Research Review by Dr. Shawn Thistle©

Date:

Nov. 2006

Study Title:

Surgical vs. nonoperative treatment for lumbar disk herniation: The Spine Patient Outcomes Research Trial (SPORT): A randomized trial

Authors:

Weinstein JN et al.

Publication Information:

JAMA 2006; 296: 2441-2450.

Summary:

Lumbar discectomy is a common surgical procedure used to treat herniated lumbar discs. It most commonly involves physical removal of herniated disc material, and sometimes part of, or the entire involved disc. The vast majority of these procedures are elective, and it has been demonstrated in previous studies that a distinct regional variance is evident in its use - up to a 15-fold difference in different parts of the United States. This, in addition to lower international rates has raised concern regarding the frequency and appropriateness of these procedures.

Low back pain with radiating leg pain is very common. As we all know, the decision to proceed with surgery should follow a course of conservative nonoperative care (in the absence of explicit surgical indicators such as cauda equina syndrome or rapidly progressive neurological deficit). Guidelines and systematic reviews are variable in their recommendations for conservative therapy options - no consensus currently exists in the literature.

Recently the success rate of lumbar discectomy (and low back surgery in general) has been called into question, and is currently the focus of a large research effort. The recent recognition of a clinical entity known as "failed back surgery syndrome" underlines this concern.

This is one of the larger studies on this topic that garnered much attention in print and television media. The Spine Patient Outcomes Research Trial (SPORT) began in March 2000, and aimed to compare the outcomes of surgical versus non-surgical treatment for lumbar intervertebral disc herniation, spinal stenosis, and degenerative spondylolisthesis. The trial is published as two separate papers, this one a randomized cohort and the other an observational cohort. SPORT was conducted at 13 multidisciplinary clinics in 11 US states.

Patients were considered for inclusion in this study if they met the following criteria:
  • age > 18 years
  • diagnosis by treating physician of intervertebral disc herniation and persistent symptoms despite nonoperative treatment for at least 6 weeks
  • radicular pain (below the knee for lower lumbar herniations and anterior thigh for higher lumbar herniations)
  • positive SLR at 30-70° or positive femoral tension sign or corresponding neurological deficit
Exclusion criteria for this study included:
  • prior lumbar surgery
  • cauda equine syndrome
  • scoliosis > 15°
  • segemental instability (defined as > 10° angular motion or > 4mm translation on imaging)
  • vertebral fractures, infections, tumours
  • inflammatory spondyloarthropathy
  • pregnancy
501 patients who agreed to randomization were randomized to either a standard surgery group (open discectomy) or a nonoperative group. The nonoperative group received "usual care". The study protocol suggested that "usual care" consist of active physical therapy, education/counseling, home exercise instruction, and NSAIDs (if tolerated). Nonoperative treatment was not standardized beyond these suggestions, and treatment protocols were allowed to be individualized based on the patient.

The primary outcome measures used in this trial were the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) bodily pain and physical function scales, the American Orthopaedic Surgeons MODEMS version of the Oswestry Disability Index (ODI). Outcomes were assessed at baseline, 6 weeks, 3 months, 6 months, and 1 and 2 years from enrollment.

Secondary outcomes included patient-reported self-improvement, work status, and satisfaction with current symptoms and with care.

Pertinent Results:

  • the study population had an mean age of 42, with the majority being male, white, employed, and having at least some college education
  • a variety of nonoperative treatments were used in the study including: education/counseling (93% of patients), anti-inflammatory medicine (61%), opiate medication (46%), epidural injections (> 50%), activity restriction (29%), and nondescript physical therapy (44%)
  • both treatment groups showed improvements at the follow-up times, with a small advantage showing for surgery (not statistically significant)
  • non-adherence and cross-over was prevalent in both groups - by the two year point 45% of those in the nonoperative care group had undergone surgery, and only 60% of those randomized to the surgery group actually had surgery - this alters the validity of the intent-to-treat analysis that was performed.

Conclusions & Practical Application:

This study showed that patients in both groups improved during the 2 year study period. Between group differences in improvements showed a small, but non-statistically significant advantage for surgery.

The authors conclude that based on the large amount of non-adherence and treatment group cross-over affecting both groups limits the conclusions that can be made about the treatments in this study.

I thought it was interesting that the nonoperative treatments (at least from a physical therapy/exercise perspective) were so poorly described. As it turned out, most patients in that group were given medications (even opiates) and over 50% had epidural injections! "Conservative care" can sometimes take on different meanings when read in the context of a surgical study!

I think this study could have been improved if a standardized physical therapy and exercise protocol had been employed in the usual care group. It seems the high prevalence of a variety of drugs in the usual care group may confound the results as well.

The only take-home message from this study is that both nonoperative and surgical treatments provide beneficial outcomes for patients with herniated lumbar discs. Which form of treatment is superior is yet to be determined. Surgery carries obvious risks that nonoperative care does not.

We should all be judicious in suggesting surgery as an option and be mindful of the existing evidence in discussing this issue with our patients.