Cost effectiveness of disc prosthesis versus lumbar fusion in patients with chronic low back pain: randomized controlled trial with 2-year follow-up

The Decline of Lumbar Artificial Disc Replacement

Lower back pain associated with degenerative disc disease is a common occurrence, with many surgical treatments targeting the degenerated disc to relieve symptoms. Current surgical options for degenerative disc disease primarily consist of a discectomy followed by either spinal fusion or artificial disc replacement, with the former being increasingly more common in the lumbar region despite the risk of adjacent segment disease. Though artificial disc replacement aims to provide an increase in range of motion and decreases risk of adjacent segment disease, surgeons are increasingly opting for spinal fusion in the lumbar region. This review investigates underlying factors that may be contributing to this trend by assessing lumbar artificial disc replacement selection criteria, clinical outcomes, surgical technique, complications, revision burden, and overall cost. While these factors had some role in the physician's decision, ultimately the narrow selection criteria and lack of cost reimbursement by insurance has primarily led to the decline in lumbar artificial disc replacement.

Lumbar Disc Replacement Versus Interbody Fusion: Meta-analysis of Complications and Clinical Outcomes

Background

Lumbar spinal fusion is a commonly performed operation with relatively high complication and revision surgery rates. Lumbar disc replacement is less commonly performed but may have some benefits over spinal fusion. This meta-analysis aims to compare the outcomes of lumbar disc replacement (LDR) versus interbody fusion (IBF), assessing their comparative safety and effectiveness in treating lumbar DDD.

Methods

PubMed, Cochrane, and Google Scholar (pages 1-2) were searched up until February 2024. The studied outcomes included operative room (OR) time, estimated blood loss (EBL), length of hospital stay (LOS), complications, reoperations, Oswestry Disability Index (ODI), back pain, and leg pain.

Results

Ten studies were included in this meta-analysis, of which six were randomized controlled trials, three were retrospective studies, and one was a prospective study. A total of 1720 patients were included, with 1034 undergoing LDR and 686 undergoing IBF. No statistically significant differences were observed in OR time, EBL, or LOS between the LDR and IBF groups. The analysis also showed no significant differences in the rates of complications, reoperations, and leg pain between the two groups. However, the LDR group demonstrated a statistically significant reduction in mean back pain (p=0.04) compared to the IBF group.

Conclusion

Both LDR and IBF procedures offer similar results in managing CLBP, considering OR time, EBL, LOS, complication rates, reoperations, and leg pain, with slight superiority of back pain improvement in LDR. This study supports the use of both procedures in managing degenerative spinal disease.

Methodology of economic evaluations in spine surgery: a systematic review and qualitative assessment

OBJECTIVES

The present study is a systematic review conducted as part of a methodological approach to develop evidence-based recommendations for economic evaluations in spine surgery. The aim of this systematic review is to evaluate the methodology and quality of currently available clinical cost-effectiveness studies in spine surgery.

STUDY DESIGN

Systematic literature review.

DATA SOURCES

PubMed, Web of Science, Embase, Cochrane, Cumulative Index to Nursing and Allied Health Literature, EconLit and The National Institute for Health Research Economic Evaluation Database were searched through 8 December 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were included if they met all of the following eligibility criteria: (1) spine surgery, (2) the study cost-effectiveness and (3) clinical study. Model-based studies were excluded.

DATA EXTRACTION AND SYNTHESIS

The following data items were extracted and evaluated: pathology, number of participants, intervention(s), year, country, study design, time horizon, comparator(s), utility measurement, effectivity measurement, costs measured, perspective, main result and study quality.

RESULTS

130 economic evaluations were included. Seventy-four of these studies were retrospective studies. The majority of the studies had a time horizon shorter than 2 years. Utility measures varied between the EuroQol 5 dimensions and variations of the Short-Form Health Survey. Effect measures varied widely between Visual Analogue Scale for pain, Neck Disability Index, Oswestry Disability Index, reoperation rates and adverse events. All studies included direct costs from a healthcare perspective. Indirect costs were included in 47 studies. Total Consensus Health Economic Criteria scores ranged from 2 to 18, with a mean score of 12.0 over all 130 studies.

CONCLUSIONS

The comparability of economic evaluations in spine surgery is extremely low due to different study designs, follow-up duration and outcome measurements such as utility, effectiveness and costs. This illustrates the need for uniformity in conducting and reporting economic evaluations in spine surgery.

Evaluation of outcomes of discectomy with a dynamic neutralization system in treatment of lumbar disk herniation

OBJECTIVE

The study aimed to explore the clinical outcomes of discectomy with dynamic neutralization system (Dynesys) for single-segmental lumbar disk herniation (LDH) versus simple discectomy.

METHODS

The eligible patients with single-segmental LDH were randomly divided into the discectomy with Dynesys group (group A) and the simple discectomy group (group B). The Oswestry disability index (ODI), visual analog score (VAS), radiological results of intervertebral height and range of motion (ROM) of the treated segment were evaluated pre- and post-operatively in both groups. Operation duration and blood loss were recorded. Complications, reoperation, and mortality were also assessed. All patients received a 2-year follow-up.

RESULTS

123 (96.1%) participants completed the follow-up. The operation duration and blood loss of group B were significantly lower than those of group A (p<0.05). After operation, ODI and VAS were improved significantly in both groups, and there was no significant difference between the two groups immediately after surgery. But a rising trend was found in ODI and VAS of group B, especially after the 1-year follow-up (p<0.05). X-rays showed a continuing loss of intervertebral height of the treated segment in group B, while it was preserved in group A (p<0.05). ROM of the treated segment was also maintained stable in group A.

CONCLUSION

Discectomy with Dynesys is safe and effective for LDH treatment.

National trends in the utilization of lumbar disc replacement for lumbar degenerative disc disease over a 10-year period, 2010 to 2019

Background

Lumbar fusion (LF) is commonly performed to manage lumbar degenerative disc disease (LDDD) that has failed conservative measures. However, lumbar disc replacement (LDR) procedures are increasingly prevalent and designed to preserve motion in carefully selected patients.

Methods

A retrospective cohort study was performed using the National Inpatient Sample (NIS), queried from 2010 to 2019 to identify patients undergoing single and double-level LF or LDR with a diagnosis of LDDD using International Classification of Diseases (ICD) 9th (ICD-9) and 10th (ICD-10) revision diagnostic and procedure codes. Propensity score matching (PSM) with a ratio of 2:1 was performed. All cost estimates reflect reported hospital costs adjusted to December 2019 United States Dollars.

Results

A total of 1,129,121 LF cases (99.3%) and 8,049 LDR cases (0.7%) were identified, with 364,637 (32.3%) and 712 (8.8%) comprising two-level surgeries, respectively. 1,712 LDRs were performed in 2010 (1.27% of all), decreasing to 565 in 2013 (0.52%), and increased slightly to 870 in 2019 (0.74%). LDR patients were significantly more likely to be younger (mean age 41.2 vs. 57.1, P<0.001) and healthier (mean ECI 0.88 vs. 1.80, P<0.001). On matched analysis, LDR hospital costs were $4,529 less (P<0.001) and length of stay was 0.65 days shorter (P<0.001) than LF patients. LDR patients had lower rates of any complication (7.0% vs. 13.2%, P<0.001), neurologic complication (3.0% vs. 4.2%, P=0.006), and blood transfusion (3.1% vs. 8.1%, P<0.001) compared to LF patients.

Conclusions

The prevalence of LDR procedures decreased from 2010-2017 but began to increase again in 2018 and 2019. Single-level LDR was associated with reduced costs and length of stay (LOS), and lower rates of blood transfusion compared to LF in patients with LDDD.

Cervical and Lumbar Disc Arthroplasty: A Review of Current Implant Design and Outcomes

While spinal disc pathology has traditionally been treated using fusion-based procedures, recent interest in motion-preserving disc arthroplasties has grown. Traditional spinal fusion is associated with loss of motion, alteration of native spine kinematics, and increased risks of adjacent segment disease. The motion conferred by disc arthroplasty is believed to combat these complications. While the first implant designs resulted in poor patient outcomes, recent advances in implant design and technology have shown promising radiographic and clinical outcomes when compared with traditional fusion. These results have led to a rapid increase in the utilization of disc arthroplasty, with rates of cervical arthroplasty nearly tripling over the course of 7 years. The purpose of this review was to discuss the evolution of implant design, the current implant designs utilized, and their associated outcomes. Although disc arthroplasty shows significant promise in addressing some of the drawbacks associated with fusion, it is not without its own risks. Osteolysis, implant migration, and the development of heterotopic ossification have all been associated with disc arthroplasty. As interest in these procedures grows, so does the interest in developing improved implant designs aimed at decreasing these adverse outcomes. Though they are still relatively new, cervical and lumbar disc arthroplasty are likely to become foundational methodologies for the treatment of disc pathology.

Defining the relative utility of lumbar spine surgery: A systematic literature review of common surgical procedures and their impact on health states

Degenerative lumbar spondylosis is a common indication for patients undergoing spine surgery. As healthcare costs rise, measuring quality of life (QOL) gains after surgical procedures is critical in assessing value. We set out to: 1) compare baseline and postoperative EuroQol-5D (EQ-5D) scores for lumbar spine surgery and common surgical procedures to obtain post-operative quality-adjusted life year (QALY) gain, and 2) establish the relative utility of lumbar spine surgery as compared to other commonly performed surgical procedures. A systematic literature review was conducted to identify all studies reporting preoperative/baseline and postoperative EQ-5D scores for common surgical procedures. For each study, the number of patients included and baseline/preoperative and follow-up mean EQ-5D scores were recorded, and mean QALY gained for each intervention was calculated. A total of 67 studies comprising 95,014 patients were identified. Patients with lumbar spondylosis had the worst reported QOL at baseline compared to other surgical cohorts. The greatest QALY gain was seen in patients undergoing hip arthroplasty (0.38), knee arthroplasty (0.35) and lumbar spine surgery (0.32), nearly 2.5-fold greater QALY gained than for all other procedures. The low preoperative QOL, coupled with the improvements offered with surgery, highlight the utility and value of lumbar spine surgery compared to other common surgical procedures.

Final Long-Term Reporting from a Randomized Controlled IDE Trial for Lumbar Artificial Discs in Single-Level Degenerative Disc Disease: 7-Year Results

BACKGROUND

This study compared 7-year safety and efficacy outcomes of activL and ProDisc-L lumbar total disc replacements in patients with symptomatic, single-level lumbar degenerative disc disease (DDD). The objectives are to report 7-year outcomes of the trial, evaluate the outcomes for patients lost to follow-up, and determine whether early outcomes predict long-term outcomes.

METHODS

This was a prospective, multicenter, randomized, controlled investigational device exemption study. Eligible patients with symptomatic, single-level lumbar DDD had failed ≥6 months of nonsurgical management. Patients (N = 283) were randomized to receive activL (n = 218) or ProDisc-L (n = 65). At 7 years, data were available from 206 patients (activL, 160; ProDisc-L, 46). Logistic regression models were fit to predict 7-year outcomes for patients lost to follow-up after 2 years.

RESULTS

At 7 years, the activL group was noninferior to the ProDisc-L group on the primary composite endpoint (P = .0369). Both groups showed significant reductions in back/leg pain severity and improvements in disability index and quality-of-life relative to baseline (P < .0001). In both groups, opioid use was significantly reduced at 7 years (0%) relative to baseline (P < .01), and the overall reoperation rates were low (4.6%). activL patients showed a significantly better range of motion (ROM) for flexion-extension rotation than ProDisc-L patients (P = .0334). A significantly higher proportion of activL patients did not report serious adverse events (activL, 62%; ProDisc-L, 43%; P = .011). Predictive modeling indicated that >70% of patients (depending on outcome) lost to follow-up after 2 years would show clinically significant improvement at 7 years if improvements were achieved at 2 years.

CONCLUSIONS

The benefits of activL and ProDisc-L are maintained after 7 years, with significant improvements from baseline observed in pain, function, and opioid use. activL is more effective at preserving ROM than ProDisc-L and has a more favorable safety profile. Improvements in other primary and secondary outcomes were similar between both disc designs.

LEVEL OF EVIDENCE

1.

Intraosseous Basivertebral Nerve Ablation for the Treatment of Chronic Low Back Pain: 2-Year Results From a Prospective Randomized Double-Blind Sham-Controlled Multicenter Study

Background

The purpose of the present study is to report the 2-year clinical outcomes for chronic low back pain (CLBP) patients treated with radiofrequency (RF) ablation of the basivertebral nerve (BVN) in a randomized controlled trial that previously reported 1-year follow up.

Methods

A total of 147 patients were treated with RF ablation of the BVN in a randomized controlled trial designed to demonstrate safety and efficacy as part of a Food and Drug Administration-Investigational Device Exemption trial. Evaluations, including patient self-assessments, physical and neurological examinations, and safety assessments, were performed at 2 and 6 weeks, and 3, 6, 12, 18, and 24 months postoperatively. Participants randomized to the sham control arm were allowed to cross to RF ablation at 12 months. Due to a high rate of crossover, RF ablation treated participants acted as their own control in a comparison to baseline for the 24-month outcomes.

Results

Clinical improvements in the Oswestry Disability Index (ODI), Visual Analog Scale (VAS), and the Medical Outcomes Trust Short-Form Health Survey Physical Component Summary were statistically significant compared to baseline at all follow-up time points through 2 years. The mean percent improvements in ODI and VAS compared to baseline at 2 years were 53.7 and 52.9%, respectively. Responder rates for ODI and VAS were also maintained through 2 years with patients showing clinically meaningful improvements in both: ODI ≥ 10-point improvement in 76.4% of patients and ODI ≥ 20-point improvement in 57.5%; VAS ≥ 1.5 cm improvement in 70.2% of patients.

Conclusions

Patients treated with RF ablation of the BVN for CLBP exhibited sustained clinical benefits in ODI and VAS and maintained high responder rates at 2 years following treatment. Basivertebral nerve ablation appears to be a durable, minimally invasive treatment for the relief of CLBP.

What Factors Influence Reimbursement for 1 to 2 Level Anterior Cervical Discectomy and Fusion Procedures?

STUDY DESIGN

Retrospective review.

OBJECTIVE

To determine reimbursement associated with an anterior cervical discectomy and fusion (ACDF) and the demographic factors influencing reimbursement for an ACDF.

SUMMARY OF BACKGROUND DATA

ACDF has been shown to be a cost-effective procedure. However, there has been minimal analysis of factors influencing reimbursement for this procedure.

METHODS

Clinical and financial data were retrospectively reviewed for 176 patients undergoing an ACDF procedure in 2013 and 2014. Patients were included if they had primary ACDF and excluded if they were treated for a traumatic cervical spine fracture, infection, failed primary procedure, front/back procedure, or total disc replacement procedure. Clinical factors analyzed included number of levels fused, surgical time, length of stay in the hospital, estimated blood loss, implant type, Charleson Comorbidity Index (CCI), and preoperative diagnosis. Payer type and reimbursement associated with physician and hospital fees were collected for each patient. A multiple linear regression model determined the factors influencing reimbursement data using a backward conditional stepwise methodology. Variables were only included in multivariate analysis if there was a significant (P < 0.05) impact on reimbursement within univariate analysis.

RESULTS

One hundred and twenty-eight patients met inclusion criteria. The average reimbursement per patient was $24,622 (+/- standard deviation of 14,616). The only significant factors influencing reimbursement was payer type (P < 0.001) and length of hospital stay (P < 0.001). These two independent multivariate determinants of reimbursement only accounted for 18.6% of reimbursement variability.

CONCLUSION

There is substantial variability in reimbursement for ACDF procedures. Multivariate analysis indicates that payer type and length of hospital stay significantly influence reimbursement. Our model, however, only explained a small proportion of reimbursement variability indicating that factors outside our analysis may significantly affect hospital reimbursement.

LEVEL OF EVIDENCE

3.

Clinical Impact and Economic Burden of Hospital-Acquired Conditions Following Common Surgical Procedures

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To assess the clinical impact and economic burden of the three most common hospital-acquired conditions (HACs) that occur within 30-day postoperatively for all spine surgeries and to compare these rates with other common surgical procedures.

SUMMARY OF BACKGROUND DATA

HACs are part of a non-payment policy by the Centers for Medicare and Medicaid Services and thus prompt hospitals to improve patient outcomes and safety.

METHODS

Patients more than 18 years who underwent elective spine surgery were identified in American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005 to 2013. Primary outcomes were cost associated with the occurrence of three most common HACs. Cost associated with HAC occurrence derived from the PearlDiver database.

RESULTS

Ninety thousand five hundred fifty one elective spine surgery patients were identified, where 3021 (3.3%) developed at least one HAC. Surgical site infection (SSI) was the most common HAC (1.4%), then urinary tract infection (UTI) (1.3%) and venous thromboembolism (VTE) (0.8%). Length of stay (LOS) was longer for patients who experienced a HAC (5.1 vs. 3.2 d, P < 0.001). When adjusted for age, sex, and Charlson Comorbidity Index, LOS was 1.48 ± 0.04 days longer (P < 0.001) and payments were $8893 ± $148 greater (P < 0.001) for patients with at least one HAC. With the exception of craniotomy, patients undergoing common procedures with HAC had increased LOS and higher payments (P < 0.001). Adjusted additional LOS was 0.44 ± 0.02 and 0.38 ± 0.03 days for total knee arthroplasty and total hip arthroplasty, and payments were $1974 and $1882 greater. HACs following hip fracture repair were associated with 1.30 ± 0.11 days LOS and $4842 in payments (P < 0.001). Compared with elective spine surgery, only bariatric and cardiothoracic surgery demonstrated greater adjusted additional payments for patients with at least one HAC ($9975 and $10,868, respectively).

CONCLUSION

HACs in elective spine surgery are associated with a substantial cost burden to the health care system. When adjusted for demographic factors and comorbidities, average LOS is 1.48 days longer and episode payments are $8893 greater for patients who experience at least one HAC compared with those who do not.

LEVEL OF EVIDENCE

3.

Comparison of Lumbar Total Disc Replacement With Surgical Spinal Fusion for the Treatment of Single-Level Degenerative Disc Disease: A Meta-Analysis of 5-Year Outcomes From Randomized Controlled Trials

STUDY DESIGN

Meta-analysis.

OBJECTIVES

To evaluate the long-term efficacy and safety of total disc replacement (TDR) compared with fusion in patients with functionally disabling chronic low back pain due to single-level lumbar degenerative disc disease (DDD) at 5 years.

METHODS

PubMed and Cochrane Central Register of Controlled Trials databases were searched for randomized controlled trials reporting outcomes at 5 years for TDR compared with fusion in patients with single-level lumbar DDD. Outcomes included Oswestry Disability Index (ODI) success, back pain scores, reoperations, and patient satisfaction. All analyses were conducted using a random-effects model; analyses were reported as relative risk (RR) ratios and mean differences (MDs). Sensitivity analyses were conducted for different outcome definitions, high loss to follow-up, and high heterogeneity.

RESULTS

The meta-analysis included 4 studies. TDR patients had a significantly greater likelihood of ODI success (RR 1.0912; 95% CI 1.0004, 1.1903) and patient satisfaction (RR 1.13; 95% CI 1.03, 1.24) and a significantly lower risk of reoperation (RR 0.52; 95% CI 0.35, 0.77) than fusion patients. There was no association with improvement in back pain scores whether patients received TDR or fusion (MD -2.79; 95% CI -8.09, 2.51). Most results were robust to sensitivity analyses. Results for ODI success and patient satisfaction were sensitive to different outcome definitions but remained in favor of TDR.

CONCLUSIONS

TDR is an effective alternative to fusion for lumbar DDD. It offers several clinical advantages over the longer term that can benefit the patient and reduce health care burden, without additional safety consequences.

Heterogeneity of Reporting Outcomes in the Spine Surgery Literature

STUDY DESIGN

Review of spine surgery literature between 2005 and 2014 to assess the reporting of patient outcomes by determining the variability of use of patient outcomes metrics in the following categories: pain and disability, patient satisfaction, readmission, and depression.

OBJECTIVE

Expose the heterogeneity of outcomes reporting and discuss current initiatives to create more homogenous outcomes databases.

SUMMARY OF BACKGROUND DATA

There has been a recent focus on the reporting of quality metrics associated with spine surgery outcomes. However, little consensus exists on the optimal metrics that should be used to measure spine surgery outcomes.

MATERIALS AND METHODS

A PubMed search of all spine surgery manuscripts from January 2005 through December 2014 was performed. Linear regression analyses were performed on individual metrics as well as outcomes categories as a fraction of total papers reviewing surgical outcomes.

RESULTS

Outcomes reporting has increased significantly between January 1, 2005 and December 31, 2014 [175/2871 (6.1%) vs. 764/5603 (13.6%), respectively; P<0.001; R=98.1%]. For the category of pain and disability reporting, Visual Analog Score demonstrated a statistically significant decrease in use from 2005 through 2014 [56/76 (73.7%) vs. 300/520 (57.7%), respectively; P<0.001], whereas Oswestry Disability Index increased significantly in use [19/76 (25.0%) vs. 182/520 (35.0%), respectively; P<0.001]. For quality of life, EuroQOL-5 Dimensions increased significantly in use between 2005 and 2014 [4/23 (17.4%) vs. 30/87 (34.5%), respectively; P<0.01]. In contrast, use of 36 Item Short Form Survey significantly decreased [19/23 (82.6%) vs. 57/87 (65.5%), respectively; P<0.01]. For depression, only the Zung Depression Scale underwent a significant increase in usage between 2005 and 2014 [0/0 (0%) vs. 7/13 (53.8%), respectively; P<0.01].

CONCLUSIONS

Although spine surgery outcome reporting has increased significantly over the past 10 years, there remains considerable heterogeneity in regards to individual outcomes metrics utilized. This heterogeneity makes it difficult to compare outcomes across studies and to accurately extrapolate outcomes to clinical practice.

National Trends for Primary and Revision Lumbar Disc Arthroplasty Throughout the United States

STUDY DESIGN

Retrospective database study.

OBJECTIVES

Analysis of economic and demographic data concerning lumbar disc arthroplasty (LDA) throughout the United States to improve value-based care and health care utilization.

METHODS

The National Inpatient Sample database was queried for patients who underwent primary or revision LDA between 2005 and 2013. Demographic and economic data included total surgeries, costs, length of stay, and frequency of routine discharge. The National Inpatient Sample database represents a 20% sample of discharges from US hospitals weighted to provide national estimates.

RESULTS

Primary LDA decreased 86% from 3059 to 420 from 2005 to 2013. The mean total cost of LDA increased 33% from $17 747 to $23 804. The mean length of stay decreased from 2.8 to 2.4 days. The mean routine discharge (home discharge without visiting nursing care) remained constant at 91%. Revision procedures (removal, supplemental fixation, or reoperation at the treated level) declined 30% from 194 to 135 cases over the study period. The mean revision burden, defined as the ratio of revision procedures to the sum of primary and revision procedures, was 12% (range 6% to 24%). The mean total cost of revisions ranged from $12 752 to $22 282.

CONCLUSIONS

From 2005 to 2013, primary LDA significantly declined in the United States by 86% despite several studies pointing to improved efficacy and cost-efficiency. This disparity may be related to a lack of surgeon reimbursement from insurance companies. Congruently, the number of revision LDA cases has declined 30%, while revision burden has risen from 6% to 24%.

Clinical Diagnostic Tests versus Medial Branch Blocks for Adults with Persisting Cervical Zygapophyseal Joint Pain: A Systematic Review and Meta-Analysis

Purpose: A systematic review and meta-analysis were performed to identify clinical tests for diagnosing cervical zygapophyseal joint pain (CZP) and to determine their diagnostic accuracy. Method: A search strategy was carried out to find relevant evidence published in CINAHL, Embase, MEDLINE, and PEDro from 1980 to January 1, 2015, pertaining to the clinical diagnosis of CZP. Quality assessment was completed using the Quality Assessment of Diagnostic Accuracy Studies-2. Results were analyzed to pool sensitivity and specificity and clarify diagnostic value. Results: Seven articles (n=463) were included for data synthesis and review. Intersegmental mobility tests were found to have the highest diagnostic accuracy, with pooled sensitivity of 0.91 (95% CI: 0.85, 0.94) and specificity of 0.74 (95% CI: 0.65, 0.81). The pooled sensitivity for mechanical sensitivity (palpation) was 0.88 (95% CI: 0.78, 0.95), and specificity was 0.61 (95% CI: 0.50, 0.71). Conclusion: Limited studies are available that discuss the clinical diagnosis of CZP, and significant heterogeneity is present in the available data. In this review, intersegmental mobility tests were found to be the most accurate. Clustering of tests, agreement on a reference standard, and further exploration of CZP referral patterns are recommended.

Total Disc Replacement Versus Anterior-Posterior Interbody Fusion in the Lumbar Spine and Lumbosacral Junction: A Cost Analysis

STUDY DESIGN

Prospective observational cohort study.

OBJECTIVES

To analyze clinical and economic results in patients with degenerative disc disease in the lumbar area for patients who received combined anterior and posterior fusion or total disc replacement (TDR).

METHODS

The study included 75 patients, 38 in the fusion group and 37 in the TDR group, who received either anterior/posterior fusion or TDR for lumbar disc disease from January 2005 to December 2008 with a minimum follow-up of 24 months. We collected data with regard to clinical parameters, demographics, visual analogue scale scores, Oswestry Disability Index scores, SF-36 and SF-6D data, surgery time, amount of blood loss, transfusion of blood products, number of levels, duration of hospital stay, and complications. For cost analysis, general infrastructure, theatre costs, as well as implant costs were examined, leading to primary hospital costs. Furthermore, average revision costs were examined, based on the actual data. Statistical analysis was performed using t tests for normal contribution and Mann-Whitney test for skew distributed values. The significance level was set to .05.

RESULTS

There was a higher surgery time, more blood loss, and longer hospital stay for the fusion group, compared with the TDR group. In addition, the hospital costs for the primary procedure and revision were 35% higher in the fusion group. The clinical data in terms of SF-36 and SF-6D showed no difference between these 2 groups.

CONCLUSIONS

TDR is a good alternative to anterior and posterior lumbar fusion in terms of short follow-up analysis for clinical data and cost analysis. General advice cannot be given due to missing data for long-term costs in terms of surgical treatment of adjacent level or further fusion techniques.

We Need to Talk about Lumbar Total Disc Replacement

BACKGROUND

Replacement of a diseased lumbar intervertebral disc with an artificial device, a procedure known as lumbar total disc replacement (LTDR), has been practiced since the 1980s.

METHODS

Comprehensive review of published literature germane to LTDR, but comment is restricted to high-quality evidence reporting implantation of lumbar artificial discs that have been commercially available for at least 15 years at the time of writing and which continue to be commercially available.

RESULTS

LTDR is shown to be a noninferior (and sometimes superior) alternative to lumbar fusion in patients with discogenic low back pain and/or radicular pain attributable to lumbar disc degenerative disease (LDDD). Further, LTDR is a motion-preserving procedure, and evidence is emerging that it may also result in risk reduction for subsequent development and/or progression of adjacent segment disease.

CONCLUSIONS

In spite of the substantial logistical challenges to the safe introduction of LTDR to a health care facility, the procedure continues to gain acceptance, albeit slowly.

CLINICAL RELEVANCE

Patients with LDDD who are considering an offer of spinal surgery can only provide valid and informed consent if they have been made aware of all reasonable surgical and nonsurgical options that may benefit them. Accordingly, and in those cases in which LTDR may have a role to play, patients under consideration for other forms of spinal surgery should be informed that this valid procedure exists.

Comparison of therapies in lumbar degenerative disc disease: a network meta-analysis of randomized controlled trials

Aim: To compare the efficacy and safety of total disc replacement, lumbar fusion, and conservative care in the treatment of single-level lumbar degenerative disc disease (DDD). Materials & methods: A network meta-analysis was conducted to determine the relative impact of lumbar DDD therapies on Oswestry Disability Index (ODI) success, back pain score, patient satisfaction, employment status, and reoperation. Odds ratios or mean differences and 95% credible intervals were reported. Results: Six studies were included (1417 participants). Overall, the activL total disc replacement device had the most favorable results for ODI success, back pain, and patient satisfaction. Results for employment status and reoperation were similar across therapies. Conclusion: activL substantially improves ODI success, back pain, and patient satisfaction compared with other therapies for single-level lumbar DDD.

Five-Year Reoperation Rates of 2-Level Lumbar Total Disk Replacement Versus Fusion: Results of a Prospective, Randomized Clinical Trial

STUDY DESIGN

Long-term analysis of prospective randomized clinical trial data.

SUMMARY OF BACKGROUND DATA

Lumbar total disk replacement (TDR) has been found to have equivalent or superior clinical outcomes compared with fusion and decreased radiographic incidence of adjacent level degeneration in single-level cases.

OBJECTIVE

The purpose of this particular analysis was to determine the incidence and risk factors for secondary surgery in patients treated with TDR or circumferential fusion at 2 contiguous levels of the lumbar spine.

METHODS

A total of 229 patients were treated and randomized to receive either TDR or circumferential fusion to treat degenerative disk disease at 2 contiguous levels between L3 and S1 (TDR, n=161; fusion, n=68).

RESULTS

Overall, at final 5-year follow-up, 9.6% of subjects underwent a secondary surgery in this study. The overall rate of adjacent segment disease was 3.5% (8/229). At 5 years, the percentage of subjects undergoing secondary surgeries was significantly lower in the TDR group versus fusion (5.6% vs. 19.1%, P=0.0027).Most secondary surgeries (65%, 17/26) occurred at the index levels. Index level secondary surgeries were most common in the fusion cohort (16.2%, 11/68 subjects) versus TDR (3.1%, 5/161 subjects, P=0.0009). There no statistically significant difference in the adjacent level reoperation rate between TDR (2.5%, 4/161) and fusion (5.9%, 4/68). The most common reason for index levels reoperation was instrumentation removal (n=9). Excluding the instrumentation removals, there was not a significant difference between the treatments in index level reoperations or in reoperations overall.

CONCLUSIONS

There were significantly fewer reoperations in TDR patients compared with fusion patients. However, most of the secondary surgeries were instrumentation removal in the fusion cohort. Discounting the instrumentation removals, there was no significant difference in reoperations between TDR and fusion. These results are indicative that lumbar TDR is noninferior to fusion.

A cost-utility analysis of Dynesys dynamic stabilization versus instrumented fusion for the treatment of degenerative lumbar spine diseases

BACKGROUND

Symptomatic chronic low back and leg pain resulting from lumbar spine degenerative disorders is highly prevalent in China, and for some patients, surgery is the final option for improvement. Several techniques for spinal non-fusion have been introduced to reduce the side-effects of fusion methods and hasten postoperative recovery. In this study, the authors have evaluated the cost-effectiveness of Dynesys posterior dynamic stabilization system (DY) compared with lumbar fusion techniques in the treatment of single-level degenerative lumbar spinal conditions.

METHODS

A total of 221 patients undergoing single-level elective primary surgery for degenerative lumbar pathology were included. 2-Year postoperative health outcomes of Visual Analogue Scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), 36-Item Short Form Health Survey (SF-36) and EuroQol-5 Dimensions (EQ-5D) questionnaires were recorded. 2-Year back-related medical resource use, missed work, and health-state values (Quality-adjusted life-year [QALY]) were assessed. Cost-effectiveness was determined by the incremental cost per QALY gained.

RESULTS

At each follow-up point, both cohorts were associated with significant improvements in VAS scores, ODI, SF-36 scores and EQ-5D QALY scores, which persisted at the 2-year evaluation. The 2-year total mean cost per patient were significantly lower for Dynesys system ($20,150) compared to fusion techniques ($25,581, $27,862 and $27,314, respectively) (P < 0.001). Using EQ-5D, the mean cumulative 2-year QALYs gained were statistically equivalent between the four groups (0.28, 0.27, 0.30 and 0.30 units, respectively) (P = 0.74). Results indicate that patients implanted with the DY system derive lower total costs and more utility, on average, than those treated with fusion.

CONCLUSIONS

The Dynesys dynamic stabilization system is cost effective compared to instrumented lumbar fusion for treatment of single-level degenerative lumbar disorders. It is not possible to state whether DY or lumbar fusion is more cost-effective after 2 years.

Health economic evidence gaps and methodological constraints in low back pain and neck pain: Results of the Research Agenda for Health Economic Evaluation (RAHEE) project

Despite the increased interest in economic evaluations, there are difficulties in applying the results of such studies in practice. Therefore, the "Research Agenda for Health Economic Evaluation" (RAHEE) project was initiated, which aimed to improve the use of health economic evidence in practice for the 10 highest burden conditions in the European Union (including low back pain [LBP] and neck pain [NP]). This was done by undertaking literature mapping and convening an Expert Panel meeting, during which the literature mapping results were discussed and evidence gaps and methodological constraints were identified. The current paper is a part of the RAHEE project and aimed to identify economic evidence gaps and methodological constraints in the LBP and NP literature, in particular. The literature mapping revealed that economic evidence was unavailable for various commonly used LBP and NP treatments (e.g., injections, traction, and discography). Even if economic evidence was available, many treatments were only evaluated in a single study or studies for the same intervention were highly heterogeneous in terms of their patient population, control condition, follow-up duration, setting, and/or economic perspective. Up until now, this has prevented economic evaluation results from being statistically pooled in the LBP and NP literature, and strong conclusions about the cost-effectiveness of LBP and NP treatments can therefore not be made. The Expert Panel identified the need for further high-quality economic evaluations, especially on surgery versus conservative care and competing treatment options for chronic LBP. Handling of uncertainty and reporting quality were considered the most important methodological challenges.

A systematic literature review of time to return to work and narcotic use after lumbar spinal fusion using minimal invasive and open surgery techniques

BACKGROUND

Chronic low back pain is a common health problem for adult workers and causes an enormous economic burden. With the improvement of minimally invasive surgical techniques (MIS) in spinal fusion and the development of fusion devices, more lumbar operations are today being performed through a less invasive technique. When compared with open surgeries (OS), MIS has demonstrated better clinical outcomes including operation time, blood loss, complication rates and length of hospital stay. The aim of this review was to identify and summarize evidence on the time to return to work and the duration of post-operation narcotic use for patients who had lumbar spinal fusion operations using MIS and OS techniques.

METHODS

A systematic literature review was performed including studies identified from PubMed, EMBASE, the Cochrane Collaboration, and the Centre for Review and Dissemination (CRD) (January 2004–April 2014) for publications reporting on time to return to work and post-operation narcotic use after MIS or OS lumbar spinal fusion surgeries.

RESULTS

Out of a total of 36 included studies, 28 reported on the time to return to work and 17 on the narcotic use after MIS or OS. Four studies described the time to return to work directly comparing MIS and OS. Three studies, from the US, directly compared the duration of narcotic use between MIS- transforaminal lumbar interbody fusion (TLIF) and OS-TLIF. In addition to the time to return to work, 23 studies reported on the rate of return to work and the employment rate before and after surgery, and two Swedish studies presented sick leave data.

CONCLUSION

There is a gap of good quality data describing the time to return to work and narcotic use after lumbar spinal fusion operations using MIS or OS techniques. However, the current systematic literature review indicates that patients who have lumbar spinal fusion operations, with the MIS procedure, generally return to work after surgery more quickly and require less post-operation narcotics for pain control compared to patients who have OS.

A systematic review and meta-analysis of outcomes in hybrid constructs for multi-level lumbar degenerative disc disease

A systematic review and meta-analysis was performed to assess the effect of hybrid constructs which involve a total disc arthroplasty (TDA) with stand-alone anterior lumbar interbody fusion (ALIF) versus non-hybrid constructs including multi-level TDA, multi-level transforaminal lumbar interbody fusion (TLIF) with posterior transpedicular fixation or multi-level stand-alone ALIF as a surgical intervention for degenerative disc disease (DDD) in the lumbar spine. Primary outcomes analysed included the Oswestry Disability Index (ODI) and the Visual Analogue Scale (VAS) for back pain. A systematic search of Medline, Embase, Pubmed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Google Scholar was undertaken by two separate reviewers and a meta-analysis of the outcomes was performed. Three studies met our search criteria. When comparing hybrid constructs to multi-level TDA or lumbar fusion (LF) improvements in back pain were found with a VAS back pain score reduction of 1.38 (P<0.00001) postoperatively and a VAS back pain score reduction of 0.99 points (P=0.0006) at 2-years follow-up. Results so far slightly favour clinically significant improved VAS back pain score outcomes postoperatively and at 2-years follow-up for hybrid constructs in multi-level lumbar DDD of the spine when compared with non-hybrid multi-level LF or TDA. It cannot however be concluded that a hybrid construct is superior to multi-level LF or TDA based on this meta-analysis. The results highlight the need for further prospective studies to delineate best practice in the management of degenerative disc disease of the lumbar spine.

A review of economic factors related to the delivery of health care for chronic low back pain

INTRODUCTION AND METHODS

We describe tools used to evaluate the economic impact of health care interventions, discuss the economic burden of chronic low back pain, and review evidence on the cost-effectiveness of treating failed back surgery syndrome with spinal cord stimulation, intrathecal drug delivery, acupuncture, epidural injections, disc prosthesis, lumbar fusion, and noninvasive therapies. We also mention the lack of cost studies for emerging therapies, such as vibrotherapy and peripheral nerve field stimulation. Topics include types of cost studies; the economic perspectives taken by such studies; direct and indirect costs; measures of success; definitions of cost-effectiveness, incremental cost-effectiveness, incremental cost-utility ratios, and quality-adjusted life years; the concept of maximum willingness to pay; and the use of cost-effectiveness models.

CONCLUSION

The fact that chronic low back pain arises from a variety of causes makes choosing appropriate treatment difficult. Determining the cost-effectiveness of various treatments for chronic low back pain depends on well-designed and well-executed randomized controlled trials with parallel economic evaluations. Researchers can use economic models to extrapolate costs and outcomes over the long term.

Economic impact of minimally invasive lumbar surgery

Cost effectiveness has been demonstrated for traditional lumbar discectomy, lumbar laminectomy as well as for instrumented and noninstrumented arthrodesis. While emerging evidence suggests that minimally invasive spine surgery reduces morbidity, duration of hospitalization, and accelerates return to activites of daily living, data regarding cost effectiveness of these novel techniques is limited. The current study analyzes all available data on minimally invasive techniques for lumbar discectomy, decompression, short-segment fusion and deformity surgery. In general, minimally invasive spine procedures appear to hold promise in quicker patient recovery times and earlier return to work. Thus, minimally invasive lumbar spine surgery appears to have the potential to be a cost-effective intervention. Moreover, novel less invasive procedures are less destabilizing and may therefore be utilized in certain indications that traditionally required arthrodesis procedures. However, there is a lack of studies analyzing the economic impact of minimally invasive spine surgery. Future studies are necessary to confirm the durability and further define indications for minimally invasive lumbar spine procedures.

ISASS Policy Statement - Lumbar Artificial Disc

PURPOSE

The primary goal of this Policy Statement is to educate patients, physicians, medical providers, reviewers, adjustors, case managers, insurers, and all others involved or affected by insurance coverage decisions regarding lumbar disc replacement surgery.

PROCEDURES

This Policy Statement was developed by a panel of physicians selected by the Board of Directors of ISASS for their expertise and experience with lumbar TDR. The panel's recommendation was entirely based on the best evidence-based scientific research available regarding the safety and effectiveness of lumbar TDR.

Variations in cost calculations in spine surgery cost-effectiveness research

OBJECT

Cost-effectiveness research in spine surgery has been a prominent focus over the last decade. However, there has yet to be a standardized method developed for calculation of costs in such studies. This lack of a standardized costing methodology may lead to conflicting conclusions on the cost-effectiveness of an intervention for a specific diagnosis. The primary objective of this study was to systematically review all cost-effectiveness studies published on spine surgery and compare and contrast various costing methodologies used.

METHODS

The authors performed a systematic review of the cost-effectiveness literature related to spine surgery. All cost-effectiveness analyses pertaining to spine surgery were identified using the cost-effectiveness analysis registry database of the Tufts Medical Center Institute for Clinical Research and Health Policy, and the MEDLINE database. Each article was reviewed to determine the study subject, methodology, and results. Data were collected from each study, including costs, interventions, cost calculation method, perspective of cost calculation, and definitions of direct and indirect costs if available.

RESULTS

Thirty-seven cost-effectiveness studies on spine surgery were included in the present study. Twenty-seven (73%) of the studies involved the lumbar spine and the remaining 10 (27%) involved the cervical spine. Of the 37 studies, 13 (35%) used Medicare reimbursements, 12 (32%) used a case-costing database, 3 (8%) used cost-to-charge ratios (CCRs), 2 (5%) used a combination of Medicare reimbursements and CCRs, 3 (8%) used the United Kingdom National Health Service reimbursement system, 2 (5%) used a Dutch reimbursement system, 1 (3%) used the United Kingdom Department of Health data, and 1 (3%) used the Tricare Military Reimbursement system. Nineteen (51%) studies completed their cost analysis from the societal perspective, 11 (30%) from the hospital perspective, and 7 (19%) from the payer perspective. Of those studies with a societal perspective, 14 (38%) reported actual indirect costs.

CONCLUSIONS

Changes in cost have a direct impact on the value equation for concluding whether an intervention is cost-effective. It is essential to develop a standardized, accurate means of calculating costs. Comparability and transparency are essential, such that studies can be compared properly and policy makers can be appropriately informed when making decisions for our health care system based on the results of these studies.

Accurately measuring the quality and effectiveness of lumbar surgery in registry efforts: determining the most valid and responsive instruments

BACKGROUND CONTEXT

Prospective registries have emerged as a feasible way to capture real-world care across large patient populations. However, the proven validity of more robust and cumbersome patient-reported outcomes instruments (PROis) must be balanced with what is feasible to apply in large-scale registry efforts.

PURPOSE

To determine the relative validity and responsiveness of common PROis in accurately determining effectiveness of lumbar fusion for degenerative lumbar spondylolisthesis in registry efforts.

STUDY DESIGN

Prospective cohort study.

PATIENT SAMPLE

Fifty-eight patients undergoing transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar spondylolisthesis

OUTCOME MEASURES

Patient-reported outcome measures for pain (numeric rating scale for back and leg pain [NRS-BP, NRS-LP]), disability (Oswestry Disability Index [ODI]), general health (Short Form [SF]-12), quality of life (QOL) (EuroQol five dimensions [EQ-5D]), and depression (Zung depression scale [ZDS]) were assessed.

METHODS

Fifty-eight patients undergoing primary TLIF for lumbar spondylolisthesis were entered into an institutional registry and prospectively followed for 2 years. Baseline and 2-year patient-reported outcomes were assessed. To assess the validity of PROis to discriminate between effective and noneffective improvements, receiver operating characteristic curves were generated for each outcomes instrument. An area under the curve (AUC) of ≥0.80 was considered an accurate discriminator. The difference between standardized response means (SRMs) in patients reporting meaningful improvement versus not was calculated to determine the relative responsiveness of each instrument.

RESULTS

For pain and disability, ODI had AUC=0.94, suggesting it as an accurate discriminator of meaningful improvement. Oswestry Disability Index was most responsive to postoperative improvement (SRM difference: 2.18), followed by NRS-BP and NRS-LP. For general health and QOL, SF-12 physical component score (AUC: 0.90), ZDS (AUC: 0.89), and SF-12 mental component score (AUC: 0.85) were all accurate discriminators of meaningful improvement, however, EQ-5D was most accurate (AUC: 0.97). EuroQol five dimensions was also most responsive (SRM difference: 2.83).

CONCLUSIONS

For pain and disability, ODI was the most valid and responsive measure of effectiveness of lumbar fusion. Numeric rating scale-BP and NRS-LP should not be used as substitutes for ODI in measuring effectiveness of care in registry efforts. For health-related QOL, EQ-5D was the most valid and responsive measure of improvement, however, SF-12 and ZDS are valid alternatives with less responsiveness.

Cost-effective studies in spine surgeries: a narrative review

BACKGROUND CONTEXT

Although the pathologic processes that affect the spine remain largely unchanged, our techniques to correct them continue to evolve with the development of novel medical and surgical interventions. Although the primary purpose of new technologies is to improve patients' quality of life, the economic impact of such therapies must be considered.

PURPOSE

To review the available peer-reviewed literature on spine surgery that addresses the cost-effectiveness of various treatments and technologies.

STUDY DESIGN

A narrative literature review.

METHODS

Articles published between January 1, 2000 and December 31, 2012 were selected from two Pubmed searches using keywords cost-effectiveness AND spine (216 articles) and cost analysis AND spine (358 articles). Relevant articles on cost analyses and cost-effectiveness were selected by the authors and reviewed.

RESULTS

Cervical and lumbar surgeries (anterior cervical discectomy and fusion, standard open lumbar discectomy, and standard posterior lumbar laminectomy) are reasonably cost effective at 2 years after the procedure (<100,000 US dollars per quality-adjusted life years gained) and become more cost effective with time because of sustained clinical improvements with relatively low additional incurred costs. The usage of transfusion avoidance technology is not cost effective because of the low risk of complications associated with allogenic transfusions. Although intraoperative neuromonitoring and imaging modalities are both cost saving and cost-effective, their cost-effectiveness is largely dependent on the baseline rate of neurologic complications and implant misplacement, respectively. More rigorous studies are needed to evaluate the cost-effectiveness of recombinant bone morphogenetic protein.

CONCLUSIONS

An ideal new technology should be able to achieve maximal improvement in patient health at a cost that society is willing to pay. The cost-effectiveness of technologies and treatments in spine care is dependent on their durability and the rate and severity of the baseline clinical problem that the treatment was designed to address.

Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 3: assessment of economic outcome

A comprehensive economic analysis generally involves the calculation of indirect and direct health costs from a societal perspective as opposed to simply reporting costs from a hospital or payer perspective. Hospital charges for a surgical procedure must be converted to cost data when performing a cost-effectiveness analysis. Once cost data has been calculated, quality-adjusted life year data from a surgical treatment are calculated by using a preference-based health-related quality-of-life instrument such as the EQ-5D. A recent cost-utility analysis from a single study has demonstrated the long-term (over an 8-year time period) benefits of circumferential fusions over stand-alone posterolateral fusions. In addition, economic analysis from a single study has found that lumbar fusion for selected patients with low-back pain can be recommended from an economic perspective. Recent economic analysis, from a single study, finds that femoral ring allograft might be more cost-effective compared with a specific titanium cage when performing an anterior lumbar interbody fusion plus posterolateral fusion.

Swespine: the Swedish spine register : the 2012 report

Introduction

Swespine, the Swedish National Spine Register, has existed for 20 years and is in general use within the country since over 10 years regarding degenerative lumbar spine disorders. Today there are protocols for registering all disorders of the entire spinal column.

Materials and methods

Patient-based pre- and postoperative questionnaires, completed before surgery and at 1, 2, 5 and 10 years postoperatively. Among patient-based data are VAS pain, ODI, SF-36 and EQ-5D. Postoperatively evaluation of leg and back pain as compared to preoperatively ("global assessment"), overall satisfaction with outcome and working conditions are registered in addition to the same parameters as preoperatively evaluation. A yearly report is produced including an analytic part of a certain topic, in this issue disc prosthesis surgery.

More than 75,000 surgically treated patients are registered to date with an increasing number yearly. The present report includes 7,285 patients; 1-, 2- and 5-year follow-up data of previously operated patients are also included for lumbar disorders as well as for disc prosthesis surgery.

Results

For the degenerative lumbar spine disorders (disc herniation, spinal stenosis, spondylolisthesis and DDD) significant improvements are seen in all aspects as exemplified by pronounced improvement regarding EQ-5D and ODI. Results seem to be stable over time. Spinal stenosis is the most common indication for spine surgery. Disc prosthesis surgery yields results on a par with fusion surgery in disc degenerative pain. The utility of spine surgery is well documented by the results.

Conclusion

Results of spine surgery as documented on a national basis can be utilized for quality assurance and quality improvement as well as for research purposes, documenting changes over time and bench marking when introducing new surgical techniques. A basis for international comparisons is also laid.

Total disc replacement

Total disc replacement (TDR) (partial disc replacement will not be described) has been used in the lumbar spine since the 1980s, and more recently in the cervical spine. Although the biomechanical concepts are the same and both are inserted through an anterior approach, lumbar TDR is conventionally indicated for chronic low back pain, whereas cervical TDR is used for soft discal hernia resulting in cervicobrachial neuralgia. The insertion technique must be rigorous, with precise centering in the disc space, taking account of vascular anatomy, which is more complex in the lumbar region, particularly proximally to L5-S1. All of the numerous studies, including prospective randomized comparative trials, have demonstrated non-inferiority to fusion, or even short-term superiority regarding speed of improvement. The main implant-related complication is bridging heterotopic ossification with resulting loss of range of motion and increased rates of adjacent segment degeneration, although with an incidence lower than after arthrodesis. A sufficiently long follow-up, which has not yet been reached, will be necessary to establish definitively an advantage for TDR, particularly in the cervical spine.

Accurately Measuring Outcomes After Surgery for Adult Chiari I Malformation

BACKGROUND:

There has been a transition to using patient-reported outcome instruments (PROi) to assess surgical effectiveness. However, none of these instruments have been validated for outcomes of adult Chiari I malformation (CMI).

OBJECTIVE:

The aim of this study was to determine the relative validity and responsiveness of various PROi in measuring outcomes after surgery for CMI.

METHODS:

Fifty patients undergoing suboccipital craniotomy for adult CMI were prospectively followed for 1 year. Baseline and 1-year patient-reported outcomes (visual analog scale for head pain and visual analog scale for neck pain, Neck Disability Index [NDI], Headache Disability Index, SF-12, Zung Self-Rating Depression Scale, and EuroQol-5D [EQ-5D]) were assessed. A level of improvement in general health after surgery was defined as meaningful improvement. Receiver-operating characteristic curves were generated to assess the validity of PROi to discriminate between meaningful improvement and not. The difference between standardized response means (SRMs) in patients reporting meaningful improvement vs not as calculated to determine the relative responsiveness of each outcome instrument.

RESULTS:

For pain and disability, the NDI was the most accurate discriminator of meaningful effectiveness (area under the curve: 0.90) and also most responsive to postoperative improvement (standardized response means difference: 1.87). For general health and quality of life, the SF-12 PCS, EQ-5D, and Zung Self-Rating Depression Scale were all accurate discriminators; however, SF-12 Physical Component Scale (SF-12 PCS) and EQ-5D were most accurate. SF-12 PCS was also most responsive.

CONCLUSION:

For pain and disability, NDI is the most valid and responsive measure of improvement after surgery for CMI. For health-related quality of life, SF-12 PCS and EQ-5D are the most valid and responsive measures. NDI with SF-12 or EQ-5D is the most valid in patients with CMI and should be considered in cost-effectiveness studies.

Cost-effectiveness of lumbar artificial intervertebral disc replacement: driven by the choice of comparator

BACKGROUND

Lower back pain is a common and costly condition in Australia. This paper aims to conduct an economic evaluation of lumbar artificial intervertebral disc replacement (AIDR) compared with lumbar fusion for the treatment of patients suffering from significant axial back pain and/or radicular (nerve root) pain, secondary to disc degeneration or prolapse, who have failed conservative treatment.

METHODS

A cost-effectiveness approach was used to compare costs and benefits of AIDR to five fusion approaches. Resource use was based on Medicare Benefits Schedule claims data and expert opinion. Effectiveness and re-operation rates were based on published randomized controlled trials. The key clinical outcomes considered were narcotic medication discontinuation, achievement of overall clinical success, achievement of Oswestry Disability Index success and quality-adjusted life-years gained.

RESULTS

AIDR was estimated to be cost-saving compared with fusion overall ($1600/patient); however, anterior lumbar interbody fusion and posterolateral fusion were less costly by $2155 and $807, respectively. The incremental cost-effectiveness depends on the outcome considered and the comparator.

CONCLUSIONS

AIDR is potentially a cost-saving treatment for lumbar disc degeneration, although longer-term follow-up data are required to substantiate this claim. The incremental cost-effectiveness depends on the outcome considered and the comparator, and further research is required before any firm conclusions can be drawn.

Total disc replacement for chronic back pain in the presence of disc degeneration

BACKGROUND

In the search for better surgical treatment of chronic low-back pain (LBP) in the presence of disc degeneration, total disc replacement has received increasing attention in recent years. A possible advantage of total disc replacement compared with fusion is maintained mobility at the operated level, which has been suggested to reduce the chance of adjacent segment degeneration.

OBJECTIVES

The aim of this systematic review was to assess the effect of total disc replacement for chronic low-back pain in the presence of lumbar disc degeneration compared with other treatment options in terms of patient-centred improvement, motion preservation and adjacent segment degeneration.

SEARCH METHODS

A comprehensive search in Cochrane Back Review Group (CBRG) trials register, CENTRAL, MEDLINE, EMBASE, BIOSIS, ISI, and the FDA register was conducted. We also checked the reference lists and performed citation tracking of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing total disc replacement with any other intervention for degenerative disc disease.

DATA COLLECTION AND ANALYSIS

We assessed risk of bias per study using the criteria of the CBRG. Quality of evidence was graded according to the GRADE approach. Two review authors independently selected studies and assessed risk of bias of the studies. Results and upper bounds of confidence intervals were compared against predefined clinically relevant differences.

MAIN RESULTS

We included 40 publications, describing seven unique RCT's. The follow-up of the studies was 24 months, with only one extended to five years. Five studies had a low risk of bias, although there is a risk of bias in the included studies due to sponsoring and absence of any kind of blinding. One study compared disc replacement against rehabilitation and found a statistically significant advantage in favour of surgery, which, however, did not reach the predefined threshold for clinical relevance. Six studies compared disc replacement against fusion and found that the mean improvement in VAS back pain was 5.2 mm (of 100 mm) higher (two studies, 676 patients; 95% confidence interval (CI) 0.18 to 10.26) with a low quality of evidence while from the same studies leg pain showed no difference. The improvement of Oswestry score at 24 months in the disc replacement group was 4.27 points more than in the fusion group (five studies; 1207 patients; 95% CI 1.85 to 6.68) with a low quality of evidence. Both upper bounds of the confidence intervals for VAS back pain and Oswestry score were below the predefined clinically relevant difference. Choice of control group (circumferential or anterior fusion) did not appear to result in different outcomes.

AUTHORS' CONCLUSIONS

Although statistically significant, the differences between disc replacement and conventional fusion surgery for degenerative disc disease were not beyond the generally accepted clinical important differences with respect to short-term pain relief, disability and Quality of Life. Moreover, these analyses only represent a highly selected population. The primary goal of prevention of adjacent level disease and facet joint degeneration by using total disc replacement, as noted by the manufacturers and distributors, was not properly assessed and not a research question at all. Unfortunately, evidence from observational studies could not be used because of the high risk of bias, while these could have improved external validity assessment of complications in less selected patient groups. Non-randomised studies should however be very clear about patient selection and should incorporate independent, blinded outcome assessment, which was not the case in the excluded studies. Therefore, because we believe that harm and complications may occur after years, we believe that the spine surgery community should be prudent about adopting this technology on a large scale, despite the fact that total disc replacement seems to be effective in treating low-back pain in selected patients, and in the short term is at least equivalent to fusion surgery.

Predictors of outcome after surgery with disc prosthesis and rehabilitation in patients with chronic low back pain and degenerative disc: 2-year follow-up

PURPOSE

A prospective study to evaluate whether certain baseline characteristics can predict outcome in patients treated with disc prosthesis or multidisciplinary rehabilitation.

METHODS

Secondary analysis of 154 patients with chronic low back pain (LBP) for at least 1 year and degenerative discs originally recruited for a randomized trial. Outcome measures were Oswestry Disability Index (ODI) dichotomized to < or ≥15 points improvement and whether subjects were working at 2-year follow-up. A multiple logistic regression analysis was used.

RESULTS

In patients treated with disc prosthesis, long duration of LBP and high Fear-Avoidance Beliefs for work (FABQ-W) predicted worse ODI outcome [odds ratio (OR) = 1.9, 95% confidence interval (CI) 1.2-3.2 and OR = 1.7, CI 1.2-2.4 for every 5 years or 5 points]. Modic type I or II predicted better ODI outcome (OR = 5.3, CI 1.1-25.3). In patients treated with rehabilitation, a high ODI, low emotional distress (HSCL-25), and no daily narcotics predicted better outcome for ODI (OR = 2.5, CI 1.4-4.5 for every 5 ODI points, OR = 2.1, CI 1.1-5.1 for every 0.5 HSCL points and OR = 23.6, CI 2.1-266.8 for no daily narcotics). Low FABQ-W and working at baseline predicted working at 2-year follow-up after both treatments (OR = 1.3, CI 1.0-1.5 for every 5 points and OR = 4.1, CI 1.2-13.2, respectively).

CONCLUSIONS

Shorter duration of LBP, Modic type I or II changes and low FABQ-W were the best predictors of success after treatment with disc prosthesis, while high ODI, low distress and not using narcotics daily predicted better outcome of rehabilitation. Low FABQ-W and working predicted working at follow-up.

Validity and responsiveness of the Core Outcome Measures Index (COMI) for the neck

PURPOSE

Patient-orientated outcome questionnaires are essential to evaluate treatment success. To compare different treatments, hospitals, and surgeons, standardised questionnaires are required. The present study examined the validity and responsiveness of the Core Outcome Measurement Index for neck pain (COMI-neck), a short, multidimensional outcome instrument.

METHODS

Questionnaires were completed by patients with degenerative problems of the cervical spine undergoing cervical disc arthroplasty before (N = 89) and 3 months after (N = 75) surgery. The questionnaires comprised the EuroQol-Five Dimension (EQ-5D), the North American Spine Society Cervical Spine Outcome Assessment Instrument (NASS-cervical) and the COMI-neck.

RESULTS

The COMI and NASS-cervical scores displayed no notable floor or ceiling effects at any time point whereas for the EQ-5D, the highest values [corrected] were reached in around 32.5% of patients at follow-up. With one exception (symptom-specific well-being), the individual COMI items and the COMI summary score correlated to the expected extent (R = 0.4-0.8) with the scores of the chosen reference questionnaires. The area under the curve (AUC) generated by ROC analysis was significantly higher for the COMI (0.96) than for any other instrument/subscale when self reported treatment outcome was used as the external criterion, dichotomised as "good" (operation helped a lot/helped) versus "poor" (operation helped only a little/didn't help/made things worse). The COMI had a high effect size (standardised response mean; SRM) (2.34) for the good global outcome group and a low SRM for the poor outcome group (0.34). The EQ-5D and the NASS-cervical lacked this ability to differentiate between the two groups, showing less distinct SRMs for good and poor outcome groups.

CONCLUSIONS

This study provides evidence that the COMI-neck is a valid and responsive questionnaire in the population of patients examined. Further investigations should examine its applicability in other patient groups with less severe neck pain or undergoing other treatment modalities.