What does Peul et al suggest?

Sciatica: BackgroundSciatica is relatively common; lifetime

incidence is 13% to 40% (Frymoyer, 1992)Annual incidence of an episode of sciatica is

1% to 5% (Frymoyer, 1988)Ancient Greeks used the term sciatica to

describe pains or “ischias” (Stafford et al, 2007)Initially known as Cotugno’s Disease after the

anatomist who wrote the first book on the condition in the 1700’s (Delaney, 1980)

Sciatica: Epidemiology

Source: Stafford et al, 2007

Source: www.google.com/health

Sciatica: PathophysiologySeveral etiologies proposed:

(1) Inflammatory (1) Phospholipase A2 (Saal et al, 1990; Franson et al,

1992)(2) TNF-α (Karppinen et al, 2003)

(2) Immune-mediated(3) Mechanical

Sciatica: Inflammatory?

Stafford et al, 2007

Sciatica: Immune-mediated?Raised antibody levels to glycosphingolipids

were detected in (Brisby et al, 2002): 71% of patients with acute sciatica61% at 4 yr follow-up54% of those undergoing discectomy

Peul et al, 2007, New England Journal of Medicine

BackgroundNo consensus on how long non-surgical

(“conservative”) therapy should be tried prior to surgery (Luijsterburg et al, 2004)

Authors suggest “sociocultural preferences” account for differences

Dutch guidelines: after 6 weeks of conservative treatment, offer surgery

In the US, largely practitioner dependent in terms of referral to physical therapy vs. referral to surgery

US vs. Switzerland expert panels differ little (Vader et al, 2000)

Methods: EligibilityMulticenter, prospective, randomized trialInclusion Criteria: (1) 18 to 65 years (2)

radiologically confirmed disc herniation (3) sciatica lasting 6-12 weeks

Exclusion Criteria: (1) Cauda equina (2) Muscle paralysis (3) Absent movement against gravity (4) Similar sciatica episode within 12 months (5) Previous spine surgery (6) Bony stenosis (7) Spondylolisthesis (8) Pregnancy (9) Severe co-existing disease

Randomization via computer-generated block scheme

Methods: Treatment General or spinal anesthesia Minimal, unilateral transflaval approachAnnular fenestration with curettage and

removal of disk material No attempt to perform a subtotal diskectomy Home rehabilitation supervised by

physiotherapists using standardized protocol

Methods: ConservativeGP informed patients of favorable prognosis and

encouraged them to visit website with more information

Pain medication was adjusted according to previous study protocol (Peul et al, 2005)

Patients fearful of moving were referred to physiotherapists

Microdiskectomy was offered to patients with sciatica persisting for 6 months

Patients with (1) increasing leg pain non-responsive to pain meds (2) progressive neurologic deficits were offered surgery earlier than 6 months

Methods: SurveysRoland Disability Questionnaire for Sciatica (Ostelo et

al, 2003)Visual Analogue Scale for Leg Pain (Capodaglio, 2001)Likert Self-Rating (Dawes, 2008)Primary outcomes: (1) Functional disability (2)

Intensity of leg pain (3) Global perceived recoverySecondary outcomes: recorded at 8, 26, and 52 weeksSecondary outcome visits: (1) neuro exam (2)

independent research nurse made (a) functional (b) economic observations

SF-36Sciatica Frequency and Bothersomeness Index (Grovle

et al, 2008)

Methods: Surveys Cont’dProlo functional observational assessmentProlo economic observational assessmentMcGill affective score

Methods: StatsPrimary aims:

Disease specific disability with respect to daily functioning (Roland and VAS)

Median time to recovery (Likert scale as a function of time)

Power of .9 with two-tailed significance at .05 level to detect at least a 3 point difference on Roland

SPSS version 12Hazard ratio to compute speed of recovery

Hazard Ratio “A hazard ratio of 2 means that treatment

will cause the patient to heal faster, but in a very specific sense. In the context of hazard ratio, “fast” means that a treated patient who has not yet healed by a certain time has twice the chance of being healed at the next point in time compared to someone in the control group” (Spruance et al, 2004)

DiscussionMicrodiskectomy techniqueSubgroups: sciatica when sittingAdequate reflection of productivity costs and

quality of life missing for the “conservative” groupObjective information on the course of symptomsLimited generalizability:

(1) Nurses guided pain management in conservative group

(2) Lack of blinding of patient and practitioner(3) Sampling timepoints may have underestimated time

to recovery

CritiqueBlinding and the Placebo Effect?

PatientsIndependent research nurse

Scale to analyze “median time to recovery”Limited generalizability (Netherlands vs. US)Intention to treat (Hollis et al, 1999)Hazard ratio (Spruance et al, 2004)Physiologic mechanisms behind sciatica

Implications and Future DirectionsHealth reform and rationingEpidural injections for sciatica?Does type of surgery (e.g. MIS) influence the

outcome?

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2001 Jun;11(2):69-74Grøvle L, Haugen AJ, Keller A, Natvig B, Brox JI, Grotle M. Reliability, validity, and responsiveness of the Norwegian versions of the Maine-Seattle Back Questionnaire and the Sciatica Bothersomeness and Frequency Indices. Spine (Phila Pa 1976). 2008 Oct 1;33(21):2347-53.

Spruance, Spotswood L., Reid, Julia E., Grace, Michael, Samore, Matthew Hazard Ratio in Clinical Trials Antimicrob. Agents Chemother. 2004 48: 2787-2792

Hollis S, Campbell F. What is meant by intention to treat analysis? Survey of published randomised controlled trials. BMJ. 1999 Sep 11;319(7211):670-4.