Adjacent Level Fractures Research Articles

Sandwich Vertebral Fracture in the Study of Adjacent-Level Fracture after Vertebral Cement Augmentation

Sandwich Vertebral Fracture in the Study of Adjacent-Level Fracture after Vertebral Cement Augmentation

Effect of the Location of Endplate Cement Extravasation on Adjacent Level Fracture in Osteoporotic Patients Undergoing Vertebroplasty and Kyphoplasty

Background: The most widely researched risk/complication following vertebroplasty (VP) or kyphoplasty (KP) is that of adjacent level fracture (ALF). Current literature results regarding the effect of intradiscal extravasation of cement on the risk of ALF is conflicting with about half of the studies concluding there is no added risk with endplate extravasation and half of the studies reporting opposite conclusions. Objective: The purpose of the study is to further stratify the data to determine whether specifically the location and extent of endplate cement extravasation more strongly affect ALF risk in osteoporotic patients following either VP or balloon KP. Study Design: Retrospective cohort study. Setting: University teaching hospital Methods: One hundred and fifty-six cemented levels in 80 patients, treated at a single center between 2008 and 2012 were reviewed. Age, gender, T-score, body mass index, and osteoporosis type (primary or secondary) were recorded. An ALF was defined as a fracture: 1) in a non-cemented vertebra; 2) adjacent to a cemented level; and 3) not due to trauma or malignancy. Location of the cement extravasation (anterior, middle, or posterior third of the vertebral body) and extravasation extent (percentage of the intervertebral disc height occupied by the bolus) were measured. A logistic modeling strategy permitted examining the association between the location and extent of extravasation and the odds of ALF. Results: ALF occurred in 14 of the 52 patients (27%) and 20 of the 98 levels (20.4%) remaining after exclusions. Odds of ALF were 5.9 times higher (95% CI: 1.6 to 21.2, P = 0.008) with extravasation when compared to no leakage. Odds of ALF in a given patient were 22.6 times higher (95% CI: 3.0 to 170.9, P = 0.003) with anterior extravasation when compared to no leakage. Leakage in the middle or posterior thirds and extent of extravasation were not associated with ALF. Limitations: Limitations of the study include the retrospective study design and small sample size as well as the retrospective implementation of follow-up criteria posing risk of selection bias. Conclusions: Cement endplate extravasation isolated to the anterior third of the vertebral body is associated with is significantly higher odds of ALF after VP or KP in patients with osteoporosis. Key words: Adjacent vertebral fracture, intradiscal leak, osteoporotic compression

Outcome of percutaneous balloon kyphoplasty in vertebral compression fractures.

Background:Incidence of vertebral compression fractures (VCFs) is increasing due to increase in human life expectancy and prevalence of osteoporosis. Vertebroplasty had been traditional treatment for pain, but it neither attempts to restore vertebral body height nor eliminates spinal deformity and is associated with a high rate of cement leakage. Balloon kyphoplasty involves introduction of inflatable balloon into the fractured body of vertebra for elevation of the end-plates prior to fixation of the fracture with bone cement. This study evaluates short term functional and radiological outcomes of balloon kyphoplasty. The secondary aim is to explore short-term complications of the procedure.Materials and Methods:A retrospective study of 199 kyphoplasty procedures in 135 patients from March 2009 to March 2012 were evaluated with short form-36 (SF-36) score, visual analogue scale (VAS), detailed neurological and radiological evaluations. The mean followup was 18 months (range 12–20 months). Statistical analysis including paired sample t-test was done with statistical package for social sciences.Results:Statistically significant improvements in SF-36 (from 34.29 to 48.53, an improvement of 14.24, standard deviation (SD) - 20.08 P < 0.0001), VAS (drop of 4.49, from 6.74 to 2.24, SD - 1.44, P < 0.0001), percentage restoration of lost vertebral height (from 30.62% to 16.19%, improvement of 14.43%, SD - 15.37, P < 0.0001) and kyphotic angle correction (from 17.41° to 10.59°, improvement of 6.82, SD - 7.26°, P < 0.0001) were noted postoperatively. Six patients had cement embolism, 65 had cement leak and three had adjacent level fracture which required repeat kyphoplasty later. One patient with history of ischemic heart disease had cardiac arrest during the procedure. No patients had neurological deterioration in the followup period.Conclusions:Kyphoplasty is a safe and effective treatment for VCFs. It improves physical function, reduces pain and corrects kyphotic deformity.

Economic Analysis of Kiva VCF Treatment System Compared to Balloon Kyphoplasty Using Randomized Kiva Safety and Effectiveness Trial (KAST) Data

Background: Vertebral compression fractures (VCFs) are the most common osteoporotic fractures and cause persistent pain, kyphotic deformity, weight loss, depression, reduced quality of life, and even death. Current surgical approaches for the treatment of VCF include vertebroplasty (VP) and balloon kyphoplasty (BK). The Kiva® VCF Treatment System (Kiva System) is a next-generation alternative surgical intervention in which a percutaneously introduced nitinol Osteo Coil guidewire is advanced through a deployment cannula and subsequently a PEEK Implant is implanted incrementally and fully coiled in the vertebral body. The Kiva System’s effectiveness for the treatment of VCF has been evaluated in a large randomized controlled trial, the Kiva Safety and Effectiveness Trial (KAST). The Kiva System was non-inferior to BK with respect to pain reduction (70.8% vs. 71.8% in Visual Analogue Scale) and physical function restoration (38.1 % vs. 42.2% reduction in Oswestry Disability Index) while using less bone cement. The economic impact of the Kiva system has yet to be analyzed. Objective: To analyze hospital resource use and costs of the Kiva System over 2 years for the treatment of VCF compared to BK. Setting: A representative US hospital. Study Design: Economic analysis of the KAST randomized trial, focusing on hospital resource use and costs. Methods: The analysis was conducted from a hospital perspective and utilized clinical data from KAST as well as unit-cost data from the published literature. The cost of initial VCF surgery, reoperation cost, device market cost, and other medical costs were compared between the Kiva System and BK. The relative risk reduction rate in adjacent-level fracture with Kiva [31.6% (95% CI: -22.5%, 61.9%)] demonstrated in KAST was used in this analysis. Results: With 304 vertebral augmentation procedures performed in a representative U.S. hospital over 2 years, the Kiva System will produce a direct medical cost savings of $1,118 per patient and $280,876 per hospital. This cost saving with the Kiva System was attributable to 19 reduced adjacent-level fractures with the Kiva System. Limitations: This study does not compare the Kiva System with VP or any other non-surgical procedures for the treatment of VCF. Conclusion: This first-ever economic analysis of the KAST data showed that the Kiva System for vertebral augmentation is hospital resource and cost saving over BK in a hospital setting over 2 years. These savings are attributable to reduced risk of developing adjacent-level fractures with the Kiva System compared to BK. Key words: Vertebral compression fracture, vertebral augmentation, osteoporosis, adjacent-level fractures, kyphoplasty, balloon kyphoplasty, Kiva System

Comparison of Percutaneous Vertebroplasty and Balloon Kyphoplasty for the Treatment of Single Level Vertebral Compression Fractures: A Meta-analysis of the Literature

Background: Percutaneous vertebroplasty (PVP) and percutaneous balloon kyphoplasty (PKP) can increase bone strength as well as alleviate the pain caused by vertebral compression fractures (VCFs), and both procedures rely on polymethyl methacrylate (PMMA) cement injected into the fractured vertebra for mechanical stabilization of the VCFs. However, there is debate over which of these 2 surgical procedures can give better short-term and long-term outcomes. A lot of studies and meta-analysis were designed to assess the advantages and drawbacks of PKP and PVP in the treatment of VCFs, but most of them didn’t consider the effect of VCF levels on the treatment outcome, which can influence the results. Objective: To assess the safety and efficacy of PKP compared to PVP in the treatment of single level osteoporotic vertebral compression fractures (OVCF). Study Design: Studies with the following criteria were included: patients with VCFs due to osteoporosis; PKP comparing PVP; study design, RCT or prospective or retrospective comparative studies. Furthermore, the studies which reported at least one of the following outcomes: subjective pain perception, quality of life evaluation, incidence of new adjacent vertebral fracture, bone cement leakage, and post-operative kyphotic angle. Articles were excluded in our meta-analysis if they had a neoplastic etiology (i.e., metastasis or myeloma), infection, neural compression, traumatic fracture, neurological deficit, spinal stenosis, severe degenerative diseases of the spine, previous surgery at the involved vertebral body, and PKP or PVP with other invasive or semi-invasive intervention treatment. Setting: University hospital. Methods: A systematic search of all articles published through May 2014 was performed by Medline, EMASE, OVID, and other databases. All the articles that compared PKP with PVP on single level OVCF were identified. The evidence quality levels of the selected articles were evaluated by Grade system. Data about the clinical outcomes and complications were extracted and analyzed. Results: Eight studies, encompassing 845 patients, met the inclusion criteria. Overall, the results indicated that there were significant differences between the 2 groups in the short-term visual analog scale (VAS) scores, the long-term Oswestry Disability Index (ODI), short- and long-term kyphosis angle, the kyphosis angle improvement, the injected cement, and the cement leakage rates. However, there were no significant differences in the long-term VAS scores, the short-term ODI scores, the short- and long-term SF-36 scores, or the adjacent-level fracture rates. Limitations: Statistical efficacy can be improved by more studies, low evidence based non-RCT articles are likely to induce various types of bias, no accurate definition of short-term and long-term outcome time points. Conclusion: PKP and PVP are both safe and effective surgical procedures in treating OVCF. PKP has a similar long-term pain relief, function outcome (short-term ODI scores, short-and long-term SF-36 scores), and new adjacent VCFs in comparison to PVP. PKP is superior to PVP for the injected cement volume, the short-term pain relief, the improvement of short- and long-term kyphotic angle, and lower cement leakage rate. However, PKP has a longer operation time and higher material cost than PVP. To confirm this evaluation, a large multi-center randomized controlled trial (RCT) should be conducted. Key words: Percutaneous, kyphoplasty, vertebroplasty, osteoporosis vertebral compression fracture, pain, meta-analysis Pain Physician 201

Short-segment percutaneous pedicle screw fixation with cement augmentation for tumor-induced spinal instability

Background contextPathologic vertebral compression fractures (VCFs) represent a major source of morbidity and diminished quality of life in the spinal oncology population. Procedures with low morbidity that effectively treat patients with pathologic fractures are especially important in the cancer population where life expectancy is limited. Vertebroplasty and kyphoplasty are often not effective for mechanically unstable pathologic fractures extending into the pedicle and facet joints. Combination of cement augmentation and percutaneous instrumented stabilization represents a minimally invasive treatment option that does not delay radiation and systemic therapy. PurposeThe objective of the study was to evaluate the safety and efficacy of cement-augmented short-segment percutaneous posterolateral instrumentation for tumor-associated VCF with pedicle and joint involvement. MethodsForty-four consecutive patients underwent cement-augmented percutaneous spinal fixation for unstable tumors between 2011 and 2014. Retrospective analysis of prospectively collected data, including visual analog pain scale (VAS) response score and procedural complications, was performed. ResultsPatients with a median composite Spinal Instability Neoplastic Scale score of 10 (range=8–15) were treated with constructs spanning one to four disk spaces (median of two spaces, constituting 84% of all cases). The proportion of patients with severe pain decreased from 86% preoperatively to 0%; 65% of patients reported no referable instability pain postoperatively. There was one adjacent-level fracture responsive to kyphoplasty, and one case of asymptomatic screw pullout. Two patients subsequently required decompression in the setting of disease progression despite radiation; there was no perioperative morbidity. ConclusionsPercutaneous cement-augmented posterolateral spinal fixation is a safe and effective option for palliation of appropriately selected mechanically unstable VCF that extends into pedicle and/or joint.

Cortical screw trajectory for instrumentation and fusion in the setting of osteopathic compression fracture allows for percutaneous kyphoplasty for adjacent level compression fractures

Spinal fixation in the osteoporotic patient can be challenging due to the poor trabecular bone quality of the vertebral body. Patients with osteoporotic vertebral body compression fractures are at risk for future compression fractures at adjacent levels, especially after cement augmentation. The purpose of this technical report is to describe the utilization of a cortical screw trajectory along with kyphoplasty for a patient with an osteoporotic compression fracture as well as degenerative spinal disease. This trajectory allows for the possibility of percutaneous pedicle access in the event of future compression fractures. Our patient underwent a decompressive laminectomy and kyphoplasty at the level of an osteoporotic compression fracture. The fracture was stabilized with cortical screw instrumentation and fusion at a level above and a level below the fracture. Subsequently the patient developed an adjacent level fracture within the fusion construct. Due to the utilization of a cortical screw trajectory for the initial fusion, the traditional pedicle trajectory was still accessible. As a result, the new fracture was treated with a percutaneous kyphoplasty through a standard pedicle trajectory. In conclusion, the use of a cortical screw trajectory for stabilization of osteoporotic compression fractures provides for a stronger bone screw interface and avoids osteoporotic trabecular vertebral body bone. At the same time this trajectory allows for future percutaneous pedicular access in the event that the patient suffers future compression fractures.

The relationship between the spinopelvic balance and the incidence of adjacent vertebral fractures following percutaneous vertebroplasty.

We evaluated the relationship between sagittal spinopelvic parameters and the occurrence of adjacent vertebral fractures (AVF) and determined the possible risk factor. The most important factors for AVFs are the degree of osteoporosis and altered biomechanics due to the spinopelvic imbalance in the fractured area of the spine. We intend to evaluate the relationship between sagittal spinopelvic parameters and the occurrence of adjacent vertebral fractures following the initial compression fracture and to determine the possible dominant risk factor associated with new compression fractures. From March 2010 to May 2012, 240 consecutive patients with painful vertebral compression fractures (VCFs) were enrolled in a retrospective study. Ninety-one patients with VCFs underwent percutaneous vertebroplasty (VP) at 112 levels. The sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), and segmental kyphotic angle on sagittal standing radiographs were used to evaluate radiologic outcomes. In 2 years, 15 out of 134 patients (11.1%) treated with conservative treatment, and 12 out of 91 patients (13.1%) treated with VP sustained adjacent level fracture. More patients with the BMD higher or equal to 3.0 experienced a new fracture than those with a BMD less than 3.0 (p = 0.019), and the risk for adjacent level fractures decreased significantly when segmental kyphotic angle was less than 11° (p = 0.001), SVA was less than 6 cm (p = 0.001), SS was higher or equal to 25° (p = 0.004), and LL was higher or equal to 25° (p = 0.020). The most important factors for new VCFs after the initial compression fractures are the degree of osteoporosis and altered biomechanics due to the spinopelvic imbalance in the fractured area of the spine. Regarding the spinopelvic alignment to investigate the relationship with a subsequent AVF, segmental kyphotic angle, SS, LL, and SVA may be a potential predictor.

Prone position in balloon kyphoplasty leads to no secondary vertebral compression fractures in osteoporotic spine - a MRI study.

Purpose: Vertebral compression fractures are the most common fractures in the elderly. Long lasting pain and deformity is responsible for consecutive impairment with markedly reduced life quality, increased morbidity and mortality. The beneficial effects of balloon kyphoplasty are verified in many studies. Subsequent fracture risk is not finally clarified, cement related risks and deformity related risks are discussed. There is less knowledge about the risk of bone marrow edema and new fractures during balloon kyphoplasty procedure. The goal of this study is to examine, if prone position during kyphoplasty is an independent risk factor for new fractures in the osteoporotic spine. Methods: Consecutive MRI study of 20 patients with fresh, non-traumatic thoracolumbar vertebral compression fractures and balloon kyphoplasty treatment. MRI Scans of the thoracolumbar spine were obtained after surgery, before patients have been mobilized. Specific MRI changes like new bone marrow edema, signal intensity changes in adjacent and remote segments and new fractures were assessed by specialized neuro-radiologist. Results: 20 MR images were examined within 48 hours after balloon kyphoplasty procedure. 85% did not show bone marrow edema extent changes after kyphoplasty. We found minor increase of bone marrow edema within the augmented vertebral body in 3 cases. We did not find any new bone marrow edema and no new fractures in adjacent and remote segments after balloon kyphoplasty treatment.Conclusion: Prone position leads to no new bone marrow edema and no new fractures in the osteoporotic spine. Accordingly, prone position has no risk for adjacent level fractures in osteoporotic spines.

A Statistical Model to Predict Subsequent Fracture after Kyphoplasty

Polymethylmethacrylate (PMMA) augmentation of osteoporotic compression fractures (VCFs) is a well-established procedure for pain relief. Numerous investigators have reported an increased risk for adjacent level fracture due to increased stress transmitted by the PMMA augmented vertebral body. I believe that most, if not all, of these studies are invalid due to selection biases or improper statistical analysis. Previous studies assess risk of adjacent fracture as a dichotomous variable. I believe that risk of adjacent fracture should be evaluated as a continuous variable.

Vertebroplasty versus kyphoplasty in osteoporotic vertebral compression fracture: a meta-analysis of prospective comparative studies.

The goal of this article is to evaluate the efficacy and the safety of the percutaneous vertebroplasty (PVP) versus percutaneous kyphoplasty (PKP) in dealing with the osteoporotic vertebral compression fracture (OVCF). In July 2014, a comprehensive systematic computer-based online search was performed by using the databases of PubMed, EMBASE, Cochrane Library, Web of Science, Wan Fang, and the China Biological Medicine. Only prospective comparative trials (PCT) and randomized controlled trials (RCT) that compared PVP with PKP were included. Trials were screened based on the inclusion and exclusion criteria previously formed. The Cochrane collaboration guidelines were also used to assess the quality of these included studies. The primary data of these studies [volume of the cement, postoperative vertebral height, visual analog scale (VAS) score and Oswestry Disability Index (ODI) score after the surgery, and so on] were carefully abstracted and processed by Revman 5.2.0 software The publication bias of the main results (cement leakage and adjacent-level fracture) were examined by Stata 12.0 (Begg and Egger test). Furthermore, the stability of the main results were also detected by sensitivity and cumulative analyses. Six RCT and 14 PCT studies involving 1,429 patients met our criteria and were included finally. Comparing these two methods, the PKP group took more operation time [SMD = 0.66, 95 % CI (0.28, 1.03), p = 0.0006] with higher anterior vertebral body height [SMD = 1.40, 95 % CI (0.49, 2.32), p = 0.003], greatly reduced Cobb angle in the long run [SMD = -0.61, 95 % CI (-1.04, -0.19), p = 0.005] and had lower risk of cement leakage. However, in VAS scores and ODI scores after the surgery whether for the short-term efficacy (no more than 1 week after the surgery) or long-term efficacy (more than six months), Cobb angle in the short run and new fracture in the adjacent level, no statistically differences were found between the two groups. Based on current evidence, PVP takes less time in the operation, while it has greater risk of cement leakage, was inferior in reducing Cobb angle in the long term and results in lower anterior vertebral body height after the surgery. For pain relief, which is the main desire of the patients, both procedures provide significant improvement in VAS and ODI pain scores. PVP is still an effective procedure.

Predictors of kyphotic deformity in osteoporotic vertebral compression fractures: a radiological study.

To report the radiological predictors of kyphotic deformity in osteoporotic vertebral compression fractures (OVCF). This is a retrospective study of 64 consecutive patients with OVCF. We studied the radiographic features in the immediate post-injury image of patients, who developed significant (more than 30°) segmental kyphotic deformity at final follow-up and compared them with those patients who did not. Thirty-three (82.5%) out of 40 patients with fracture at thoracolumbar (TL) junction, 5 (33.3%) patients out of 15 with fracture at lumbar (L) spine and 7 (77.7%) patients out of 9 with fracture at thoracic (T) spine developed significant segmental kyphotic deformity. Forty-one (75.9%) [TL-33 (80.5%), L-4 (33.33%) and T-4 (80%)] out of 54 [TL-37 (68.51%), L-12 (22.23%) and T-5 (9.26%)] patients with superior endplate fracture developed significant segmental kyphotic deformity. Forty patients (86.9%) [TL-28 (70%), L-6 (15%) and T-6 (15%)] out of 46 [TL-32 (69.56%), L-8 (17.4%) and T-6 (13.04%)] with anterior cortical wall fracture developed significant segmental kyphotic deformity. Five patients (71.42%) [TL-2 (40%) and T-3 (60%)] out of 7 [TL-02 (28.58%), L-01 (14.28%), T-04 (57.14%)] with adjacent level fracture developed significant segmental kyphotic deformity. The average immediate post-injury kyphosis of 11° (5°-25°) increased to 29° (15°-50°) at final follow-up. Progressive segmental kyphotic collapse following an OVCF seems unavoidable. Patients with TL junction and superior endplate fracture are probably at the highest risk for significant segmental kyphotic deformity.

The Retrospective Analysis of the Effect of Balloon Kyphoplasty to the Adjacent-segment Fracture in 171 Patients

Analysis of the adjacent-segment fractures in 171 balloon kyphoplasty (BK)-performed patients. The purpose of this study was to investigate the risk factors for new symptomatic vertebral compression fractures (VCF) after BK. Although there are many studies about the incidence and possible risk factors for occurrence of adjacent-level fractures, there is no consensus on the increased risk of adjacent-level fractures after BK. We performed a retrospective analysis of 171 patients treated with percutaneous kyphoplasty. The follow-up period was 41.04±21.78 months. The occurrence of new symptomatic VCF was recorded after the procedure. We evaluated the variables of patient age and sex, the amount of injected cement, the initial kyphotic angle (KA) of VCF, the change of the KA after BK, the severity of osteoporosis, and the percentage of height restoration of the vertebral body. Furthermore, possible risk factors were reported for new symptomatic VCFs. The only 2 factors identified as being significantly associated with adjacent-level fractures were the sex (P=0.001) of the patient and the preoperative KA (P=0.013). The patients with new symptomatic compression fracture had higher initial KA than those without fractures. The female group had higher risk than the male group in occurrence of the new vertebra fractures. The severity of the osteoporosis (low bone mineral density) was not a determinant in occurrence of the new VCF after BK. If the patients experience severe or mild back pain with higher preoperative KA, especially in the first 2 months, then they deserve detailed radiologic examination. To avoid subsequent fracture in the same or adjacent level, vertebral body should be filled adequately and sagittal balance should be obtained with KA correction. BK alone did not influence the incidence of subsequent VCF.

Natural History and Risk Factors for Adjacent Vertebral Fractures in the Fracture Intervention Trial

Retrospective analysis of prospectively collected follow-up data for 2.9 years. To determine the natural history of subsequent morphometric fracture rates at adjacent levels (one level above or below a previous known baseline fracture) in a large patient database. The long-term risk and risk factors for adjacent-level vertebral fractures in patients with osteoporosis are unknown. The fracture intervention trial is a large randomized, placebo-controlled trial of alendronate treatment for osteoporosis. Data from both bisphosphonate-treated and bisphosphonate-naive patients (N = 1950, vertebral fracture arm) was analyzed to detect incident morphometric fracture rates. During a mean follow-up of 2.9 years, 3.4% of patients in the alendronate group and 7.4% in the placebo group experienced adjacent-level vertebral fractures. The annual rate of adjacent-level vertebral fractures was 1.2% in the alendronate group, and 2.5% in the placebo group (overall, 1.8% per year in both groups combined). As expected, the thoracolumbar region (defined as T11, T12, and L1) seemed to be the most prone to new adjacent-level fractures. Among females with baseline prevalent fractures at the thoracolumbar junction, who subsequently experienced at least one new fracture anywhere along the spine (N = 124), 40.3% had a new adjacent-level fracture in this region. Older age at randomization, lower bone mineral density, inactivity, and placebo therapy were significantly associated with the development of adjacent-level fractures in univariate analysis (P ≤ 0.05). Multivariate analysis indicated decreased odds of adjacent-level fractures with bisphosphonate therapy and higher bone mineral density, and increased odds with older age at randomization (P ≤ 0.05). New vertebral fractures adjacent to prevalent fractures occurred relatively infrequently in this treatment trial of alendronate in females with osteoporosis, and were more common with older age at randomization, lower bone mineral density and placebo treatment.

Cluster Phenomenon of Vertebral Refractures After Percutaneous Vertebroplasty in a Patient With Glucocorticosteroid-Induced Osteoporosis

A case report and literature review. To describe a rare cluster phenomenon of spontaneous vertebral refractures in a patient with glucocorticosteroid-induced osteoporosis (GIOP) subsequent to percutaneous vertebroplasty (PVP) for the management of initial vertebral compression fractures (VCFs). PVP has become the popular strategy for stabilizing osteoporotic VCFs and obtaining rapid pain alleviation and earlier restoration of mobility in both patients with primary osteoporosis and patients with glucocorticosteroid-induced osteoporosis. However, current data are insufficient to recommend routine use of PVP for VCFs caused by GIOP as recent retrospective studies indicate that the risk of vertebral refractures is much higher in patients with GIOP than those with primary osteoporosis. We reported a 63-year-old Chinese female with GIOP as well as pulmonary infection who underwent PVP for the management of initial VCFs, experienced the cluster phenomenon of spontaneous vertebral refractures. Within a 4-month period, she underwent a total of 6 PVP operations with 13 cement-augmented vertebral bodies from T5-L5. Eleven refractures after the initial PVP procedures included 3 remote-level fractures, 4 adjacent-level fractures, 1 pincher body fracture, and 3 fractures in previously augmented bodies. The average interval between each PVP operation was 23.6 days. The use of PVP as a therapeutic alternative for the treatment of VCFs in patients with GIOP is still controversial. As seen in our case, even when the management decisions were made in consideration of the patient's pulmonary infection, the outcome was disastrous with the cluster phenomenon of vertebral refractures. Current findings suggest a compelling need for high-quality studies investigating cement augmentation procedures in patients with VCF with GIOP.

Cement Directed Kyphoplasty Reduces Cement Leakage as Compared With Vertebroplasty

A novel randomized, controlled, unblinded clinical trial comparing 2 procedural interventions for painful osteoporotic vertebral compression fractures. The primary study objective was to evaluate cement leakage for a cement directed kyphoplasty system (CDKS) with anteriorly biased cement flow and vertebroplasty. The secondary study objective was to compare adjacent level fracture rates and vertebral body height for these 2 intervention methods. Cement leakage remains a significant clinical problem associated with vertebroplasty and kyphoplasty procedures. Uncontrolled cement flow in the posterior direction can result in leakage into the vertebral veins or spinal canal, leading to potentially serious clinical complications. Seventy-seven patients with painful osteoporotic vertebral compression fractures were enrolled. Patients were randomized 2:1 for treatment with CDKS (49 patients, 65 levels) or vertebroplasty (28 patients, 39 levels). Cement leakage was evaluated from radiographs and computed tomographic scans. Three- and 12-month follow-ups included additional radiographs and computed tomographic scans to assess changes in vertebral body height and the incidence of new fractures. Treatment with CDKS significantly reduced the number of levels with leaks and the total number of leaks per level, as compared with vertebroplasty (P = 0.0132 and P = 0.0012, respectively). Significantly, fewer lateral cortical and spinal canal leaks (posterior leaks) occurred in the CDKS group (P = 0.0050, P = 0.02260, respectively). Three adjacent level fractures occurred in the vertebroplasty group, as compared with 2 in the CDKS group. Vertebral body height maintenance was equivalent. Cement directed kyphoplasty effectively reduces posterior cement leakage, reducing the risk of leakage related complications. 2.

Does the cement stiffness affect fatigue fracture strength of vertebrae after cement augmentation in osteoporotic patients?

Normal progression of osteoporosis or the rigid reinforcement of the fractured vertebral body with polymethyl methacrylate (PMMA) cement is being discussed as a cause for adjacent-level fractures after vertebroplasty. The purpose of this study was to investigate whether augmentation with low stiffness cement can decrease the risk of adjacent-level fractures in low-quality bone. Eighteen female osteoporotic lumbar specimens (L1-L5) were harvested and divided into three groups according to bone mineral density: (I) native; (II) PMMA; (III) modified PMMA (lower stiffness). For the PMMA and modified PMMA groups, a compression fracture was first mechanically induced in L3, and then the fracture received vertebroplasty treatment. The cement stiffness reduction of the modified PMMA group was achieved via an addition of 8 mL of serum to the typical PMMA base. All specimens were exposed to cyclic loading (4 Hz) and a stepwise increasing applied peak force. Cement stiffness was tested according to ISO 5833. A 51% decrease in cement stiffness was achieved in the modified PMMA group (954 ± 141 vs. 1,937 ± 478 MPa, p < 0.001). Fatigue fracture force (the force level during cyclic loading at which the deformation experienced a sudden increase; FFF) was significantly affected by bone quality (r (2) = 0.39, p = 0.006) and by the initial fracture force (the force necessary to create the initial fracture in L3 prior to augmentation; r (2) = 0.82, p < 0.001). Using initial fracture force as a covariate, the FFF of the modified PMMA group (1,764 ± 49 N) was significantly higher than in the PMMA group (1,544 ± 55 N; p = 0.03). A possible method to reduce adjacent-level fractures after vertebroplasty in patients with reduced bone quality could be the use of a lower modulus cement. Therefore, mixing cement with biocompatible fluids could prove useful to tailor cement properties in the operating theater.

The Effect of Fracture Severity and Fill Volume on the Mechanical Properties of Osteoporotic Vertebral Bodies Following Vertebroplasty

Vertebroplasty (VP) is a widely accepted treatment for osteoporotic compression fractures. It involves percutaneous cement injection to restore mechanical stability to reduce pain. VP is regarded as a safe intervention but complications from cement extravasation and the potential increased risk for adjacent level fractures after augmentation have been reported. High viscosity cement have been introduced and have been shown to reduce cement venous leakage when compared to standard low viscosity cement.

Sandwich Vertebral Fracture in the Study of Adjacent-level Fracture After Vertebral Cement Augmentation

The literature is inconclusive on the development of adjacent-level vertebral fracture after initial cement augmentation. A preliminary hypotheses is that cement injection exaggerates force transmission to the adjacent vertebral bodies, thereby predisposing those levels to future fractures. A sandwich vertebra is an intact vertebral body located between 2 previously cemented vertebrae. The purpose of this study was to determine whether the risk of adjacent-level fracture increased due to load shift after a cement injection procedure. The authors retrospectively investigated the rate of adjacent-level fracture after sandwiching compared with conservative treatment and determined the potential causative factors of sandwich vertebral fracture. Age, sex, weight, height, body mass index, follow-up period, and location of sandwich level (T10-L2 or nonT10-L2 junction) were assessed. Surgical variables, including surgical procedure (vertebroplasty or balloon kyphoplasty), surgical approach (through uni- or bilateral pedicle), volume of cement injected into the painful vertebrae, cement leakage into the intervertebral disk, cumulative number of treated levels, and pre- and postoperative kyphotic angulation of the sandwich region, were also analyzed. Nine of 42 sandwiched levels developed fatigue fractures, whereas 11 of 71 patients treated with conservative therapy sustained new vertebral fractures adjacent to the treated levels. Only preoperative kyphotic angulation was the variable positively associated with sandwich vertebral fracture at follow-up (P=.021). Although subjected to double load shifts, the sandwich vertebra was not prone to structural failure. Thus, cement augmentation protocol does not increase the incidence of adjacent vertebral fracture.

Adjacent level fracture after osteoporotic vertebral compression fracture: a nonrandomized prospective study comparing balloon kyphoplasty with conservative therapy

In literature, there are conflicting clinical data regarding the incidence of subsequent fracture after balloon kyphoplasty (BK); moreover, the risk of adjacent vertebral fractures has not been well established because there are limited comparative data available with conservatively treated control groups. The purpose of this prospective nonrandomized comparative study was to analyze the incidence and possible risk factors of adjacent level fracture comparing BK with conservative therapy. Consecutive patients satisfying the inclusion criteria of acute vertebral fracture pain (occurring within 1-6 weeks of the event and not relieved by oral analgesia) and imaging criteria of acute fracture activity were enrolled. All patients meeting the inclusion criteria were offered BK. The patients who declined BK and agreed to longitudinal evaluation were treated conservatively and constituted the control group. In 3 out of 46 patients (6.5%) treated with BK and in 10 out of 61 patients treated conservatively (16.4%), the adjacent level fracture occurred within 1 year. The degree of local kyphosis and bone mineral density (BMD) were identified as important predictive factors for adjacent level fracture. These results indicated that BK carries a low risk of adjacent level fractures. Lower BMD values and altered biomechanics in the treated area of the spine due to resistant kyphosis are possible predictive factors for adjacent level fractures. A positive effect of BK over conventional treatment was observed upon reduction of the incidence of adjacent level fracture, vertebral morphology, and pain reduction.