Herniated lumbar disc: injection interventions for sciatica
Lumbar disc herniation is a relatively common, painful, and disabling condition, but has a reasonably good outcome with expedient treatment. Most patients with severe symptoms, needing additional care than provided by their general practitioner, will improve on medication and with physiotherapy input. Patients with sciatica that is initially severe or persistent in the absence of neurological deficit may be good candidates for injection treatments. A small number of patients with persistent nerve root pain beyond 3 months from onset, progressive neurological deficit, or cauda equina syndrome are candidates for surgery.
Focus of the review
There is a reasonable evidence base surrounding the use of medication and also about the specific role of surgery in this condition. Injections have been in widespread clinical practice for many years, and yet there has been a general recognition that the evidence base does not support their clinical use, although there is evidence that injections may offer effective pain relief from sciatica in the short term. This is one area of medicine where the pragmatic clinical approach needs to be supported by relevant clinical evidence.
Comments on evidence
As in many areas of spinal practice, lack of high-quality clinical trials makes evidence-based clinical practice difficult. Many relevant trials have heterogeneous entry criteria and outcome measures. External validity may at times be a problem. Pragmatically, injection treatments are used to treat severe leg pain due to lumbar spinal nerve root involvement, especially when symptoms do not improve in the first 2 months and despite primary care treatments in the form of medication and physiotherapy. The primary outcome measures should be early relief of leg pain and improvement in function. This should be compared with other conservative interventions used in such presentations, and there should be long-term follow-up.
Search and appraisal summary
The update literature search for this overview was carried out from the date of the last search, June 2010, to May 2014. A back search from 1966 was performed for the new options added to the scope at this update. For more information on the electronic databases searched and criteria applied during assessment of studies for potential relevance to the overview, please see the Methods section. Searching of electronic databases retrieved 320 studies. After deduplication and removal of conference abstracts, 240 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 171 studies and the further review of 69 full publications. Of the 69 full articles evaluated, four systematic reviews and one RCT were added at this update.
Substantive changes at this update
Epidural corticosteroid injection (with or without local anaesthetic) One new systematic review added. Categorisation unchanged (unknown effectiveness).
Epidural injection with local anaesthetic alone New option. No evidence found. Categorised as 'unknown effectiveness'.
Nerve root block with local anaesthetic alone New option. One RCT found. Categorised as 'unknown effectiveness'.
INTRODUCTION: Herniated lumbar disc is a displacement of disc material (nucleus pulposus or annulus fibrosus) beyond the intervertebral disc space. The highest prevalence is among people aged 30 to 50 years, with a male to female ratio of 2:1. METHODS AND OUTCOMES: We conducted a systematic overview, aiming to answer the following clinical question: What are the effects of injection interventions for clinical symptoms of sciatica relating to confirmed or suspected herniated lumbar disc? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2014 (BMJ Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview). RESULTS: At this update, searching of electronic databases retrieved 320 studies. After deduplication and removal of conference abstracts, 240 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 171 studies and the further review of 69 full publications. Of the 69 full articles evaluated, four systematic reviews and one RCT were added at this update. We performed a GRADE evaluation for 13 PICO combinations. CONCLUSIONS: In this systematic overview, we categorised the efficacy for four interventions based on information about the effectiveness and safety of epidural corticosteroid injection (with or without local anaesthetic), epidural injection with local anaesthetic alone, nerve root block with corticosteroid injection (with or without local anaesthetic), and nerve root block with local anaesthetic injection alone.