinal pain, manipulation, if not contraindicated, results in greater short-term improvement than acupuncture or medication. However, the data do not strongly support the use of only manipulation, only acupuncture, or only nonsteroidal antiinflammatory drugs for the treatment of chronic spinal pain. The results from this exploratory study need confirmation from future larger studies.
6. In daily practice, manual therapy is a favorable treatment option for patients with neck pain compared with physical therapy or continued care by a general practitioner.
7. Short-term results (at 7 weeks) have shown that MT speeded recovery compared with GP care and, to a lesser extent, also compared with PT. In the long-term, GP treatment and PT caught up with MT, and differences between the three treatment groups decreased and lost statistical significance at the 13-week and 52-week follow-up. MT IS NOT SUPERIOR [SAME TRIAL AS No 6]
8. In this randomized clinical trial, for patients with chronic neck pain, Chuna manual therapy was more effective than usual care in terms of pain and functional recovery at 5 weeks and 1 year after randomization. These results support the need to consider recommending manual therapies as primary care treatments for chronic neck pain.
9. In patients with chronic spinal pain syndromes, spinal manipulation, if not contraindicated, may be the only treatment modality of the assessed regimens that provides broad and significant long-term benefit. SAME TRIAL AS No 5
10. An impairment-based manual physical therapy and exercise (MTE) program resulted in clinically and statistically significant short- and long-term improvements in pain, disability, and patient-perceived recovery in patients with mechanical neck pain when compared to a program comprising advice, a mobility exercise, and subtherapeutic ultrasound. THIS STUDY DID NOT TEST MT ALONE AND SHOULD NOT HAVE BEEN INCLUDED

I cannot bring myself to characterising this as an overall positive result for MT; anyone who can is guilty of wishful thinking, in my view. The small differences in favor of MT that (some of) the trials report have little to do with the effectiveness of MT itself. They are almost certainly due to the fact that none of these studies were placebo-controlled and double blind (even though this would clearly be possible). In contrast to popping a pill, MT involves extra attention, physical touch, empathy, etc. These factors easily suffice to bring about the small differences that some studies report.

It follows that the main conclusion of the authors of the review should be modified:

There is no compelling evidence to show that MT is more effective for people with neck pain in both short and long-term when compared to patients receiving oral pain medications.