Efficacy of lumbar discectomy and percutaneous treatments for lumbar disc herniation

Value in Single-level Lumbar Discectomy: Surgical Disposable Item Cost and Relationship to Patient-reported Outcomes

STUDY DESIGN

This is a retrospective study.

OBJECTIVE

Compare improvements in health status measures (HSMs) and surgical costs to determine whether use of more costly items has any relationship to clinical outcome and value in lumbar disc surgery.

SUMMARY OF BACKGROUND DATA

Association between cost, outcomes, and value in spine surgery, including lumbar discectomy is poorly understood. Outcomes were calculated as difference in mean HSM scores between preoperative and postoperative timeframes. Prospective validated patient-reported HSMs studied were EuroQol quality of life index score (EQ-5D), Pain Disability Questionnaire (PDQ), and Patient Health Questionnaire (PHQ-9). Surgical costs consisted of disposable items and implants used in operating room.

METHODS

We retrospectively identified all adult patients at Cleveland Clinic main campus between October 2009 and August 2013 who underwent lumbar discectomy (652) using administrative billing data, Current Procedural Terminology (CPT) code 63030. HSMs were obtained from Cleveland Clinic Knowledge Program Data Registry.

RESULTS

In total, 67% of operations performed in the outpatient or ambulatory setting, 33% in the inpatient setting. Among 9 surgeons who performed >10 lumbar discectomies, there were 72.4 operations per surgeon, on average. Mean surgical costs of each surgeon differed (P<0.0001). In a multivariable regression, only the surgeon and surgery type (outpatient or inpatient) were statistically correlated with surgical costs (P<0.0001 and 0.046, respectively). Changes in EQ-5D, PDQ, and PHQ-9 were not correlated with surgical costs (P=0.76, 0.07, 0.76, respectively). In multivariable regression, only surgical cost was significantly correlated to mean difference in PDQ (P=0.030). More costly surgeries resulted in worse PDQ outcomes.

CONCLUSIONS

Mean surgical costs varied statistically among 9 surgeons; costs were not shown to be positively correlated with patient outcomes. Performing an operation using more costly disposable supplies/implants does not seem to improve patient outcomes and should be considered when constructing preference cards and during an operation.

Appropriateness criteria for surgery improve clinical outcomes in patients with low back pain and/or sciatica

STUDY DESIGN

Prospective, controlled, observational outcome study using clinical, radiographic, and patient/physician-based questionnaire data, with patient outcomes at 12 months follow-up.

OBJECTIVE

To validate appropriateness criteria for low back surgery.

SUMMARY OF BACKGROUND DATA

Most surgical treatment failures are attributed to poor patient selection, but no widely accepted consensus exists on detailed indications for appropriate surgery.

METHODS

Appropriateness criteria for low back surgery have been developed by a multispecialty panel using the RAND appropriateness method. Based on panel criteria, a prospective study compared outcomes of patients appropriately and inappropriately treated at a single institution with 12 months follow-up assessment. Included were patients with low back pain and/or sciatica referred to the neurosurgical department. Information about symptoms, neurologic signs, the health-related quality of life (SF-36), disability status (Roland-Morris), and pain intensity (VAS) was assessed at baseline, at 6 months, and at 12 months follow-up. The appropriateness criteria were administered prospectively to each clinical situation and outside of the clinical setting, with the surgeon and patients blinded to the results of the panel decision. The patients were further stratified into 2 groups: appropriate treatment group (ATG) and inappropriate treatment group (ITG).

RESULTS

Overall, 398 patients completed all forms at 12 months. Treatment was considered appropriate for 365 participants and inappropriate for 33 participants. The mean improvement in the SF-36 physical component score at 12 months was significantly higher in the ATG (mean: 12.3 points) than in the ITG (mean: 6.8 points) (P = 0.01), as well as the mean improvement in the SF-36 mental component score (ATG mean: 5.0 points; ITG mean: -0.5 points) (P = 0.02). Improvement was also significantly higher in the ATG for the mean VAS back pain (ATG mean: 2.3 points; ITG mean: 0.8 points; P = 0.02) and Roland-Morris disability score (ATG mean: 7.7 points; ITG mean: 4.2 points; P = 0.004). The ATG also had a higher improvement in mean VAS for sciatica (4.0 points) than the ITG (2.8 points), but the difference was not significant (P = 0.08). The SF-36 General Health score declined in both groups after 12 months, however, the decline was worse in the ITG (mean decline: 8.2 points) than in the ATG (mean decline: 1.2 points) (P = 0.04). Overall, in comparison to ITG patients, ATG patients had significantly higher improvement at 12 months, both statistically and clinically.

CONCLUSION

In comparison to previously reported literature, our study is the first to assess the utility of appropriateness criteria for low back surgery at 1-year follow-up with multiple outcome dimensions. Our results confirm the hypothesis that application of appropriateness criteria can significantly improve patient outcomes.

Nonsurgical interventional therapies for low back pain: a review of the evidence for an American Pain Society clinical practice guideline

STUDY DESIGN

Systematic review.

OBJECTIVE

To systematically assess benefits and harms of nonsurgical interventional therapies for low back and radicular pain.

SUMMARY OF BACKGROUND DATA

Although use of certain interventional therapies is common or increasing, there is also uncertainty or controversy about their efficacy.

METHODS

Electronic database searches on Ovid MEDLINE and the Cochrane databases were conducted through July 2008 to identify randomized controlled trials and systematic reviews of local injections, botulinum toxin injection, prolotherapy, epidural steroid injection, facet joint injection, therapeutic medial branch block, sacroiliac joint injection, intradiscal steroid injection, chemonucleolysis, radiofrequency denervation, intradiscal electrothermal therapy, percutaneous intradiscal radiofrequency thermocoagulation, Coblation nucleoplasty, and spinal cord stimulation. All relevant studies were methodologically assessed by 2 independent reviewers using criteria developed by the Cochrane Back Review Group (for trials) and by Oxman (for systematic reviews). A qualitative synthesis of results was performed using methods adapted from the US Preventive Services Task Force.

RESULTS

For sciatica or prolapsed lumbar disc with radiculopathy, we found good evidence that chemonucleolysis is moderately superior to placebo injection but inferior to surgery, and fair evidence that epidural steroid injection is moderately effective for short-term (but not long-term) symptom relief. We found fair evidence that spinal cord stimulation is moderately effective for failed back surgery syndrome with persistent radiculopathy, though device-related complications are common. We found good or fair evidence that prolotherapy, facet joint injection, intradiscal steroid injection, and percutaneous intradiscal radiofrequency thermocoagulation are not effective. Insufficient evidence exists to reliably evaluate other interventional therapies.

CONCLUSION

Few nonsurgical interventional therapies for low back pain have been shown to be effective in randomized, placebo-controlled trials.

Surgery for low back pain: a review of the evidence for an American Pain Society Clinical Practice Guideline

STUDY DESIGN

Systematic review.

OBJECTIVE

To systematically assess benefits and harms of surgery for nonradicular back pain with common degenerative changes, radiculopathy with herniated lumbar disc, and symptomatic spinal stenosis.

SUMMARY OF BACKGROUND DATA

Although back surgery rates continue to increase, there is uncertainty or controversy about utility of back surgery for various conditions.

METHODS

Electronic database searches on Ovid MEDLINE and the Cochrane databases were conducted through July 2008 to identify randomized controlled trials and systematic reviews of the above therapies. All relevant studies were methodologically assessed by 2 independent reviewers using criteria developed by the Cochrane Back Review Group (for trials) and Oxman (for systematic reviews). A qualitative synthesis of results was performed using methods adapted from the US Preventive Services Task Force.

RESULTS

For nonradicular low back pain with common degenerative changes, we found fair evidence that fusion is no better than intensive rehabilitation with a cognitive-behavioral emphasis for improvement in pain or function, but slightly to moderately superior to standard (nonintensive) nonsurgical therapy. Less than half of patients experience optimal outcomes (defined as no more than sporadic pain, slight restriction of function, and occasional analgesics) following fusion. Clinical benefits of instrumented versus noninstrumented fusion are unclear. For radiculopathy with herniated lumbar disc, we found good evidence that standard open discectomy and microdiscectomy are moderately superior to nonsurgical therapy for improvement in pain and function through 2 to 3 months. For symptomatic spinal stenosis with or without degenerative spondylolisthesis, we found good evidence that decompressive surgery is moderately superior to nonsurgical therapy through 1 to 2 years. For both conditions, patients on average experience improvement either with or without surgery, and benefits associated with surgery decrease with long-term follow-up in some trials. Although there is fair evidence that artificial disc replacement is similarly effective compared to fusion for single level degenerative disc disease and that an interspinous spacer device is superior to nonsurgical therapy for 1- or 2-level spinal stenosis with symptoms relieved with forward flexion, insufficient evidence exists to judge long-term benefits or harms.

CONCLUSION

Surgery for radiculopathy with herniated lumbar disc and symptomatic spinal stenosis is associated with short-term benefits compared to nonsurgical therapy, though benefits diminish with long-term follow-up in some trials. For nonradicular back pain with common degenerative changes, fusion is no more effective than intensive rehabilitation, but associated with small to moderate benefits compared to standard nonsurgical therapy.

A systematic review of randomised clinical trials using posterior discectomy to treat lumbar disc herniations

The focus of this study was to examine the safety and effectiveness of three different discectomy techniques using a posterior approach for the treatment of herniated lumbar discs. There are only a small number of prospective randomised studies comparing posterior lumbar discectomy techniques, and no recent systematic review has been published on this matter. Using the Cochrane Collaboration guidelines, all randomised or "quasi-randomised" clinical trials, comparing classic, microsurgical, and endoscopic lumbar discectomies using a posterior approach were systematically reviewed. No statistically significant differences were found between these techniques regarding improvement in pain, sensory deficits, motor strength, reflexes, and patient satisfaction. Current data suggest that the microsurgical and endoscopic techniques are superior to the classic technique for the treatment of single level lumbar disc herniations with respect to volume of blood loss, systemic repercussions, and duration of hospital stay. All three surgical techniques were found to be effective for the treatment of single level lumbar disc herniations in patients without degenerative vertebral deformities. No conclusions could be drawn from the clinical randomised studies reviewed regarding the safety of the three techniques studied due to insufficient data on postoperative complications.

Surgical interventions for lumbar disc prolapse: updated Cochrane Review

STUDY DESIGN

An updated Cochrane Review.

OBJECTIVES

To assess the effects of surgical interventions for the treatment of lumbar disc prolapse.

SUMMARY OF BACKGROUND DATA

Disc prolapse accounts for 5% of low back disorders yet is one of the most common reasons for surgery. There is still little scientific evidence supporting some interventions.

METHODS

Use of standard Cochrane review methods to analyze all randomized controlled trials published up to January 1, 2007.

RESULTS

Forty randomized controlled trials (RCTs) and 2 quasi-RCTs were identified. Many of the early trials were of some form of chemonucleolysis, whereas the majority of the later studies either compared different techniques of discectomy or the use of some form of membrane to reduce epidural scarring. Four trials directly compared discectomy with conservative management, and these give suggestive rather than conclusive results. However, other trials show that discectomy produces better clinical outcomes than chemonucleolysis, and that in turn is better than placebo. Microdiscectomy gives broadly comparable results to standard discectomy. Recent trials of an interposition gel covering the dura (5 trials) and of fat (4 trials) show that they can reduce scar formation, although there is limited evidence about the effect on clinical outcomes. There is insufficient evidence on other percutaneous discectomy techniques to draw firm conclusions. Three small RCTs of laser discectomy do not provide conclusive evidence on its efficacy. There are no published RCTs of coblation therapy or transforaminal endoscopic discectomy.

CONCLUSION

Surgical discectomy for carefully selected patients with sciatica due to lumbar disc prolapse provides faster relief from the acute attack than conservative management, although any positive or negative effects on the lifetime natural history of the underlying disc disease are still unclear. The evidence for other minimally invasive techniques remains unclear except for chemonucleolysis using chymopapain, which is no longer widely available.

MR imaging and osseous spinal intervention and intervertebral disk intervention

Percutaneous spine intervention, a wide range of invasive spine procedures performed through a puncture hole or through a small incision not requiring soft tissue closure and with few or no skin sutures or staples, is rapidly emerging as an effective alternative to open surgery. This article describes many of the minimally invasive osseous, intervertebral disk, and spinal nerve interventions currently being performed, including both well-established procedures and procedures developed recently. A general introduction to these types of procedures is provided, along with the characteristic pre- and postprocedural MR imaging appearance related to these techniques. The article also discusses reported and theoretical complications that may arise and their respective MR imaging appearances.

Surgical interventions for lumbar disc prolapse

BACKGROUND

Disc prolapse accounts for five percent of low-back disorders but is one of the most common reasons for surgery.

OBJECTIVES

The objective of this review was to assess the effects of surgical interventions for the treatment of lumbar disc prolapse.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, PubMed, Spine and abstracts of the main spine society meetings within the last five years. We also checked the reference lists of each retrieved articles and corresponded with experts. All data found up to 1 January 2007 are included.

SELECTION CRITERIA

Randomized trials (RCT) and quasi-randomized trials (QRCT) of the surgical management of lumbar disc prolapse.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial quality and extracted data from published papers. Additional information was sought from the authors if necessary.

MAIN RESULTS

Forty RCTs and two QRCTs were identified, including 17 new trials since the first edition of this review in 1999. Many of the early trials were of some form of chemonucleolysis, whereas the majority of the later studies either compared different techniques of discectomy or the use of some form of membrane to reduce epidural scarring. Despite the critical importance of knowing whether surgery is beneficial for disc prolapse, only four trials have directly compared discectomy with conservative management and these give suggestive rather than conclusive results. However, other trials show that discectomy produces better clinical outcomes than chemonucleolysis and that in turn is better than placebo. Microdiscectomy gives broadly comparable results to standard discectomy. Recent trials of an inter-position gel covering the dura (five trials) and of fat (four trials) show that they can reduce scar formation, though there is limited evidence about the effect on clinical outcomes. There is insufficient evidence on other percutaneous discectomy techniques to draw firm conclusions. Three small RCTs of laser discectomy do not provide conclusive evidence on its efficacy, There are no published RCTs of coblation therapy or trans-foraminal endoscopic discectomy.

AUTHORS' CONCLUSIONS

Surgical discectomy for carefully selected patients with sciatica due to lumbar disc prolapse provides faster relief from the acute attack than conservative management, although any positive or negative effects on the lifetime natural history of the underlying disc disease are still unclear. Microdiscectomy gives broadly comparable results to open discectomy. The evidence on other minimally invasive techniques remains unclear (with the exception of chemonucleolysis using chymopapain, which is no longer widely available).

Surgical interventions for lumbar disc prolapse

BACKGROUND

Disc prolapse accounts for five percent of low-back disorders but is one of the most common reasons for surgery.

OBJECTIVES

The objective of this review was to assess the effects of surgical interventions for the treatment of lumbar disc prolapse.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, PubMed, Spine and abstracts of the main spine society meetings within the last five years. We also checked the reference lists of each retrieved articles and corresponded with experts. All data found up to 1 June 2006 are included.

SELECTION CRITERIA

Randomized trials (RCT) and quasi-randomized trials (QRCT) of the surgical management of lumbar disc prolapse.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial quality and extracted data from published papers. Additional information was sought from the authors if necessary.

MAIN RESULTS

Thirty-nine RCTs and two QRCTs were identified, including 16 new trials since the first edition of this review in 1999. Many of the early trials were of some form of chemonucleolysis, whereas the majority of the later studies either compared different techniques of discectomy or the use of some form of membrane to reduce epidural scarring. Despite the critical importance of knowing whether surgery is beneficial for disc prolapse, only three trials have directly compared discectomy with conservative management and these give suggestive rather than conclusive results. However, other trials show that discectomy produces better clinical outcomes than chemonucleolysis and that in turn is better than placebo. Microdiscectomy gives broadly comparable results to standard discectomy. Recent trials of an inter-position gel covering the dura (five trials) and of fat (four trials) show that they can reduce scar formation, though there is limited evidence about the effect on clinical outcomes. There is insufficient evidence on other percutaneous discectomy techniques to draw firm conclusions. Three small RCTs of laser discectomy do not provide conclusive evidence on its efficacy, There are no published RCTs of coblation therapy or trans-foraminal endoscopic discectomy.

AUTHORS' CONCLUSIONS

Surgical discectomy for carefully selected patients with sciatica due to lumbar disc prolapse provides faster relief from the acute attack than conservative management, although any positive or negative effects on the lifetime natural history of the underlying disc disease are still unclear. Microdiscectomy gives broadly comparable results to open discectomy. The evidence on other minimally invasive techniques remains unclear (with the exception of chemonucleolysis using chymopapain, which is no longer widely available).

Nucleoplasty With or Without Intradiscal Electrothermal Therapy (IDET) as a Treatment for Lumbar Herniated Disc

BACKGROUND AND OBJECTIVE

In industrialized societies, the prevalence of radicular low back pain has exploded in recent years. The growing economic and personal costs of this challenging entity have led to the development of a wide array of new treatments, ranging from pharmacotherapy with neuropathic medications to open surgical treatment. Among the therapeutic options to emerge are a plethora of minimally invasive treatments aimed at removing nuclear material and lowering intradiscal pressure through devices inserted percutaneously into intervertebral discs. Yet there is a compelling lack of clinical evidence to support the use of these procedures. This study was undertaken to determine the treatment outcomes of 16 consecutive patients with lumbar radicular pain secondary to a herniated disc who underwent nucleoplasty as their primary therapy.

METHODS

Included in this series were nine patients with significant axial back pain, sitting intolerance, and positive discography who also underwent intradiscal electrothermal therapy (IDET). Among the 7 patients who only had nucleoplasty, 4 had 2 discs treated and 3 had 1 disc. In the 9 patients who also had IDET, 6 had 1 disc treated and 3 had 2 discs treated. Of the 32 total disc treatments, 20 were at L5-S1, 10 were at L4-5 and 2, one each for IDET and nucleoplasty, were at L3-4.

RESULTS

In the overall cohort, the average Visual Analogue Scale (VAS) pain score decreased from 6.7 to 5.6 at a mean follow-up of 9 months. In the seven patients who underwent only nucleoplasty, the mean VAS score decreased from 6.0 to 4.8. Only one patient reported a >/=50% reduction in pain score.

CONCLUSIONS

We conclude that with use of the present selection criteria, nucleoplasty is not an effective long-term treatment for lumbar radiculopathy, either alone or with IDET. Before conducting future clinical trials, we recommend modifying these criteria to include only those patients with small (<6-mm) contained disc herniations whose annular integrity is documented by computed tomography discography and corresponding radicular symptoms confirmed by either selective nerve root blocks or electromyography and nerve conduction studies.

Discectomy strategies for lumbar disc herniation: results of the LAPDOG trial

Since its introduction in the 1970s percutaneous treatment of lumbar disc herniation has been an attractive concept that has been the object of technical development and clinical application throughout the world. Little scientific evaluation of the efficacy and effectiveness of the procedure has been done. To estimate the success rates of automated percutaneous and conventional discectomy in comparable patients and to document the resource consumption of patients treated in these ways, a multicenter randomized clinical trial designed to compare both treatment efficacy and cost-effectiveness of automated percutaneous discectomy and conventional discectomy in adult patients with no prior lumbar spinal surgery, no coexistent lumbar spinal disease, unilateral single level lumbar radiculopathy with images confirming disc herniation at the appropriate level. In the course of the trial important technical advances allowing epidural extraction of free-fragment disc herniation was incorporated into the trial. It was not possible to enroll the required number of patients to complete the trial. Of 5735 screened patients, 95 were eligible and 36 were enrolled. Two elected watchful waiting and did not have any surgical procedure. Eight patients were lost to follow-up. Among the 27 evaluable patients, 41% of the percutaneous discectomy patients and 40% of the conventional discectomy patients were assessed as achieving "success" on the primary outcome measure. No clinical trial of any percutaneous discectomy technique provides definitive evidence supporting the efficacy or effectiveness of the procedure. Such evidence should be required by patients to whom such procedures are proposed and those who are asked to pay for them.

Discectomy strategies for lumbar disc herniation: study design and implications for clinical research

Although previous studies have found automated percutaneous discectomy and epidural percutaneous discectomy to be less efficacious than conventional discectomy, these percutaneous procedures may be effective and cost-effective as a first surgical treatment for herniated lumbar disc. Percutaneous procedures for herniated lumbar disc continue to be performed throughout the world without definitive evidence of efficacy or effectiveness. The objective of this article is to report the design considerations and final design of a study with the following objectives: (1) to estimate the efficacy of automated percutaneous and conventional discectomy in treating single level herniated lumbar discs in comparable patient populations, and (2) to test the hypothesis that the use of percutaneous discectomy as the first surgical procedure in such patients would result in less cost and fewer complications than utilizing conventional discectomy as the first procedure. A multicenter randomized clinical trial was designed that followed published eligibility criteria closely, allowed flexibility in timing of surgery (while collecting natural history information on patients identified before electing surgery), incorporated adjustments for newly developed technology and accommodated the unusual demands of assessing a procedure acknowledged to have inferior medical outcomes when compared to conventional therapy but which offered potential advantages in cost and safety. The study was successfully designed and funded. In its implementation we experienced several obstacles that may affect the success of other clinical trials. Despite using established eligibility criteria, our patient enrollment was lower than expected. Academic health centers and traditional research settings are seeing fewer patients who would be eligible for discectomy; private clinical centers are treating eligible patients but lack the incentives to participate in clinical research. Automated percutaneous discectomy and epidural percutaneous discectomy are widely performed procedures and, despite the aforementioned obstacles, their efficacy and cost-effectiveness need to be scientifically evaluated if we are committed to delivering appropriate patient care.

Hérnia discal: procedimentos de tratamento

A hérnia de disco é um processo em que ocorre a ruptura do anel fibroso, com subsequente deslocamento da massa central do disco nos espaços intervertebrais. É considerada uma patologia extremamente comum, que causa séria inabilidade em seus portadores. Estima-se que 2 a 3 % da população sejam acometidos desse processo, cuja prevalência é de 4,8% em homens e 2,5% em mulheres, acima de 35 anos. São fatores de risco, causas ambientais, posturais, desequilíbrios musculares e possivelmente, a influência genética. A terapia conservadora tem sido a preferida como a primeira escolha de tratamento, cujos objetivos são o alívio da dor, o aumento da capacidade funcional e o retardamento da progressão da doença. Nesta revisão, são abordadas as principais metodologias, de acordo com a literatura, dando ênfase ao uso de fármacos analgésicos e anti-inflamatórios, o uso de órteses, a acupuntura, o repouso e a adoção de um programa de exercícios adequados.

Appropriateness of surgery for sciatica: reliability of guidelines from expert panels

STUDY DESIGN

Reliability study of guidelines development.

OBJECTIVE

To compare criteria for low back surgery between two expert panels.

BACKGROUND

Reliability of expert panels for determining appropriateness of indications for surgical procedures has heretofore received little attention.

METHODS

Two multidisciplinary expert panels of similar composition were convened, in the United States and in Switzerland, to evaluate the appropriateness of 720 distinct clinical scenarios involving sciatica. Each indication was assigned to a category of appropriate, uncertain, and inappropriate. The appropriateness of the 720 theoretical scenarios were compared between the two panels, and both sets of criteria were applied to two series of actual cases.

RESULTS

Seventy-nine percent (n = 566) of the 720 theoretical indications were assigned to identical categories of appropriateness by both panels (kappa = 0.63; P < 0.001). Only 2 of the 720 scenarios elicited frank disagreement. The percentage of the 720 indications that were considered appropriate differed between the two panels (U.S.: 3%; Swiss: 11%, P < 0.001), as did the percentage of intrapanel agreement for indications (U.S.: 51%, Swiss: 64%, P < 0.001). When the same theoretical scenarios were matched with two series of actual cases (n = 181 and 149) agreement was moderate (kappa = 0.46) to fair (kappa = 0.30).

CONCLUSION

There was substantial agreement on the appropriateness of surgery for theoretical cases of sciatica between independent expert panels from two countries. A better understanding of discordant ratings, especially for actual cases, should precede attempts at transposing recommendations emanating from a panel in one country to another.

The Cochrane review of surgery for lumbar disc prolapse and degenerative lumbar spondylosis

STUDY DESIGN

A Cochrane review of randomized controlled trials.

OBJECTIVES

To collate the scientific evidence on surgical management for lumbar-disc prolapse and degenerative lumbar spondylosis.

SUMMARY OF BACKGROUND DATA

Surgical investigations and interventions account for as much as one third of the health care costs for spinal disorders, but the scientific evidence for most procedures still is unclear.

METHODS

A highly sensitive search strategy identified all published randomized controlled trials. Cochrane methodology was used for meta-analysis of the results.

RESULTS

Twenty-six randomized controlled trials of surgery for lumbar disc prolapse and 14 trials of surgery for degenerative lumbar spondylosis were identified. Methodologic weaknesses were found in many of the trials. Only one trial directly compared discectomy and conservative management. Meta-analyses showed that surgical discectomy produces better clinical outcomes than chemonucleolysis, which is better than placebo. Three trials showed no difference in clinical outcomes between microdiscectomy and standard discectomy, but in three other studies, both produced better results than percutaneous discectomy. Three trials showed that inserting an interposition membrane after discectomy does not significantly reduce scar formation or alter clinical outcomes. Five heterogeneous trials on spinal stenosis and degenerative spondylolisthesis permit very limited conclusions. There were nine trials of instrumented versus noninstrumented fusion: Meta-analysis showed that instrumentation may facilitate fusion but does not improve clinical outcomes.

CONCLUSIONS

There is now strong evidence on the relative effectiveness of surgical discectomy versus chemonucleolysis versus placebo. There is considerable evidence on the clinical effectiveness of discectomy for carefully selected patients with sciatica caused by lumbar disc prolapse that fails to resolve with conservative management. There is no scientific evidence on the effectiveness of any form of surgical decompression or fusion for degenerative lumbar spondylosis compared with natural history, placebo, or conservative management. The Cochrane reviews will be updated continuously as other trials become available.

Statistical approaches in the development of clinical practice guidelines from expert panels: the case of laminectomy in sciatica patients

BACKGROUND

Variation in expert opinion and lack of a systematic methodology hinder the development of reliable clinical practice guidelines. However standardized protocols have been defined to quantify, combine, and summarize expert judgments. In addition, statistical methods may help to outline guidelines based on simplified models of these judgments.

METHODS

To test this hypothesis, stepwise logistic regression (SLR) and classification tree pruning (CTP) were used to predict the results of two expert panels (USA 1992 and Switzerland 1995) on laminectomy in sciatica conditions. Both panels, using the RAND-UCLA explicit method, assessed whether the procedure would be inappropriate or of potential use in 720 case scenarios combining 7 relevant factors.

RESULTS

Laminectomy was rated as inappropriate in 60% and 70% of the scenarios by the US and Swiss panels, respectively. Either statistical method, in both panels, based its simplest model on the same 4 factors, as follows: imaging test results; disability; neurological findings; and conservative treatment trials (in decreasing order); the influence of 2 other factors, duration of pain and nerve root irritation, were only marginal. The correct classification rates of the models were 89% and 93% for SLR and 93% and 85% for CTP. Adopting the CTP US algorithm as a guideline would lead to consider performing laminectomy only in patients with imaging evidence of hernia, relatively severe disability, reflex abnormalities, and previous nonsurgical treatment. Adherence to the corresponding CTP Swiss algorithm would result in less restrictive conditions.

CONCLUSION

The statistical techniques proved as useful instruments to structure and simplify appropriateness criteria developed by expert panels and to outline parsimonious decision models for clinical practice.