Research Review by Dr. Shawn Thistle©

Date:

June 2007

Study Title:

Surgery versus prolonged conservative treatment for sciatica

Authors:

Peul WC et al.

Publication Information:

New England Journal of Medicine 2007; 356(22): 2245-2256.

Summary:

Sciatica is a term commonly misused by patients and therapists of all disciplines. Typically, the term has been used to refer to radiating pain in any area of the lower limb supplied by one or more nerve roots of the lumbar or sacral plexus. In order to represent true "sciatica" however, the radiculopathy must involve the sciatic nerve (which contains nerve fibres originating from L4-S3).

Unfortunately, many patients and clinicians will use the term for any pain experienced in the gluteal region or in the leg, which can wrongfully exclude other differential diagnoses for pain in these areas such as myofascial conditions, hip pathology, sacroiliac joint problems etc. This can be misleading, particularly when patients consult the internet for information about their "sciatica".

The most common cause of true sciatica is a lumbar disc herniation (LDH), which causes an inflammatory reaction around the nerve root(s), resulting in symptoms of radiculopathy. This is a common condition, with the annual incidence estimated to be 5 cases per 1000 people. Despite the often severe clinical symptoms, the natural history of sciatica secondary to a LDH is favourable.

Even without surgery, sciatica improves in 75% of patients within 8-12 weeks of onset, and most herniations seen on imaging will shrink over time.

Surgical intervention is often considered a last resort for patients with sciatica. Despite this assertion, the rate of spine surgery has steadily increased in recent years, even after adjusting the data for the aging population. Spinal fusion surgery represents a $16 000 000 000 (that's BILLION) industry, with over 300 000 surgeries performed per year in the United States alone (NOTE: this doesn't even include outpatient discectomies, which are becoming very common).

When surgery is utilized in well-defined cases, it can be a successful intervention for sciatica, but should be considered only if symptoms persist after a trial period of conservative care, or if progressive neurological deficit occurs (such as cauda equina syndrome). The timing of surgical intervention represents a difficult and important decision in many manual medicine practices. One of the problems in making an evidence-based decision is that a consensus does not exist on how long conservative therapy should be attempted, and what techniques or treatments are most efficacious for the condition.

This study, a multi-centre, prospective, randomized trial involving patients with severe sciatica for 6-12 weeks, investigated whether a strategy of early surgery resulted in better outcomes at one year when compared to a continued period of conservative treatment for 6 months (followed by surgery for patients who have not improved).

In order to be eligible for this study, patients had to be 18-65 years of age, have a disc herniation confirmed on advanced imaging, and have a diagnosis of incapacitating lumbosacral radicular syndrome for 6-12 weeks after assessment by a neurologist.

Exclusion criteria included:
  • cauda equina syndrome
  • prior spinal surgery
  • muscle paralysis, or insufficient strength to move against gravity
  • previous episode of similar symptoms within the previous 12 months
  • bony stenosis
  • spondylolisthesis
  • pregnancy
  • presence of other severe disease
283 eligible patients were randomized to one of two groups:
  1. Early Surgery (n=141) - patients were scheduled for surgery within 2 weeks of study inception (median time 1.9 weeks), with the goal of decompressing the involved nerve root and removing the herniated portion of the disc. Usual care was provided to the patients as per the protocols of the individual surgical departments.
  2. Prolonged Conservative Care (n=142) - patients were given advice by their general practitioner about the favourable prognosis for their condition, and were directed to visit the trial's website, which contained information about the natural history of the condition, and the expectation for complete recovery regardless of the initial severity of their symptoms. If necessary, prescription pain medication was administered according to existing clinical guidelines. Further, patients who were fearful of moving were referred to a physiotherapist. If symptoms persisted for 6 months after randomization, patients underwent surgery.
Patients were assessed with a variety of outcome measures throughout the one year study period at 2, 4, 8, 12, 26, 38, and 52 weeks. Primary outcome measures included the Roland-Morris Disability Questionnaire for sciatica, the 100-mm Visual Analogue Scale for leg pain, and a 7-point Likert Scale self-rating of global perceived improvement. Secondary outcomes measured at 8, 26, and 52 weeks included a repeated neurological examination, functional and economic observational assessments by a research nurse, the Medical Outcomes Study SF-36 Scale, the Sciatica Frequency and Bothersomeness Index, and 100-mm Visual Analogue Scale for health perception. Recovery was defined as complete or near complete resolution of symptoms as measured on the 7-point Likert Scale.

Pertinent results of this study include:
  • no significant differences were present at baseline between the two study groups
  • 16 of the 141 subjects in the surgical group recovered before their surgery, while 3.2% of those operated on required a second surgery during the study period due to recurrent sciatica
  • in the conservative care group, 55 patients underwent surgery during the study period due to lack of symptom resolution
  • after surgery, leg and back pain diminished quickly, whereas a slower, linear recovery was noted in the conservative group
  • differences in outcomes favoured the surgical group initially, with patients recovering twice as fast as those in the conservative group - the greatest difference occurred between 8-12 weeks (remember, patients did not undergo surgery until week 2 or 3, so keep surgical recovery time in mind)
  • however, at one year, there were no significant differences in outcomes between the two groups, including leg pain
  • patients in the conservative group who underwent surgery had similar improvements to other subjects at one year
  • in both groups, the probability of perceived recovery at one year was 95%

Conclusions & Practical Application:

The results of this study indicate that patients with sciatica experience similar outcomes at one year whether they undergo surgery or pursue conservative therapy. These results are in agreement with previous studies, including the recently published SPORT (Spine Patient Outcomes Research Trials) studies (see previous Reviews in the RRS database). Both the SPORT studies and this study had significant cross-over in the study groups, which did not affect the consistency of the results.

There are some drawbacks to this study that warrant discussion, some of which should be obvious to a manual medicine practitioner:
  • The conservative care utilized in this study did not necessarily reflect usual practice. This group received an extremely minimal intervention, and many likely received no manual therapy at all. No description of any intervention provided by a physiotherapist was provided, nor was the number of patients that were referred for physiotherapy.
  • blinding of subjects was impossible
  • time to recovery was determined by examinations at predetermined intervals, which may have underestimated rate of recovery in both groups
  • 'usual care' at the hospitals was not defined, and may have included some type of rehabilitation therapy
  • no analysis was performed to determine patient satisfaction with surgery or conservative care, which would have strengthened this study
The state of the literature regarding surgical intervention for sciatica is becoming more complete. Overall, surgery is very effective for this condition, with most patients experiencing rapid pain relief. This should be weighed against the risks of surgery, as well as functional status, job demands, financial outcomes etc. when making the decision. Manual therapists should inform their patients of the potential for faster symptom resolution with surgery, while emphasizing that outcomes are similar in the longer-term (~ 1 year). The patient must then weigh their options and make a decision with their healthcare team.

Further studies are still required to investigate manual therapy interventions (manipulation, soft tissue therapy, rehabilitation, acupuncture etc.) for sciatica to determine which are most effective. Once manual therapy has been given a fair chance in well designed trials, a more realistic comparison between surgical and 'conservative' care can be performed.