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

Cost-effectiveness of surgical interventions in low-income and middle-income countries: a systematic review and critical analysis of recent evidence

BACKGROUND

Cost-effectiveness evidence is a critical tool to support resource allocation decisions. There is growing recognition that the development of benefit packages for surgical care should be guided by such evidence, particularly in resource-constraint settings.

METHODS

We conducted a systematic review of evidence (Medline, Embase, Global Health, EconLit and grey literature) on the cost-effectiveness of surgery across low-income and middle-income countries published between January 2013 and January 2023. We included studies with minor and major therapeutic surgeries and minimally invasive intraluminal and endovascular interventions. We computed and compared the average cost-effectiveness ratios (ACERs) for different surgical interventions to the respective national gross domestic product per capita to determine cost-effectiveness and to common traditional public health interventions.

RESULTS

We identified 87 unique studies out of 20 070 articles screened. Studies spanned 23 countries, with China (n=20), Thailand (n=12), Brazil (n=8) and Iran (n=8) accounting for about 55% of the evidence. Overall, the median ACERs across procedure groups ranged from I$17/disability-adjusted life year (DALY) for laparotomies to I$170 186/DALY for bariatric surgeries. Most of the ACER estimates were classified as cost-effective (89%) or very cost-effective (76%). Low-complexity surgical interventions compared favourably to common public health interventions.

CONCLUSION

These findings reinforce the growing body of evidence that investments in surgery are economically smart. There remains however paucity of high-quality evidence that would allow decision-makers to assess the comparative cost-effectiveness of surgery and to determine best buys across a wide range of specialties and interventions. A concerted effort is needed to advance the generation and utilisation of economic evidence in the drive towards scale-up of surgical care across low-income and middle-income countries.

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.

Medium and long-term radiographic and clinical outcomes of Dynesys dynamic stabilization versus instrumented fusion for degenerative lumbar spine diseases

BACKGROUND

Dynesys stabilization (DS) is utilized to preserve mobility at the instrumental segments and prevent adjacent segment pathology in clinical practice. However, the advantages of DS method in medium and long-term follow-up remain controversial.

OBJECTIVE

To compare the radiographic and clinical outcomes between DS and instrumented fusion in the treatment of degenerative lumbar spine disease with or without grade I spondylolisthesis with a minimum follow-up period of 2 years.

METHODS

We conducted a comprehensive search of PubMed, EMBASE, Cochrane, and Web of Science databases, Chinese National Knowledge Databases, and Wanfang Database for potentially eligible articles. Clinical outcomes were assessed in terms of VAS and ODI scores, screw loosening and breakage, and surgical revision. Radiographic outcomes were assessed in terms of postoperative range of movement (ROM) and disc heigh. Moreover, adjacent segment degeneration (ASDeg) and adjacent segment disease (ASDis) were evaluated.

RESULTS

Seventeen studies with 1296 patients were included in the meta-analysis. The DS group was associated with significantly lower postoperative VAS scores for low-back and leg pain, and lower rate of surgical revision than the fusion group. Moreover, the Dynesys group showed significantly less ASDeg than the fusion group but showed no significant advantage over the fusion group in terms of preventing ASDis. Additionally, the ROM at the stabilized segments of the fusion group decreased significantly and that at the adjacent segments increased significantly compared with those of the DS group.

CONCLUSION

DS showed comparable clinical outcomes and provided benefits in preserving the motion at the stabilized segments, thus limiting the hypermobility at the adjacent segments and preventing ASDeg compared with the fusion method in degenerative disease with or without grade I spondylolisthesis.

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.

Comparison of novel stabilisation device with various stabilisation approaches: A finite element based biomechanical analysis

The treatment of spinal failure requires suitable instrumentation, which is based on numerous concepts such as rigid fixation, semi-rigid and dynamic stabilisation. In the present work, the biomechanical investigation of various fixation systems on the lumbar segment L2-L3 was performed employing finite element analysis. Different devices were considered: novel stabilisation device (NSD), rigid implant (RI) and existing dynamic stabilisation device (EDSD). All instrumented models were loaded with a condition of 400 N compressive force with a moment of 10Nm during flexion, extension, lateral bending and axial rotation. The results of range of motion change (RMC), von-Mises stress and strain were compared. The spinal biomechanics post instrumentation resulted significantly sensitive to the geometrical feature of the implant. The obtained results showed that NSD has intermediate motion characteristics in between dynamic stabilisation and rigid fixation. However, the optimum features of a novel stabilisation device for the treatment of spinal failure still need to be verified employing in-vivo, in-vitro studies.

Mobility-Preserving Surgery for Lumbar Spinal Stenosis: WFNS Spine Committee Recommendations

Background

Although decompression is the basis of surgical treatment for lumbar spinal stenosis (LSS), under various circumstances instrumented fusion is performed as well. The rationale for mobility-preserving operations for LSS is preventing adjacent segment disease (ASD). We review the rationale for mobility preservation in ASD and discuss related topics such as indications for fusion and the evolving role of minimally invasive approaches to lumbar spine decompression. Our focus is on systematic review and consensus discussion of mobility-preserving surgical methods as related to surgery for LSS.

Methods

Groups of spinal surgeons (members of the World Federation of Neurosurgical Societies Spine Committee) performed systematic reviews of dynamic fixation systems, including hybrid constructs, and of interspinous process devices; consensus statements were generated based on the reviews at 2 voting sessions by the committee several months apart. Additional review of background data was performed, and the results summarized in this review.

Results

Decompression is the basis of surgical treatment of LSS. Fusion is an option, especially when spondylolisthesis or instability are present, but indications remain controversial. ASD incidence reports show high variability. ASD may represent the natural progression of degenerative disease in many cases. Older age, poor sagittal balance, and multilevel fusion may be associated with more ASD. Dynamic fixation constructs are treatment options that may help prevent ASD.

Multi-segmental lumbar spinal stenosis treated with Dynesys stabilization versus lumbar fusion in elderly patients: a retrospective study with a minimum of 5 years' follow-up

INTRODUCTION

Middle- and long-term outcomes of multi-segmental lumbar spinal stenosis treated with Dynesys stabilization (DS) have rarely been reported. Older age and multi-segmental degeneration may be positive factors in achieving satisfactory outcomes following DS. The present study aimed to compare the middle- and long-term outcomes of DS with lumbar fusion for treatment of multi-segmental lumbar spinal stenosis (ms-LSS) in elderly patients.

MATERIALS AND METHODS

This study retrospectively analyzed patients with ms-LSS treated by DS or lumbar fusion from January 2011 to April 2013. Twenty-two patients were included in the Dynesys group, and 44 patients treated by lumbar fusion and rigid fixation were included in the fusion group. Clinical outcomes were assessed by VAS and ODI. Radiological outcomes were measured by range of motion (ROM) of stabilized segments and the proximal adjacent segment, intervertebral disc height (DH) and L1-S1 lumbar lordosis angle (LL). Modified Pfirrmann grade score was used to access disc degeneration.

OUTCOMES

The mean follow-up time of the Dynesys group and fusion group was 68.50 ± 6.40 and 70.14 ± 7.26 months, respectively. Baseline data were similar between the two groups. There were no significant differences between the two groups in terms of improvement of clinical outcomes (VAS and ODI). DS preserved a certain degree of ROM (3.74 ± 2.00) of surgical segments. ROM of proximal adjacent segment underwent an increase in both groups at the final follow-up. The DH of the surgical segments and proximal adjacent segment in both groups was significantly lower than that before surgery (P = 0.000). LL of both groups improved (P = 0.000), and there was no significant difference between the two groups. The modified Pfirrmann score of proximal adjacent segment of both groups increased at the final follow-up. The fusion group underwent a more significant increase (P = 0.000), whereas the inter-group difference showed no significance (P = 0.090).

CONCLUSION

DS is a safe and effective surgical treatment of multi-segmental lumbar spinal stenosis in the elderly population. DS preserves a certain degree of mobility of surgical segments.

Single balloon versus double balloon bipedicular kyphoplasty: a systematic review and meta-analysis

INTRODUCTION

Kyphoplasty has been widely used to treat vertebral compression fractures (VCFs). In standard procedure of kyphoplasty, two balloons were inserted into the vertebral body through bipedicular and inflated simultaneously, while using a single balloon two times is also a common method in clinic to lessen the financial burden of patients. However, the effect and safety of single balloon versus double balloon bipedicular kyphoplasty are still controversy.

METHODS

In this systematic review and meta-analysis, eligible studies were identified through a comprehensive literature search of PubMed, Cochrane library EMBASE, Web of Science, Wanfang, CNKI, VIP and CBM until January 1, 2018. Results from individual studies were pooled using a random or fixed effects model.

RESULTS

Seven articles were included in the systematic review and five studies were consisted in meta-analysis. We observed no significant difference between single balloon and double balloon bipedicular kyphoplasty in visual analog scale (VAS), angle (kyphotic angle and Cobb angle), consumption (operation time, cement volume and volume of bleeding), vertebral height (anterior height, medium height and posterior height) and complications (cement leakage and new VCFs), while the cost of single balloon bipedicular kyphoplasty is lower than that of double balloon bipedicular kyphoplasty. The results of our meta-analysis also demonstrated that single balloon can significantly improve the VAS, angle and vertebral height of patients suffering from VCFs.

CONCLUSION

This systematic review and meta-analysis collectively concludes that single balloon bipedicular kyphoplasty is as effective as double balloon bipedicular kyphoplasty in improving clinical symptoms, deformity and complications of VCFs but not so expensive. These slides can be retrieved under Electronic Supplementary Material.

Finite element simulation and clinical follow-up of lumbar spine biomechanics with dynamic fixations

Arthrodesis is a recommended treatment in advanced stages of degenerative disc disease. Despite dynamic fixations were designed to prevent abnormal motions with better physiological load transmission, improving lumbar pain and reducing stress on adjacent segments, contradictory results have been obtained. This study was designed to compare differences in the biomechanical behaviour between the healthy lumbar spine and the spine with DYNESYS and DIAM fixation, respectively, at L4-L5 level. Behaviour under flexion, extension, lateral bending and axial rotation are compared using healthy lumbar spine as reference. Three 3D finite element models of lumbar spine (healthy, DYNESYS and DIAM implemented, respectively) were developed, together a clinical follow-up of 58 patients operated on for degenerative disc disease. DYNESYS produced higher variations of motion with a maximum value for lateral bending, decreasing intradiscal pressure and facet joint forces at instrumented level, whereas screw insertion zones concentrated stress. DIAM increased movement during flexion, decreased it in another three movements, and produced stress concentration at the apophyses at instrumented level. Dynamic systems, used as single systems without vertebral fusion, could be a good alternative to degenerative disc disease for grade II and grade III of Pfirrmann.