Cement volume is the most important modifiable predictor for pain relief in BKP: results from SWISSspine, a nationwide registry

Analysis of injected cement volume and clinical outcomes following balloon-assisted kyphoplasty in a series of 368 patients

OBJECTIVE

Balloon-assisted kyphoplasty (BAK) is a modified vertebroplasty technique developed to treat vertebral compression fractures (VCFs) secondary to osteoporosis. This study investigates the association between injected cement volume and the development of subsequent VCFs after BAK.

METHODS

A retrospective analysis of 368 patients who underwent BAK at a single institution was performed from 2001 to 2021. Inclusion was defined by at least 2 years of follow-up. Clinical characteristics and outcomes following BAK, including subsequent fractures at adjacent and remote levels, were identified. Patients that underwent a thoracic BAK were stratified by injected cement volume: below or equal to the median (≤ 6.0 mL, 265 vertebrae) or above the median (> 6.0 mL, 144 vertebrae). Patients that underwent a lumbar BAK were similarly stratified: below or equal to the median (≤ 8.0 mL, 233 vertebrae) or above the median (>8.0 mL, 160 vertebrae).

RESULTS

A total of 802 vertebrae were treated. The average volume of cement was recorded in the thoracic (6.2 ± 1.9 mL) and lumbar (7.8 ± 1.8 mL) vertebrae. In the thoracic spine, vertebrae that were injected with > 6.0 mL of cement underwent a greater change in local kyphotic angle (P = 0.0001) and were more likely to develop adjacent-level VCFs (P = 0.032) after kyphoplasty. Univariate analysis did not elucidate any additional risk factors. There were no statistical differences in clinical outcomes between the three groups of lumbar vertebrae.

CONCLUSIONS

Larger volumes of injected cement were associated with a greater change in local kyphosis and subsequent adjacent-level fractures after BAK in the thoracic spine. This association was not found in the lumbar spine. Close attention to injected cement volumes must be made in the thoracic spine and patients who undergo significant kyphotic correction should be carefully observed postoperatively.

Computed Tomography Volumetry of Bone Cement: Retrospective Blinded Validation of Commercially Available Semi-automated Edge Detection Software

OBJECTIVE

Cement volumes are increasingly linked to orthopedic oncology and neurosurgical outcomes (construct durability, adjacent fracture), but manual cement volumetry remains time prohibitive. The authors aim to report performance of PACS-integrated volumetric software specifically for barium-enhanced polymethylmethacrylate cement.

METHODS

Institutional review board-approved single-institution retrospective review of patients from 2019-2022 undergoing kyphoplasty for pathological compression fractures with a quantitative cement infuser providing true cement volume. An operator blinded to true cement volumes retrospectively performed software-assisted volumetry on follow-up computed tomography scans.

RESULTS

Included were 91 kyphoplasty levels in 56 patients: mean age, 62 years (range, 34-85 years), 73% female. True cement volume (available for 44 of 66 procedures) was mean 4.5 mL per level (range, 1.2-15.6 mL). Measured cement volume (available for all procedures) yielded a mean of 6.1 mL per level (range, 1.5-27.9 mL). For the 57 levels (39 patients) where both true and measured cement volumes were available, linear regression intercept and slope were 1.46 (95% CI = 0.97-1.95, P < 0.001) and 0.52 (CI = 0.47-0.57, P < 0.001), respectively, suggesting measured volume averaged 1.46 mL greater than true volume, with each additional milliliter of measured volume corresponding to approximately 0.52 mL of true volume. There was no significant difference in the relationship between estimated and actual cement volume in thoracic levels (intercept = -0.24, CI = -1.13 to 0.66, P = 0.61; slope = 0.03, CI = -0.14 to 0.19, P = 0.73) compared with lumbar levels. The goodness-of-fit of the regression model was strong ( R2 = 0.81). Discrepancies ranged from 90% underestimation to 52% overestimation; average, 17% overestimation.

CONCLUSIONS

Semi-automated volumetry maintained a strong correlation with true volumes across the thoracic and lumbar curvatures, overestimating cement volume by a mean of 17% or 1.46 mL.

What are the Risk Factors for Residual Pain After Percutaneous Vertebroplasty or Kyphoplasty? A Meta-Analysis

BACKGROUND

Although many risk factors for residual pain following percutaneous vertebroplasty or kyphoplasty (PVP or PKP) have been reported in many studies, research methods and cohorts differ greatly. A previous meta-analysis identified patient- and operation-specific risk factors for residual pain. This study aimed to examine the available data and identify significant risk factors for residual pain after PVP or PKP.

METHODS

PubMed, EMBASE, Web of Science, and the Chinese Wanfang Database were searched for relevant research in English and Chinese, and full-text publications including patients with and without residual pain were compared. Only studies presenting odds ratios from multivariate analysis of residual pain data were considered. To evaluate the impact of the results of the selected articles, Review Manager 5.4 was used.

RESULTS

Twelve publications including a total of 3120 patients met the requirements. The meta-analysis examined 10 factors associated with residual pain and categorized them as either patient- or operation-associated factors. Thoracolumbar fascia injury, intravertebral vacuum cleft, depression, and number of fractured vertebrae were all significant patient-associated parameters for residual pain. Significant operation-associated risk factors included bone cement distribution and intraoperative facet joint injury.

CONCLUSIONS

In this meta-analysis, we identified several significant risk factors for residual pain after PVP or PKP. These findings may be helpful for patient counseling and surgical planning.

Truths and myths about augmentation techniques in the treatment of fragility fractures

The main event of osteoporosis is fragility fractures. Vertebral compression fractures are the most commonly fragility fracture related to osteoporosis. Our goal is to review the available literature to confirm or deny concepts learned about spinal cementation and adapt our clinical practice according to scientific evidence. In the complex world of spine surgery, constant innovations seek to improve the quality of life of patients. Among these, vertebral augmentation has emerged as an increasingly popular technique, but often shrouded in myths and misunderstandings. In this systematic review, we will thoroughly explore the truths behind vertebral augmentation, unraveling common myths and providing a clear insight into this technique. As specialists in the field, it is crucial to understand the reality surrounding these interventions to offer our patients the best possible information and make informed decisions.

Retrospective Cohort Study of Early versus Delayed Ballon Kyphoplasty Intervention for Osteoporotic Vertebral Fracture Treatment

Objectives: To investigate the outcomes of early balloon kyphoplasty (BKP) intervention compared with late intervention for osteoporotic vertebral fracture (OVF). Background: Osteoporotic vertebral fracture can lead to kyphotic deformity, severe back pain, depression, and disturbances in activities of daily living (ADL). Balloon kyphoplasty has been widely utilized to treat symptomatic OVFs and has proven to be a very effective surgical option for this condition. Furthermore, BKP is relatively a safe and effective method due to its reduced acrylic cement leakage and greater kyphosis correction. Materials and Methods: A retrospective cohort study was conducted at our hospital for patients who underwent BKP for osteoporotic vertebral fractures in the time frame between January 2020 and December 2022. Ninety-nine patients were included in this study, and they were classified into two groups: in total, 36 patients underwent early BKP intervention (EI) at <4 weeks, and 63 patients underwent late BKP intervention (LI) at ≥4 weeks. We performed a clinical, radiological and statistical comparative evaluation for the both groups with a mean follow-up of one year. Results: Adjacent segmental fractures were more frequently observed in the LI group compared to the EI group (33.3% vs. 13.9%, p = 0.034). There was a significant improvement in postoperative vertebral angles in both groups (p = 0.036). The cement volume injected was 7.42 mL in the EI, compared with 6.3 mL in the LI (p = 0.007). The mean surgery time was shorter in the EI, at 30.2 min, compared with 37.1 min for the LI, presenting a significant difference (p = 0.0004). There was no statistical difference in the pain visual analog scale (VAS) between the two groups (p = 0.711), and there was no statistical difference in cement leakage (p = 0.192). Conclusions/Level of Evidence: Early BKP for OVF treatment may achieve better outcomes and fewer adjacent segmental fractures than delayed intervention.

Predictors of residual low back pain in patients with osteoporotic vertebral fractures following percutaneous kyphoplasty

Objective

Patients with osteoporotic vertebral fractures (OVFs) often suffer from residual low back pain (LBP) after percutaneous kyphoplasty (PKP). The purpose of this study was to identify risk factors for postoperative residual LBP and to develop a nomogram to predict the occurrence of residual LBP.

Methods

We retrospectively reviewed 236 patients who underwent PKP for OVFs and had a minimum follow-up of 12 months. The mean age was 72.1 ± 6.3, 74.3% were female and 25.7% were male. Patients with LBP VAS scores ≥ 3.5 at the 12th month postoperatively were considered to have residual LBP. Risk factors for residual LBP were identified by univariate and multifactorial logistic regression analysis. Then, a predictive nomogram was constructed and validated using the bootstrap method. The discrimination, calibration, and clinical utility of the nomogram were assessed using a receiver operating characteristic curve (ROC), a calibration curve, and a decision curve analysis (DCA).

Results

univariate and multifactorial logistic regression analysis identified depression (P = 0.02), intravertebral vacuum cleft (P = 0.01), no anti-osteoporosis treatment (P < 0.001), cement volume <3 ml (P = 0.02), and cement distrubution (P = 0.01) as independent risk factors for residual LBP. The area under the ROC was 0.83 (0.74-0.93) and further validated by bootstrap method was 0.83 (0.73-0.92). The calibration curve illustrated the consistency between the predicted probability and the observed results. DCA showed that nomogram exhibits clinical utility and net benefit when the threshold probability is between 6% and 73%.

Conclusions

Our study found that depression, intravertebral vacuum cleft, no anti-osteoporosis treatment, cement volume <3 ml and cement distribution represent independent risk factors for residual LBP. The nomogram containing the above five predictors can accurately predict the risk of residual LBP after surgery.

Correlation Analysis between Residual Pain after Vertebral Augmentation and the Diffusion Distribution of Bone Cement: A Retrospective Cohort Study

Objective

To explore the influence and potential factors of the bone cement dispersion state on residual pain after vertebral augmentation.

Methods

The cases included in this retrospective cohort study were patients treated with vertebral augmentation (VA) for osteoporotic vertebral compression fractures (OVCFs) between July 2018 and June 2021. According to the type of cement diffusion distribution, the patients were divided into a sufficient diffusion group (Group A) and an insufficient diffusion group (Group B). The differences in the baseline data, visual analog scale (VAS), Oswestry disability index score (ODI), injured vertebral height (IVH), and local kyphosis angle (LKA) between the two groups were analyzed. Assessments were performed preoperatively on the 2nd day postoperation and at the last follow-up. The imaging data of injured vertebrae were accurately reconstructed by a GE AW4.7 workstation, and the differences in the vertebral body volume, bone cement volume, and bone cement volume ratio were compared between the groups.

Result

After screening, 36 patients were included. (1) The postoperative VAS and ODI scores of the two groups were significantly improved compared with the preoperative scores. (2) On the 2nd day postoperation and the last follow-up, the VAS and ODI scores of Group A were significantly different from those of Group B, and Group A outperformed Group B. (3) The IVH and LKA of the two groups were improved after the operation, and no significant difference was found between the groups. (4) Significant differences were found in the bone cement volume and bone cement volume ratio between the groups, and Group A was larger than Group B.

Conclusions

Sufficient bone cement diffusion can reduce residual pain after vertebral augmentation.

A novel scoring system to predict the residual back pain after percutaneous kyphoplasty for osteoporotic vertebral compression fracture

Objective

To establish a scoring system to predict the residual back pain after percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fracture (OVCF).

Materials and methods

We retrospectively reviewed the clinical records of 98 patients who were diagnosed of single-vertebral OVCF and underwent PKP surgery in our department from January 2015 to December 2017. The following clinical characteristics including age, gender, disease course, fracture location, fracture type, segmental kyphosis, and bone cement volume were all recorded, and the effects of these factors on postoperative pain (at 1-month and 6-month postoperative) were also analyzed respectively. Based on 6-month postoperative VAS score, the included patients were divided into two groups, namely the residual back pain group (19 patients) and the non-residual back pain group (79 patients). The independent risk factors of residual back pain after PKP were screened and the scoring system was established by the multivariate logistic regression analysis. The performance of this scoring system was also prospectively validated using the clinical data of 45 patients with single-vertebral OVCF from January 2018 to December 2019.

Results

The scoring system was consist of five clinical characteristics which were confirmed as significant predictors of residual back pain after PKP, namely, age ≥60 years (P = 0.021), fracture location = thoracic or lumbar (P = 0.002), fracture type = OF4 type (P = 0.018), segmental kyphosis ≥20° (P = 0.014), and bone cement volume <5 ml (P = 0.001). Patients in the residual back pain group showed a significant higher score than the non-residual back pain group (6.84 ± 1.71 vs. 2.66 ± 1.97, t = 8.499, P < 0.001), and the optimal cut-off value for the scoring system was 5 points. The sensitivity and specificity of the scoring system for predicting residual back pain after PKP were 84.21% and 87.34%, respectively, in derivation set and 78.57% and 83.87% in validation set.

Conclusion

This novel scoring system showed satisfactory diagnostic efficacy in predicting residual back pain after PKP for single-vertebral OVCF. Patients with the score of 5–9 had a high risk of postoperative residual back pain, while the patients with score of 0–4 was low.

The Effects of Bone Cement Volume in Percutaneous Vertebroplasty for Thoracolumbar Junction Vertebral Compression Fractures: A Clinical Comparative Study

We compared the outcomes of patients treated with different volumes of polymethyl methacrylate bone cement during percutaneous vertebroplasty (PVP) for thoracolumbar vertebral compression fractures. We performed a comparative, retrospective study of 316 patients who underwent PVP for a single-level thoracolumbar vertebral compression fracture. Patients were divided into two groups: group A (≤5 mL; n = 146) and group B (>5 mL; n = 170). The visual analogue scale (VAS) for pain and the Roland-Morris Disability Questionnaire (RDQ) scores were compared between the two groups at 1 week and at 1, 6, 12, and 24 months after PVP. The incidence of cement leakage into the intervertebral discs was evaluated by a postoperative lateral radiograph assessment. Patients were evaluated for new fractures 1 and 2 years after PVP or when new fractures were suspected. Among the 316 patients enrolled, 245 completed the clinical research. No difference between groups A and B in terms of the VAS, RDQ, and rate of complications at all time points after surgery was observed. The presence of intervertebral disc leakage was a relative risk (RR) for subsequent total vertebral fracture (RR, 6.42; 95% confidence interval (CI), 2.72-14.19; P < 0.0001) and adjacent vertebral fracture (RR, 8.03; 95% CI, 2.74-23.54; P = 0.0001). A high volume of bone cement may increase the rate of subsequent total and adjacent vertebral fractures. However, the occurrence of intervertebral disc leakage is the principal risk factor for these negative outcomes of PVP.

Osteoporotic Thoracolumbar Vertebral Fractures With Neurological Deficit Treated by Balloon Kyphoplasty Augmented with Newly Developed Minimally Invasive Posterior Hook Stabilization

Most osteoporotic vertebral fractures (OVFs) are treated conservatively, but surgery is often indicated for residual pain, neuropathy, or severe deformity. OVFs tend to develop in elderly patients, so less invasive surgery is desirable. Surgery is mainly performed to stabilize the fractured vertebral body. Percutaneous cement augmentation, such as via balloon kyphoplasty (BKP), has produced satisfactory results as a surgical method for managing OVFs. Posterior fixation with implants is often performed with or without cement augmentation when stronger fixation is considered necessary for OVFs with local kyphosis and angular instability. Pedicle screws (PSs) are widely used as an implant for posterior fixation, but given the risk of backing out in bones with severe osteoporosis, several measures have been taken to increase the strength such as by adding hooks. In cases of osteoporosis, hooks that can use cortical bone as an anchor are considered more useful than PS but are rarely used in minimally invasive surgery. We developed a minimally invasive posterior hook stabilization approach to directly stabilize the posterior spinal components as a new augmentation method for BKP and applied it to four cases of thoracolumbar OVF with neurological symptoms. The operation time was about 60 minutes, including BKP, and the estimated blood loss was about 10 ml. No postoperative implant problems occurred, and in all cases, neurological symptoms, such as buttocks and leg pain, were alleviated at an early stage after surgery. One patient had a postoperative adjacent vertebral body fracture that was conservatively treatable. Minimally invasive posterior hook stabilization, which we developed as a way of augmenting BKP, was considered useful for managing vertebral body fractures of the thoracolumbar spine with local kyphosis and angular instability.

Development and validation of a nomogram for predicting the probability of new vertebral compression fractures after vertebral augmentation of osteoporotic vertebral compression fractures

INTRODUCTION

New vertebral compression fractures (NVCFs) are adverse events after vertebral augmentation of osteoporotic vertebral compression fractures (OVCFs). Predicting the risk of vertebral compression fractures (VCFs) accurately after surgery is still a significant challenge for spinal surgeons. The aim of our study was to identify risk factors of NCVFs after vertebral augmentation of OVCFs and develop a nomogram.

METHODS

We retrospectively reviewed the medical records of patients with OVCFs who underwent percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP). Patients were divided into the NVCFs group and control group, base on the patients with or without NVCFs within 2 years follow-up period after surgery. A training cohort of 403 patients diagnosed in our hospital from June 2014 to December 2016 was used for model development. The independent predictive factors of postoperative VCFs were determined by least absolute shrinkage and selection operator (LASSO) logistic regression, univariate analysis and multivariate logistic regression analysis. We provided a nomogram for predicting the risk of NVCFs based on independent predictive factors and used the receiver operating characteristic curve (ROC), calibration curve, and decision curve analyses (DCA) to evaluated the prognostic performance. After internal validation, the nomogram was further evaluated in a validation cohort of 159 patients included between January 2017 and June 2018.

RESULTS

Of the 403 patients in the training cohort, 49(12.16%) were NVCFs at an average of 16.7 (1 to 23) months within the 2 years follow-up period. Of the 159 patients in the validation cohort, 17(10.69%) were NVCFs at an average of 8.7 (1 to 15) months within the 2 years follow-up period. In the training cohort, the proportions of elderly patients older than 80 years were 32.65 and 13.56% in the NVCFs and control group, respectively (p = 0.003). The percentages of patients with previous fracture history were 26.53 and 12.71% in the NVCFs and control group, respectively (p = 0.010). The volume of bone cement were 4.43 ± 0.88 mL and 4.02 ± 1.13 mL in the NVCFs and Control group, respectively (p = 0.014). The differences have statistical significance in the bone cement leakage, bone cement dispersion, contact with endplate, anti-osteoporotic treatment, post-op Cobb angle and Cobb angle restoration characteristics between the two groups. The model was established by multivariate logistic regression analysis to obtain independent predictors. In the training and validation cohort, the AUC of the nomogram were 0.882 (95% confidence interval (CI), 0.824-0.940) and 0.869 (95% CI: 0.811-0.927), respectively. The C index of the nomogram was 0.886 in the training cohort and 0.893 in the validation cohort, demonstrating good discrimination. In the training and validation cohort, the optimal calibration curves demonstrated the coincidence between prediction and actual status, and the decision curve analysis demonstrated that the full model had the highest clinical net benefit across the entire range of threshold probabilities.

CONCLUSION

A nomogram for predicting NVCFs after vertebral augmentation was established and validated. For patients evaluated by this model with predictive high risk of developing postoperative VCFs, postoperative management strategies such as enhance osteoporosis-related health education and management should be considered.

Selections of Bone Cement Viscosity and Volume in Percutaneous Vertebroplasty: A Retrospective Cohort Study

OBJECTIVE

We sought to evaluate the efficacy and complications of percutaneous vertebroplasty with different viscosities and volumes of bone cement in treating osteoporotic vertebral compression fractures (OVCFs).

METHOD

We conducted a retrospective cohort study of 307 patients treated for a single thoracolumbar level (T12-L2) OVCF in our hospital between January 2014 and December 2019. The patients were divided into 6 groups according to different viscosities (I: low-viscosity bone cement, II: high-viscosity bone cement) and injection volumes (A, 2-4 mL; B, 4-6 mL; C, 6-8 mL) of bone cement. Clinical and radiologic characteristics including visual analog scale, local kyphotic angle, anterior vertebral height ratio, cement leakage, and vertebral body recollapse rate were collected preoperatively, 2 days postoperation, and at the last follow-up to assess the efficacy and complications of each group.

RESULTS

Regarding efficacy, there was no significant difference between the 2 kinds of bone cement. Injecting >4 mL of cement can provide patients with good improvements of clinical indicators and a low vertebral body recollapse rate. Injecting 6-8 mL of bone cement slightly improved the radiologic indicators. However, the leakage rate of low-viscosity bone cement increased significantly when the volume exceeded 6 mL. The leakage rate of high-viscosity bone cement did not increase significantly at the volume of 6-8 mL.

CONCLUSIONS

In summary, when treating single thoracolumbar level OVCFs, the recommended volume of low-viscosity bone cement is 4-6 mL while the optimal volume of high-viscosity bone cement is 6-8 mL.

[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.

Pain relief and associated factors in patients undergoing vertebroplasty due to osteoporotic vertebral fracture

BACKGROUND

Osteoporotic vertebral fracture (OVF) is a common spinal fracture in the elderly population treated with conservative or surgical techniques. Patients with such fractures may experience chronic pain due to nonunion and instability, deformity with kyphosis and neurologic symptoms due to neural compression. Surgical interventions have definite roles in treatments especially when conservative therapy fails. Cement augmentation in forms of vertebroplasty and kyphoplasty or even surgical fixation with or without column reconstruction are among our armamentarium to deal with problems arising during the treatment of these patients.

METHODS

We entered patients with OVF who did not respond to conservative treatments for more than 4 weeks and were candidates for vertebroplasty. Pain Visual Analog Scale (PVAS) was assessed for patients before the procedure, in the first month and 6 months after surgeries. We also analyzed factors including time passed from fractures, amounts of injected cement, age, sex, types of fractures, segmental kyphosis and sites of fractures. Data were collected and analyzed using SPSS software version 24.

RESULTS

A total number of 140 patients entered. The mean age of the patients was 64.90±7.97 years. Mean preoperative pain level was 8.35±0.97 points on VAS (0-10) score. The mean Post-operative VAS score after one month and after six months were 4.65±0.66 and 5.28±0.75 respectively. The mean consumed cement volume was 5.77±1.40 ml. Cement volume of more than 5 ml was injected for 53.6% of patients. 78.7% of fractures were located in T10-L2 levels (thoracolumbar fractures). 14.2% of fractures in L3-L5 (lumbar fractures) and 7.1% in T4-T9 (thoracic fractures). 53.6% of the patients had kyphosis levels below 20 degrees. Reduction of pain in patients younger than 60 years was more than patients older than 60 years but both groups indicated pain reduction (P<0.001). The end-plate fracture had a higher likelihood of pain relief compared with burst or retropulsed fractures (OR=1.161). Patients with thoracolumbar fractures had higher chances of pain reduction compared with other locations (OR=1.870). Kyphosis less than 20 degrees and also cement volume more than 5 ml had also significant effects on reducing the pain after surgeries (OR=2.054 and OR=2.412 respectively (P<0.05)).

CONCLUSION

Vertebroplasty is an effective option in treating patients with OVF who have not respond to conservative treatment. Factors such as younger age, OVFs involving either end-plates, more than 5 ml of cement injection, segmental kyphosis below 20 degrees and thoracolumbar fractures are associated with better results for pain amelioration.

Analysis of injected cement volume and clinical outcomes following kyphoplasty for vertebral compression fractures

Background:

It has been suggested that greater volumes of cement injected during kyphoplasty correlate with improved vertebral body height restoration and kyphotic angulation correction. However, there is little evidence tying cement volume to patient outcomes. Here, we analyzed the association between cement volume and outcome utilizing indices of pain, disability, and quality of life.

Methods:

One hundred and thirty-six patients undergoing kyphoplasty were analyzed retrospectively. The total volume of bone cement injected was recorded intraoperatively for each patient; the average total cement volume was 5.44 cc. Pre- and postoperative outcome indices were documented, using the visual analog scale (VAS), Roland-Morris disability index (RMDI), and the EuroQol 5 Dimension instrument (EQ5D). Pearson’s correlations and linear regression models were derived for the association of total cement volume with each of the patient outcome measures. This was a retrospective cohort study.

Results:

The average change in VAS, RMDI, and EQ5D scores for all patients was −6.8, +8.3, and +0.41, respectively. For VAS, RMDI, and EQ5D improvements, neither Pearson’s correlations nor multiple linear regression models revealed a correlation or an association with total cement volume.

Conclusion:

For patients undergoing kyphoplasty, outcomes were not associated with the total injected cement volume; all had a significant reduction in pain and most exhibited decreased disability with improved quality of life.

Cement injection and postoperative vertebral fractures during vertebroplasty

Objective

Vertebroplasty is the most widely used method for treating osteoporotic vertebral compression fractures (OVCF). During this procedure, bone cement is injected into the vertebral body. Fracture and additional fractures can occur adjacent to the treatment site. Thus, we studied factors causing such vertebral fractures after vertebroplasty and calculated the appropriate amount of bone cement to inject.

Methods

From September 2012 to March 2016, 187 patients with OVCF undergoing vertebroplasty were selected, and 112 patients with complete follow-up information were selected. Of these, 28 had adjacent vertebral fractures (refracture group) during the follow-up period, and 84 patients had no adjacent vertebral fractures (control group). Then, sex, age, body weight, bone mineral density (BMD), and bone cement injection (bone cement injection volume and bone fracture vertebral volume percent) were compared.

Results

All patients had significant pain relief within 24 h (preoperative and postoperative [24 h later] VAS scores were 7.4 ± 0.8 and 2.3 ± 0.5, respectively). The age and weight were not statistically significantly different (P > 0.05). BMD values were statistically significantly different between groups as was sex (P < 0.05).

Conclusions

Bone cement injection volume, BMD values, and sex were statistically significantly related to adjacent vertebral fractures after vertebroplasty, and cement injection volumes exceeding 40.5% caused adjacent vertebral fractures.

ISASS Policy 2018-Vertebral Augmentation: Coverage Indications, Limitations, and/or Medical Necessity

The ISASS Policy Statement on vertebral augmentation has the objectives to provide a background and an update with the latest clinical evidence for the international spine community. A SpineLine Panel Review (2010) appropriately recommended an exploration of "the seeming disconnect between the conclusions of … two [Level I] PRCT's and previous experience and data" regarding vertebral augmentation. ISASS responded by supporting a comprehensive meta-analysis to help frame a cogent historical analysis of vertebral augmentation. This ISASS Policy 2018 is based on a thorough literature search for relevant studies, including systematic reviews and meta-analyses, that are subjected to thorough quality appraisal for the purpose of informing public opinion and decision making. Given the abundance of high-quality information, ISASS can confidently advocate that there is strong support for vertebral augmentation in the treatment of symptomatic vertebral compression fractures.

Mechanism of formation of intravertebral clefts in osteoporotic vertebral compression fractures: An in vitro biomechanical study

BACKGROUND CONTEXT

Intravertebral clefts (IVCs) are vacuum-like cavities commonly associated with osteoporotic vertebral compression fractures (OVCFs). IVCs promote cement leakage during kyphoplasty, suggesting a physical link with the basivertebral foramen, although this is uncertain.

PURPOSE

The present study aims to create IVCs in mechanical experiments on cadaveric spines in order to clarify their pathogenesis, structure, and links with the basivertebral foramen.

STUDY DESIGN AND METHODS

In total, 15 three-vertebra lumbar specimens from five cadavers aged 68 to 71 years were subjected to axial compressive overload followed by cyclic loading in flexion and extension to create an OVCF together with an IVC. Computed tomography scans and radiographs were used to confirm structural changes and micro-CT was used to measure trabecular bone properties in five specimens. Unipedicular vertebroplasty was then performed on 10 damaged specimens until fluoroscopy revealed extravasation of cement.

RESULTS

In every specimen, loading created an OVCF with an IVC. Dissection and imaging showed that the IVC was always connected with the basivertebral foramen. The central vertebral region, including the IVC, had the lowest connectivity density, trabecular number, and bone volume fraction, and the highest trabecular separation. Vertebroplasty caused cement leakage through the basivertebral foramen in nine specimens and into an adjacent disc in one specimen.

CONCLUSION

Cyclic loading in flexion and extension applied to a fractured osteoporotic vertebra can create an IVC, which then allows cement leakage via the basivertebral foramen.

Is Balloon kyphoplasty a better treatment than percutaneous vertebroplasty for chronic obstructive pulmonary disease (COPD) patients with osteoporotic vertebral compression fractures (OVCFs)?

BACKGROUND

Although several studies reported that Balloon kyphoplasty (BK) or percutaneous vertebroplasty (PVP) could improve pulmonary functions, there is no study to compare the efficacy and safety of 2 procedures in COPD patients with osteoporotic vertebral compression fractures (OVCFs) and investigate the reason why they could improve pulmonary functions.

METHOD

Two procedures, including BK and PVP were performed in 61 COPD patients with single-level OVCFS. VAS-score, ODI, pulmonary function and radiological parameters (Anterior vertebral body height ratio, posterior vertebral body height ratio and Local kyphotic angle) were evaluated preoperatively and 1 week, 3 months and 12 moths postoperatively, respectively. The operation time and cement leakage rate were also recorded.

RESULT

The operation time was longer in BK than PVP (37.5 ± 7.4 versus 27.6 ± 6.2 min per vertebra). Both groups got an equally significant improvement in pain relief, functional result, pulmonary functions and demonstrated similar cement leakage rate (BK: 6.5%; PVP: 10%). Radiologically, BK is favored than PVP. A significant relationship between VAS and pulmonary functions except FEV₁ was observed in first week postoperatively, while the ODI was related to MVV in first 3 months postoperatively.

CONCLUSION

Both BK and PVP provided equally significant back pain relief and improvements of respiratory functions in patients affected by COPD with single level OVCFs. BK was favored in radiography, this improvement was not related to pain relief and improvement of pulmonary functions. Given much higher cost of BK, similar effectiveness and safety of BK and PVP, in COPD patients with OVCFs, PVP may be a better choice.

Radiofrequency-Targeted Vertebral Augmentation: Case Report of a Patient with 7 Osteoporotic Vertebral Fractures in a Variant of Osteogenesis Imperfecta

Introduction

Radiofrequency-targeted vertebral augmentation (RF-TVA) is a recognized treatment for painful compression fractures. RF-TVA in a patient with multiple compression fractures due to type I osteogenesis imperfecta (OI) has not been previously reported.

Case Presentation

A 54-year-old patient with type I OI is presented with a segmental thoracic hyperkyphosis and 7 recent vertebral compression fractures. Because of persistent severe thoracolumbar back pain despite conservative therapy, RF-TVA was indicated. Nocturnal back pain was almost completely relieved at all postoperative time points evaluated. However, overall pain relief dropped only slightly from 7 to 5 on the numerical rating scale (NRS) at the 6-week follow-up, and there was only a small decrease in the Oswestry Disability Index (ODI) from 72% to 63%. An MRI at the 3-month follow-up revealed hyperintensity at levels T11 and T12, indicating slight recollapsing. At the 6-month follow-up, the ODI improved to 55%, although overall pain had worsened to 6 on the NRS. Pain at rest remained at a very low level.

Conclusion

Despite the remaining lumbago, RF-TVA may be a good option for patients with OI who have multiple fractures. However, fractures at multiple levels and segmental thoracic hyperkyphosis may increase the risk for recollapsing and ongoing pain.

Does an osteoporotic vertebral fracture treated by balloon kyphoplasty successfully achieve bone union during the follow-up? A retrospective study with a minimum 2-year follow-up

OBJECTIVE

To investigate whether bone union is achieved in osteoporotic vertebral fracture (OVF) patients who undergo balloon kyphoplasty (BKP).

METHODS

Thirty-six vertebrae, which were followed-up for more than two years after BKP, were evaluated in the present study. Bone union was assessed by using CT scans and lateral X-ray films obtained in the sitting and supine positions.

RESULTS

Twenty-seven vertebrae exhibited bone union at the final follow-up. The VAS scores improved in all cases.

CONCLUSIONS

Unstable vertebrae after treatment may develop complications; thus special attention should be paid to the treated vertebrae until bone union has been achieved.

Percutaneous cement augmentation for osteoporotic vertebral fractures

Thoracolumbar vertebral fracture incidents usually occur secondary to a high velocity trauma in young patients and to minor trauma or spontaneously in older people.

Osteoporotic vertebral fractures are the most common osteoporotic fractures and affect one-fifth of the osteoporotic population.

Percutaneous fixation by ‘vertebroplasty’ is a tempting alternative for open surgical management of these fractures.

Despite discouraging initial results of early trials for vertebroplasty, cement augmentation proved its superiority for the treatment of symptomatic osteoporotic vertebral fracture when compared with optimal medical treatment.

Early intervention is also gaining ground recently.

Kyphoplasty has the advantage over vertebroplasty of reducing kyphosis and cement leak.

Stentoplasty, a new variant of cement augmentation, is also showing promising outcomes.

In this review, we describe the additional techniques of cement augmentation, stressing the important aspects for success, and recommend a thorough evaluation of thoracolumbar fractures in osteoporotic patients to select eligible patients that will benefit the most from percutaneous augmentation. A detailed treatment algorithm is then proposed.

Cite this article: EFORT Open Rev 2017;2:293–299. DOI: 10.1302/2058-5241.2.160057

Decreased extrusion of calcium phosphate cement versus high viscosity PMMA cement into spongious bone marrow-an ex vivo and in vivo study in sheep vertebrae

BACKGROUND CONTEXT

Vertebroplasty or kyphoplasty of osteoporotic vertebral fractures bears the risk of pulmonary cement embolism (3.5%-23%) caused by leakage of commonly applied acrylic polymethylmethacrylate (PMMA) cement to spongious bone marrow or outside of the vertebrae. Ultraviscous cement and specific augmentation systems have been developed to reduce such adverse effects. Rapidly setting, resorbable, physiological calcium phosphate cement (CPC) may also represent a suitable alternative.

PURPOSE

This study aimed to compare the intravertebral extrusion of CPC and PMMA cement in an ex vivo and in vivo study in sheep.

STUDY DESIGN/SETTING

A prospective experimental animal study was carried out.

METHODS

Defects (diameter 5 mm; 15 mm depth) were created by a ventrolateral percutaneous approach in lumbar vertebrae of female Merino sheep (2-4 years) either ex vivo (n=17) or in vivo (n=6), and injected with: (1) CPC (L3); (2) CPC reinforced with 10% poly(l-lactide-co-glycolide) (PLGA) fibers (L4); or (3) PMMA cement (L5; Kyphon HV-R). Controls were untouched (L1) or empty defects (L2). The effects of the cement injections were assessed in vivo by blood gas analysis and ex vivo by computed tomography (CT), micro-CT (voxel size: 67 µm), histology, and biomechanical testing.

RESULTS

Following ex vivo injection, micro-CT documented significantly increased extrusion of PMMA cement in comparison to CPC (+/- fibers) starting at a distance of 1 mm from the edge of the defect (confirmed by histology); this was also demonstrated by micro-CT following in vivo cement injection. In addition, blood gas analysis showed consistently significantly lower values for the fraction of oxygenized hemoglobin/total hemoglobin (FO₂Hb) in the arterial blood until 25 minutes following injection of the PMMA cement (p ≤ .05 vs. CPC; 7, 15 minutes). Biomechanical testing following ex vivo injection showed significantly lower compressive strength and Young modulus than untouched controls for the empty defect (40% and 34% reduction, respectively) and all three cement-injected defects (21%-27% and 29%-32% reduction, respectively), without significant differences among the cements.

CONCLUSIONS

Because of comparable compressive strength, but significantly lower cement extrusion into spongious bone marrow than PMMA cement, physiological CPC (+/- PLGA fibers) may represent an attractive alternative to PMMA for vertebroplasty or kyphoplasty of osteoporotic vertebral fractures to reduce the frequency or severity of adverse effects.

A Classification System for the Spread of Polymethyl Methacrylate in Vertebral Bodies Treated with Vertebral Augmentation

In this study, we develop a classification system for describing polymethyl methacrylate (PMMA) spread in vertebral bodies after kyphoplasty or vertebroplasty for vertebral compression fractures (VCFs) and for assessing whether PMMA spread varies between operators, VCF etiology, or vertebral level. Intraoperative fluoroscopic images of 198 vertebral levels were reviewed in 137 patients (women, 84; men, 53; mean age, 75.8 ± 12.5; and those with a diagnosis of osteoporosis, 63%) treated with kyphoplasty between January 01, 2015 and May 31, 2015 at a single center to create a 5-class descriptive system. PMMA spread patterns in the same images were then classified by 2 board-certified radiologists, and a third board-certified radiologist resolved conflicts. A total of 2 primary PMMA spread patterns were identified, namely, acinar and globular, with subtypes of localized acinar, diffuse globular, and mixed, to describe an equal combination of patterns. Interrater reliability using the system was moderate (κ = 0.47). After resolving conflicts, the most common spread class was globular (n = 63), followed by mixed (n = 58), diffuse globular (n = 30), acinar (n = 27), and localized acinar (n = 20). The spread class after treatment by the 2 most frequent operators differed significantly (n₁ = 63, n₂ = 70; P < .0001). There was no difference in the spread class between VCF etiologies or vertebral levels. PMMA spread may, therefore, be a modifiable parameter that affects kyphoplasty and vertebroplasty efficacy and adverse events.

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

OBJECTIVE

This study investigated the benefit of prophylactic vertebroplasty of the adjacent vertebrae in single-segment osteoporotic vertebral body fractures treated with kyphoplasty.

METHODS

All patients treated with kyphoplasty for osteoporotic single-segment fractures between January 2007 and August 2012 were included in this retrospective study. The patients received either kyphoplasty alone (kyphoplasty group) or kyphoplasty with additional vertebroplasty of the adjacent segment (vertebroplasty group). The segmental kyphosis with the rate of adjacent-segment fractures (ASFs) and remote fractures were studied on plain lateral radiographs preoperatively, postoperatively, at 3 months, and at final follow-up.

RESULTS

Thirty-seven (82%) of a possible 45 patients were included for the analysis, with a mean follow-up of 16 months (range 3–54 months). The study population included 31 women, and the mean age of the total patient population was 72 years old (range 53–86 years). In 21 patients (57%), the fracture was in the thoracolumbar junction. Eighteen patients were treated with additional vertebroplasty and 19 with kyphoplasty only. The segmental kyphosis increased in both groups at final follow-up. A fracture through the primary treated vertebra (kyphoplasty) was found in 4 (22%) of the vertebroplasty group and in 3 (16%) of the kyphoplasty group (p = 0.6). An ASF was found in 50% (n = 9) of the vertebroplasty group and in 16% (n = 3) of the kyphoplasty group (p = 0.03). Remote fractures occurred in 1 patient in each group (p = 1.0).

CONCLUSIONS

Prophylactic vertebroplasty of the adjacent vertebra in patients with single-segment osteoporotic fractures as performed in this study did not decrease the rate of adjacent fractures. Based on these retrospective data, the possible benefits of prophylactic vertebroplasty do not compensate for the possible risks of an additional cement augmentation.

Vertebral Augmentation: State of the Art

Osteoporotic vertebral compression fractures (OVF) are an increasing public health problem. Cement augmentation (vertebroplasty of kyphoplasty) helps stabilize painful OVF refractory to medical treatment. This stabilization is thought to improve pain and functional outcome. Vertebroplasty consists of injecting cement into a fractured vertebra using a percutaneous transpedicular approach. Balloon kyphoplasty uses an inflatable balloon prior to injecting the cement. Although kyphoplasty is associated with significant improvement of local kyphosis and less cement leakage, this does not result in long-term clinical and functional improvement. Moreover, vertebroplasty is favored by some due to the high cost of kyphoplasty. The injection of cement increases the stiffness of the fracture vertebrae. This can lead, in theory, to adjacent OVF. However, many studies found no increase of subsequent fracture when comparing medical treatment to cement augmentation. Kyphoplasty can have a protective effect due to restoration of sagittal balance.

Percutaneous vertebroplasty for patients with metastatic compression fractures of the thoracolumbar spine: clinical and radiological factors affecting functional outcomes

BACKGROUND CONTEXT

Vertebroplasty (VP), including balloon kyphoplasty (BKP), has long been accepted as a minimally invasive surgical intervention for the stabilization of painful vertebral compression fractures. In metastatic compression fracture (MCF), cancer often invades the paravertebral structure and involves the posterior column of the vertebrae.

PURPOSE

In the present study, we first analyzed how clinical features of MCF affect functional outcomes after VP. Second, we evaluated whether BKP is more beneficial than simple VP (SVP) in MCF.

STUDY DESIGN/SETTING

This is a retrospective observational study.

PATIENT SAMPLE

Three hundred forty-two patients who underwent VP for painful MCF from solid cancer were included. We excluded MCF from hematopoietic cancer, such as leukemia or multiple myeloma.

OUTCOME MEASURES

Pain improvement was evaluated using the visual analog scale (VAS; range: 0-10), and if the VAS score decreased by at least three points the treatment was considered effective. Postoperative change in Karnofsky performance status (KPS) and drug requirement for pain control were also measured as functional outcomes.

METHODS

An institutional database at the National Cancer Center of Korea was searched to identify all patients who underwent VP for painful MCF between March 2002 and September 2013. Demographic data, as well as preoperative and postoperative clinical factors, were collected from patients' medical records. Radiological features, including paravertebral extension of tumors and the extent of three-column involvement, were reviewed from pretreatment magnetic resonance imaging (MRIs). These clinical and radiological factors were then analyzed for their influence on functional outcomes.

RESULTS

The mean preoperative VAS score was 5.8; this improved to a mean of 2.7 after VP. Effective improvement in VAS score (≥3) was achieved in 206 patients (60%). Patients with radiculopathy, as well as those with involvement of (1) the posterior column or (2) more than four out of six columns, presented with significantly higher pretreatment VAS scores and experienced more effective improvement after treatment (p<.05). Two hundred thirty-eight patients (70%) underwent SVP, whereas the remaining 104 patients underwent BKP. The pretreatment degree of compression was significantly higher in BKP (mean: 47%) than in SVP patients (mean: 30%) (p<.001). However, preoperative VAS scores were not significantly different between the two groups, and the resultant VAS score improvement was also not significantly different. Although BKP patients reported to have a greater chance of more than 3 mL of cement injection (p=.01), the mean amount of cement injected was not different between the two groups. Patients with other bone metastases showed a significantly poorer KPS improvement rate (p=.015). Patients having moderately or slowly growing cancer according to the Tomita classification had a greater chance of reduced drug requirements 1 month after the procedure (p=.004).

CONCLUSIONS

Paravertebral extension and posterior column involvement of MCF did not preclude pain improvement after VP. Balloon kyphoplasty for MCF failed to show enhanced pain improvement relative to SVP. Metastatic compression fracture patients with other bone metastases or rapidly growing tumors had a lower chance of performance improvement and reduced drug requirements, respectively.

CONTROVERSIES ON VERTEBROPLASTY AND KYPHOPLASTY FOR VERTEBRAL COMPRESSION FRACTURES

Vertebroplasty and kyphoplasty are widely used for osteoporotic and cancer-related vertebral compression fractures refractory to medical treatment. Many aspects of these procedures have been extensively discussed in the literature during the last few years. In this article, we perform a critical appraisal of current evidence on effectiveness and ongoing controversies regarding surgical technique, indications and contraindications, clinical outcomes and potential complications of these procedures.

Lavage prior to vertebral augmentation reduces the risk for cement leakage

PURPOSE

This study aimed at assessing the cement leakage rate and the filling pattern in patients treated with vertebroplasty, kyphoplasty and stentoplasty with and without a newly developed lavage technique.

STUDY DESIGN

Retrospective clinical case-control study.

METHODS

A newly developed bipedicular lavage technique prior to cement application was applied in 64 patients (45.1 %) with 116 vertebrae, ("lavage" group). A conventional bipedicular cement injection technique was used in 78 patients (54.9 %) with 99 levels ("controls"). The outcome measures were filling patterns and leakage rates.

RESULTS

The overall leakage rate (venous, cortical defect, intradiscal) was 37.9 % in the lavage and 83.8 % in the control group (p < 0.001). Venous leakage (lavage 12.9 % vs. controls 31.3 %; p = 0.001) and cortical defect leakage (lavage 17.2 % vs. controls 63.3 %; p < 0.001) were significantly lower in the lavage group compared to "controls," whereas intradiscal leakages were similar in both groups (lavage 12.1 % vs. controls 15.2 %; p = 0.51). For venous leakage multivariate logistic regression analysis showed lavage to be the only independent predictor. Lavage was associated with 0.33-times (95 % CI 0.16-0.65; p = 0.001) lower likelihood for leakage in compared to controls.

CONCLUSIONS

Vertebral body lavage prior to cement augmentation is a safe technique to reduce cement leakage in a clinical setting and has the potential to prevent pulmonary fat embolism. Moreover, a better filling pattern can be achieved.

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.

Real-life results of balloon kyphoplasty for vertebral compression fractures from the SWISSspine registry

BACKGROUND CONTEXT

The Swiss Federal Office of Public Health mandated a nationwide health technology assessment-registry for balloon kyphoplasty (BKP) for decision making on reimbursement of these interventions. The early results of the registry led to a permanent coverage of BKP by basic health insurance. The documentation was continued for further evidence generation.

PURPOSE

This analysis reports on the 1 year results of patients after BKP treatment.

STUDY DESIGN

Prospective multicenter observational case series.

PATIENT SAMPLE

The data on 625 cases with 819 treated vertebrae were documented from March 2005 to May 2012.

OUTCOME MEASURES

Surgeon-administered outcome instruments were primary intervention form for BKP and the follow-up form; patient self-reported measures were EuroQol-5D questionnaire, North American Spine Society outcome instrument /Core Outcome Measures Index (including visual analog scale), and a comorbidity questionnaire. Outcome measures were back pain, medication, quality of life (QoL), cement extrusions, and new fractures within the first postoperative year.

METHODS

Data were recorded preoperatively and at 3 to 6-month and 1-year follow-ups. Wilcoxon signed-rank test was used for comparison of pre- with postoperative measurements. Multivariate logistic regression was used to identify factors with a significant influence on the outcome.

RESULTS

Seventy percent of patients were women with mean age of 71 years (range, 18-91 years); mean age of men was 65 years (range, 15-93 years). Significant and clinically relevant reduction of back pain, improvement of QoL, and reduction of pain killer consumption was seen within the first postoperative year. Preoperative back pain decreased from 69.3 to 29.0 at 3 to 6-month and remained unchanged at 1-year follow-ups. Consequently, QoL improved from 0.23 to 0.71 and 0.75 at the same follow-up intervals. The overall vertebra-based cement extrusion rates with and without extrusions into intervertebral discs were 22.1% and 15.3%, respectively. Symptomatic cement extrusions with radiculopathy were five (0.8%). A new vertebral fracture within a year from the BKP surgery was observed in 18.4% of the patients.

CONCLUSIONS

The results of the largest observational study for BKP so far are consistent with published randomized trials and systematic reviews. In this routine health care setting, BKP is safe and effective in reducing pain, improving QoL, and lowering pain_killer consumption and has an acceptable rate of cement extrusions. Postoperative outcome results show clear and significant clinical improvement at early follow-up that remain stable during the first postoperative year.

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.

Adverse prognostic factors and optimal intervention time for kyphoplasty/vertebroplasty in osteoporotic fractures

Introduction. While evidence supports the efficacy of vertebral augmentation (kyphoplasty and vertebroplasty) for the treatment of osteoporotic fractures, randomized trials disputed the value of vertebroplasty. The aim of this analysis is to determine the subset of patients that may not benefit from surgical intervention and find the optimal intervention time. Methods. 27 prospective multiple-arm studies with cohorts of more than 20 patients were included in this meta-analysis. We hereby report the results from the metaregression and subset analysis of those trials reporting on treatment of osteoporotic fractures with kyphoplasty and/or vertebroplasty. Results. Early intervention (first 7 weeks after fracture) yielded more pain relief. However, spontaneous recovery was encountered in hyperacute fractures (less than 2 weeks old). Patients suffering from thoracic fractures or severely deformed vertebrae tended to report inferior results. We also attempted to formulate a treatment algorithm. Conclusion. Intervention in the hyperacute period should not be pursued, while augmentation after 7 weeks yields less consistent results. In cases of thoracic fractures and significant vertebral collapse, surgeons or interventional radiologists may resort earlier to operation and be less conservative, although those parameters need to be addressed in future randomized trials.