What does Peul et al suggest?

Sciatica: Background Sciatica 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:

Sciatica: Pathophysiology Several etiologies proposed: (1) Inflammatory (1) Phospholipase A 2 (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 sciatica 61% at 4 yr follow-up 54% of those undergoing discectomy

Peul et al, 2007, New England Journal of Medicine

Background No 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: Eligibility Multicenter, prospective, randomized trial Inclusion 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 approach Annular fenestration with curettage and removal of disk material No attempt to perform a subtotal diskectomy Home rehabilitation supervised by physiotherapists using standardized protocol

Methods: Conservative GP 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: Surveys Roland 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 recovery Secondary outcomes: recorded at 8, 26, and 52 weeks Secondary outcome visits: (1) neuro exam (2) independent research nurse made (a) functional (b) economic observations SF-36 Sciatica Frequency and Bothersomeness Index (Grovle et al, 2008)

Methods: Surveys Cont’d Prolo functional observational assessment Prolo economic observational assessment McGill affective score

Methods: Stats Primary 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 12 Hazard 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)

Discussion Microdiskectomy technique Subgroups: sciatica when sitting Adequate reflection of productivity costs and quality of life missing for the “conservative” group Objective information on the course of symptoms Limited 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

Critique Blinding and the Placebo Effect? Patients Independent 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 Directions Health reform and rationing Epidural injections for sciatica? Does type of surgery (e.g. MIS) influence the outcome?

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