Research Review By Dr. Robert Rodine©

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Date Posted:

March 2011

Study Title:

Spinal manipulation or mobilization for radiculopathy: A systematic review

Authors:

Leininger et al.

Author's Affiliations:

Northwestern Health Sciences University, Bloomington MN, USA

Publication Information:

Physical Medicine & Rehabilitation Clinics of North America 2011; 105-125.

Background Information:

Radiculopathy has a prevalence of 9.8 per 1000 cases in the lumbar spine and 3.5 per 1000 cases in the cervical spine (1). While representing a relatively rare clinical presentation, it is still of great concern to both patients and clinicians.

While conservative therapy remains a first line therapeutic option for the majority of radiculopathy patients, there is limited evidence on which to base therapeutic recommendations. With respect to manual therapies such as manipulation and mobilization (SMT/MOB), it has been estimated that 90% of such treatments are delivered by chiropractors (2). As such, it is extremely important that chiropractors, and others who employ these techniques, have a strong understanding of the evidence base from which treatment recommendations are derived.

The study reviewed here is a systematic review of randomized controlled trials on the use of SMT/MOB for the treatment of cervical, thoracic and lumbar radiculopathy.

Pertinent Results:

Cervical Radiculopathy:

In total, the literature search identified 5 randomized controlled trials on the use of SMT/MOB for the treatment of cervical radiculopathy. Three trials isolated the use of SMT/MOB whereas the remaining 2 used SMT/MOB in combination with other therapies. Overall, the quality of research was low, with a high risk of bias. Given the small number of trials, each will be presented separately.
  1. Howe et al. (1983) conducted an RCT on patients with or without arm/hand pain. On closer inspection of the paper, less than half of the study population presented with arm/hand pain. Subjects were treated with 1-3 treatments (frequency was not disclosed) and assessed for improvements in lateral flexion and rotational range of motion immediately following treatment, at 1 week and at 3 weeks. When subjects with arm/hand pain were separated from the remainder of the group, there was no significant difference in range of motion found at any time point when compared to the control group (3).
  2. Allison et al. (2002) assessed the use of MOB and home exercise in patients with cervico-brachial pain compared to a control group. A small improvement was found in patients in the short term for pain and disability levels, however the values were not significant when compared to controls (4).
  3. Walker et al. (2008) found a small, but non-significant, difference in the short and long term when comparing SMT/MOB and home exercise to a usual care group. A notable limitation of this study was the pragmatic design, which did not differentiate between which patients received SMT and which patients received MOB. Additionally, the study evaluated patients with mechanically identified neck pain that presented with or without upper extremity symptoms. Without a more proper breakdown of the clinical baseline, it is probable that at least some patients were experiencing upper extremity symptoms due to myogenic and arthrogenic referral, as compared to neuro-/discogenic (5).
  4. Shin et al. (2006) compared the use of Chuna (a traditional Korean manual therapy) manipulation to traction for patients with identified cervical disc herniations, finding a superior outcome for short term pain relief with the manual treatment. While these results sound promising, further review of this paper found that it was submitted under the section of Letters To The Editor, therefore foregoing the peer-review process (6).
  5. The final paper, Moretti et al. (2004), involved patients with cervico-brachial pain (specifically identified as being of mechanical origin), comparing SMT to exercise and massage. While SMT proved to be superior to the comparative group for short term pain relief, closer review of the paper was not possible given that its publication appears to be in the Italian language (7).
Overall, the presented evidence for SMT/MOB in the treatment of cervical radiculopathy appears to be minimal, low quality and demonstrates a high risk of bias. Additionally, the presented papers appear have several limitations that limit the conclusions we can make from this review, given that two studies examined a mixed group of neck pain patients, two examined patients with upper extremity pain of mechanical origin and the only study that specifically identified cervical disc herniations was not peer-reviewed.

Thoracic Radiculopathy:

Based on the performed literature search, no trials were identified outlining the use of SMT/MOB in the treatment of thoracic radiculopathy.

EDITOR’S NOTE: Symptomatic thoracic disc herniation [TDH] is thought to represent less than 1% of all spinal complaints (11). Further, TDH has been detected in imaging studies in 10-30% of asymptomatic patients (while thoracic disc degeneration is noted in ~15%) (12).

Lumbosacral Radiculopathy:

In total, the literature search identified 11 randomized controlled trials on the use of SMT/MOB for the treatment of lumbosacral radiculopathy. Only one study was deemed to have a low risk of bias and to be of moderate quality. The remaining ten studies were rated as low in quality. Ten of the studies isolated the use of SMT/MOB whereas one used a combination of therapies. Given the number of studies identified, results will be presented as interpreted by the authors.

Based on the eleven studies identified, moderate evidence exists for the use of SMT in the treatment of acute leg and back pain, as compared to sham SMT in both the short and long term. The use of SMT and/or MOB for lumbosacral radiculopathy is supported only by low to very-low quality evidence.

Clinical Application & Conclusions:

The current review, while presenting limitations and weaknesses in its findings, offers clinicians a bird’s eye view of the evidence base for manipulative therapy in the treatment of radiculopathy. Mainly, there is an obvious need for more research.

Given that there is a small evidence base of high-quality randomized trials, clinicians are left to rely on a small collection of case series (not evaluated within this review), case reports, expert opinion and clinical experience. While these are weaker forms of evidence, they still represent a component of evidence-based care.

This brings us back to the primary role of the clinician, which is to guide the patient in making the treatment choices that suite their needs and circumstances, to continuously review the patient’s clinical status and their treatment plan, to compare clinical progress to the natural history of the suspected disorder and to help the patient appropriately weigh the pros and cons of their treatment options. By understanding what constitutes the current evidence-base for manipulative therapy in radiculopathy, the clinician is better suited to fulfill these directives and better guide patient care.

This systematic review is only a piece of the puzzle in directing us on how to best approach radiculopathy. Hopefully future well designed trials will help us fill in the gaps when a project like this is repeated.

Study Methods:

The authors attempted to conduct a systematic review on randomized controlled trials, when in fact they conducted a review on randomized comparative trials (consisting of either a control group or a comparative treatment group). While many of the included studies are listed as randomized clinical trials, not all included a true control group, the authors did not address this within their methods.

The authors conducted a literature search up until August of 2010, retrieving studies published in the English language. The databases of Cochrane, Medline, CINAHL, the Index to Chiropractic Literature, Mantis and PEDro were searched.

Studies were included if they listed spine-related extremity symptoms and evaluated SMT and/or MOB as a primary therapy in at least one intervention group. The authors stated that only patient reported outcome measures were evaluated, such as pain, disability and global perceived effect. Short term outcomes were deemed to be a timeline of less than 3 months, whereas long term was deemed to be at or after 6 months.

A dual reviewer process was utilized to assess which studies would be included in addition to the risk-of-bias/quality assessment that was undertaken for each included study.

Overall, 631 potential studies were reduced down to 16 trials that examined a total of 2132 subjects.

Study Strengths / Weaknesses:

There are several significant limitations to this study. Firstly, using the example of the cervical radiculopathy results, the identified studies did not appear to be highly relevant to radiculopathy cases. As we know, upper extremity pain can have many causes, hence the frequent research division of non-specific mechanical neck pain and specific neck pain. Given that many of the included studies evaluated neck pain patients with or without upper extremity pain and did not specifically identify the cause to detail a diagnosis of cervical radiculopathy, these results need to be reviewed with caution. While helpful in understanding the current evidence-base, they should most certainly not be used as the best available evidence.

Given the limitations discovered within the cervical section, the lumbosacral results must also be questioned for bias.

Most notably, a limitation of this study is that the authors chose to specifically review randomized controlled trials. The rationale for this appears to be in support of a higher quality review. However, given the obvious heterogeneity of only a handful of studies, data pooling could not be possible. As a result, a presentation of only one study design offers limited utility. In fact, case series on the use of SMT/MOB are available in the treatment of radiculopathy. In particular, there is a rapidly growing body of evidence for the use of LVLA mobilizations from the physiotherapy field. As well, an excellent case series by Murphy et al. examines the use of SMT for cervical radiculopathy, not to mention the work of Stern et al and Christensen et al. for lumbosacral radiculopathy (8-10).

While this study did offer an excellent description of the inclusion/exclusion criteria, they did not specify that radiculopathy cases would have to be confirmed (via special imaging, nerve conduction tests or clinical examination) and they did not stipulate that studies required peer-review. These are significant limitations given the purpose of the paper.

Another limitation of this review lies in its description of outcome measures evaluated in the included studies. The authors stated that they would only be evaluating patient reported outcome measures, such as pain. However, in the case of Howe et al., results reported range of motion evaluations only. Yet, this study was still included.

This paper is nonetheless still valuable to clinicians as it once again relays the scarcity of research in this area. Clinicians should consider this flaw to our evidence-base when addressing patients with suspected radiculopathy or when dealing with interprofessional relations. Knowing the limitations of your own field and still being able to provide a plausible rationale for care demonstrates great clinical strength and still translates to evidence-informed care.

Additional References:

  1. Casey E. Natural History of Radiculopathy. Phys Med Rehabil Clin N Am 2011; 11:1-5.
  2. Shekelle PG. Spinal Manipulation. Spine 1994; 19:858-61.
  3. Howe et al. Manipulation of the cervical spine-a pilot study. J R Coll Gen Pract 1983; 33:574-9.
  4. Allison et al. A randomized clinical trial of manual therapy for cervico-brachial pain syndrome-a pilot study. Man Ther 2002; 7:95-102.
  5. Walker et al. The effectiveness of manual physical therapy and exercise for mechanical neck pain: a randomized clinical trial. Spine 2008; 33:2371-8.
  6. Shin et al. Comparison between the effects of Chuna manipulation therapy and cervical traction treatment on pain in patients with herniated cervical disc: a randomized clinical pilot trial. Am J Chin Med 2006; 34:923-5.
  7. Moretti et al. Manipulative therapy in the treatment of benign cervicobrachialgia or mechanical origin. Chir Organ Mov 2004; 89:81-6.
  8. Murphy et al. A nonsurgical approach to the management of patients with cervical radiculopathy: a prospective observational cohort study. J Manipulative Physiol Ther 2006; 29: 279-287.
  9. Stern et al. A series of consecutive cases of low back pain with radiating leg pain treated by chiropractors. J Manipulative Physiol Ther 1995; 18:335-42.
  10. Christensen et al. Chiropractic outcomes managing radiculopathy in a hospital setting: a retrospective review of 162 patients. J Chiro Med 2008; 7: 115-25.
  11. Derby R et al. Non-surgical interventional treatment of cervical and thoracic radiculopathies. Pain Physician 2004; 7: 389-394.
  12. Freedman MK et al. Interventions in chronic pain management: 2. Diagnosis of cervical and thoracic pain syndromes. Arch Phys Med Rehabil 2008; 89(suppl 1): S41-S46.