Balloon kyphoplasty versus KIVA vertebral augmentation--comparison of 2 techniques for osteoporotic vertebral body fractures: a prospective randomized study

Mechanical Vertebral Body Augmentation Versus Conventional Balloon Kyphoplasty for Osteoporotic Thoracolumbar Compression Fractures: A Systematic Review and Meta-Analysis of Outcomes

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

Surgical management of osteoporotic vertebral compression fractures (OVCFs) has traditionally consisted of vertebroplasty or kyphoplasty procedures. Mechanical percutaneous vertebral body augmentation (MPVA) systems have recently been introduced as alternatives to traditional methods. However, the effectiveness of MPVA systems vs conventional augmentation techniques for OVCFs remains unclear. This serves as the premise for this study.

METHODS

A systematic review and meta-analysis was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies of interest included randomized controlled trials (RCTs) which directly compared patient outcomes following kyphoplasty to patients treated with MPVA systems. Clinical and radiological findings were collated and compared for significance between cohorts.

RESULTS

6 RCTs were identified with 1024 patients total. The mean age of all patients was 73.5 years. 17% of the cohort were male, 83% were female. 515 patients underwent kyphoplasty and 509 underwent mechanical vertebral body augmentation using MPVA systems. MPVAs showed similar efficacy for restoration of vertebral body height (P = .18), total complications (P = .36), cement extravasation (P = .58) and device-related complications (P = .06). MPVAs also showed reduced rates of all new fractures (16.4% vs 22.2%; P = .17) and adjacent fractures (14.7% vs 18.9%; P = .23), with improved visual analogue scale (VAS) scores at 6-month (P = .13).

CONCLUSION

The results of this meta-analysis highlight no significant improvement in clinical or radiological outcomes for MPVA systems when compared to balloon kyphoplasty for vertebral body augmentation. Further research is needed to establish a true benefit over traditional operative methods.

Risk of adjacent level fracture after percutaneous vertebroplasty and kyphoplasty vs natural history for the management of osteoporotic vertebral compression fractures: a network meta-analysis of randomized controlled trials

OBJECTIVES

Percutaneous vertebroplasty and kyphoplasty are common interventions for osteoporotic vertebral compression fractures. However, there is concern about an increased risk of adjacent-level fractures after treatment. This study aimed to compare the risk of adjacent-level fractures after vertebroplasty and kyphoplasty with the natural history after osteoporotic vertebral compression fractures.

MATERIALS AND METHODS

A network meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate the risk of adjacent-level fractures after vertebroplasty and kyphoplasty compared to the natural history after osteoporotic vertebral compression fractures. Frequentist network meta-analysis was conducted using the "netmeta" package, and heterogeneity was assessed using Q statistics. The pooled risk ratio (RR) and 95% confidence intervals (CI) were calculated using random effects.

RESULTS

Twenty-three RCTs with a total of 2838 patients were included in the analysis. The network meta-analysis showed comparable risks of adjacent-level fractures between vertebroplasty, kyphoplasty, and natural history after osteoporotic vertebral compression fractures with a mean follow-up of 21.2 (range: 3-49.4 months). The pooled RR for adjacent-level fractures after kyphoplasty compared to natural history was 1.35 (95% CI, 0.78-2.34, p = 0.23) and for vertebroplasty compared to natural history was 1.16 (95% CI, 0.62-2.14) p = 0.51. The risk of bias assessment showed a low to moderate risk of bias among included RCTs.

CONCLUSION

There was no difference in the risk of adjacent-level fractures after vertebroplasty and kyphoplasty compared to natural history after osteoporotic vertebral compression fractures. The inclusion of a large patient number and network meta-analysis of RCTs serve evidence-based clinical practice.

CLINICAL RELEVANCE STATEMENT

The risk of adjacent-level fracture following percutaneous vertebroplasty or kyphoplasty is similar to that observed in the natural history after osteoporotic vertebral compression fractures.

KEY POINTS

RCTs have examined the risk of adjacent-level fracture after intervention for osteoporotic vertebral compression fractures. There was no difference between vertebroplasty and kyphoplasty patients compared to the natural disease history for adjacent compression fractures. This is strong evidence that interventional treatments for these fractures do not increase the risk of adjacent fractures.

A novel device with pedicular anchorage provides better biomechanical properties than balloon kyphoplasty for the treatment of vertebral compression fractures

PURPOSE

To compare the biomechanical behavior of vertebrae with vertebral compression fractures (VCF) treated by a novel system with pedicular anchorage (dowelplasty) versus balloon kyphoplasty.

METHODS

Four cadaveric spines (T12-L5) were harvested, cleaned from soft tissues, and separated into vertebrae. Axial compressive loads were applied to each vertebra until a VCF was generated. Half of the vertebrae (n = 11) were instrumented using the "dowelplasty" system, consisting of a hollow titanium dowel anchored into the pedicle, through which a cannulated titanium nail is inserted and locked and through which cement is injected. The other half (n = 11) were instrumented using balloon kyphoplasty. Axial compressive loads were re-applied to each vertebra until fracture. Fracture load and fracture energy were calculated from load-displacement data for the pre- and post-treatment states.

RESULTS

Compared to balloon kyphoplasty, dowelplasty granted greater net change in fracture load (373N; 95%CI,-331-1076N) and fracture energy (755Nmm; 95%CI,-563-2072Nmm). A sensitivity analysis was performed without L4 and L5 vertebrae from the dowelplasty group, since the length of the cannulated nails was too short for these vertebrae: compared to balloon kyphoplasty, dowelplasty granted an even greater net change in fracture load (680N; 95%CI,-96-1457N) and fracture energy (1274Nmm; 95%CI,-233-2781Nmm).

CONCLUSION

Treating VCFs with dowelplasty grants increased fracture load and fracture energy compared to the pre-treatment state. Furthermore, dowelplasty grants greater improvement in fracture load and fracture energy compared to balloon kyphoplasty, which suggests that dowelplasty may be a good alternative for the treatment of VCF.

LEVEL OF EVIDENCE

level IV.

Biomechanical evaluation of a novel minimally invasive pedicle bone cement screw applied to the treatment of Kümmel's disease in porcine vertebrae

Background and objective: Treatment of Kümmel's Disease (KD) with pure percutaneous kyphoplasty carries a greater likelihood of bone cement displacement due to hardened bone and defect of the peripheral cortex. In this study, we designed a novel minimally invasive pedicle bone cement screw and evaluate the effectiveness and safety of this modified surgical instruments in porcine vertebrae. Methods: 18 mature porcine spine specimens were obtained and soaked in 10% formaldehyde solution for 24 h. 0.5000 mmol/L EDTA-Na2 solution was used to develop in vitro osteoporosis models of porcine vertebrae. They were all made with the bone deficiency at the anterior edge of L1. These specimens were randomly divided into 3 groups for different ways of treatment: Group A: pure percutaneous kyphoplasty (PKP) group; Group B: unilateral novel minimally invasive pedicle bone cement screw fixation combined with PKP group; Group C: bilateral novel minimally invasive pedicle bone cement screw fixation combined with PKP group. The MTS multi-degree of freedom simulation test system was used for biomechanical tests, including axial loading of 500 N pressure, range of motion (ROM) in flexion, extension, left/right lateral bending, and left/right axial rotation at 5 Nm, and the displacement of bone cement mass at maximum angles of 5° and 10°. Result: The three groups were well filled with bone cement, no leakage or displacement of bone cement was observed, and the height of the vertebrae was higher than pre-operation (p < 0.05). In the left/right axial rotation, the specimens were still significantly different (p < 0.05) from the intact specimens in terms of ROM after PKP. In other directions, ROM of all group had no significant difference (p < 0.05) and was close to the intact vertebrae. Compared with PKP group, the relative displacement of bone cement in groups B and C was smaller (p < 0.05). Conclusion: In the in vitro animal vertebral models, the treatment of KD with the placement of novel pedicle minimally invasive bone cement screw combined with PKP can effectively restore the vertebral height, improve the stability of the affected vertebra and prevent the displacement of bone cement. Biomechanically, there is no significant difference between bilateral and unilateral fixation.

Effect of a new transpedicular vertebral device for the treatment or prevention of vertebral compression fractures: A finite element study

BACKGROUND

A finite element study was performed to investigate the biomechanical performance of a novel transpedicular implant (V-STRUT©, Hyprevention, France) made of PEEK (polyetheretherketone) material in terms of strengthening the osteoporotic vertebra and the thoraco-lumbar spine. The objective was to assess numerically the efficacy of the implant to reduce the stress distribution within bone and absorb part of the stress by the implant thanks to its optimized material selection close to that of normal bone.

METHODS

A numerical model was generated based on a scan of an osteoporotic patient. The model is composed of three consecutive vertebrae and intervertebral discs. A heterogeneous distribution of bone material properties was assigned to the bone. In order to investigate the rationale of the device material selection, three FE models were developed (i) without the device to serve a reference model, (ii) with device made in Titanium material and (iii) with device made in PEEK material. Stiffness and stress distribution within the spine segment were computed and compared in order to assess the implants' performances.

FINDINGS

The results obtained by the simulations indicated that the novel transpedicular implant made of PEEK material provided support to the superior vertebral endplate, restored the thoraco-lumbar spine segment stiffness and reduced the stress applied to the vertebrae under the compressive load.

INTERPRETATION

Implant geometry in combination with its material properties are very important factors to restore vertebral strength and stiffness and limiting the risk of fracture at the same vertebra or adjacent ones.

The American Society of Pain and Neuroscience (ASPN) Evidence-Based Clinical Guideline of Interventional Treatments for Low Back Pain

Introduction

Painful lumbar spinal disorders represent a leading cause of disability in the US and worldwide. Interventional treatments for lumbar disorders are an effective treatment for the pain and disability from low back pain. Although many established and emerging interventional procedures are currently available, there exists a need for a defined guideline for their appropriateness, effectiveness, and safety.

Objective

The ASPN Back Guideline was developed to provide clinicians the most comprehensive review of interventional treatments for lower back disorders. Clinicians should utilize the ASPN Back Guideline to evaluate the quality of the literature, safety, and efficacy of interventional treatments for lower back disorders.

Methods

The American Society of Pain and Neuroscience (ASPN) identified an educational need for a comprehensive clinical guideline to provide evidence-based recommendations. Experts from the fields of Anesthesiology, Physiatry, Neurology, Neurosurgery, Radiology, and Pain Psychology developed the ASPN Back Guideline. The world literature in English was searched using Medline, EMBASE, Cochrane CENTRAL, BioMed Central, Web of Science, Google Scholar, PubMed, Current Contents Connect, Scopus, and meeting abstracts to identify and compile the evidence (per section) for back-related pain. Search words were selected based upon the section represented. Identified peer-reviewed literature was critiqued using United States Preventive Services Task Force (USPSTF) criteria and consensus points are presented.

Results

After a comprehensive review and analysis of the available evidence, the ASPN Back Guideline group was able to rate the literature and provide therapy grades to each of the most commonly available interventional treatments for low back pain.

Conclusion

The ASPN Back Guideline represents the first comprehensive analysis and grading of the existing and emerging interventional treatments available for low back pain. This will be a living document which will be periodically updated to the current standard of care based on the available evidence within peer-reviewed literature.

Risk factors for recollapse of new vertebral compression fractures after percutaneous kyphoplasty in geriatric patients: establishment of a nomogram

Background

The main objective of this study was to investigate the risk factors for recollapse of new vertebral compression fractures (NVCFs) after percutaneous kyphoplasty (PKP) treatment for osteoporotic vertebral compression fracture (OVCF) and to construct a new nomogram model.

Methods

We retrospectively analysed single-level OVCFs from January 2017 to June 2020, randomizing patients to a training set and a testing set. In the training set, independent risk factors for NVCFs in OVCF patients treated with PKP were obtained by univariate and multivariate regression analyses. These risk factors were then used as the basis for constructing a nomogram model. Finally, internal validation of the built model was performed in the testing set using the consistency index (C-index), receiver operating characteristic (ROC) curves, calibration curves and decision curve analysis (DCA).

Results

In total, 371 patients were included in this study. NVCFs occurred in 21.7% of the training set patients, and multivariate regression analysis showed that a low Hounsfield unit (HU) value, cement leakage, and thoracolumbar (TL) junction fracture were independent risk factors for NVCF after PKP. The C-index was 0.81 (95% CI: 0.74–0.81), and the validation showed that the predicted values of the established model were in good agreement with the actual values.

Conclusions

In this study, three independent risk factors were obtained by regression analysis. A nomogram model was constructed to guide clinical work and to make clinical decisions relatively accurately to prevent the occurrence of vertebral recollapse fractures.

Establishment and Validation of a Nomogram for the Risk of New Vertebral Compression Fractures After Percutaneous Vertebroplasty in Patients With Osteoporotic Vertebral Compression Fractures: A Retrospective Study

Purpose

New vertebral compression fractures(NVCFs) after minimally invasive surgery in patients with osteoporotic vertebral compression fracture (OVCF) is a challenging issue worldwide. Predicting the occurrence of NVCFs is key to addressing such questions. Therefore, we aimed to investigate the risk factors for patients who developed NVCFs after undergoing surgical treatment and establish a nomogram model to reduce the occurrence of NVCFs.

Methods

This study is a retrospective analysis that collected the general characteristics and surgical features of patients who underwent surgical treatment at 2 central institutions between January 2017 and December 2020. Patients were divided into training and testing sets based on the presence or absence of NVCFs. Independent risk factors for NVCFs were obtained in the training set of patients, and then a nomogram model was constructed. Internal and external validation of the nomogram model was performed using the consistency index (C index), receiver operating characteristic curve(ROC), calibration curves, and decision curve analysis (DCA).

Results

A total of 562 patients were included in this study. Patients from the first center were used for nomogram construction and internal validation, and patients from the second center were used as an external validation population. Multivariate regression analysis showed that age, Hounsfield unit (Hu) value, cement leakage, and thoracolumbar (TL) junction fracture were independent risk factors for NVCFs after minimally invasive surgery. The C index was .85, and the validation of internal and external validation shows that the predicted values of the established model is in good agreement with the actual values.

Conclusions

In this study, 4 independent risk factors were obtained by regression analysis, and a nomogram model was constructed to guide clinical work. The application of this model can help surgeons to make more accurate judgments to prevent the occurrence of NVCFs.

Therapeutic Efficacy of Third-Generation Percutaneous Vertebral Augmentation System (PVAS) in Osteoporotic Vertebral Compression Fractures (OVCFs): A Systematic Review and Meta-analysis

Purpose

This study aimed to assess whether the third-generation PVAS was superior to percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) in treating patients with OVCFs.

Methods

Databases, including Pubmed, Embase, and Cochrane library, were searched to identify relevant interventional and observational articles in vivo or in vitro comparing the third-generation PVAS to PVP/PKP in OVCFs patients. A meta-analysis was performed under the guidelines of the Cochrane Reviewer's Handbook.

Results

11 in vivo articles involving 1035 patients with 1320 segments of diseased vertebral bodies and 8 in vitro studies enrolling 40 specimens with 202 vertebral bodies were identified. The vivo studies indicated no significant differences were found in visual analog scale (VAS), Oswestry Disability Index (ODI), operation time, or injected cement volume (P > 0.05). The third-generation PVAS was associated with significant improvement in vertebral height and Cobb angle (P < 0.05) and also with a significantly lower risk of cement leakages and new fractures (P < 0.05). The vitro studies suggest that the third-generation PVAS was associated with better anterior vertebral height (AVH) and kyphotic angle (KA) after deflation and cement. No significant differences were found in stiffness or failure load after cement between the two groups (P > 0.05).

Conclusion

Based on current evidence, although providing similar improvement in VAS and ODI, the third-generation PVAS may be superior to PVP/PKP in local kyphosis correction, vertebral height maintenance, and adverse events reduction. Further high-quality randomized studies are required to confirm these results.

Influence of Industry in Hydrocephalus and Vertebral Augmentation Literature

OBJECTIVE

To investigate whether financial bias exists in hydrocephalus and vertebral augmentation literature.

METHODS

A systematic literature search was performed in PubMed of studies concerning vertebral augmentation and cerebrospinal fluid valves. The relationship between reported conflicts of interest and the nature of the conclusion (positive vs. neutral and negative) was analyzed.

RESULTS

Having a conflict of interest was significantly associated with reporting a positive conclusion in studies investigating valves for hydrocephalus (92.3% positive conclusion vs. 36.4%; P = 0.001), but not for cement augmentation studies (80.5% positive conclusion vs. 65.7%; P = 0.087). As studies concerning vertebral augmentation implants had only positive conclusions, no analysis could be performed.

CONCLUSIONS

Our findings suggest a positive relationship between reported conflict of interest and positive outcome in neurosurgical literature concerning cerebrospinal fluid valves.

Balloon Kyphoplasty vs Vertebroplasty: A Systematic Review of Height Restoration in Osteoporotic Vertebral Compression Fractures

Purpose of Review

This systematic review comprehensively compared balloon kyphoplasty and vertebroplasty with respect to height restoration and pain relief.

Recent Findings

PRISMA guidelines were utilized to compare balloon kyphoplasty and vertebroplasty, focusing on the primary outcome of height restoration and the secondary outcomes of pain relief and functionality. A total of 33 randomized controlled trials were included; 20 reviewed balloon kyphoplasty, 7 reviewed vertebroplasty, and 6 compared vertebroplasty to balloon kyphoplasty. Both treatments restored some vertebral body height and showed benefits in pain reduction and improved patient-reported functionality.

Summary

Balloon kyphoplasty and vertebroplasty are effective treatments for vertebral compression fractures and this review suggests that balloon kyphoplasty may be favored for vertebral height restoration. Further studies are needed to conclude whether balloon kyphoplasty or vertebroplasty is superior for alleviating pain.

Risk factors of new vertebral compression fracture after percutaneous vertebroplasty or percutaneous kyphoplasty

BACKGROUND

New vertebral compression fracture (VCF) may occur in patients who underwent percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fracture (OVCF). However, the risk factors of new VCF remain controversial. The research aimed to analyze the risk factors of new VCF after PVP or PKP.

METHODS

From August 2019 to March 2021, we retrospectively analyzed the patients who underwent PVP or PKP for OVCF at our institution. Age, gender, body mass index (BMI), smoking, drinking, hypertension, diabetes, fracture location, surgical method, Hounsfield unit (HU) value, preoperative degree of anterior vertebral compression (DAVC), bisphosphonates, bone cement volume, bone cement leakage, and cement distribution were collected. The risk factors were obtained by univariate and multivariate analysis of the data.

RESULTS

A total of 247 patients were included in the study. There were 23 patients (9.3%) with new VCF after PVP or PKP. Univariate analysis showed that age (p < 0.001), BMI (p = 0.002), fracture location (p = 0.030), and a low HU value (p < 0.001) were significantly associated with new VCF after PVP or PKP. A low HU value was an independent risk factor for new VCF after PVP or PKP obtained by multivariate regression analysis (OR = 0.963; 95% CI, 0.943-0.984, p = 0.001).

CONCLUSIONS

In this study, a low HU value was an independent risk factor of new VCF after PVP or PKP.

Do sandwich vertebral bodies increase the risk of post-augmentation fractures? A retrospective cohort study

Until now, there have been only a few retrospective studies that focused on the outcomes of sandwich vertebral bodies (SVBs). This is a long-term retrospective cohort study to investigate the SVBs. We found that although patients with SVBs had a relatively high risk of developing new fractures after VA, the incidence rate of new fractures was not significantly different from that of the control group. However, the statistical power of this study was very limited. Therefore, and because the refracture rate in these patients is substantial, routine long-term monitoring of patients after VA for osteoporosis is strongly recommended.

BACKGROUND

Sandwich vertebral bodies (SVBs) are intact unaugmented vertebral bodies between two previously augmented vertebrae. Until recently, only a few studies have reported the outcomes and strategies for SVBs. This retrospective cohort study aimed to describe the clinical features and incidence of new fractures in patients with SVBs.

METHODS

The clinical data were collected from 179 patients with 237 symptomatic osteoporotic vertebral compression fractures who underwent vertebral augmentation (VA). Among them, 23 patients with 24 levels of SVBs were included. Spinal radiographs (X-ray and CT) of all patients were evaluated prior to surgery 1 day after primary VA and during follow-up.

RESULTS

All patients successfully underwent PKP with an average follow-up period of 21.48 months. Asymptomatic cement leakage occurred in four patients (17.4%), and eight patients (34.8%) developed new fractures following primary PKP, including four sandwich, six adjacent, four remote vertebral fractures, and one re-collapse of cemented vertebrae. The incidence of new fractures in the SVB and control groups was 16.7% (4/24) and 13.0% (6/46), respectively, but there was no significant difference.

CONCLUSIONS

Although patients with SVBs had a relatively high risk of developing new fractures after VA, the incidence rate of new fractures was not significantly different from that of the control group. However, the statistical power of this study was very limited. Therefore, and because the refracture rate in these patients is substantial, routine long-term monitoring of patients after VA for osteoporosis is strongly recommended.

Systematic Review and Meta-Analysis of 3 Treatment Arms for Vertebral Compression Fractures: A Comparison of Improvement in Pain, Adjacent-Level Fractures, and Quality of Life Between Vertebroplasty, Kyphoplasty, and Nonoperative Management

BACKGROUND

Osteoporotic vertebral fractures (OVFs) have become increasingly common, and previous nonrandomized and randomized controlled trials (RCTs) have compared the effects of cement augmentation versus nonoperative management on the clinical outcome. This meta-analysis focuses on RCTs and the calculated differences between cement augmentation techniques and nonsurgical management in outcome (e.g., pain reduction, adjacent-level fractures, and quality of life [QOL]).

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, and the following scientific search engines were used: MEDLINE, Embase, Cochrane, Web of Science, and Scopus. The inclusion criteria included RCTs that addressed different treatment strategies for OVF. The primary outcome was pain, which was determined by a visual analog scale (VAS) score; the secondary outcomes were the risk of adjacent-level fractures and QOL (as determined by the EuroQol-5 Dimension [EQ-5D] questionnaire, the Oswestry Disability Index [ODI], the Quality of Life Questionnaire of the European Foundation for Osteoporosis [QUALEFFO], and the Roland-Morris Disability Questionnaire [RDQ]). Patients were assigned to 3 groups according to their treatment: vertebroplasty (VP), kyphoplasty (KP), and nonoperative management (NOM). The short-term (weeks), midterm (months), and long-term (>1 year) effects were compared. A random effects model was used to summarize the treatment effect, including I2 for assessing heterogeneity and the revised Cochrane risk-of-bias 2 (RoB 2) tool for assessment of ROB. Funnel plots were used to assess risk of publication bias. The log of the odds ratio (OR) between treatments is reported.

RESULTS

After screening of 1,861 references, 53 underwent full-text analysis and 16 trials (30.2%) were included. Eleven trials (68.8%) compared VP and NOM, 1 (6.3%) compared KP and NOM, and 4 (25.0%) compared KP and VP. Improvement of pain was better by 1.31 points (95% confidence interval [CI], 0.41 to 2.21; p < 0.001) after VP when compared with NOM in short-term follow-up. Pain effects were similar after VP and KP (midterm difference of 0.0 points; 95% CI, -0.25 to 0.25). The risk of adjacent-level fractures was not increased after any treatment (log OR, -0.16; 95% CI, -0.83 to 0.5; NOM vs. VP or KP). QOL did not differ significantly between the VP or KP and NOM groups except in the short term when measured by the RDQ.

CONCLUSIONS

This meta-analysis provides evidence in favor of the surgical treatment of OVFs. Surgery was associated with greater improvement of pain and was unrelated to the development of adjacent-level fractures or QOL. Although improvements in sagittal balance after surgery were poorly documented, surgical treatment may be warranted if pain is a relevant problem.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Invasive Treatments for Low Back Disorders

OBJECTIVE

This abbreviated version of the American College of Occupational and Environmental Medicine's Low Back Disorders guideline reviews the evidence and recommendations developed for invasive treatments used to manage low back disorders.

METHODS

Comprehensive systematic literature reviews were accomplished with article abstraction, critiquing, grading, evidence table compilation, and guideline finalization by a multidisciplinary expert panel and extensive peer-review to develop evidence-based guidance. Consensus recommendations were formulated when evidence was lacking and often relied on analogy to other disorders for which evidence exists. A total of 47 high-quality and 321 moderate-quality trials were identified for invasive management of low back disorders.

RESULTS

Guidance has been developed for the invasive management of acute, subacute, and chronic low back disorders and rehabilitation. This includes 49 specific recommendations.

CONCLUSION

Quality evidence should guide invasive treatment for all phases of managing low back disorders.

Fragility Analysis of Statistically Significant Outcomes of Randomized Control Trials in Spine Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The aim of this study was to assess the robustness of statistically significant outcomes from randomized control trials (RCTs) in spine surgery using Fragility Index (FI) which is a novel metric measuring the number of events upon which statistical significance of the outcome depends.

SUMMARY OF BACKGROUND DATA

Many trials in Spine surgery were characterized by fewer outcome events along with small sample size. FI helps us identify the robustness of the results from such studies with statistically significant dichotomous outcomes.

METHODS

We conducted independent and in duplicate, a systematic review of published RCTs in spine surgery from PubMed Central, Embase, and Cochrane Database. RCTs with 1:1 prospective study design and reporting statistically significant dichotomous primary or secondary outcomes were included. FI was calculated for each RCT and its correlation with various factors was analyzed.

RESULTS

Seventy trials met inclusion criteria with a median sample size of 133 (interquartile range [IQR]: 80-218) and median reported events per trial was 38 (IQR: 13-94). The median FI score was 2 (IQR: 0-5), which means if we switch two patients from nonevent to event, the statistical significance of the outcome is lost. The FI score was less than the number of patients lost to follow-up in 28 of 70 trials. The FI score was found to positively correlated with sample size (r = 0.431, P = 0.001), total number of outcome events (r = 0.305, P = 0.01) while negatively correlated with P value (r = -0.392, P = 0.001). Funding, journal impact-factor, risk of bias domains, and year of publication did not have a significant correlation.

CONCLUSION

Statistically significant dichotomous outcomes reported in spine surgery RCTs are more often fragile and outcomes of the patients lost to follow-up could have changed the significance of results and hence it needs caution before transcending their results into clinical application. The addition of FI in routine reporting of RCTs would guide readers on the robustness of the statistical significance of outcomes. RCTs with FI ≥5 without any patient lost to follow-up can be considered to have clinically robust results.Level of Evidence: 1.

Advances in Vertebral Augmentation Systems for Osteoporotic Vertebral Compression Fractures

Osteoporotic vertebral compression fracture (OVCF) is a common cause of pain and disability and is steadily increasing due to the growth of the elderly population. To date, percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) are almost universally accepted as appropriate vertebral augmentation procedures for OVCFs. There are many advantages of vertebral augmentation, such as short surgical time, performance under local anaesthesia, and rapid pain relief. However, there are certain issues regarding the utilization of these vertebral augmentations, such as loss of vertebral height, cement leakage, and adjacent vertebral refracture. Hence, the treatment for OVCF has changed in recent years. Satisfactory clinical results have been obtained worldwide after application of the OsseoFix System, the SpineJack System, radiofrequency kyphoplasty of the vertebral body, and the Kiva VCF treatment system. The following review discusses the development of the current techniques used for vertebral augmentation.

Comparison Between 7 Osteoporotic Vertebral Compression Fractures Treatments: Systematic Review and Network Meta-analysis

BACKGROUND

Vertebroplasty (VP), kyphoplasty (KP), SpineJack system (SJ), radiofrequency kyphoplasty (RFK), Kiva system (Kiva), Sky kyphoplasty system (SK), and conservative treatment are widely used in the treatment of osteoporotic vertebral compression fractures (OVCFs). However, it is still unknown which is the best intervention. The aim of the current study was to evaluate the effectiveness and safety of VP, KP, SJ, RFK, Kiva, SK, and CT in the treatment of OVCFs.

METHODS

Randomized controlled trials and cohort studies comparing VP, KP, SJ, RFK, Kiva, SK, or CT for the treatment of OVCFs were identified on the basis of databases including PubMed, the Cochrane Library, Web of Science, and Springer Link. A network meta-analysis was performed using STATA 15.1.

RESULTS

A total of 56 studies with 6974 patients and 7 interventions were included in this study. The results of the surface under the cumulative probability demonstrated that SK was the best intervention in decreasing VAS scores and recovering middle vertebral height, RFK was the best intervention in improving ODI scores and decreasing incidence of new fractures, SJ was the best intervention to restore kyphosis angle, and Kiva was the best intervention to reduce incidence of bone cement leakage. Cluster analysis showed that SK was the preferable intervention on the basis of the outcomes of VAS, ODI, middle vertebral height, and kyphotic angle, and RFK was the preferable treatment in decreasing the incidence of adverse events. In our network meta-analysis, node-splitting analysis and loop inconsistency analysis showed no significant inconsistencies.

CONCLUSIONS

SK may be the most effective treatment in relieving pain, improving the quality of life, and recovering vertebral body height and kyphotic angle, while RFK may be the safest intervention for OVCFs. However, considering the limitations of this study, more high-quality trials are needed in the future to confirm the current conclusion.

Vertebral augmentation with spinal implants: third-generation vertebroplasty

This article is to review the different types of vertebral augmentation implants recently becoming available for the treatment of benign and malignant spinal compression fractures. After a detailed description of the augmentation implants, we review the available clinical data. We will conclude with a summary of the advantages and disadvantages of vertebral implants and how they can affect the future treatment options of compression fractures.

Evaluation of pain reduction and height restoration post vertebral augmentation using a polyether ether ketone (PEEK) polymer implant for the treatment of split (Magerl A2) vertebral fractures: a prospective, long-term, non-randomized study

OBJECTIVES

The purposes of the study were to evaluate the safety and long-term efficacy of augmented vertebroplasty using a polyether ether ketone (PEEK) implant, for the treatment of lumbar or thoracic vertebral fractures (A2 according to the Magerl's AO classification) and to analyze pain reduction, height restoration, and complications during a 2-year follow-up period.

METHODS

Prospective non-randomized evaluation was performed for 21 painful split vertebral fractures (20 patients, 14 females, 6 males; mean age 72.80 ± 10.991) treated with percutaneous vertebral augmentation using a PEEK device, under fluoroscopic guidance. Pain before the procedure and after 6, 12, and 24 months was evaluated using a numeric visual scale (NVS) questionnaire. Imaging was performed by CT and X-rays. The minimum craniocaudal diameter at the level of the fracture and the maximum craniocaudal diameter at the middle of the fractured vertebra were measured. Statistical analysis was performed to evaluate pain decrease and height restoration.

RESULTS

Successful implant positioning was achieved in all cases. No major clinical complications were observed. Comparing the mean pain scores at baseline (8.69 ± 1.138) and the first day after the treatment (1.19 ± 1.424), there was a decrease of 7.50 NVS units (p < 0.001). Minimum and maximum vertebral body heights were increased after the procedure 56.58% and 13.7% respectively (p < 0.001). Both pain relief and height restoration remained statistically significant (p < 0.001) during the follow-up period.

CONCLUSION

A2 Magerl thoracic or lumbar fractures could be successfully treated with PEEK implant-assisted vertebral augmentation. Randomized studies with larger sample sizes should be done to confirm the effectiveness of the technique.

KEY POINTS

• Vertebral augmentation using a PEEK implant for the treatment of A2 Magerl lumbar or thoracic vertebral fractures seems to be effective both in terms of pain reduction and height restoration. • Effects on pain reduction and height restoration have a long-term duration. • The technique seems to be safe for the treatment of A2 Magerl fractures, without major complications in our study group.

A Review and Clinical Perspective of the Impact of Osteoporosis on the Spine

Introduction

Osteopenia and osteoporosis are common conditions in the United States. The health consequences of low bone density can be dire, from poor surgical outcomes to increased mortality rates following a fracture.

Significance

This article highlights the impact low bone density has on spine health in terms of vertebral fragility fractures and its adverse effects on elective spine surgery. It also reviews the clinical importance of bone health assessment and optimization.

Results

Vertebral fractures are the most common fragility fractures with significant consequences related to patient morbidity and mortality. Additionally, a vertebral fracture is the best predictor of a subsequent fracture. These fractures constitute sentinel events in osteoporosis that require further evaluation and treatment of the patient's underlying bone disease. In addition to fractures, osteopenia and osteoporosis have deleterious effects on elective spine surgery from screw pullout to fusion rates. Adequate evaluation and treatment of a patient's underlying bone disease in these situations have been shown to improve patient outcomes.

Conclusion

With an increased understanding of the prevalence of low bone mass and its consequences as well an understanding of how to identify these patients and appropriately intervene, spine surgeons can effectively decrease the rates of adverse health outcomes related to low bone mass.

Treatment of a High-risk Thoracolumbar Compression Fracture Using Bilateral Expandable Titanium SpineJack Implants

In this case, an 80-year-old active patient developed an acute osteoporotic fracture after a fall at L1 above a previous interlaminar implant at L4-5 for stenosis with neurogenic claudication. Radiologic studies found both intra-discal and intra-vertebral vacuum clefts that are highly correlated with instability and progressive kyphosis. Long-term experience with kyphoplasty has shown that acute and subacute fractures can often be re-expanded; however, over three months to one year, the correction is frequently lost and the vertebral height continues to decrease leading to increased risk of both continued deformity and especially adjacent level fractures. The use of newly available titanium intra-vertebral implants combined with bone cement restores and maintains vertebral height and correction of deformities. Long-term studies also demonstrate a reduced risk of adjacent level fractures compared to balloon kyphoplasty. Using vertebral body implants that remain in place within the fractured vertebral body the initial height correction can be better maintained leading to less adjacent level fractures.

Balloon Kyphoplasty in the Treatment of Neoplastic Spine Lesions: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

To assess the efficacy of kyphoplasty in controlling pain and improving quality of life in oncologic patients with metastatic spinal disease and pathologic compression fractures of the spine.

METHODS

A literature search through medical database was conducted (using PubMed, EMBASE, Cochrane, and LILACS) for randomized controlled trials comparing balloon kyphoplasty versus the traditional treatment for compression fractures of the spine due to metastatic disease. Two investigators independently assessed all titles and abstracts to select potential articles to be included. Inclusion criteria consisted of randomized controlled trials involving patients with pathologic compression fractures due to spinal metastasis or multiple myeloma treated with balloon kyphoplasty procedure as one of the study interventions, while the control group was any other treatment modality. The risk of bias in individual studies was assessed.

RESULTS

Two studies, with a combined total of 181 patients, met inclusion criteria. Because of data heterogeneity, the meta-analysis was not possible, and individual analysis of studies was performed. There is moderate evidence that patients treated with balloon kyphoplasty displayed better scores for pain (Numeric Rating Scale), disability (Roland-Morris Disability Questionnaire), quality of life (Short Form-36 Health Survey), and functional status (Karnofsky Performance Status) compared with those undergoing the conventional treatment. Patients treated with kyphoplasty also have better recovery of vertebral height.

CONCLUSIONS

This study concluded that balloon kyphoplasty could be considered as an early treatment option for patients with symptomatic neoplastic spinal disease, although further randomized clinical trials should be performed for improvement of the quality of evidence.

Re-expansion of Osteoporotic Compression Fractures Using Bilateral SpineJack Implants: Early Clinical Experience and Biomechanical Considerations

Thoraco-lumbar osteoporotic compression fractures have a higher incidence of continued collapse with development of deformity and progression to vertebra plana when untreated and even after vertebral augmentation (VA) or balloon kyphoplasty (BKP). Even when there is the restoration of height and improvement in angulation, multiple long-term follow-up series have repeatedly documented that over time, many patients lose the initial height correction and in a smaller group the vertebral body re-collapses leading to the development of progressive deformity with an increased risk for adjacent level fractures. At first, larger balloons and more cement were used to try and avoid these problems, but it did not reduce the risk of adjacent fractures. Several procedures were developed to place various types of intervertebral implants combined with bone cement to maintain the initial height correction. Initial studies with these implants showed a reduction in adjacent level fractures but the systems did not proceed to market. The SpineJack^R (SJ) system (Stryker Corp, Kalamazoo, MI), consisting of bilateral expandable titanium implants supplemented with bone cement, was first used approximately 10 years ago in Europe and recently gained FDA approval in the United States. This system provides more symmetric and balanced lateral and anterior support and is effective with lesser amounts of bone cement compared to BKP. Follow-up studies have documented that there is equal or better pain control, with better long-term results based both on maintaining vertebral height restoration and deformity correction. Most importantly, statistically it clearly reduces the risk of adjacent level fractures by at least 60%. The biomechanical effects of intravertebral implants for osteoporotic fractures in regard to the risk of adjacent level fractures and preliminary experience with the use of the SJ is reviewed.

The role of cement augmentation with percutaneous vertebroplasty and balloon kyphoplasty for the treatment of vertebral compression fractures in multiple myeloma: a consensus statement from the International Myeloma Working Group (IMWG)

Multiple myeloma (MM) represents approximately 15% of haematological malignancies and most of the patients present with bone involvement. Focal or diffuse spinal osteolysis may result in significant morbidity by causing painful progressive vertebral compression fractures (VCFs) and deformities. Advances in the systemic treatment of myeloma have achieved high response rates and prolonged the survival significantly. Early diagnosis and management of skeletal events contribute to improving the prognosis and quality of life of MM patients. The management of patients with significant pain due to VCFs in the acute phase is not standardised. While some patients are successfully treated conservatively, and pain relief is achieved within a few weeks, a large percentage has disabling pain and morbidity and hence they are considered for surgical intervention. Balloon kyphoplasty and percutaneous vertebroplasty are minimally invasive procedures which have been shown to relieve pain and restore function. Despite increasing positive evidence for the use of these procedures, the indications, timing, efficacy, safety and their role in the treatment algorithm of myeloma spinal disease are yet to be elucidated. This paper reports an update of the consensus statement from the International Myeloma Working Group on the role of cement augmentation in myeloma patients with VCFs.

The Efficacy and Safety of Vertebral Augmentation: A Second ASBMR Task Force Report

Vertebral augmentation is among the current standards of care to reduce pain in patients with vertebral fractures (VF), yet a lack of consensus regarding efficacy and safety of percutaneous vertebroplasty and kyphoplasty raises questions on what basis clinicians should choose one therapy over another. Given the lack of consensus in the field, the American Society for Bone and Mineral Research (ASBMR) leadership charged this Task Force to address key questions on the efficacy and safety of vertebral augmentation and other nonpharmacological approaches for the treatment of pain after VF. This report details the findings and recommendations of this Task Force. For patients with acutely painful VF, percutaneous vertebroplasty provides no demonstrable clinically significant benefit over placebo. Results did not differ according to duration of pain. There is also insufficient evidence to support kyphoplasty over nonsurgical management, percutaneous vertebroplasty, vertebral body stenting, or KIVA®. There is limited evidence to determine the risk of incident VF or serious adverse effects (AE) related to either percutaneous vertebroplasty or kyphoplasty. No recommendation can be made about harms, but they cannot be excluded. For patients with painful VF, it is unclear whether spinal bracing improves physical function, disability, or quality of life. Exercise may improve mobility and may reduce pain and fear of falling but does not reduce falls or fractures in individuals with VF. General and intervention-specific research recommendations stress the need to reduce study bias and address methodological flaws in study design and data collection. This includes the need for larger sample sizes, inclusion of a placebo control, more data on serious AE, and more research on nonpharmacologic interventions. Routine use of vertebral augmentation is not supported by current evidence. When it is offered, patients should be fully informed about the evidence. Anti-osteoporotic medications reduce the risk of subsequent vertebral fractures by 40-70%. © 2018 American Society for Bone and Mineral Research.

Improved biomechanics of two alternative kyphoplasty cementation methods limit vertebral recollapse

The clinical efficacy of vertebral cement augmentation for compression fractures (VCFs) remains undetermined. Recent studies have shown that refracture and progression of deformity may occur after augmentation with significant clinical consequences. Vertebral body height loss following kyphoplasty has also been observed with cyclic loading. We hypothesized that height loss is partly due to lack of cement fill past the margin of cancellous bone created by balloon expansion with subsequent failure under load. The biomechanical characteristics of two alternative cementation techniques were compared to standard kyphoplasty in cyclically loaded cadaveric VCF constructs. Sectioned osteoporotic thoracolumbar cadaveric spines were compressed to 75% of anterior vertebral height. Specimens were then allocated to standard kyphoplasty, balloon pressurization (BP), with reinflation of the balloon after 50% cement injection, or endplate post (EP), with perforation of the cavity rim using an articulating curette prior to injection. Following cementation, each specimen was preconditioned and loaded over 100,000 cycles. All techniques improved vertebral height (p's < 0.005). The EP and BP techniques provided greater cement fill than the standard technique (p's ≤ 0.01). Normalized vertebral height loss following 100,000 cycles was reduced with the EP technique versus standard kyphoplasty (p < 0.04). Height loss was inversely correlated with cement fill (p < 0.03). No vertebral recollapse occurred with the EP technique in blinded radiographic analysis. Statement of clinical significance: The EP technique demonstrated improved biomechanical characteristics versus the standard technique in cadaveric osteoporotic VCF constructs with decreased recollapse following cementation. This technique may have increased efficacy in cases when kyphoplasty more substantially improves vertebral body height. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3225-3230, 2018.

New vertebral fractures after osteoporotic vertebral compression fracture between balloon kyphoplasty and nonsurgical treatment PRISMA

BACKGROUND

Because of aging of population, osteoporotic vertebral compression fracture (OVCF) appears an increasing incidence rate. Conservative therapy (CT) and balloon kyphoplasty (BKP) have been used to treat OVCFs. However, an increase in new vertebral compression fractures at nontreated levels following BKP is of concern. It is still not clear whether new fractures were a result of BKP and the purpose of this meta-analysis was to evaluate the new fractures risk after BKP compared with CT.

METHODS

An exhaustive literature search of PubMed, EMBASE, and the Cochrane Library was conducted to identify randomized controlled trials and prospective nonrandomized controlled study that compared BKP with CT for patients suffering OVCF. A random-effect model was used. Results were reported as standardized mean difference or risk ratio with 95% confidence interval.

RESULTS

Twelve studies were included and there was no significant difference in total new fractures (P = .33) and adjacent fractures (P = .83) between 2 treatments. Subgroup analyses did not demonstrate significant differences in follow-up period, mean age, anti-osteoporosis therapy, and the proportion of women.

CONCLUSION

Our systematic review revealed that an increased risk of fracture of vertebral bodies was not associated with BKP compared with CT.

Review of Vertebral Augmentation: An Updated Meta-analysis of the Effectiveness

Background

To update vertebral augmentation literature by comparing outcomes between vertebroplasty (VP), balloon kyphoplasty (BKP), vertebral augmentation with implant (VAI), and nonsurgical management (NSM) for treating vertebral compression fractures (VCFs).

Methods

A PubMed literature search was conducted with keywords kyphoplasty, vertebroplasty, vertebral body stent, and vertebral augmentation AND implant for English-language articles from February 1, 2011, to November 22, 2016. Among the results, 25 met the inclusion criteria for the meta-analysis. Inclusion criteria were prospective comparative studies for mid-/lower-thoracic and lumbar VCFs enrolling at least 20 patients. Exclusion criteria included studies that were single arm, systematic reviews and meta-analyses, traumatic nonosteoporotic or cancer-related fractures, lack of clinical outcomes, or non-Level I and non-Level II studies. Standardized mean difference between baseline and end point for each outcome was calculated, and treatment groups were pooled using random effects meta-analysis.

Results

Visual analog scale pain reduction for BKP and VP was -4.05 and -3.88, respectively. VP was better than but not significantly different from NSM (-2.66), yet BKP showed significant improvement from both NSM and VAI (-2.77). The Oswestry Disability Index reduction for BKP showed a significant improvement over VAI (P < .001). There was no significant difference in changes between BKP and VP for anterior (P = .226) and posterior (P = .293) vertebral height restoration. There was no significant difference in subsequent fractures following BKP (32.7%; 95% confidence interval [CI]: 8.8%-56.6%) or VP (28.3%; 95% CI: 7.0%-49.7%) compared with NSM (15.9%; 95% CI: 5.2%-26.6%).

Conclusions/Level of Evidence

Based on Level I and II studies, BKP had significantly better and VP tended to have better pain reduction compared with NSM. BKP tended to have better height restoration than VP. Additionally, BKP had significant improvements in pain reduction and disability score as compared with VAI.

Clinical Relevance

This meta-analysis serves to further define and support the safety and efficacy of vertebral augmentation.

Vertebral Fragility Fractures (VFF)-Who, when and how to operate

Vertebral Fragility Fractures (VFF) are common and lead to pain, long term disability and increased mortality. Most patients will have mild to moderate pain symptoms and can be managed conservatively. However, patients with severe pain who have minimal or no pain relief with potent analgesia, or who only achieve adequate pain relief with high doses of morphine based analgesia which results in significant adverse events, should be considered for vertebral augmentation. Ideally, for vertebral augmentation, patients should present within four months of the fracture (onset of acute pain) and have at least 3 weeks of failure of conservative treatment although early intervention may be more appropriate for hospitalised patients, who tend to be older, more frail and likely to be less tolerant to the adverse effects of conservative treatment. The Cardiovascular and Interventional Radiological Society of Europe (CIRSE) recommends Percutaneous Vertebroplasty as the first line surgical augmentation technique for VFF in older people, which has been shown to improve pain symptoms, allow early restoration of functional mobility and may reduce the risk of further vertebral collapse. CIRSE recommends percutaneous Balloon Kyphoplasty as second line treatment in VFF, although the optimal indication is for acute traumatic vertebral fractures (less than 7-10 days) in younger people. Assessment and treatment of underlying osteoporosis is important to reduce the risk of further fractures in older people with VFF.

Pain, Quality of Life, and Safety Outcomes of Kyphoplasty for Vertebral Compression Fractures: Report of a Task Force of the American Society for Bone and Mineral Research

The relative efficacy and harms of balloon kyphoplasty (BK) for treating vertebral compression fractures (VCF) are uncertain. We searched multiple electronic databases to March 2016 for randomized and quasi-randomized controlled trials comparing BK with control treatment (nonsurgical management [NSM], percutaneous vertebroplasty [PV], KIVA VCF treatment system [Benvenue Medical, Inc., Santa Clara, CA, USA], vertebral body stenting, or other) in adults with VCF. Outcomes included back pain, back disability, quality of life, new VCF, and adverse events (AEs). One reviewer extracted data, a second checked accuracy, and two rated risk of bias (ROB). Mean differences and 95% confidence intervals (CIs) were calculated using inverse-variance models. Risk ratios of new VCF and AE were calculated using Mantel-Haenszel models. Ten unique trials enrolled 1837 participants (age range, 61 to 76 years; 74% female), all rated as having high or uncertain ROB. Versus NSM, BK was associated with greater reductions in pain, back-related disability, and better quality of life (k = 1 trial) that appeared to lessen over time, but were less than minimally clinically important differences. Risk of new VCF at 3 and 12 months was not significantly different (k = 2 trials). Risk of any AE was increased at 1 month (RR = 1.73; 95% CI, 1.36 to 2.21). There were no significant differences between BK and PV in back pain, back disability, quality of life, risk of new VCF, or any AE (k = 1 to 3 trials). Limitations included lack of a BK versus sham comparison, availability of only one RCT of BK versus NSM, and lack of study blinding. Individuals with painful VCF experienced symptomatic improvement compared with baseline with all interventions. The clinical importance of the greater improvements with BK versus NSM is unclear, may be due to placebo effect, and may not counterbalance short-term AE risks. Outcomes appeared similar between BK and other surgical interventions. Well-conducted randomized trials comparing BK with sham would help resolve remaining uncertainty about the relative benefits and harms of BK. © 2017 American Society for Bone and Mineral Research.

Spinal Compression Fracture Management: A Review of Current Treatment Strategies and Possible Future Avenues

STUDY DESIGN

Narrative review.

OBJECTIVE

Despite the numerous treatment options for vertebral compression fractures, a consensus opinion for the management of patients with these factures has not been established. This review is meant to provide an up-to-date overview of the most common treatment strategies for compression fractures and to suggest possible routes for the development of clearer treatment guidelines.

METHODS

A comprehensive database search of PubMed was performed. All results from the past 30 years were obtained and evaluated based on title and abstract. The full length of relevant studies was analyzed for level of evidence, and the strongest studies were used in this review.

RESULTS

The major treatment strategies for patients with compression fractures are conservative pain management and vertebral augmentation. Despite potential adverse effects, medical management, including nonsteroidal anti-inflammatory drugs, calcitonin, teriparatide, and bisphosphonates, remains the first-line therapy for patients. Evidence suggests that vertebral augmentation, especially some of the newer procedures, have the potential to dramatically reduce pain and improve quality of life. At this time, balloon-assisted kyphoplasty is the procedure with the most evidence of support.

CONCLUSIONS

Based on current literature, it is evident that there is a lack of standard of care for patients with vertebral compression fractures, which is either due to lack of evidence that a procedure is successful or due to serious adverse effects encountered with prolonged treatment. For a consensus to be reached, prospective clinical trials need to be formulated with potential new biomarkers to assess efficacy of treatment strategies.

Better Height Restoration, Greater Kyphosis Correction, and Fewer Refractures of Cemented Vertebrae by Using an Intravertebral Reduction Device: a 1-Year Follow-up Study

PURPOSE

This study compared the radiologic and clinical outcomes of kyphoplasty with intravertebral reduction device (IRD) and vertebroplasty (VP) in treating osteoporotic vertebral compression fractures (OVCFs).

MATERIALS AND METHODS

We enrolled 75 patients with OVCFs who were aged >60 years and treated them through VP or kyphoplasty with IRD. The radiologic outcomes, namely the anterior and middle body heights (ABH and MBH, respectively) and kyphotic angle (KA), were measured preoperatively and at postoperative 1 week, 3 months, 6 months, and 1 year. The refracture was identified on the basis of a decrease in ABH, MBH, or KA compared with those at postoperative 1 week. Visual analog scale (VAS) for pain and complications were recorded. The incidence of adjacent and nonadjacent fractures was also recorded.

RESULTS

We treated 36 patients with kyphoplasty with IRD (IRD group) and 39 through VP (VP group). The patient characteristics were comparable in both groups. The KA and its restoration were more favorable after IRD than after VP. Although ABHs were not different in either group, their restoration was more efficient after IRD than after VP. MBHs, their restoration, and their refracture rates were better after IRD than after VP. VAS pain scores and complication rates were not different between the groups. The incidences of adjacent or nonadjacent fractures were not different between the 2 groups.

CONCLUSION

Our findings reveal significantly more efficient height restoration and kyphosis correction and fewer refractures in the IRD group. IRD may not increase the risk of adjacent or nonadjacent fractures.

Treatment of vertebral compression fractures with the cranio-caudal expandable implant SpineJack®: Technical note and outcomes in 77 consecutive patients

In vertebral compression fractures, the potential of kyphoplasty for restoring vertebral height is limited by the loss of restored height that occurs when the balloon is deflated and removed. SpineJack(®) is also inserted percutaneously but is then left within the vertebral body after its expansion to reduce the fracture, thus avoiding loss of correction before the injection of cement. SpineJack(®) was used in 77 patients to treat 83 recent VCFs (55.4% at L1-L2) due to trauma (59.7%) or osteoporosis (40.3%). Three (3.9%) complications were recorded, but none was related to SpineJack(®): there was one case each of symptomatic cement leakage along a secondary pedicular fracture line; infection; and incipient device migration at the beginning of the learning curve. The rate of adjacent fractures was only 2.6%. The 5-year outcomes demonstrate that SpineJack(®) provides both immediate and long-term benefits in terms of pain relief, functional recovery, and maintenance of vertebral height restoration.

LEVEL OF EVIDENCE

IV, retrospective study.

The fragility of statistically significant findings from randomized trials in spine surgery: a systematic survey

BACKGROUND CONTEXT

Randomized controlled trials (RCTs) are the most trustworthy source for evaluating treatment effects, but RCTs of spine surgery interventions often produce discordant results. The Fragility Index is a novel metric to inform about the robustness of statistically significant results.

PURPOSE

The aim was to determine the robustness of statistically significant results from RCTs of spine surgery interventions.

STUDY DESIGN/SETTING

This was a systematic survey.

PATIENT SAMPLE

The sample included RCTs of spine surgery interventions.

OUTCOME MEASURES

The Fragility Index is the minimum number of patients in a trial whose status would have to change from a nonevent to an event to change a statistically significant result to a nonsignificant result. Events refer to the occurrence of any dichotomous outcome, such as successful fusion, incident fracture, adjacent segment degeneration, or achievement of a certain functional score. A small Fragility Index indicates that the statistical significance of a result hinges on only a few events, and a large Fragility Index increases one's confidence in the observed treatment effects.

METHODS

We systematically reviewed a database for evidence-based orthopedics and identified all the RCTs that reported at least one positive outcome (ie, p<.05). Two reviewers independently assessed eligibility and extracted data. We used the Fisher exact test to compute Fragility Index values and multivariable linear regression to evaluate potential associated factors.

RESULTS

We identified 40 eligible RCTs with a median sample size of 132 patients (interquartile range [IQR] 79-208) and a median total number of outcome events for the chosen outcome of 31 (IQR 13-63). The median Fragility Index was two (IQR 1-3), which means that adding two events to one of the trial's treatment arms eliminated its statistical significance. The Fragility Index was less than or equal to three events in 75% of the trials, and was less than or equal to the number of patients lost to follow-up in 65% of the trials. Fragility Index values correlated positively with total sample size (r=0.35; p<.05). When adjusted for losses to follow-up and risk of bias, increasing Fragility Index values were associated only with increasingly significant reported p values (p<.01).

CONCLUSIONS

Statistically significant results in spine surgery RCTs are frequently fragile. The addition of only a small number of outcome events can completely eliminate significance. Surgeons, researchers, and other evidence users should exercise caution when interpreting the findings from RCTs with low Fragility Index values and applying these results to patient care.

KAST Study: The Kiva System As a Vertebral Augmentation Treatment-A Safety and Effectiveness Trial: A Randomized, Noninferiority Trial Comparing the Kiva System With Balloon Kyphoplasty in Treatment of Osteoporotic Vertebral Compression Fractures

STUDY DESIGN

The KAST (Kiva Safety and Effectiveness Trial) study was a pivotal, multicenter, randomized control trial for evaluation of safety and effectiveness in the treatment of patients with painful, osteoporotic vertebral compression fractures (VCFs).

OBJECTIVE

The objective was to demonstrate noninferiority of the Kiva system to balloon kyphoplasty (BK) with respect to the composite primary endpoint.

SUMMARY OF BACKGROUND DATA

Annual incidence of osteoporotic VCFs is prevalent. Optimal treatment of VCFs should address pain, function, and deformity. Kiva is a novel implant for vertebral augmentation in the treatment of VCFs.

METHODS

A total of 300 subjects with 1 or 2 painful osteoporotic VCFs were randomized to blindly receive Kiva (n = 153) or BK (n = 147). Subjects were followed through 12 months. The primary endpoint was a composite at 12 months defined as a reduction in fracture pain by at least 15 mm on the visual analogue scale, maintenance or improvement in function on the Oswestry Disability Index, and absence of device-related serious adverse events. Secondary endpoints included cement usage, extravasation, and adjacent level fracture.

RESULTS

A mean improvement of 70.8 and 71.8 points in the visual analogue scale score and 38.1 and 42.2 points in the Oswestry Disability Index was noted in Kiva and BK, respectively. No device-related serious adverse events occurred. Despite significant differences in risk factors favoring the control group at baseline, the primary endpoint demonstrated noninferiority of Kiva to BK. Analysis of secondary endpoints revealed superiority with respect to cement use and site-reported extravasation and a positive trend in adjacent level fracture warranting further study.

CONCLUSION

The KAST study successfully established that the Kiva system is noninferior to BK based on a composite primary endpoint assessment incorporating pain-, function-, and device-related serious adverse events for the treatment of VCFs due to osteoporosis. Kiva was shown to be noninferior to BK and revealed a positive trend in several secondary endpoints.

LEVEL OF EVIDENCE

1.

Controversial issues in kyphoplasty and vertebroplasty in malignant vertebral fractures

BACKGROUND

Kyphoplasty (KP) and vertebroplasty (VP) have been successfully employed in the treatment of pathological vertebral fractures.

METHODS

A critical review of the medical literature was performed and controversial issues were analyzed.

RESULTS

Evidence supports KP as the treatment of choice to control fracture pain and the possible restoration of sagittal balance, provided that no overt instability or myelopathy is present, the fracture is painful and other pain generators have been excluded, and positive radiological findings are present. Unilateral procedures yield similar results to bilateral ones and should be pursued whenever feasible. Biopsy should be routinely performed and 3 to 4 levels may be augmented in a single operation. Higher cement filling appears to yield better results. Radiotherapy is complementary with KP and VP but must be individualized.

CONCLUSIONS

In cases of painful cancer fractures, if overt instability or myelopathy is not present, unilateral KP should be pursued, whenever feasible, followed by radiotherapy. The technological advances in hardware and biomaterials, as well as combining KP with other modalities, will help ensure a safe and more effective procedure. Address.

Clinical outcome after the use of a new craniocaudal expandable implant for vertebral compression fracture treatment: one year results from a prospective multicentric study

The purpose of this prospective multicentric observational study was to confirm the safety and clinical performance of a craniocaudal expandable implant used in combination with high viscosity PMMA bone cement for the treatment of vertebral compression fractures. Thirty-nine VCFs in 32 patients were treated using the SpineJack minimally invasive surgery protocol. Outcome was determined by using the Visual Analogue Scale for measuring pain, the Oswestry Disability Index for scoring functional capacity, and the self-reporting European Quality of Life scores for the quality of life. Safety was evaluated by reporting all adverse events. The occurrence of cement leakages was assessed by either radiographs or CT scan or both. Statistically significant improvements were found regarding pain, function, and quality of life. The global pain score reduction at 1 year was 80.9% compared to the preoperative situation and the result of the Oswestry Disability Index showed a decrease from 65.0% at baseline to 10.5% at 12 months postoperatively. The cement leakage rate was 30.8%. No device- or surgery-related complications were found. This observational study demonstrates promising and persistent results consisting of immediate and sustained pain relief and durable clinical improvement after the procedure and throughout the 1-year follow-up period.

Safety of balloon kyphoplasty in the treatment of osteoporotic vertebral compression fractures in Europe: a meta-analysis of randomized controlled trials

PURPOSE

The study aims to evaluate the safety of balloon kyphoplasty in the treatment of painful osteoporotic vertebral compression fractures in Europe.

METHODS

Systematic review of the literature, until September 2013, and meta-analysis of randomized controlled trials performed in Europe assessing the safety of balloon kyphoplasty in patients with symptomatic osteoporotic vertebral fractures. Outcomes sought include cement leaks, serious clinical complications and new vertebral fractures.

RESULTS

Six randomized controlled trials fulfilled the inclusion criteria. These studies included data on 525 treated levels in 424 patients. Cement leakages were detected in 18.3 % (95 % CI 11.6, 23.0) of fractures intervened. In about 0.5 % (95 % CI 0.1, 1.1) of fractures leakages proved to be symptomatic. Serious clinical complications were recorded in 11.5 % (95 % CI 1.1, 21.7) of patients treated with balloon kyphoplasty with several of these cases requiring intensive treatment or postoperative surgery. New vertebral fractures were detected in 20.7 % (95 % CI 0.4, 40.9) of patients treated but rates showed an upward pattern when the follow-up period increased. In 54 % of such cases, the fractures were located in regions adjacent to the treated level.

CONCLUSIONS

The safety profile and associated complications of balloon kyphoplasty shown in this analysis, based on the evidence provided by existing randomized controlled trials, can be of help to the practicing clinician who must contrast them with the potential benefits of the technique. These data represent an important step towards a balanced evaluation of the intervention though, a better reporting and more reliable data on long-term assessment of potential sequelae are needed.

Cement augmentation in a thoracolumbar fracture model: reduction and stability after balloon kyphoplasty versus vertebral body stenting

STUDY DESIGN

In vitro biomechanical investigation.

OBJECTIVE

To assess differences in kyphosis after balloon kyphoplasty (BKP) or vertebral body stenting (VBS).

SUMMARY OF BACKGROUND DATA

Cement augmentation techniques allow early mobilization in patients with osteoporotic thoracolumbar fractures. Biomechanically, the grade of reduction and preservation are as important as in nonosteoporotic fractures. With BKP, negative effects of balloon deflation on the reduction and whether specific combinations of materials may preserve the reduction are as yet unclear.

METHODS

Twelve bisegmental human thoracolumbar specimens (6×T12-L2, 6×L3-L5; age at death, 76.3 yr; range, 63-89 yr; female:male ratio, 3:3; bone mineral density, 68.1 g/cm; mean, 12.9 g/cm) were tested in a spine simulator with pure moments of 7.5 Nm to assess primary and secondary stability. After flexibility testing of the intact specimens, an eccentric compression force induced standardized fractures, which were reduced using either BKP or VBS against a flexional moment of 2.5 Nm. Primary and secondary stability were assessed using range of motion in a spine tester. The specimens were tested after each of 3 periods of cyclic flexion loading. The kyphotic angle of the index vertebra was measured radiographically.

RESULTS

The 2 techniques achieved comparable reduction against a relatively high bending moment in this model. Neither technique restored the stability of the intact state; with increasing loads, the range of motion continuously increased to the level of fractured specimen to the level of the fractured specimen. Although the deflation effect on the kyphotic angle was lower with VBS (P≤0.05), there were no significant differences between the techniques relative to angle restoration.

CONCLUSION

Both augmentation techniques are able to restore vertebral body height after thoracolumbar fractures. The deflation effect on the kyphotic angle was less with VBS than with BKP. High flexion moments during implantation limit the effectiveness of reduction using cement augmentation methods.

LEVEL OF EVIDENCE

N/A.

Controversial issues in kyphoplasty and vertebroplasty in osteoporotic vertebral fractures

Kyphoplasty (KP) and vertebroplasty (VP) have been successfully employed for many years for the treatment of osteoporotic vertebral fractures. The purpose of this review is to resolve the controversial issues raised by the two randomized trials that claimed no difference between VP and SHAM procedure. In particular we compare nonsurgical management (NSM) and KP and VP, in terms of clinical parameters (pain, disability, quality of life, and new fractures), cost-effectiveness, radiological variables (kyphosis correction and vertebral height restoration), and VP versus KP for cement extravasation and complications profile. Cement types and optimal filling are analyzed and technological innovations are presented. Finally unipedicular/bipedicular techniques are compared. Conclusion. VP and KP are superior to NSM in clinical and radiological parameters and probably more cost-effective. KP is superior to VP in sagittal balance improvement and cement leaking. Complications are rare but serious adverse events have been described, so caution should be exerted. Unilateral procedures should be pursued whenever feasible. Upcoming randomized trials (CEEP, OSTEO-6, STIC-2, and VERTOS IV) will provide the missing link.

Risks and benefits of percutaneous vertebroplasty or kyphoplasty in the management of osteoporotic vertebral fractures

Vertebral fracture (VF) is the most common osteoporotic fracture and is associated with high morbidity and mortality. Conservative treatment combining antalgic agents and rest is usually recommended for symptomatic VFs. The aim of this paper is to review the randomized controlled trials comparing the efficacy and safety of percutaneous vertebroplasty (VP) and percutaneous balloon kyphoplasty (KP) versus conservative treatment. VP and KP procedures are associated with an acceptable general safety. Although the case series investigating VP/KP have all shown an outstanding analgesic benefit, randomized controlled studies are rare and have yielded contradictory results. In several of these studies, a short-term analgesic benefit was observed, except in the prospective randomized sham-controlled studies. A long-term analgesic and functional benefit has rarely been noted. Several recent studies have shown that both VP and KP are associated with an increased risk of new VFs. These fractures are mostly VFs adjacent to the procedure, and they occur within a shorter time period than VFs in other locations. The main risk factors include the number of preexisting VFs, the number of VPs/KPs performed, age, decreased bone mineral density, and intradiscal cement leakage. It is therefore important to involve the patients to whom VP/KP is being proposed in the decision-making process. It is also essential to rapidly initiate a specific osteoporosis therapy when a VF occurs (ideally a bone anabolic treatment) so as to reduce the risk of fracture. Randomized controlled studies are necessary in order to better define the profile of patients who likely benefit the most from VP/KP.

Less invasive reduction and fusion of fresh A2 and A 3 traumatic L 1-L 4 fractures with a novel vertebral body augmentation implant and short pedicle screw fixation and fusion

The aim of this clinical study was to report on the efficacy in reduction and safety in PMMA leakage of a novel vertebral augmentation technique with PEEK and PMMA, together with pedicle screws in the treatment of fresh vertebral fractures in young adults. Twenty consecutive young adults aged 45 ± 11 years with fresh burst A3/AO or severely compressed A2/AO fractures underwent via a less invasive posterior approach one-staged reduction with a novel augmentation implant and PMMA plus 3-vertebrae pedicle screw fixation and fusion. Radiologic parameters as segmental kyphosis (SKA), anterior (AVBHr) and posterior vertebral body height ratio (PVBHr), spinal canal encroachment (SCE), cement leakage and functional parameters as VAS, SF-36 were measured pre- and post-operatively. Hybrid construct restored AVBHr (P < 0.000), PVBHr (P = 0.02), SKA (P = 0.015), SCE (P = 0.002) without loss of correction at an average follow-up of 17 months. PMMA leakage occurred in 3 patients (3 vertebrae) either anteriorly to the fractured vertebral body or to the adjacent disc, but in no case to the spinal canal. Two pedicle screws were malpositioned (one medially, one laterally to the pedicle at the fracture level) without neurologic sequelae. Solid posterolateral spinal fusion occurred 8-10 months post-operatively. Pre-operative VAS and SF-36 scores improved post-operatively significantly. This study showed that this novel vertebral augmentation technique using PEEK implant and PMMA reduces and stabilizes via less invasive technique A2 and A3 vertebral fractures without loss of correction and leakage to the spinal canal.

Transpedicular vertebral body augmentation reinforced with pedicle screw fixation in fresh traumatic A2 and A3 lumbar fractures: comparison between two devices and two bone cements

This retrospective study compares efficacy and safety of balloon kyphoplasty (BK) with calcium phosphate (Group A) versus KIVA implant with PMMA (Group B) reinforced with three vertebrae pedicle screw constructs for A2 and A3 single fresh non-osteoporotic lumbar (L1-L4) fractures in 38 consecutive age- and diagnosis-matched patient populations. Extracanal leakage of both low-viscosity PMMA and calcium phosphate (CP) as well as the following roentgenographic parameters: segmental kyphosis (SKA), anterior (AVBHr) and posterior (PVBHr) vertebral body height ratio, spinal canal encroachment (SCE) clearance, and functional outcome measures: VAS and SF-36, were recorded and compared between the two groups. All patients in both groups were followed for a minimum 26 (Group A) and 25 (Group B) months. Extracanal CP and PMMA leakage was observed in four (18 %) and three (15 %) vertebrae/patients of group A and B, respectively. Hybrid fixation improved AVBHr, SKA, SCE, but PVBHr only in group B. VAS and SF-36 improved postoperatively in the patients of both groups. Short-segment construct with the novel KIVA implant restored better than BK-fractured lumbar vertebral body, but this had no impact in functional outcome. Since there was no leakage difference between PMMA and calcium phosphate and no short-term adverse related to PMMA use were observed, we advice the use of PMMA in fresh traumatic lumbar fractures.

PMMA embolization to the left dorsal foot artery during percutaneous vertebroplasty for spinal metastases

PURPOSE

Distal arterial embolization to the foot with PMMA during vertebral augmentation has not been previously reported. We report a rare case of distal PMMA embolization to the dorsal foot artery during ipsilateral percutaneous lumbar vertebral augmentation in a patient with spinal osteolytic metastases.

METHODS

A 68-year-old woman was admitted because of severe disabling low back pain. Plain roentgenograms, MRI and CT-scan revealed osteolysis in the L4 and L5 vertebral bodies with prevertebral soft tissue involvement. Percutaneous vertebroplasty with PMMA was performed in L2 to L5 vertebrae under general anesthesia. Intraoperatively, leakage into the segmental vessels L3 and L5 was observed.

RESULT

Four hours after the procedure the clinical diagnosis of acute ischemia and drop foot on the left was made. CT-angiography justified linear cement leakage in the course of the left third lumbar vein and fifth lumbar artery, and to the ipsilateral common iliac artery. The patient was treated with low molecular heparin and the ischemia resolved without further sequelae 1 week postoperatively.

CONCLUSION

PMMA leakage is a complication associated with vertebroplasty and kyphoplasty. Although the outcome of the PMMA embolization to the vessels resolved without sequelae, in our case spine surgeons and interventional radiologists should be aware on this rare complication in patients with osteolytic vertebral metastases even when contemporary cement containment techniques are used.