Timing and minimal access surgery for sciatica: a summary of two randomized trials

BackgroundSciatica, better defined as sciatic neuralgia or lumbosa-cral radicular syndrome (LSRS), is a frequently diag-nosed debilitating spine disorder with an estimated yearlyincidence of 5–10 per 1,000 persons [22]. The societalimpact of low back-related disorders is quite high, as theyremain the number one cause of work disability in mostWestern countries. Sciatica manifests itself as radiatingdermatome pain regularly accompanied by diminished jerkreflexes, sensory and motor deficits. The most commoncause is a herniated lumbar disc, sometimes combinedwith bony involvement, compressing an exiting nerveroot. Less often the radicular pain is caused by a diabeticneuritis, poly-radiculoneuropathy, or tumor. Althoughlumbar disc surgery is frequently performed, the timingof this intervention and the preferred technique were untilrecently important points for debate. The performednumbers of low-back surgeries vary widely between andeven within countries and the used intervention techniquesdo seem to be based on personal or societal preferencesinstead of evidence-based medicine [10]. Currently,scientific study results have been added to medicalknowledge making rational approaches for optimal spinecare possible.DiagnosisUntil recently, classical neurological signs of LSRS wereused as a so-called accurate diagnostic tool and decision aidto refer patients for radiological confirmation of a pre-testhigh probability of nerve root compression by a herniateddisc fragment. Subsequently, a surgical indication wasroutinely made by using the same neurological signs andsymptoms as well as the correlating radiological morphol-ogy as used for diagnosis. Although it is very plausible toexpect that a good fitting history of dermatomal radiatingleg pain with provocation by the straight leg raising test andconcomitant neurological signs will result in excellentresults by surgery, scientific data are still lacking. Patientswith absent provocation by the straight leg raising testmight risk negative advice for subsequent neurosurgicalcounseling, while, vice versa, positive provocation testssometimes lead to unrealistically high expectations ofsurgical outcome. Late in the 20th century, the bed resttrial showed evidence that the diagnostic value of classicalneurological signs is not as accurate as was assumedbeforehand [18]. The most important diagnostic variablewas the dermatomal area of radiating pain. Moreover, inthis landmark study, even in patients with a clear-cutradicular syndrome confirmed by a neurologist, a herniateddisc could not be confirmed by experienced neuroradiolo-gists in one-third of the cases. This well-performed studyraised serious doubts with regard to the diagnostic value ofour neurologically trained methods of examination andclinical textbooks. Surgical studies confirmed the lack ofconsensus with regard to the exact description anddiagnosis of the LSRS caused by a herniated disc. Besidesthe diagnostic inaccuracy, classical signs fail to discriminatebetween patients that will be cured by nature compared tothose that might benefit by surgery. The presumed