Research Review By Gary J. Maguire©

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Date Posted:

March 2011

Study Title:

Conservative Management of Lumbar Disc Herniation With Associated Radiculopathy

Authors:

A J Hahne et al.

Author's Affiliations:

Musculoskeletal Research Centre, School of Physiotherapy, La Trobe University, Bundoora, Australia.

Publication Information:

Spine 2010; 35(11): E488-E504.

Background Information:

Radiculopathy in the lumbosacral spine results from the compression of one or more spinal nerve roots and is characterized by radiating leg pain, paraesthesia and clinical signs of neurologic impairment. Lumbar disc herniation is the most common cause of radiculopathy, defined as the localized displacement of disc material beyond the margins of the intervertebral disc space.

While surgical and injection therapies can be useful options for people with lumbar disc herniation with associated radiculopathy (LDHR), the high costs and potential risks associated with these interventions may explain why conservative management remains the preferred initial treatment approach. While it is well accepted that conservative management is the first line approach, the efficacy of many conservative treatments for LDHR remains unclear. Systematic reviews that have summarized the published evidence on conservative treatment for sciatica have continually failed to identify any treatments that are consistently efficacious. One potential reason for this failure relates to clinical heterogeneity among included trials and their respective participants. In particular, the authors mention that none of the systematic reviews to date have required imaging to confirm the cause of the participant’s symptoms.

This may have resulted in the inclusion of some trials where subjects were included with conditions other than LDHR (e.g. spinal stenosis or spondylolisthesis). Due to the less favorable outcomes for some conditions other than LDHR it may be plausible that the inclusion of subjects with these different pathologies may have diluted the obtained treatment effects in both the systematic reviews and the original trials.

Typically, a diagnosis of LDHR is confirmed with computed tomography (CT) or magnetic resonance imaging (MRI). An advantage of these imaging methods is their ability to visualize structural disorders that may potentially be causing the symptoms and signs of radiculopathy. The reliability of CT and MRI for detecting a LDHR has been shown to be high (1). The focus of this study was to conduct a systematic review evaluating the efficacy of conservative treatments for people with clinical AND radiologic evidence of LDHR. A secondary aim was to determine any adverse effects reported in the randomized controlled trials (RCT) that were to be reviewed.

Pertinent Results:

A total of 19 articles reporting on 18 RCTs including 1671 subjects were included in this systematic review. Seventeen trials presented short-term follow up data, 8 listed intermediate follow-up data and 4 trials contained long-term follow-up data. The most common outcome measures utilized were the visual analogue scale and the Oswestry functional outcome scale.

Results for Individual Treatment Options:
  • Advice: Two high-quality trials compared advice with microdiscectomy surgery in patients with LDHR. The pooled standardized mean difference (SMD) values for intermediate and long-term back pain intensity were found to have no statistically significant difference between groups at later follow-up intervals. Leg pain intensity was evaluated with significant effects in favor of surgery over advice. The long-term outcomes revealed no statistically significant difference between groups. When function was evaluated there was a statistically significant effect favoring surgery compared with advice at short-term follow-up. Intermediate and long-term outcomes revealed no statistically significant differences between surgery and advice. When measuring global recovery, there was statistical evidence obtained at short-term follow-up, indicating that patients receiving advice were significantly less likely than the surgical group to achieve a full or almost full recovery at short-term follow up. The difference between groups on global recovery was not maintained at intermediate and long-term follow-ups. When looking at overall global outcomes at 12 month follow-ups, one study found 83% in the advice group, and 86% in the surgery group describing their full or almost full recovery. Another study revealed full recovery of 18% of the advice group and 25% of the surgery group at 12 months. Review of follow-up data at 24 months failed at least 1 statistical test of heterogeneity for each outcome; instead, results were pooled (via a narrative analysis). This process provided strong evidence (2 high-quality trials, N = 316) that there is no difference between advice and microdiscectomy surgery for the long-term (24-month) outcomes of back pain-intensity, leg pain intensity, or function, in people with subacute LDHR.
  • Medication: Two studies investigated the use of oral diclofenac providing limited evidence that this medication is less effective than caudal epidural injection for reducing pain intensity at short and intermediate-term follow up. There also does not appear to be a difference between diclofenac and sarpogrelate.
  • Traction: Although 9 trials included traction, only 7 studies could determine the effect of traction so these were included in this review. A low-quality trial provided limited evidence that there is no difference between manual autotraction and Nachev autotraction for short-term pain intensity and function in patients with chronic LDHR. One high-quality study cited moderate evidence indicating that there is no difference between mechanical traction and either ultrasound or laser for back pain intensity, leg pain intensity, or function at short- or intermediate-term follow-ups. Another high-quality study provided moderate evidence that the addition of mechanical traction to electrotherapy methods (ultrasound, hot packs, and diadynamic currents) and medication (ibuprofen, mephenoxalone, and paracetamol) reduces the risk of having sciatica at short-term follow-up, but provides no additional short-term benefit for pain intensity or risk of having low back pain. EDITOR’S NOTE: this evidence is does not seem to justify the large number of clinics who employ ONLY mechanical traction. These clinics often employ aggressive marketing tactics and require patients to commit to long-term, expensive treatment plans.
  • Stabilization Exercises: A high-quality study revealed supporting evidence that a stabilizing exercise program is more effective than not receiving any form of treatment for reducing pain intensity at short-term follow-up (4).
  • Physical Therapy: There appears to be limited evidence that physical therapy is less effective than epidural neuroplasty for the immediate and long-term outcomes of leg pain intensity, back pain intensity, and function, for people with chronic LDHR.
  • Spinal Manipulation: A high-quality trial provided moderate evidence that in patients with acute LDHR and an intact annulus, manipulation is more effective than simulated manipulation for the outcomes of back pain intensity (short and intermediate follow-up), leg pain intensity (4 week, 6 week, and intermediate follow-up), risk of becoming free of back pain (intermediate-term follow up), and risk of becoming free of leg pain (6 week and intermediate follow-ups) (2). The same study also provided moderate evidence that there is no difference between active and simulated manipulation for leg pain intensity (2-week follow-up), risk of becoming free of back pain (short-term follow-up), and risk of becoming free of leg pain (2-week and 4-week follow-ups). Another study (low-quality) supported manipulation being more effective than mechanical traction in terms of short-term global improvement ratings. EDITOR’S NOTE: In all trials on SMT, some form of soft tissue therapy was also applied.
  • Laser and Ultrasound: A high-quality trial (moderate evidence) supports that there is no difference between laser and mechanical traction, ultrasound and mechanical traction or any difference between laser and ultrasound, for back pain intensity, leg pain intensity, or function at short and intermediate-term follow-ups.
  • Corsets: A low quality study involving the use a herbal magnetic corset added to a treatment approach of traction, electrotherapy, and massage provided additional benefits (although limited supporting evidence) in short-term pain intensity and lumbar function compared with traction, electrotherapy and massage alone.
  • Multimodal Inpatient Program: One study (high-quality) investigated the effect of adding 3 epidural injections to a multimodal inpatient treatment program consisting of bed rest, hydrotherapy, electrotherapy, back school, massage, mobilization, and exercises. The outcome data indicated no significant differences between groups, on short or intermediate-term outcomes of pain, subjective rating of outcome or function. Both groups received the same multimodal treatment programs which unfortunately did not make it possible to determine the relative effectiveness of the conservative component (of the treatment) (3).
Noted Adverse Events:
No study included in this review described an intention or methodology for evaluating adverse events. This raises the possibility of under-reporting. Traction was the most common treatment associated with adverse events. More than 16 adverse events were associated with treatment involving traction and three trials reported at least 1 adverse event in the conservative treatment groups. Adverse events associated with surgery or injections were reported in four studies.

Clinical Application & Conclusions:

This was the first systematic review on this topic that required included studies to have imaging confirmed LDH. The authors conclude from the review of the selected studies that there is strong evidence that advice is less effective than microdiscectomy at short-term follow-up for people with subacute lumbar disc herniation with associated radiculopathy (LDHR).

They did mention that advice was not directly compared to other conservative methods of treatment so conclusions on this comparison cannot be made at this time. Patients with LDHR seem to benefit from stabilization exercises which are more effective than no treatment at short-term follow-up.

Manipulation appears to be more effective than sham manipulation at short and intermediate follow-ups for people with acute symptoms and an intact annulus. Treating LDHR patients with the addition of mechanical traction to medication and electrotherapy may provide some additional short-term benefit. The authors appropriately note that additional high-quality studies would have allowed for firmer conclusions regarding adverse effects and efficacy.

They also note that some studies demonstrated equal efficacy between treatments – in these cases there would be no ‘winner’ (so to speak) that could add to the overall treatment recommendations, but each treatment in these cases could be beneficial…this may be plausible in some cases because sample sizes were small in several trials included in this review.

We should therefore be cautious when interpreting evidence summaries in this review that conclude that there is no difference between 2 interventions, as an alternative explanation may be that significant effects were missed because of low statistical power in the original trials.

EDITOR’S NOTE: From a practical perspective, we must remember that each patient is different. We must discuss various treatment options with our patients and ensure that we ask them about previous experiences with treatment. Find a method of relieving pain, activate your patient, advise and encourage them.

Study Methods:

Ten computer databases were searched for studies (1971 to 2008) focusing on patients with referred leg syndromes and radiologic confirmation of a lumbar disc herniation. The criteria for inclusion consisted of:
  • Study participants being at least 18 years of age, with referred leg symptoms with or without back pain
  • At least 75% of study participants having LDH confirmed by MRI or CT (those studies using only myelography were excluded)
  • No more than 25% of study participants having previous surgery or symptoms due to other conditions such as stenosis
  • At least one group receiving a conservative/non-injection treatment (something that did not penetrate deeper tissue – however acupuncture was considered a conservative treatment)
The authors chose to use the levels of evidence approach in the review instead of switching to the newly recommended GRADE approach. This was due to the fact that their review process had already been conducted when this recommendation occurred. Each study was evaluated using the PEDro scale - a score of 6 or more out of 10 was used to represent high quality (based on criteria used in previous reviews).

Study Strengths / Weaknesses:

While the authors attempted to focus on participants with a specific pathology, they were unable to control all potential sources of variability among participants. The minimum criteria of leg pain with LDH on CT or MRI still creates latitude for potential variation in diagnostic subgroups. Some studies may have used herniation or protrusion terms differently which the review used a specific radiologic definition of LDH. The main limitation of most studies included in this review was a lack of blinding, but as we know blinding of patients in manual therapy trials is often not possible.

From a clinical perspective, two notable treatment options not included in this review were acupuncture and positional therapy (flexion, extension, McKenzie/MDT etc.) – both could arguably be beneficial for some patients so hopefully future research will further investigate this possibility.

Additional References:

  1. Herzog RJ. The radiologic assessment for a lumbar disc herniation. Spine 1996; 21: 19S-38S.
  2. Santilli V et al. Chiropractic manipulation in the treatment of acute back pain and sciatica with disc protrusion: a randomized double-blind clinical trial of active and simulated spinal manipulation. Spine J 2006; 6: 131-137.
  3. Buchner M et al. Epidural corticosteroid injection in the conservative management of sciatica. Clin Orthop Relat Res 2000; 375: 149-156.
  4. Bakhtiary AH, Safavi-Farokhi Z, Rezasoltani A. Lumbar stabilizing exercises improve activities of daily living in patients with lumbar disc herniation. J Back Musculoskeletal Rehabil 2005;18:55–60.