Prophylactic adjacent-segment vertebroplasty following kyphoplasty for a single osteoporotic vertebral fracture and the risk of adjacent fractures: a retrospective study and clinical experience

Comparison of the Efficacy of Romosozumab and Teriparatide for the Management of Osteoporotic Vertebral Compression Fractures

OBJECTIVE

Romosozumab is increasingly employed to manage osteoporosis. However, no studies have analyzed its effects on recent osteoporotic vertebral compression fractures (OVCFs). Therefore, this study aimed to evaluate the efficacy of romosozumab compared with teriparatide in managing OVCFs.

METHODS

The electronic medical records of postmenopausal patients with recent OVCFs who were administered romosozumab or teriparatide for one year from March 2018 to August 2022 were retrospectively reviewed. We compared the 2 groups for demographics, radiological outcomes (compression ratio, Cobb angle, and bone mineral density [BMD]), and clinical outcomes (Numerical Rating Scale [NRS] for back pain).

RESULTS

Fifty-five patients with OVCFs, 32 patients treated with romosozumab and 23 with teriparatide, were included in this study. The change of BMD (g/cm2) values was significantly higher (p = 0.016) in the romosozumab (0.04 ± 0.06) than in the teriparatide group (0.00 ± 0.08) in the femur total. Furthermore, in subgroup analysis, the change of BMD (g/cm2) values in the lumbar spine was significantly higher (p = 0.016) in the romosozumab (0.12 ± 0.06) than in the teriparatide group (0.07 ± 0.06) in the lumbar spine. The decrease in NRS was significantly higher (p = 0.013) in the romosozumab (6.6 ± 2.0) than in the teriparatide group (5.5 ± 2.1). However, there was no significant difference in radiologic outcomes between the 2 groups.

CONCLUSION

Our findings suggest that romosozumab may be more effective than teriparatide in treating OVCFs in postmenopausal females, particularly in improving BMD and reducing back pain as measured by NRS.

Biomechanical analysis of sandwich vertebrae in osteoporotic patients: finite element analysis

Objective

The aim of this study was to investigate the biomechanical stress of sandwich vertebrae (SVs) and common adjacent vertebrae in different degrees of spinal mobility in daily life.

Materials and methods

A finite element model of the spinal segment of T10-L2 was developed and validated. Simultaneously, T11 and L1 fractures were simulated, and a 6-ml bone cement was constructed in their center. Under the condition of applying a 500-N axial load to the upper surface of T10 and immobilizing the lower surface of L2, moments were applied to the upper surface of T10, T11, T12, L1, and L2 and divided into five groups: M-T10, M-T11, M-T12, M-L1, and M-L2. The maximum von Mises stress of T10, T12, and L2 in different groups was calculated and analyzed.

Results

The maximum von Mises stress of T10 in the M-T10 group was 30.68 MPa, 36.13 MPa, 34.27 MPa, 33.43 MPa, 26.86 MPa, and 27.70 MPa greater than the maximum stress value of T10 in the other groups in six directions of load flexion, extension, left and right lateral bending, and left and right rotation, respectively. The T12 stress value in the M-T12 group was 29.62 MPa, 32.63 MPa, 30.03 MPa, 31.25 MPa, 26.38 MPa, and 26.25 MPa greater than the T12 stress value in the other groups in six directions. The maximum stress of L2 in M-T12 in the M-L2 group was 25.48 MPa, 36.38 MPa, 31.99 MPa, 31.07 MPa, 30.36 MPa, and 32.07 MPa, which was greater than the stress value of L2 in the other groups. When the load is on which vertebral body, it is subjected to the greatest stress.

Conclusion

We found that SVs did not always experience the highest stress. The most stressed vertebrae vary with the degree of curvature of the spine. Patients should be encouraged to avoid the same spinal curvature posture for a long time in life and work or to wear a spinal brace for protection after surgery, which can avoid long-term overload on a specific spine and disrupt its blood supply, resulting in more severe loss of spinal quality and increasing the possibility of fractures.

Early cement augmentation may be a good treatment option for pain relief for osteoporotic compression fractures: a systematic review and meta-analysis

PURPOSE

The incidence of osteoporotic compression fractures (VCFs) have been rising over the past decades. Presently, vertebral cement augmentation procedures such as balloon kyphoplasty and vertebroplasty are common treatments allowing pain relief and functional recovery. However, there is controversy on whether different timeframes for cement augmentation affects clinical outcomes. Hence, this study aimed to compare pain relief and complication rates between early versus late cement augmentation.

METHODS

A comprehensive systematic review of PubMed, EMBASE, Scopus and Cochrane Library was conducted, identifying studies that compared early versus late cement augmentation for VCFs. As the definitions of "early" and "late" phases across studies are heterogenous, we established the cut-off between early and late phase as intervals to accommodate as many studies as possible for analysis. We conducted two separate analyses with different cut-off intervals and included studies that reported interventions within these respective time intervals. In analysis 1, we included studies which grouped patients into "early" and "late" group based on a cut-off time frame of 2-4 weeks. On the other hand, in analysis 2, we included studies which grouped patients into "early" and "late" groups based on a cut-off time frame of 6-8 weeks. Meta-analysis was conducted via random-effect models, comparing outcomes of interest between early and late groups.

RESULTS

Eleven studies were included. The total cohort size was 712 and 775 patients in analysis 1 and 2 respectively. Mean follow-up was 12.9 ± 3.7 months and 11 ± 0.6 months respectively. VAS change at final follow-up was significantly greater in the early group for both analyses. (MD = - 0.66, p = 0.01; and MD = - 1.18, p < 0.005 respectively). There was no significant difference in post-operative absolute VAS score, number of cement leakage, number of adjacent compression fractures and local kyphotic angle, for both analyses. Patients in both groups experienced reductions in VAS score that exceeded the minimum clinically important difference.

CONCLUSION

Both early and late timeframes for cement augmentation offered significant improvement in pain relief, with similar post-operative absolute pain score, kyphotic angle, cement leakage and adjacent vertebral fractures. Early surgery may offer substantial pain relief in patients presenting with pain as early as < 2-4 weeks of VCFs.

Risk Factors for New Vertebral Fracture After Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures

Purpose

To analyze the risk factors for new vertebral fractures after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCFs).

Patients and Methods

We retrospectively reviewed the records of patients with symptomatic OVCFs who underwent PVP in our hospital, from January 2014 to January 2019. Demographic and lifestyle data on the presence of underlying chronic disease, preoperative bone mineral density, details of vertebral fractures, postoperative osteoporosis treatment, and new fracture development were collected. Patients were divided into postoperative fracture and non-fracture groups. To identify the independent risk factors for new vertebral fracture development, variables significant on univariate analysis were included in a multivariate regression model.

Results

Of the 2202 patients treated with PVP, 362 (16.43%) had a new postoperative vertebral fracture. All patients were followed up for >12 months (mean 14.7 months). Univariate analysis revealed no significant difference in height; body weight; preoperative bone mineral density; number of fractured vertebrae; injection volume of bone cement in a single vertebra; leakage rate of bone cement; or presence of hypertension, coronary heart disease, and chronic obstructive pulmonary disease between the fracture and non-fracture groups (P>0.05). Age, sex, smoking, alcohol consumption, diabetes mellitus, postoperative exercise, and postoperative osteoporosis treatment were associated with new vertebral fractures (all P<0.05). A multivariate analysis showed that age (odds ratio [OR]=1.212, P<0.0001), female sex (OR=1.917, P<0.0001), smoking (OR=1.538, P=0.026), and diabetes (OR=1.915, P<0.0001) were positively correlated with new vertebral fracture development, whereas postoperative exercise (OR=0.220, P<0.0001) and osteoporosis treatment (OR=0.413, P<0.0001) were negatively correlated.

Conclusion

Elderly patients, females, and those with a history of smoking and diabetes are at high risk of new vertebral fracture after PVP. Patients should be encouraged to stop smoking and consuming alcohol, control blood glucose level, participate in sufficient physical activity, and adhere to osteoporosis treatment to prevent new vertebral fractures.

Does prophylactic vertebral augmentation reduce the refracture rate in osteoporotic vertebral fracture patients: a meta-analysis

PURPOSE

In order to prevent the recurrent fracture after vertebral augmentation, the concept of prophylactic vertebral augmentation has been proposed, but its efficacy is still controversial. This study aimed to determine the efficacy of prophylactic vertebral augmentation for prevention of refracture in osteoporotic vertebral fracture patients.

METHODS

Following PRISMA guidelines, a literature search was performed using PubMed, Embase and Web of Science databases for relevant studies published until February 2021. A meta-analysis of randomized controlled trials and retrospective controlled trials comparing prophylactic group versus nonprophylactic group was conducted. The primary outcome was the incidence of new vertebral compression fracture (VCF), and secondary outcomes were incidence of adjacent vertebral fracture (AVF) and remote vertebral fracture (RVF).

RESULTS

A total of 6 studies encompassing 618 patients were included in the meta-analysis. The incidence of new VCF was reported in all six studies, and the result showed no significant difference between the two groups (OR: 0.509; 95% CI: 0.184-1.409). Four studies provided data on the incidence of AVF, and it was revealed that there was no significant difference between the two groups (OR: 0.689; 95% CI: 0.109-4.371). In view of the incidence of RVF, prophylactic group also did not differ significantly compared with nonprophylactic group (OR: 0.535; 95% CI: 0.167-1.709).

CONCLUSIONS

The current evidence suggested that prophylactic vertebral augmentation might not be appropriate to diminish the risk of new VCF. Therefore, there is a need to investigate the mechanism of refracture and explore other preventive regimens to reduce the risk.

Fracture-free probability and predictors of new symptomatic fractures in sandwich, ordinary-adjacent, and non-adjacent vertebrae: a vertebra-specific survival analysis

BACKGROUND

It is unclear whether the sandwich vertebra, is at higher risk of new symptomatic fractures (NSFs), and whether prophylactic augmentation might benefit patients with sandwich vertebrae.

OBJECTIVE

To compare fracture-free probabilities of sandwich, ordinary-adjacent, and non-adjacent vertebrae, and identify predictors of NSFs.

METHODS

Data were retrospectively analyzed for patients who had undergone vertebral augmentation resulting in sandwich vertebrae. NSF rates were determined and predictors were identified using Cox proportional hazard models.

RESULTS

The analysis included 1408 untreated vertebrae (147 sandwich, 307 ordinary-adjacent, 954 non-adjacent vertebrae) in 125 patients. NSFs involved 19 sandwich, 19 ordinary-adjacent, and 16 non-adjacent vertebrae. The NSF rate was significantly higher in the patients with sandwich vertebrae (27.2%) than among all patients (14.8%). At the vertebra-specific level, the NSFs rate was 12.9% for sandwich vertebrae, significantly higher than 6.2% for ordinary-adjacent and 1.7% for non-adjacent vertebrae. The corresponding fracture-free probabilities of sandwich, ordinary-adjacent, and non-adjacent vertebrae were 0.89, 0.95, and 0.99 at 1 year, and 0.85, 0.92, and 0.98 at 5 years (p<0.05). Cox modeling identified the following as predictors for occurrence of an NSF in a given vertebra: vertebra location, type of vertebrae, number of augmented vertebrae, and puncture method.

CONCLUSION

Sandwich vertebrae are at higher risk of NSFs than ordinary-adjacent and non-adjacent vertebrae, and several NSF risk factors were identified. Since 85% of sandwich vertebrae are fracture-free for 5 years and NSF risk increases with the number of augmented vertebrae, prophylactic augmentation of every sandwich vertebra may be unnecessary.

[Risk factors analysis of adjacent fractures after percutaneous vertebroplasty for osteoporotic vertebral compression fracture]

Objective

To investigate the risk factors of adjacent fractures after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fracture (OVCF).

Methods

A total of 2 216 patients who received PVP due to symptomatic OVCF between January 2014 and January 2017 and met the selection criteria were selected as study subjects. The clinical data was collected, including gender, age, height, body mass, history of smoking and drinking, whether the combination of hypertension, diabetes, coronary arteriosclerosis, chronic obstructive pulmonary disease (COPD), bone mineral density, the number of fractured vertebrae, the amount of cement injected into single vertebra, the cement leakage, and whether regular exercise after operation, whether regular anti-osteoporosis treatment after operation. Firstly, single factor analysis was performed on the observed indicators to preliminarily screen the influencing factors of adjacent fractures after PVP. Then, logistic regression analysis was carried out for relevant indicators with statistical significance to screen risk factors.

Results

All patients were followed up 12-24 months, with an average of 15.8 months. Among them, 227 patients (10.24%) had adjacent fractures. The univariate analysis showed that there were significant differences between the fracture group and non-fracture group in age, gender, preoperative bone density, history of smoking and drinking, COPD, the number of fractured vertebrae and the amount of bone cement injected into the single vertebra, as well as regular exercise after operation, regular anti-osteoporosis treatment after operation ( P<0.05). Further multivariate logistic regression analysis showed that the elderly and female, history of smoking, irregular exercise after operation, irregular anti-osteoporosis treatment after operation, low preoperative bone density, large number of fractured vertebrae, and small amount of bone cement injected into the single vertebra were risk factors for adjacent fractures after PVP in OVCF patients ( P<0.05).

Conclusion

The risk of adjacent fractures after PVP increases in elderly, female patients with low preoperative bone mineral density, large number of fractured vertebrae, and insufficient bone cement injection. The patients need to quit smoking, regular exercise, and anti-osteoporosis treatment after PVP.

How the clinical dosage of bone cement biomechanically affects adjacent vertebrae

Objective

This study evaluated the biomechanical changes in the adjacent vertebrae under a physiological load (500 N) when the clinically relevant amount of bone cement was injected into fractured cadaver vertebral bodies.

Methods

The embalmed cadaver thoracolumbar specimens in which each vertebral body (T12–L2) had a BMD of < 0.75 g/cm² were used for the experiment. For establishing a fracture model, the upper one third of the L1 vertebra was performed wedge osteotomy and the superior endplate was kept complete. Stiffness of specimens was measured in different states. Strain of the adjacent vertebral body and intervertebral disc were measured in pre-fracture, post-fracture, and after augmentation by non-contact optical strain measurement system.

Results

The average amount of bone cement was 4.4 ml (3.8–5.0 ml). The stiffness of after augmentation was significantly higher than the stiffness of post-fracture (p < 0.05), but still lower than pre-fracture stiffness (p < 0.05). After augmentation, the adjacent upper vertebral strain showed no significant difference (p > 0.05) with pre-fracture, while the strain of adjacent lower vertebral body was significantly higher than that before fracture (p < 0.05). In flexion, T12/L1 intervertebral disc strain was significantly greater after augmentation than after the fracture (p < 0.05), but there was no significant difference from that before the fracture (p > 0.05); L1/2 vertebral strain after augmentation was significantly less than that after the fracture (p < 0.05), but there was no significant difference from that before the fracture (p > 0.05).

Conclusions

PVP may therefore have partially reversed the abnormal strain state of adjacent vertebral bodies which was caused by fracture.

Prophylactic Percutaneous Kyphoplasty Treatment for Nonfractured Vertebral Bodies in Thoracolumbar for Osteoporotic Patients

Purpose

The occurrence of new vertebral compression fractures (VCFs) is a common complication after percutaneous kyphoplasty (PKP). Secondary VCFs after PKP occur predominantly in the thoracolumbar segment (T11 to L2). Prophylactic injections of cement into vertebral bodies in order to reduce new VCFs have rarely been reported. The main purpose of this study was to investigate whether prophylactically injecting cement into a nonfractured vertebral body at the thoracolumbar level (T11-L2) could reduce the occurrence of new VCFs.

Methods

From July 2011 to July 2018, PKP was performed in 86 consecutive patients with osteoporotic vertebral compression fractures (OVCFs) in the thoracolumbar region (T11-L2). All patients selected underwent PKP because of existing OVCFs (nonprophylactic group). Additionally, 78 consecutive patients with fractured vertebrae in the thoracolumbar region (T11-L2) with OVCFs underwent PKP and received prophylactic injections of cement into their nonfractured vertebrae in the thoracolumbar region (T11-L2) (prophylactic group). The visual analog scale (VAS) scores and incidence of new VCFs after PKP were compared between the two groups.

Results

The mean VAS scores improved from 8.00 ± 0.79 preoperatively to 1.62 ± 0.56 at the last follow-up in the nonprophylactic group and improved from 8.17 ± 0.84 to 1.76 ± 0.34 in the prophylactic group (P > 0.05). In the nonprophylactic group, 21 of 86 patients (24.4%) developed new VCFs within one year after PKP, of whom 15 patients (71.4%) developed VCFs within 3 months. In the prophylactic group, 8 of 78 patients (10.3%) developed new VCFs within one year, and 6 of these 8 patients (75%) developed new VCFs within 3 months. The incidence of new VCFs was significantly higher in the nonprophylactic group than that in the prophylactic group at one year (P = 0.018), but there were no statistically significant differences at three months (P = 0.847).

Conclusions

Prophylactic injections of cement into nonfractured (T11-L2) vertebral bodies reduced the incidence of secondary VCFs after PKP in patients with OVCFs, but there was no significant difference in local back pain (VAS) scores between the two groups.

[Thoracolumbar spinal fractures in the elderly : Classification and treatment]

Thoracolumbar fractures in the elderly are frequently associated with osteoporosis. Osteoporosis can cause fractures or be a significant comorbidity in traumatic fractures. The OF classification is based on conventional X‑ray, computed tomography (CT) scan and magnetic resonance imaging (MRI). It is easy to use and provides a clinically relevant classification of the fractures. Therapeutic decisions are made based on the clinical and radiological situation by using the OF score. The score takes the current clinical situation including patient-specific comorbidities into consideration. The treatment recommendations are based on an expert consensus opinion and include conservative and operative options. If surgery is indicated, vertebral body augmentation, percutaneous stabilization and even open surgery can be used.

Prophylactic vertebroplasty versus kyphoplasty in osteoporosis: A comprehensive biomechanical matched-pair study by in vitro compressive testing

Vertebroplasty and kyphoplasty are alternative augmentation techniques of osteoporotic vertebral compression fractures. However, shortly after augmentation, new vertebral compression fractures may occur, mostly in the adjacent vertebrae. To prevent this, prophylactic cement injection can be applied to the neighboring vertebral bodies. Although there are many evidence-based clinical studies on the potential hazards of vertebroplasty and kyphoplasty, there are only few studies comparing the prophylactic potential of the two treatments. In this matched-pair experimental biomechanical study, the two treatments were compared via destructive compressive testing of 76 non-fractured osteoporotic human lumbar vertebral bodies from 24 cadavers, augmented pair-wise with vertebroplasty or kyphoplasty. Strength, stiffness and deformability were analyzed in terms of donor age, CT-based bone density, vertebral morphometry, and cement-endplate contacts. These were investigated in a paired analysis and also in terms of the number of cement-endplate contacts. Vertebroplasty resulted in significantly, but only 19% larger stiffness, approximately equal failure load and smaller failure displacement compared to kyphoplasty. Cement-endplate contacts affect augmentation differently for the two techniques, namely, strength significantly increased with increasing number of contacts in vertebroplasty, but decreased in kyphoplasty. The reasons for these contrasting behavior included the fundamentally different augmentation method, the resulting different construction and location of cement clouds and the different form and location of failure. These results indicate that both prophylactic vertebroplasty and kyphoplasty of non-fractured adjacent vertebrae may be advantageous to avoid subsequent fractures after post-fracture vertebroplasty and kyphoplasty, respectively. However, cement bridging in vertebroplasty and central cement placement in kyphoplasty are advantageous in prevention.

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.