Surgical versus non

Objective To investigate the effectiveness and safety of surgery compared with non-surgical treatment for sciatica.

Design Systematic review and meta-analysis.

Data sources Medline, Embase, CINAHL, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and the World Health Organisation International Clinical Trials Registry Platform from database inception to June 2022.

Eligibility criteria for selecting studies Randomised controlled trials comparing any surgical treatment with non-surgical treatment, epidural steroid injections, or placebo or sham surgery, in people with sciatica of any duration due to lumbar disc herniation (diagnosed by radiological imaging).

Data extraction and synthesis Two independent reviewers extracted data. Leg pain and disability were the primary outcomes. Adverse events, back pain, quality of life, and satisfaction with treatment were the secondary outcomes. Pain and disability scores were converted to a scale of 0 (no pain or disability) to 100 (worst pain or disability). Data were pooled using a random effects model. Risk of bias was assessed with the Cochrane Collaboration’s tool and certainty of evidence with the grading of recommendations assessment, development, and evaluation (GRADE) framework. Follow-up times were into immediate term (≤six weeks), short term (>six weeks and ≤three months), medium term (>three and six weeks and ≤three months), medium term (>three and 25% of participants in this comparison were from studies at high risk of bias (supplemental file 3), inconsistency (substantial unexplained interstudy heterogeneity, I2 >50), imprecision (95% confidence interval were 20 points different to the point estimates), and, and small study effects (>25% of participants were from small studies (3 months), approach of discectomy (micro or open). We also did post hoc subgroup analyses to explore the influence of analgesics in the comparator group (yes or no), small study effects (Fig 1

Study flow diagram. ICTRP=International Clinical Trials Registry Platform

Characteristics of included trials comparing surgery to non-surgical treatment for sciatica. Data are number (percentage), unless otherwise given

Characteristics of included trials comparing surgery to non-surgical treatment for sciatica. Data are number (percentage), unless otherwise given

The 24 trials investigated various surgical procedures: discectomy (n=12), chemonucleolysis with chymopapain (n=5), chemonucleolysis with condoliase (n=2), plasma disc decompression (n=4), and ozone ablation (n=1). The comparators were classified as non-surgical treatment (n=14), epidural steroid injections (n=4), and placebo or sham surgery (n=6).

Twenty one (88%) of 24 trials had at least one domain classified as high risk of bias (supplemental file 11). Eighteen trials did not mask the participants and trial staff and, therefore, were at high risk of performance and detection bias. Eight trials had high numbers lost to follow-up and were rated at high risk of attrition bias. We regarded the three industry sponsored trials also to be a high risk of bias because the independence of the investigators was not stated.

Twelve trials (n=1711 participants) investigated the effectiveness of discectomy compared with non-surgical treatment (10 trials) or epidural steroid injections (two trials).

Seven trials reported leg pain and disability outcomes for discectomy compared with non-surgical treatment. Very low to low certainty evidence showed that discectomy resulted in a moderate reduction in leg pain at the immediate term (mean difference −12.1 (95% confidence interval −23.6 to −0.5)) and short term (−11.7 (−18.6 to −4.7)), a small reduction at medium term (−6.5 (−11.0 to −2.1)), but negligible effect at long term (−2.3 (−4.5 to −0.2); table 3,fig 2, fig 3). For disability, discectomy only resulted in small effects at the immediate term (−7.1 (−10.7 to −3.6)), short term (−7.2 ( −11.7 to −2.7)), and medium term (−5.4 (−9.4 to −1.4)), but negligible effect at long term (−4.8 (−8.0 to −1.6); table 3 and fig 4, fig 5 ).

Summary of findings and certainty of evidence for leg pain, disability, and back pain (discectomy)

Mean differences (95% CI) for leg pain in trials assessing the effectiveness of discectomy versus non-surgical treatment. Pain intensity is expressed on a 0-100 scale. Studies are ordered by weight. SE=standard error; CI=confidence interval; IV=inverse variance

Mean differences (95% CI) for leg pain in trials assessing the effectiveness of discectomy versus non-surgical treatment. Pain intensity is expressed on a 0-100 scale. Studies are ordered by weight. SE=standard error; CI=confidence interval; IV=inverse variance

Mean differences (95% CI) for disability in trials assessing the effectiveness of discectomy versus non-surgical treatment. Disability is expressed on a 0-100 scale. Studies are ordered by weight. SE=standard error; CI=confidence interval; IV=inverse variance

Mean differences (95% CI) for disability in trials assessing the effectiveness of discectomy versus non-surgical treatment. Disability is expressed on a 0-100 scale. Studies are ordered by weight. SE=standard error; CI=confidence interval; IV=inverse variance

Five trials reported outcomes after 12 months.126343655 At 24 months, discectomy did not reduce leg pain (−1.1 (−3.6 to 1.4)) or disability (−1.5 (−4.3 to 1.3)) compared with non-surgical treatment. Similar findings were also observed at months 36, 48, 60, and 96 (fig 2, fig 3, fig 4, fig 5).

Five trials reported findings for back pain.3436475154 Compared with non-surgical treatment, evidence was of very low certainty that discectomy did not reduce back pain at the immediate term (medium difference −6.8 (95% confidence interval −15.3 to 1.6)) and long term (−7.0 (−15.4 to 1.5)), but did so at the short term (−11.0 (−19.6 to −2.5)) and medium term (−10.2 (−18.7 to −1.7); supplemental file 12).

Five trials1343637384144465155 reported outcomes for quality of life and four1263438445155 reported treatment satisfaction (not pooled due to heterogeneity). For quality of life, except for one trial at the short term follow-up,36 the included trials found no between group differences at all time points. Conflicting results were found for treatment satisfaction (supplemental file 8).

Two trials compared the effectiveness of discectomy with epidural steroid injections.3152 Very low to low certainty of evidence showed that discectomy reduced leg pain at all time points. The effect was large at immediate term (medium difference −27.0 (95% confidence interval −34.8 to −19.2)), moderate at short term (−15.1 (−23.5 to −6.7)) and medium term (−14.8 (−28.3 to −1.3)), and small at long term (−7.3 (−14.4 to −0.3)).

Compared with epidural steroid injections, discectomy provided moderate effects on disability at short term, but had no effects at medium and long term. For back pain, small effects were observed at short and medium term and no effect at long term (table 3 and supplemental file 13). No trials reported outcomes for quality of life and treatment satisfaction.

Three trials compared plasma disc decompression with non-surgical treatment.404248 Very low to low certainty evidence showed that plasma disc decompression reduced leg pain at the immediate and long term (moderate effects), but had no effect at short term (supplemental files 6, 14a); and reduced disability at immediate, short, and long term (moderate to large effects; supplemental files 7, 14b). Compared with epidural steroid injections, plasma disc decompression resulted in moderate to large effects on leg pain and disability at the immediate, short, and medium term (low certainty evidence; supplemental files 6, 7, and 15). Outcomes for quality of life and treatment satisfaction are presented in supplemental file 8.

Two trials compared chemonucleolysis using condoliase with placebo.505356 Low certainty evidence indicated moderate effects on leg pain at all time points, and small effects on disability at short and long term (supplemental file 16).

Five trials investigated the effectiveness or efficacy of chemonucleolysis with chymopapain compared with placebo (n=4) 2425275657 or manipulative therapy (n=1).30 Very low to low certainty evidence indicated (except for chemonucleolysis with chymopapain versus placebo at immediate term) that this treatment combination did not reduce leg pain, disability, and back pain in any time points specified (supplemental files 17 and 18). Other outcomes are presented in supplemental file 8.

Eight trials reported at least one safety outcome for discectomy.126313436373844465152 Low certainty evidence showed no between group differences in the risk of any adverse events between discectomy and non-surgical treatment (risk ratio 1.34 (95% confidence interval 0.91 to 1.98); supplemental file 19a). Compared with epidural steroid injections, discectomy had a slightly higher risk of any adverse event (1.76 (1.03 to 3.02); supplemental file 19b). Surgery related complications were reported by seven trials. Dural tears and wound complications were the most frequently reported adverse events (supplemental file 9). All cause mortality was rare and similar between discectomy and non-surgical groups (1.73 (0.19 to 15.36); supplemental files 9). No trials reported any surgery related deaths.

The risks of adverse events in plasma disc decompression and chemonucleolysis were also similar between the surgical and non-surgical groups. The results could not be pooled because of the low number of studies (supplemental file 9).

Detailed results for the subgroup and exploratory sensitivity analysis are presented in supplemental file 10. Discectomy had smaller effects on leg pain (mean difference −3.1 (95% confidence interval −5.7 to −0.4)) in trials that included analgesics in the comparators than did trials without analgesics (−21.4 (−30.3 to −12.4)) at the medium term. In small studies, discectomy had greater effects on disability (−10.1 (−13.9 to −6.3)) compared with larger studies (−4.4 (−7.7 to −1.0)). A post-hoc analysis indicated that in trials that did not specify unsuccessful non-surgical treatment as a prerequisite of entering the trial, discectomy had larger effects in reducing leg pain at immediate term (−19.3 (−30.4 to −8.2) v −1.2 (−5.5 to 3.1)) and improving disability at short term (−10.6 (−14.0 to −7.3) v −1.3 (−9.8 to 7.3)) than did trials that only included participants who had unsuccessful non-surgical treatment. Mean symptom duration at baseline (less or greater than three months), and the approach of discectomy (micro or open), did not influence treatment outcomes.

We found very low to low certainty evidence that discectomy, compared with non-surgical treatment, reduced leg pain and disability. The effect sizes of leg pain reduction declined from moderate at immediate and short term, to negligible effect over a year. The extent of the benefit on disability was smaller, with small effect sizes observed up to the medium term follow-up only. No benefits on pain or disability were noted at or after 12 months. Discectomy was also superior to epidural steroid injections, but the size of the effects also reduced over time from large at immediate term to small at long term. Data for disability was equivocal, because a moderate effect size was only observed at short term, but no other benefits were observed at any other time point. Evidence supported plasma disc decompression and chemonucleolysis with condoliase at some time points but was of low certainty.

We did not find an increased risk of adverse events when discectomy was compared with non-surgical treatment. But the reporting might have been inconsistent: the included trials had a high crossover rate between groups and were likely underpowered to detect adverse events. However, one example in a review of observational studies of discectomy complication rates (n=42 studies; >4000 participants)58 showed 12.5-13.3% people had an adverse event. Reoperation, recurrent disc complications, dural tear, nerve root injury, and wound complications were the most common adverse events in open or micro discectomy. These data provide further context and insights into the safety profile of discectomy for sciatica.

This review provides the most comprehensive synthesis of the evidence on surgical procedures for sciatica to date. Different from recent reviews,131516 we included trials of a homogeneous population, surgical procedure, comparator, studies published in English and other languages,2733394347 and new robust trials,5051525355 making this review the most comprehensive update on the evidence for the surgical management of sciatica.

This review has limitations. Although we included a larger number of trials compared with previous reviews,1315 the certainty of evidence ranged from low to very low. High crossover rates from the non-surgical arm to the surgical arm (ranged from 30% to 54%) occurred in many trials, which means the effects of surgery on clinical outcomes could have been underestimated, particularly in the later time points. As mentioned previously, the included trials are underpowered and inappropriately designed to effectively evaluate adverse event occurrence.

Reporting of non-surgical comparators was generally poor, with most trials not describing what types of treatments participants received, who provided these treatments, how they were provided, and how much treatment they received. For example, the SPORT trial reported the type of non-surgical treatment received by participants (physical therapy (73% of patients), epidural injections (50%), and medical treatments (eg, non-steroidal anti-inflammatory drugs; >50%) without specifying other details.1 Similarly Bailey and colleagues’ trial only reported that education, activity and exercise, oral analgesics, physiotherapy, and epidural glucocorticoid injection were used in the non-surgical group, without providing specific data on the proportion of patients receiving each of these non-surgical treatments.51 Furthermore, non-surgical treatments varied considerably within and between countries. For example, the use of epidural steroid injections varies widely among different US states, as do referrals to physiotherapy between Denmark and the Netherlands.5960 The two included Chinese trials used traditional Chinese medicine in the non-surgical group, which lacks evidence supporting its effectiveness.394761 In our review, we grouped all non-surgical interventions together, however, these interventions were not only poorly detailed but also highly heterogeneous. Therefore, questions remain as to whether non-surgical treatment provided in the control arms of many trials represents a suboptimal approach to treating sciatica, in addition to the ramifications that this uncertainty would have on its comparison to discectomy.62 However, evidence is scarce in supporting many non-surgical treatments for sciatica.6364

Other than radiographical evidence of disc herniation and corresponding signs or symptoms, the included studies varied in their method of identifying patients who would be considered for surgery. Differences were apparent in the requirement of unsuccessful non-surgical treatment,13141 having incapacitating sciatica,36 or having persistent (>four months) sciatica.51 Seven (58.3%) of 12 trials did not specify how they identified patients.26343947495254 Thus, the study populations might vary across included trials. Also, participants were not typical patients with sciatica from the community because they were assessed for eligibility by surgeons.13651

Compared with the most recent review, which only pooled data for disability within 24 months,15 our review provides results on leg pain, disability, back pain, and adverse events from the immediate term to five years after randomisation. Thus, unlike the equivocal benefits previously reported,13 we found that discectomy was initially beneficial but the effect declined over time, compared with either non-surgical care or epidural steroid injections. Generally, discectomy resulted in faster relief in pain and disability, but only up to 12 months. We also investigated the optimal timing of surgery for sciatica by conducting a subgroup analysis by symptom duration (less or greater than three months). Greater reductions in leg pain were reported in people with symptoms for less than three months at immediate and medium term, however, the differences were not significant. A post hoc exploratory subgroup analysis of unsuccessful non-surgical treatment suggests that trials without specifying the non-surgical treatment in the inclusion criteria reported higher effects in reducing leg pain (immediate term) and improving disability (short term) than did trials with unsuccessful non-surgical treatment.

We presented discectomy primarily because this surgical treatment is the most widely used for lumbar disc herniation.1 Nevertheless, the choice of surgical treatment by surgeon varies between countries.65 Thus, in our review, we presented results for a broader range of surgical procedures. Plasma disc decompression showed a moderate effect on leg pain and disability when compared with non-surgical treatment or epidural steroid injections. Similarly, chemonucleolysis with condoliase was shown to have moderate effects on leg pain and slight effects on disability.

International guidelines generally recommend surgical treatment for sciatica secondary to lumbar disc herniation if patients have not responded to comprehensive non-surgical treatment.678 These recommendations are because many people with acute sciatica will have improvements in their condition over time.3 Generally, our review supports these recommendations because non-surgical treatment was shown to be able to lead to similar outcomes at long term or even longer follow-ups. However, benefits could vary among different groups of people with sciatica. Attempts have been made to specify who might benefit more from early discectomy for people with sciatica.6667 People with more severe pain in their leg and disability were shown to be more likely to have persistent and debilitating symptoms at 12 months.67 Thus, this subgroup might benefit from early discectomy because our review has shown that surgical treatment might lead to faster leg pain reduction. Added to that is the evidence that early discectomy is cost effective compared with prolonged non-surgical treatment in the context of the Dutch health system.68 These findings challenge the notion that non-surgical treatment should always be the first line treatment for sciatica. In people with sciatica who regard rapid pain relief as an important treatment goal, and who feel that the benefits of discectomy outweigh the risks and costs, discectomy could be an early management option.

As a result of the treatment’s invasive nature and the substantial costs of surgery, we would encourage clinicians to discuss with their patients that discectomy can provide rapid relief of leg pain, but that non-surgical treatment can achieve similar results, although at a slower pace and with a potential chance of requiring delayed surgery if they do not respond to non-surgical treatment.

Although discectomy is widely used, the certainty of evidence supporting its use is only low to very low. All trials evaluating discectomy were not blinded and had high crossover rates. Evidence on plasma disc decompression and chemonucleolysis is limited by the low number of studies and small sample sizes. Large placebo controlled trials evaluating surgical treatment for sciatica have the potential to advance this field. However, the use of placebo controls in surgical trials has challenges.18 Furthermore, investigations into which group of people with sciatica are likely to benefit from early surgery is also key for clinicians to make individualised recommendations.

Very low to low certainty evidence suggests that discectomy was superior to non-surgical treatment or epidural steroid injections in reducing leg pain and disability in people with sciatica with a surgical indication, but the benefits over non-surgical care reduced over time. Discectomy might be an option for people who require rapid leg pain relief and disability improvement, when the benefits outweigh the risks and costs related to surgery.

Discectomy and other surgical procedures are widely used for the treatment of sciatica secondary to lumbar disc herniation

Guidelines recommend discectomy when non-surgical treatments are unsuccessful, and imaging features are consistent with sciatica

Evidence supporting surgical treatment for sciatica is uncertain; reviews have substantial limitations in literature coverage, population selection, and method

Very low to low certainty evidence suggests that discectomy was superior to non-surgical treatment or epidural steroid injections in reducing leg pain and disability in people with sciatica with a surgical indication, but benefits reduced over time

Discectomy might be considered an early management option in people who the benefits of early improvement in leg pain or disability outweigh the costs and potential risks

Discectomy might cause surgical related complications, but trials included in this review are likely underpowered to detect harms with low incidences (eg, wound infection, recurrent disc herniation, and persistent postsurgical pain)

Not required.

No additional data are available.

Contributors: All authors contributed to the review protocol. CL, GEF, CAS, and C-WCL designed the search strategy and selected studies. CL, GEF, and QC extracted the data. CL analysed the data. CL drafted the manuscript and GEF, CAS, and C-WCL contributed to the drafting of the review. IAH, CSB, WCP, and BK revised the manuscript critically for important intellectual content. All authors approved the final version of the article. All authors had access to all the data in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis. CL is guarantor. The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.

Funding: No specific funding was received for this research. CL reports receipt of a PhD scholarship from the National Health Medical Research Council (NHMRC) of Australia. GEF reports receipt of Australia’s NHMRC Investigator Grant (APP2009808). C-WCL is funded by an Australia’s NHMRC Investigator Grant (APP1193939).

Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/disclosure-of-interest and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years. CSB, WCP, and BK report being involved in trials included in the review,5136 and declare that they were not taking any part in assessing that trial in this review.

The lead author (CL) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; no important aspects of the study have been omitted.

Dissemination to participants and related patient and public communities: We plan to collaborate with the media office of the authors’ institutes to disseminate the findings. The strategy may include press releases, dissemination via media outlets and social media platforms, explainer articles for clinicians and patients, and presentations at professional conferences.

Provenance and peer review: Not commissioned; externally peer reviewed.

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