The positive correlation between upper adjacent vertebral fracture and the kyphosis angle of injured vertebral body after percutaneous kyphoplasty: An in vitro study

The cranial vertebral body suffers a higher risk of adjacent vertebral fracture due to the poor biomechanical environment in patients with percutaneous vertebralplasty

BACKGROUND CONTEXT

Adjacent vertebral fracture (AVF), a frequent complication of PVP, is influenced by factors such as osteoporosis progression, increased intervertebral cement leakage (ICL), and biomechanical deterioration. Notably, the risk of AVF is notably elevated in the cranial vertebral body compared with the caudal counterpart. Despite this knowledge, the underlying pathological mechanism remains elusive.

PURPOSE

This study delves into the role of biomechanical deterioration as a pivotal factor in the heightened risk of AVF in the cranial vertebral body following PVP. By isolating this variable, we aim to unravel its prominence relative to other potential risk factors.

STUDY DESIGN

A retrospective study and corresponding numerical mechanical simulations.

PATIENT SAMPLE

Clinical data from 101 patients treated by PVP were reviewed in this study.

OUTCOME MEASURES

Clinical assessments involved measuring Hounsfield unit (HU) values of adjacent vertebral bodies as a representation of patients' bone mineral density (BMD). Additionally, the rates of ICL were compared among these patients. Numerical simulations were conducted to compute stress values in the cranial and caudal vertebral bodies under various body positions.

METHODS

In a retrospective analysis of PVP patients spanning July 2016 to August 2019, we scrutinized the HU values of adjacent vertebral bodies to discern disparities in BMD between cranial and caudal regions. Additionally, we compared ICL rates on both cranial and caudal sides. To augment our investigation, well-validated numerical models simulated the PVP procedure, enabling the computation of maximum stress values in cranial and caudal vertebral bodies across varying body positions.

RESULTS

The incidence rate of cranial AVF was significantly higher than the caudal side. No notable distinctions in HU values or ICL rates were observed between the cranial and caudal sides. The incidence of AVF showed no significant elevation in patients with ICL in either region. However, numerical simulations unveiled heightened stress values in the cranial vertebral body.

CONCLUSIONS

In patients postPVP, the cranial vertebral body faces a heightened risk of AVF, primarily attributed to biomechanical deterioration rather than lower BMD or an elevated ICL rate.

Pathophysiological mechanism of acute bone loss after fracture

BACKGROUND

Acute bone loss after fracture is associated with various effects on the complete recovery process and a risk of secondary fractures among patients. Studies have reported similarities in pathophysiological mechanisms involved in acute bone loss after fractures and osteoporosis. However, given the silence nature of bone loss and bone metabolism complexities, the actual underlying pathophysiological mechanisms have yet to be fully elucidated.

AIM OF REVIEW

To elaborate the latest findings in basic research with a focus on acute bone loss after fracture. To briefly highlight potential therapeutic targets and current representative drugs. To arouse researchers' attention and discussion on acute bone loss after fracture.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Bone loss after fracture is associated with immobilization, mechanical unloading, blood supply damage, sympathetic nerve regulation, and crosstalk between musculoskeletals among other factors. Current treatment strategies rely on regulation of osteoblasts and osteoclasts, therefore, there is a need to elucidate on the underlying mechanisms of acute bone loss after fractures to inform the development of efficacious and safe drugs. In addition, attention should be paid towards ensuring long-term skeletal health.

Efficacy of percutaneous kyphoplasty on vertebral compression fractures with different bone mineral densities: a retrospective study

BACKGROUND

This study was performed to investigate the clinical efficacy of percutaneous kyphoplasty (PKP) for vertebral compression fractures with different bone mineral densities (BMD).

METHODS

We performed a retrospective analysis of 232 patients with single-segment vertebral compression fractures who underwent PKP. Patients were divided into the normal BMD, osteopenia, and osteoporosis groups according to their average lumbar BMD before surgery. The visual analog scale (VAS) was used to compare differences in pain relief before and after surgery in each group. Corrections of the wedge angle and kyphotic angle before and after surgery were observed using anteroposterior and lateral radiographs and compared among the groups, as was the incidence of bone cement leakage.

RESULTS

Patients were followed up for 6-12 months, with an average follow-up time of 9.12 ± 1.68 months. The VAS score, wedge angle, and kyphotic angle of the three groups of patients decreased significantly at the end of the follow-up (P < 0.05). The changes in VAS score and wedge angle correction in the osteoporosis group were significantly larger than those in the normal BMD and osteopenia groups (P < 0.05). There were no significant differences among the three groups in terms of kyphotic angle correction or bone cement leakage rates (P > 0.05).

CONCLUSIONS

PKP has a positive effect on vertebral compression fractures with different BMD, and is especially suitable for osteoporotic vertebral compression fractures.

"Double Cross Sign" Could Be an Indicator of an Adequate Amount of Bone Cement in Kyphoplasty with the SpineJack System: A Retrospective Study

Kyphoplasty with the SpineJack system was able to restore vertebral height and stabilize the vertebra with an injection of bone cement. The goal of this study was to seek a reliable assessing method during the surgery in determining the minimum amount of bone cement required for the SpineJack system to restore vertebral height and stabilize the vertebra. We defined the “double cross sign” as bone cement that expanded vertically along the bilateral SpineJack system, and spread across the midline of the vertebral body as viewed in the anteroposterior (AP) view of the radiographic image. Sixty-five patients aged 74.5 ± 8.5 years with vertebral compression fracture were included in the study. Patients with a positive double cross sign had better ODI score than those without the double cross sign (20.0 ± 6.9 vs. 32.3 ± 8.2; p < 0.001). Postoperative regional kyphotic and local kyphotic angle were significantly better in the positive double cross sign group (11 ± 8.8 degrees vs. 5.3 ± 3.2 degrees; p = 0.001/11.7 ± 6.2 degrees vs. 6.6 ± 4.1 degrees; p = 0.001, respectively). The more stable construct was built once the double cross sign was achieved during surgery. In this study, a convenient and intuitive method in identifying the minimum but sufficient quantity of injected cement during the SpineJack procedure was developed.

Early Percutaneous Vertebroplasty Improves Bone-Cement Integration and Reduces Adjacent Fractures

BACKGROUND

Percutaneous vertebroplasty (PVP) is widely used for treatment of osteoporotic vertebral compression fractures (VCFs). However, the influence of PVP timing (early vs. late) on development of adjacent vertebral fractures has rarely been discussed. This retrospective cohort study aimed to evaluate bone-cement binding for thoracolumbar fractures (T8-L3) using a new assessment method to predict risk for adjacent vertebral fractures.

METHODS

Patients with a single-level T-score ≤ -1.0 of lumbar bone mineral density and a primary osteoporotic VCF in the thoracolumbar region (T8-L3) who underwent PVP from October 2016 to February 2018 at our medical university-affiliated hospital were included. Patients were divided into refracture and non-refracture groups. All patients underwent computed tomography after vertebroplasty. Bone-cement distribution patterns were evaluated using standardized axial computed tomography images of each cemented vertebra by 4 independent observers with ImageJ software. The smoothness index was calculated as a percentage of smooth margins.

RESULTS

Of 51 VCFs, 15 (29.4%) and 36 (70.6%) were refracture and non-refracture VCFs, respectively. The mean smoothness index (MSI) was higher in the refracture group than in the non-refracture group (P < 0.01), with an increased refracture risk that corresponded to increased MSI values (P = 0.004). Spearman correlation coefficient (0.375) showed a positive correlation between the fracture-vertebroplasty interval and MSI (P = 0.01).

CONCLUSIONS

Axial computed tomography images were used to characterize bone-cement binding properties. Patients who underwent early PVP had a lower MSI, better bone-cement integration, and fewer adjacent fractures.

Surgical Outcomes After Minimally Invasive Direct Lateral Corpectomy with Percutaneous Pedicle Screws for Osteoporotic Thoracolumbar Vertebral Collapse with Neurologic Deficits in the Thoracolumbar Spine Compared with Those After Posterior Spinal Fusion with Vertebroplasty

STUDY DESIGN

Retrospective observational study of a cohort of consecutive patients.

OBJECTIVE

The aim of this study was to compare surgical invasion, mechanical complications, and clinical and radiological outcomes 2 years after surgery between minimally invasive corpectomy following percutaneous pedicle screw placements (X-core/PPS) and posterior fixation with vertebroplasty (VP) for treating osteoporotic vertebral fractures (OVFs), which failed conservative treatment due to neurological deficits.

SUMMARY OF BACKGROUND DATA

Numerous studies have proposed surgical procedures to treat OVFs that fail conservative treatment. However, an optimal approach remains controversial because patients often have numerous comorbid medical complications, frequent instrumentation failure, and/or adjacent vertebral fracture (AVF). Recently, a minimally invasive lateral approach has attracted attention as an alternative procedure to the thoracolumbar junction for corpectomy and expandable cage replacement (X-Core Adjustable VBR System). However, its usefulness and validity is largely unknown.

METHODS

A cohort of 102 consecutive patients with OVF at T11-L1 who underwent surgery were followed up for >2 years after surgery. Ultimately 50 patients were included in the VP group and 45 in the X-core/PPS group. Surgical invasion, radiological examinations, and clinical outcomes between two procedures were compared.

RESULTS

Both X-core/PPS and VP procedures were safe and acceptable for neurological improvement and surgical invasion. The correction loss of local kyphotic angle (LKA) and occurrence of AVF were significantly less in the X-core/PPS group. Oswestry Disability Index in the X-core/PPS group at 2 years after surgery showed better recovery than that in the VP group, and no revision surgery was needed in the X-core/PPS group. Postoperative correction loss of LKA increased significantly when intraoperative endplate injury developed.

CONCLUSION

This next-generation minimally invasive anterior and posterior combined surgery was found to be a safe and useful procedure for OVF treatment to reduce correction loss, mechanical complication, and AVF, resulting in less postoperative low back pain.Level of Evidence: 3.

The Effect of Intraoperative Vertebral Anesthesia on Osteoporotic Fractures Treated With Percutaneous Kyphoplasty: A Prospective Cohort Study

STUDY DESIGN

A prospective randomized cohort study.

OBJECTIVE

The objective of this study was to investigate the effect of intraoperative vertebral anesthesia on osteoporotic vertebral compression fractures (OVCFs) when treated with percutaneous kyphoplasty (PKP).

SUMMARY OF BACKGROUND DATA

Only a few studies have evaluated the intraoperative pain reducing strategies during PKP.

MATERIALS AND METHODS

A total of 64 patients with OVCFs were enrolled in the study. All of the patients were randomized into 2 groups: the traditional local anesthesia group (from the skin to the periosteum, group A) and the experimental group (from the skin to a vertebral body, group B). Visual Analogue Scale (VAS) score was used to evaluate the degree of pain at six time points, that is, VAS before surgery, VAS during balloon dilation, VAS during bone cement injection, VAS soon after surgery, and VAS 12 hours and 24 hours after surgery. In addition, we noted the patients' willingness to undergo reoperation if necessary, and the variations in surgical complications between the 2 groups.

RESULTS

There was no significant difference in VAS score before surgery between the 2 groups (t=1.694, P=0.095). The VAS scores during balloon dilatation, bone cement injection and soon after surgery were significantly different between the 2 groups (t=4.405, P=0.000; t=2.481, P=0.016; t=2.992, P=0.004, respectively). The willingness to undergo reoperation was significantly different between 2 groups (χ=6.020, P=0.049), whereas the complications showed no significant difference (χ=0.000, P=0.754).

CONCLUSIONS

Traditional local anesthesia combined with vertebral anesthesia was effective in alleviating perioperative pain during PKP. No serious complication was noted during the operation.

LEVEL OF EVIDENCE

Level I.

Mineralized Collagen Modified Polymethyl Methacrylate Bone Cement for Osteoporotic Compression Vertebral Fracture at 1-Year Follow-up

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

This study aimed to compare the clinical effects and imaging features of polymethyl methacrylate (PMMA) bone cement with and without mineralized collagen (MC) in percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fractures (OVCFs).

SUMMARY OF BACKGROUND DATA

PKP with PMMA is widely performed for OVCF. However, numerous complications have also been reported about the PMMA bone cement. Moreover, PMMA bone cement with and without MC have not been compared with respect to their postoperative efficacy and long-term follow-up.

METHODS

From July 2016 to July 2017, 105 OVCF patients were randomly divided into two groups based on their PKP treatment: MC-PMMA group and PMMA group. Clinical operation, cement leakage, Oswestry Disability Index, visual analog scale, height of the fractured vertebrae, Cobb angle, refracture of the adjacent vertebra, recompression, and computed tomography values of the injured vertebra were compared between the two groups postoperatively and after 1-year follow-up.

RESULTS

Clinical operation showed no differences between the two groups. Visual analog scale scores, Oswestry Disability Index scores, and Cobb angles showed statistically significant differences between the two groups after 1-year follow-up. The height of the vertebral body showed significant difference at 3 days postoperatively and preoperatively in each group and significant difference after 1 year between the two groups. The rate of refracture and leakage of the MC-PMMA group was lower than that of the PMMA group. The computed tomography value of the MC-PMMA group was obviously higher than that of the PMMA group after 1-year follow-up.

CONCLUSION

MC-modified PMMA did not change the beneficial properties of PMMA. This new bone cement has better biocompatibility, can form a stable structure in the vertebral body, and improve the prognosis of patients by reducing pain and reoperation.

LEVEL OF EVIDENCE

3.

Clinical, Radiographic, and Morphometric Risk Factors for Adjacent and Remote Vertebral Compression Fractures Over a Minimum Follow-up of 4 Years After Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures: Novel Three-dimensional Voxel-Based Morphometric Analysis

OBJECTIVE

This study aimed to analyze the risk factors for secondary new vertebral compression fractures (SNVCFs) after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures.

METHODS

We evaluated the association of SNVCFs (adjacent vertebral compression fractures [AVCFs] and remote vertebral compression fractures) with clinical, radiographic, and PVP procedure-related morphologic parameters based on the data collected from 402 patients over a minimum follow-up of 4 years after PVP. Procedure-related morphologic parameters were assessed using a three-dimensional voxel-based analysis. Univariate and multivariate regression analyses were conducted.

RESULTS

On univariate analysis, bone mineral density (BMD), preoperative compression ratio, preoperative sagittal index (SI), and intradiscal bone cement leakage were significantly associated with SNVCF and AVCF (P < 0.05), whereas only BMD and preoperative SI were significantly associated with remote vertebral compression fracture (P < 0.05). A large ratio of bone cement volume to vertebral body volume and skewed bone cement distribution along the inferior-to-superior axis were especially significant risk factors for AVCF (P = 0.027 and P = 0.029, respectively). On multivariate analysis, BMD was significantly associated with SNVCF (P = 0.041), whereas upper adjacent intradiscal bone cement leakage was significantly associated with AVCF (P = 0.003).

CONCLUSIONS

Low BMD, high preoperative compression ratio, and high preoperative SI may be predictive factors for SNVCFs. In particular, to prevent AVCF, the injected bone cement should be distributed both evenly and symmetrically along the inferior-to-superior axis and the relative bone cement volume should not be excessive. Bone cement should be injected carefully to avoid upper adjacent intradiscal leakage. Prompt BMD correction is important to prevent SNVCF.

Clinical application of the pedicle in vitro restorer in percutaneous kyphoplasty

Background

Percutaneous kyphoplasty (PKP) is widely applied for the treatment of osteoporotic vertebral compression fractures (OVCFs) and has achieved satisfactory clinical results. With the accumulation of clinical cases and prolonged follow-up times, the inability to reconstruct vertebral height defects has attracted more and more attention. A comparison of clinical effects was retrospectively reviewed in 72 patients who underwent simple PKP or pedicle in vitro restorer (PIVR) combined with PKP to discuss the clinical application of self-developed PIVR used in PKP.

Methods

From August 2013 to August 2016, 72 patients with OVCFs were treated surgically, with 30 patients undergoing PKP (group A) and 42 undergoing PIVR combined with PKP (group B). Operation-related situations, radiological data, and related scores were compared between the two groups by corresponding statistical methods.

Results

Bone cement was successfully injected into 72 vertebral bodies. Sixty-three cases were followed up for an average of 14 months. There were significant differences between the two groups in the improvement of the height of the vertebral body, sagittal Cobb angle, and visual analogue scale (VAS) 1 week after the operation (P < 0.05), and the improvements of group B were better than those in group A. The cement leakage ratio was significantly different between the two groups (P < 0.05). The Oswestry Disability Index (ODI) at last follow-up was significantly different between the two groups (P < 0.05). There was no significant difference in the incidence of recurrent vertebral fractures between the two groups at the last follow-up (P > 0.05).

Conclusion

PIVR combined with PKP can overcome the limitations of PKP alone, that is, hardly restoring vertebral height and height being easily lost again with balloon removal. The combined method can also restore the vertebral fractures to a satisfactory height and effectively maintain the stability of the spine, which improves the long-term quality of life of patients. Thus, PIVR combined with PKP is a better choice for patients with OVCFs.

Evaluation of Percutaneous Vertebroplasty for Management of Symptomatic Osteoporotic Compression Fracture

INTRODUCTION

Osteoporotic vertebral compression fractures are a leading cause of disability and associated morbidities among Indian population. Worldwide, approximately 20% of elderly population above 70 years and 16% of postmenopausal women are suffering from it. Vertebral compression fractures should be aggressively treated with minimally invasive techniques such as Percutaneous Vertebroplasty (PVP) or Percutaneous Kyphoplasty (PKP) to minimize pain and disability associated with it.

AIM

To evaluate the PVP in terms of pain reduction and restoration of functional abilities among the patients suffering from symptomatic osteoporotic vertebral compression fracture.

MATERIALS AND METHODS

PVP using polymethyl methacrylate bone cement was performed between 2011 to 2013, on 25 patients admitted for symptomatic osteoporotic vertebral compression fracture in the Department of Orthopaedics, Institute of Post Graduate Medical Education and Research (IPGMER) and SSKM Hospital, Kolkata, West Bengal, India. All of them were followed up for one year. Pain and disability were evaluated with Visual Analogue Scale (VAS) and Oswestry Disability Questionnaire (ODQ) score respectively. Repeated measures ANOVA with Bonferroni post-hoc test was applied for significance testing.

RESULTS

Reduction in pain was reported by 56% of patients within 10 minutes of operation. Mean VAS score at presentation was 8.24 (±1.16). It reduced to 6.31 (±1.21) and 2.38 (±0.08) at immediate postoperative period and after 12 months respectively. There was significant reduction (p<0.05) in pain, as measured by VAS score, started at immediate postoperative period to end of follow up period up to one year. Disability, measured by ODQ score, significantly decrease (p<0.05) over time from one week to 12-month postoperatively. At presentation, ODQ score was 93.01 (±4.54). It reduced to 76.84 (±3.76), one week after operation and 16.23 (±1.17), one year after operation.

CONCLUSION

The PVP with polymethayl methacrylate bone cement is still a justified treatment procedure for osteoporotic vertebral compression fractures as it provides excellent pain relief, internal stability to the fractured vertebra thus preventing further collapse and progression of kyphosis, allowing the patients to regain normal activity at the earliest, and at a very reasonable cost with minimal complication.