The Closer Vicinity to Treated Vertebrae in Percutaneous Vertebroplasty, the Higher Rate of New Vertebral Compression Fractures at Follow-up.

OBJECTIVE: To investigate whether risk of new vertebral compression fractures (NVCFs) was associated with vicinity to treated vertebrae in percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCFs). METHODS: All OVCF (T6-L5) patients treated with PVP between January 2016 and December 2020 were retrospectively reviewed. Vicinity to treated vertebrae was defined as the number of vertebrae between an untreated and its closest treated level. The closest treated level was chosen as reference vertebra. Clinical, radiologic, and surgical parameters were compared between groups of reference vertebrae for each vicinity NVCF. RESULTS: In total, 1348 patients with 1592 fractured and 14,584 normal vertebrae were enrolled. NVCF was identified in 20.1% (271 of 1348) patients in 2.2% (319 of 14584) vertebrae in a mean follow-up time of 24.3 ± 11.9 months. Rate of NVCF in vicinity 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 level were 4.6% (130 of 2808), 2.4% (62 of 2558), 1.8% (42 of 2365), 1.5% (31 of 2131), 1.3% (23 of 1739), 1.3% (17 of 1298), 0.8% (7 of 847), 0.9% (4 of 450), 0.8% (2 of 245), 0.9% (1 of 117), and 0% (0 of 26), respectively. Rate of NVCF in vicinity 1 level was significantly higher than that in vicinity 2, 3, 4, 5, 6, 7, 8, and 9 level, respectively. However, compared to reference vertebrae for vicinity 1 NVCF, any clinical, radiologic, or surgical parameters were not significantly different in those for vicinity 2, 3, and 4 NVCF, respectively. CONCLUSIONS: The closer vicinity to treated vertebrae in PVP, the higher rate of NVCF at follow-up. However, any clinical, radiologic, or surgical parameters might not matter in this phenomenon of vicinity-related NVCF.

The correlation between self-Hounsfield units and adjacent vertebral fracture after percutaneous vertebral augmentation: a retrospective cohort study.

Background: Adjacent vertebral fracture (AVF) represents a prevalent and challenging complication after percutaneous vertebral augmentation (PVA) treatment for osteoporosis vertebral compressive fracture (OVCF). Lower bone mineral density (BMD) and intervertebral leakage are reportedly independent risk factors for AVF. Vertebral Hounsfield units (HU) measured from computed tomography (CT) scans can evaluate bone quality. This study sought to explore the risk factors associated with AVF and analyze the relationship between AVF and the Hounsfield units of adjacent vertebrae (self-HU) following PVA. Methods: In this retrospective cohort study, we included consecutive OVCF patients who presented to Xuzhou Central Hospital in Jiangsu Province, China from 1 January 2016, to 31 December 2019 for PVA treatment. Clinical and imaging data were collected, and baseline data were recorded. Patients were divided into the AVF group and the no-AVF group based on the presence of AVF during follow-up. Patients in the AVF group were further subdivided into the leakage group and the no-leakage group according to the presence of intervertebral leakage. Age, body mass index (BMI), fracture location, prior fracture, self-HU, and intervertebral leakage were included in univariate logistic regression analysis. Variables with a P value of less than 0.1 were then included in multivariate logistic regression analysis to determine the risk factors for AVF. Kaplan-Meier curves were plotted to assess the effect of intervertebral leakage on AVF using a log-rank test. Results: A total of 460 patients were included in this study and followed up for an average of 50.9 months (range, 37-83 months). Among them, 82 cases (17.83%) developed AVF and were included in the AVF group. Multivariate logistic regression analysis showed that lower self-HU [odds ratio (OR) =0.972, 95% confidence interval (CI): 0.959-0.985, P<0.001] and intervertebral leakage (OR =2.618, 95% CI: 1.415-4.844, P=0.002) were risk factors for AVF following PVA. In the AVF group, 29 patients (35.37%) with intervertebral leakage were included in the leakage group. Patients in the leakage group had a shorter time to AVF (22.07±13.83 vs. 31.42±18.73, P=0.021) and higher self-HU (78.05±16.41 vs. 64.23±20.49, P=0.002) than those in the no-leakage group. Kaplan-Meier curves showed that the fracture-free time was shorter in the leakage group compared to the no-leakage group (log-rank test, P=0.014). Conclusions: Lower self-HU and intervertebral leakage are risk factors for AVF, and higher self-HU may lead to AVF when intervertebral leakage is present.

Analysis of adjacent vertebral fracture after percutaneous vertebroplasty: do radiological or surgical features matter?

PURPOSE: To report the incidence and risk factors of adjacent vertebral fracture (AVF) after percutaneous vertebroplasty (PVP) in patients with osteoporotic vertebral compression fractures (OVCFs). We focused to investigate effect of radiological or surgical features on AVF. METHODS: All patients with OVCFs who were treated with PVP between January 2016 and December 2019 were retrospectively reviewed. Patients were followed up at least 12 months after procedure according to treatment protocol. AVF was defined as postoperatively recurrent intractable back pain and subsequently presence of fracture on magnetic resonance imaging (MRI) in adjacent levels. Clinical, radiological, and surgical factors potentially affecting occurrence of AVF were recorded and analyzed using univariate and multivariate analysis. RESULTS: Totally, 1077 patients with 1077 fractured vertebrae who underwent PVP were enrolled in the study, after inclusion and exclusion criteria were met. Mean follow-up time was 24.3 ± 11.9 months (range, 12-59 months). AVF was identified in 98 (9.1%) patients. Univariate analysis showed that seven significant factors related to AVF were older age, non-traumatic fracture, cortical disruption on anterior wall, cortical disruption on lateral wall, basivertebral foramen, type-B leakage and type-C leakage. In multivariate analysis, two clinical factors, older age (P = 0.031) and non-traumatic fracture (P = 0.002), were significantly associated with AVF. However, any radiological or surgical factor did not reach significance in final model analysis. CONCLUSIONS: Incidence of AVF after PVP in patients with OVCFs was 9.1% (98/1077). Older age and non-traumatic fracture were two clinical risk factors for AVF. Neither radiological nor surgical feature was significantly correlated with AVF.

Risk Factors for New Adjacent and Remote Vertebral Fracture After Percutaneous Vertebroplasty.

OBJECTIVE: To analyze the risk factors of new adjacent vertebral fractures (AVF) and remote vertebral fractures (RVF) after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCFs). METHODS: Patients who underwent additional PVP for new OVCFs were enrolled. In addition, we set a 1:1 age-, sex-, surgical segment-, and surgical date-matched control group, in which patients underwent PVP without new OVCFs. Data on body mass index, occurrence time of second PVP, vertebral computed tomography (CT) Hounsfield Unit (HU) at the fracture adjacent segment, and RVF segment were collected. RESULTS: A total of 44 patients who underwent additional PVP for new OVCFs at our hospital were included. AVF occurred significantly earlier than RVF (13.5 ± 14.1 vs. 30.4 ± 20.1 months, P = 0.007). Compared to the control group, the AVF segment CT HU was significantly lower in patients with AVF (28.7 ± 16.7 vs. 61.3 ± 14.7, P = 0.000), while there was no significant difference between patients with RVF and control group including both adjacent and RVF segment CT HU. Receiver operating characteristic curves identified a cutoff value of 43 for using adjacent segment CT HU to differentiate patients with AVF from controls, with a sensitivity of 80% and a specificity of 88.9%. CONCLUSIONS: Our study showed that the risk factors for AVF and RVF after PVP surgery were different. The occurrence of AVF was earlier and associated with low adjacent segment CT HU values, whereas the preoperative CT HU in both adjacent and RVF segments was not found to be associated with RVF.

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

Objective: The aim of this study was to investigate the biomechanical stress of sandwich vertebrae (SVs) and common adjacent vertebrae in different degrees of spinal mobility in daily life. Materials and methods: A finite element model of the spinal segment of T10-L2 was developed and validated. Simultaneously, T11 and L1 fractures were simulated, and a 6-ml bone cement was constructed in their center. Under the condition of applying a 500-N axial load to the upper surface of T10 and immobilizing the lower surface of L2, moments were applied to the upper surface of T10, T11, T12, L1, and L2 and divided into five groups: M-T10, M-T11, M-T12, M-L1, and M-L2. The maximum von Mises stress of T10, T12, and L2 in different groups was calculated and analyzed. Results: The maximum von Mises stress of T10 in the M-T10 group was 30.68 MPa, 36.13 MPa, 34.27 MPa, 33.43 MPa, 26.86 MPa, and 27.70 MPa greater than the maximum stress value of T10 in the other groups in six directions of load flexion, extension, left and right lateral bending, and left and right rotation, respectively. The T12 stress value in the M-T12 group was 29.62 MPa, 32.63 MPa, 30.03 MPa, 31.25 MPa, 26.38 MPa, and 26.25 MPa greater than the T12 stress value in the other groups in six directions. The maximum stress of L2 in M-T12 in the M-L2 group was 25.48 MPa, 36.38 MPa, 31.99 MPa, 31.07 MPa, 30.36 MPa, and 32.07 MPa, which was greater than the stress value of L2 in the other groups. When the load is on which vertebral body, it is subjected to the greatest stress. Conclusion: We found that SVs did not always experience the highest stress. The most stressed vertebrae vary with the degree of curvature of the spine. Patients should be encouraged to avoid the same spinal curvature posture for a long time in life and work or to wear a spinal brace for protection after surgery, which can avoid long-term overload on a specific spine and disrupt its blood supply, resulting in more severe loss of spinal quality and increasing the possibility of fractures.

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

BACKGROUND CONTEXT: Adjacent vertebral fracture (AVF), a frequent complication of PVP, is influenced by factors such as osteoporosis progression, increased intervertebral cement leakage (ICL), and biomechanical deterioration. Notably, the risk of AVF is notably elevated in the cranial vertebral body compared with the caudal counterpart. Despite this knowledge, the underlying pathological mechanism remains elusive. PURPOSE: This study delves into the role of biomechanical deterioration as a pivotal factor in the heightened risk of AVF in the cranial vertebral body following PVP. By isolating this variable, we aim to unravel its prominence relative to other potential risk factors. STUDY DESIGN: A retrospective study and corresponding numerical mechanical simulations. PATIENT SAMPLE: Clinical data from 101 patients treated by PVP were reviewed in this study. OUTCOME MEASURES: Clinical assessments involved measuring Hounsfield unit (HU) values of adjacent vertebral bodies as a representation of patients' bone mineral density (BMD). Additionally, the rates of ICL were compared among these patients. Numerical simulations were conducted to compute stress values in the cranial and caudal vertebral bodies under various body positions. METHODS: In a retrospective analysis of PVP patients spanning July 2016 to August 2019, we scrutinized the HU values of adjacent vertebral bodies to discern disparities in BMD between cranial and caudal regions. Additionally, we compared ICL rates on both cranial and caudal sides. To augment our investigation, well-validated numerical models simulated the PVP procedure, enabling the computation of maximum stress values in cranial and caudal vertebral bodies across varying body positions. RESULTS: The incidence rate of cranial AVF was significantly higher than the caudal side. No notable distinctions in HU values or ICL rates were observed between the cranial and caudal sides. The incidence of AVF showed no significant elevation in patients with ICL in either region. However, numerical simulations unveiled heightened stress values in the cranial vertebral body. CONCLUSIONS: In patients postPVP, the cranial vertebral body faces a heightened risk of AVF, primarily attributed to biomechanical deterioration rather than lower BMD or an elevated ICL rate.

Correlation Study Between Bone Cement Distribution and Adjacent Vertebral Fractures After Percutaneous Vertebroplasty.

OBJECTIVE: We investigated the correlation between bone cement distribution and adjacent vertebral fractures (AVFs) after percutaneous vertebroplasty (PVP). METHODS: We retrospectively analyzed patients who underwent single-segment PVP for osteoporotic compression fractures in our hospital from January 2016 to January 2021 and divided the patients into 2 groups, A and B, on the basis of the criterion of whether there were AVFs of the operated vertebrae within 1 year after surgery. We compared the general data of the 2 groups, assessed the ability of 3 simple X-ray-based evaluation methods to predict the occurrence of AVF within 1 year after surgery and derived a simple and accurate evaluation method. RESULTS: A total of 570 patients were included in this study: 511 patients in group A and 59 patients in group B. There were no statistical differences in the general data such as age, gender, and fracture site between the 2 groups. The posterior-anterior (PA), lateral (LAT), and PA and LAT methods showed receiver operating characteristic curve (ROC) predicted postoperative AVF of 0.611, 0.691, and 0.714, respectively. The difference between the area under curve (AUC) of the PA method and LAT method was statistically significant (P = 0.0307), the difference between the AUC of PA method and PA and LAT method was statistically significant (P < 0.001), and the difference between the AUC of LAT method and PA and LAT method was not statistically significant (P = 0.3308).There was no statistical difference between the 2 groups of patients with PA method point of 1 and statistically different between patients with points of 2 and 3. There was statistical difference in points of 1, 2 and 3 in the LAT method between the 2 groups. There was a positive correlation between cement distribution scores and AVF by linear regression analysis of the 3 evaluation methods. CONCLUSIONS: The 3 evaluation methods reliably predict AVF after PVP, with the LAT method, PA and LAT method being more predictive than the PA method, but the LAT method is simpler, with bone cement being widely distributed after crossing the midline in the PA method and contact with the upper and lower end plates in the LAT method being a risk factor for AVF.

Low hounsfield unit values at sagittal section on computed tomography predicts vertebral fracture following short spinal fusion.

BACKGROUND: Preoperative identification of osteoporosis during spine surgery is of critical importance. Additionally, the Hounsfield units (HU) measured using computed tomography (CT) have gained considerable attention. This study aimed to propose a more accurate and convenient screening method for predicting vertebral fractures after spinal fusion in elderly patients by analyzing the HU value of different range of interests of thoracolumbar spine. METHODS: Our sample pool for analysis consisted of 137 elderly female patients aged >70 years who underwent one- or two-level spinal fusion surgery with a diagnosis of adult degenerative lumbar disease. The HU values of the anterior 1/3 of the vertebral bodies based on sagittal plane and those of vertebral bodies based on axial plane at T11-L5 were measured using the perioperative CT. The incidence of postoperative vertebral fractures with respect to the HU value was investigated. RESULTS: Vertebral fractures were identified in 16 patients during the mean follow-up period of 3.8 years. While no significant association was found between HU value of L1 vertebral body or minimum HU value from axial plane and the incidence of the postoperative vertebral fracture, the minimum vertebral HU value of the anterior 1/3 of vertebral body from sagittal plane was associated with the incidence of the postoperative vertebral fracture. Patients with a minimum anterior 1/3 vertebral HU value of <80 had a higher incidence of postoperative vertebral fractures. The adjacent vertebral fractures occurred at the level of the vertebra with the lowest HU value, with a high probability. The existence of the vertebra with a minimum HU value of <80 within two levels of upper instrumented vertebrae was a risk factor for adjacent vertebral fracture. CONCLUSION: HU measurement of the anterior 1/3 of vertebral body predicts the risk of vertebral fracture after short spinal fusion surgery.

Recompression of Augmented Vertebrae after Balloon Kyphoplasty Is a Risk of Adjacent Vertebral Fracture.

Introduction: This study aimed to identify factors associated with adjacent vertebral fracture (AVF) incidence after balloon kyphoplasty (BKP). Methods: To perform the analyses, 133 vertebrae of 128 patients who underwent BKP for osteoporotic vertebral compression fracture were retrospectively investigated. According to the presence of AVF throughout a 1-year period following BKP, patients were divided into AVF (n = 22) and non-AVF (n = 111) groups. The groups were compared with respect to pre- and postoperative parameters, including the incidence of recompression of augmented vertebrae (RAV). RAV was defined as a decrease in anterior vertebral body height of at least 5 mm within the 3 months that followed BKP. To identify factors associated with AVF incidence, univariate and multivariate analyses were performed. Results: The univariate analysis revealed that the AVF group had a lower cement augmentation ratio, greater preoperative wedge angle, lower preoperative vertebral body height, lower postoperative vertebral body height 3 months post-BKP, and a greater change in vertebral body height and rate of RAV than the non-AVF group. Multivariate analysis revealed that low preoperative vertebral body height and RAV occurrence were associated with AVF incidence. Conclusions: To the best of our knowledge, this study is the first to indicate that RAV is a risk factor for AVF. Study findings indicate that the incidence of AVF can be decreased if RAV development is avoided.

Risk factors for adjacent vertebral compression fracture after fusion surgery of lumbar canal stenosis in the elderly / 中华创伤杂志

Objective:To evaluate the risk factors for adjacent vertebral compression fracture (AVCF) after fusion surgery of lumbar canal stenosis in the elderly.Methods:A retrospective cohort study was designed for 297 patients with lumbar canal stenosis who underwent fusion surgery in Hubei Provincial Hospital of Integrated Chinese and Western Medicine from January 2017 to December 2020. There were 42 males and 255 females, aged 68-85 years [(76.3±7.2)years]. The patients were divided into AVCF group ( n=67) and non-AVCF group ( n=230) according to with or without the occurrence of AVCF. The indicators recorded were the gender, age, body mass index, education level, number of combined basic diseases, course of the disease, preoperative bone mineral density, intraoperative bleeding volume, number of level fused during operation, postoperative blood transfusion volume, postoperative observation in the ICU, types of postoperative external fixation and time of external fixation. Univariate analysis was conducted to analyze the correlation between above risk factors and AVCF after fusion surgery of lumbar canal stenosis in the elderly. Multivariate Logistic regression analysis was used to determine the independent risk factors for the occurrence of AVCF in these patients. Results:In the univariate analysis, age, education level, preoperative bone mineral density, intraoperative bleeding volume, postoperative blood transfusion volume and postoperative observation in the ICU were correlated with AVCF after fusion surgery of lumbar canal stenosis in the elderly ( P<0.05 or 0.01), while there was no correlation of AVCF with gender, body mass index, number of combined basic diseases, course of the disease, number of level fused during operation, types of postoperative external fixation and time of external fixation (all P>0.05). Multivariate Logistic regression analysis showed that gender ( OR=4.02, 95% CI 1.35, 12.00, P<0.05), preoperative bone mineral density≤-2.5 SD ( OR=2.01, 95% CI 1.47, 2.75, P<0.01), intraoperative bleeding volume≥475 ml ( OR=1.01, 95% CI 1.00, 1.01, P<0.01) and postoperative blood transfusion volume≥434 ml ( OR=0.99, 95% CI 0.98, 1.00, P<0.01) were significantly associated with AVCF after fusion surgery of lumbar canal stenosis in the elderly. Conclusion:The female, bone mineral density≤-2.5 SD, intraoperative bleeding volume≥476 ml and postoperative blood transfusion volume≥434 ml are independent risk factors for AVCF after fusion surgery of lumbar canal stenosis in the elderly.

[Risk factors of adjacent vertebral refracture after percutaneous vertebroplasty for osteoporotic vertebral compression fractures in super-old patients].

OBJECTIVE: To analyze the risk factors for refracture of adjacent vertebrae after percutaneous vertebroplasty (PVP) in super-old patients with osteoporotic vertebral compression fractures(OVCFs). METHODS: A retrospective analysis was performed on 40 patients(age≥90 years) with OVCFs who underwent PVP between June 2012 and June 2019. There were 7 males and 33 females, age from 90 to 101 years old with an average of (94.6±1.6) years. Patients were divided into two groups according to whether adjacent vertebral refracture occurred after PVP. Among them, 20 patients occurred refracture after PVP (refracture group) and 20 patients did not occur it(control group). The general information, radiological data and pelvic parameters of the two groups were collected. The items included age, gender, body mass index (BMI), fracture site and bone mineral density(BMD) T-value, fracture to operation time, compression degree of injured vertebra, recovery degree of anterior edge of injured vertebra, bone cement injection amount, bone cement leakage, pelvic index(PI), pelvic tilt angle (PT), sacral angle(SS), et al. Factors that may be related to refracture were included in the single-factor study, and multivariate Logistic regression analysis was performed on the risk factors with statistical significance in the single-factor analysis to further clarify the independent risk factors for refracture of adjacent vertebral bodies after PVP. RESULTS: There were no significant differences in age, gender, fracture site, fracture to operation time, compression degree of injured vertebra and recovery degree of anterior edge of injured vertebra between two groups (P>0.05). There were significant differences in BMI, BMD T-value, bone cement injection amount and bone cement leakage rate between two groups(P<0.05). The PI and PT values of the refracture group were higher than those of the control group(P<0.05). There was no significant difference in SS between two groups (P>0.05). Multivariate Logistic regression analysis showed that decreased BMD T-value, bone cement leakage, increased PT and PI values increased the risk of recurrence of adjacent vertebral fractures in OVCFs (P<0.05). CONCLUSION: There are many risk factors for the recurrence of adjacent vertebral fractures in super-old patients with OVCFs. Patients with high PI and PT values may be one of the risk factors.

Predictive Factors for Adjacent Vertebral Fractures After Percutaneous Kyphoplasty in Patients With Osteoporotic Vertebral Compression Fracture.

BACKGROUND: Adjacent vertebral fracture (AVF) seemed to be a frequent and severe complication in osteoporotic vertebral compression fracture (OVCF) patients receiving percutaneous vertebroplasty  or percutaneous kyphoplasty (PKP), resulting in poor long-term outcome and recurrence of pain-related symptoms. Nonetheless, its mechanism remains unclear. OBJECTIVES: To investigate the potential predictor of AVF after PKP and figure out whether the intervertebral disc plays a role during the process of AVF. STUDY DESIGN: Retrospective study. SETTING: Department of Orthopedic, an affiliated hospital of a medical university. METHODS: Clinical data of OVCF patients receiving PKP were reviewed in our hospital from January 2016 to December 2020. Four hundred and forty-five patients were recruited who met the abovementioned criteria in this study. The clinical data, including age, gender, bone mineral density (BMD), vertebral height, vertebral kyphosis angle, cement volume, cement distribution, as well as adjacent disc degeneration extent, were recorded for each patient. Independent-sample t tests and chi-squared tests were performed to compare these indexes. Bivariate correlation tests and multiple linear regression analyses were performed among potential predictors. Receiver operator characteristic (ROC) analysis and Kaplan-Meier plotter were applied to evaluate the diagnostic efficiency of parameters for predicting the occurrence of AVF. RESULTS: Patients in both groups gained obvious improvements in symptomatic and radiographic indexes after first PKP. Statistically significant difference (P < 0.05) was only found between 2 groups with respect to BMD, kyphosis angle at last follow-up before second PKP, cement distribution, and disc degeneration grade. The ROC analysis showed that BMD = 15.5° was highly predictive of AVF after PKP (sensitivity, 92.2%; specificity, 24.6%; area under curve, 0.569, P = 0.109). Statistically significant difference of AVF incidence amongst patients with different cement distribution (P = 0.018) and similar trend was also found amongst patients with different disc degeneration (P = 0.000). Statistically significant difference was noted in terms of disc degeneration grade between 2 adjacent discs in AVF group. LIMITATIONS: The main limitation is the retrospective nature of this study. CONCLUSIONS: The risk of AVF should be focused, especially when OVCF patients with the following predictors: (1) BMD < -3.45; (2) kyphosis angle at last follow-up > 15.5°; (3) I or II cement distribution; and (4) IV or V disc degeneration. More prophylactic treatment should be prescribed for these patients to avoid the occurrence of AVF.

Development and internal validation of a clinical prediction model for acute adjacent vertebral fracture after vertebral augmentation : the AVA score.

AIMS: To develop and internally validate a preoperative clinical prediction model for acute adjacent vertebral fracture (AVF) after vertebral augmentation to support preoperative decision-making, named the after vertebral augmentation (AVA) score. METHODS: In this prognostic study, a multicentre, retrospective single-level vertebral augmentation cohort of 377 patients from six Japanese hospitals was used to derive an AVF prediction model. Backward stepwise selection (p < 0.05) was used to select preoperative clinical and imaging predictors for acute AVF after vertebral augmentation for up to one month, from 14 predictors. We assigned a score to each selected variable based on the regression coefficient and developed the AVA scoring system. We evaluated sensitivity and specificity for each cut-off, area under the curve (AUC), and calibration as diagnostic performance. Internal validation was conducted using bootstrapping to correct the optimism. RESULTS: Of the 377 patients used for model derivation, 58 (15%) had an acute AVF postoperatively. The following preoperative measures on multivariable analysis were summarized in the five-point AVA score: intravertebral instability (≥ 5 mm), focal kyphosis (≥ 10°), duration of symptoms (≥ 30 days), intravertebral cleft, and previous history of vertebral fracture. Internal validation showed a mean optimism of 0.019 with a corrected AUC of 0.77. A cut-off of ≤ one point was chosen to classify a low risk of AVF, for which only four of 137 patients (3%) had AVF with 92.5% sensitivity and 45.6% specificity. A cut-off of ≥ four points was chosen to classify a high risk of AVF, for which 22 of 38 (58%) had AVF with 41.5% sensitivity and 94.5% specificity. CONCLUSION: In this study, the AVA score was found to be a simple preoperative method for the identification of patients at low and high risk of postoperative acute AVF. This model could be applied to individual patients and could aid in the decision-making before vertebral augmentation. Cite this article: Bone Joint J 2022;104-B(1):97-102.

What Are the Risk Factors for Adjacent Vertebral Fracture After Vertebral Augmentation? A Meta-Analysis of Published Studies.

STUDY DESIGN: Meta-analysis. OBJECTIVES: To provide up-to-date evidence-based outcomes for the incidence and risk factors of adjacent vertebral fracture (AVF) after the vertebral augmentation. METHODS: The MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched for studies assessing the risk factors of adjacent vertebral fracture after vertebral augmentation until June 2020. The AVF incidence and factors potentially affecting AVF were extracted and pooled. RESULTS: A total of 16 studies, encompassing 2549 patients were included in the meta-analysis. The pooled incidence of AVF was 14% after vertebral augmentation. Female, lower T-score, thoracolumbar junction fracture, intravertebral cleft, more injected cement volume, intradiscal cement leakage significantly increased the risk of AVF. Age, body mass index, steroid medication, Cobb angle change, postoperative Cobb angle showed no significant association with AVF. CONCLUSIONS: Identifying the risk factors of AVF can facilitate prevention strategy to avoid the AVF. Female, T-score, thoracolumbar junction fracture, intravertebral cleft, more cement volume, and intradiscal cement leakage increased the risk of AVF.

Impact of Multifidus Muscle Atrophy on the Occurrence of Secondary Symptomatic Adjacent Osteoporotic Vertebral Compression Fractures.

To assess the potential influence of multifidus atrophy and fatty degeneration on the incidence of adjacent vertebral compression fractures within one year after the index fracture. In a retrospective cohort study, patients who underwent surgery for an OVCF were identified and baseline characteristics, fracture patterns and the occurrence of secondary adjacent fractures within one year were obtained by chart review. Multifidus muscle atrophy and fatty degeneration were determined on preoperative MRI or CT scans. In this analysis of 191 patients (mean age 77 years, SD 8, 116 female), OF type 3 was the most common type of OVCF (49.2%). Symptomatic adjacent OVCFs within one year after index fracture were observed in 23/191 patients (12%) at mean 12, SD 12 weeks (range 1-42 weeks) postoperatively. The mean multifidus muscle area was 264, SD 53 mm2 in patients with an adjacent vertebral fracture and 271, SD 92 mm2 in patients without a secondary fracture (p = 0.755). Mean multifidus fatty infiltration was graded Goutallier 2.2, SD 0.6 in patients with an adjacent fracture and Goutallier 2.2, SD 0.7 in patients without an adjacent fracture (p = 0.694). Pre-existing medication with corticosteroids was associated with the occurrence of an adjacent fracture (p = 0.006). Multifidus area and multifidus fatty infiltration had no significant effect on the occurrence of adjacent vertebral fractures within one year after the index fracture. Patients with a pre-existing medication with corticosteroids were more likely to sustain an adjacent fracture.

Radiological and clinical outcomes of balloon kyphoplasty for osteoporotic vertebral compression fracture in patients with rheumatoid arthritis.

BACKGROUND: This study was conducted to investigate the outcomes and complications of balloon kyphoplasty (KP) for the treatment of osteoporotic vertebral compression fracture (OVCF) in patients with rheumatoid arthritis (RA) and compare its radiological and clinical effects with OVCF patients without RA. METHODS: Ninety-eight patients in the RA group with 158 fractured vertebrae and 114 patients in the control group with 150 vertebrae were involved in this study. Changes in compression rate, local kyphotic angle, visual analog scale (VAS) and Oswestry disability index (ODI) scores, conditions of bone cement leakage, refracture of the operated vertebrae, and new adjacent vertebral fractures were examined after KP. In addition, patients in the RA group were divided into different groups according to the value of erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), and whether they were glucocorticoid users or not to evaluate their influence on the outcomes of KP. RESULTS: KP procedure significantly improved the compression rate, local kyphotic angle, and VAS and ODI scores in both RA and control groups (p<0.05). Changes in compression rate and local kyphotic angle in the RA group were significantly larger than that in the control group (p<0.05), and patients with RA suffered more new adjacent vertebral fractures after KP. The outcomes and complications of KP from different ESR or CRP groups did not show significant differences. The incidence of cement leakage in RA patients with glucocorticoid use was significantly higher than those who did not take glucocorticoids. In addition, RA patients with glucocorticoid use suffered more intradiscal leakage and new adjacent vertebral fractures. CONCLUSIONS: OVCF patients with RA obtained more improvement in compression rate and local kyphotic angle after KP when compared to those without RA, but they suffered more new adjacent vertebral fractures. Intradiscal leakage and new adjacent vertebral fractures occurred more in RA patients with glucocorticoid use. TRIAL REGISTRATION: Retrospectively registered.

Clinical observation of two bone cement distribution modes after percutaneous vertebroplasty for osteoporotic vertebral compression fractures.

BACKGROUND: Current findings suggest that percutaneous vertebroplasty(PVP) is a suitable therapeutic approach for osteoporotic vertebral compression fractures (OVCFs). The present retrospective study aimed to investigate the differences in clinical efficacy and related complications between the two bone cement distribution modes. METHODS: We retrospectively reviewed the medical records of the patients with single-segment OVCFs who underwent bilateral percutaneous vertebroplasty. Patients were divided into blocky and spongy group according to the type of postoperative bone cement distribution. Clinical efficacy and related complications was compared between the two bone cement distribution modes on 24 h after the operation and last follow-up. RESULTS: A total of 329 patients with an average follow up time of 17.54 months were included. The blocky group included 131 patients, 109 females(83.2 %) and 22 males(16.8 %) with a median age of 72.69 ± 7.76 years, while the Spongy group was made up of 198 patients, 38 females(19.2 %) and 160 males(80.8 %) with a median age of 71.11 ± 7.36 years. The VAS and ODI after operation improved significantly in both two groups. The VAS and ODI in the spongy group was significantly lower than that in the blocky group, 24 h postoperatively, and at the last follow-up. There were 42 cases (12.8 %) of adjacent vertebral fractures, 26 cases (19.8 %) in the blocky group and 16 cases (8.1 %) in the spongy group. There were 57 cases (17.3 %) of bone cement leakage, 18 cases (13.7 %) in blocky group and 39 cases (19.7 %) in the spongy group. At 24 h postoperatively and at the last follow-up, local kyphosis and anterior vertebral height were significantly corrected in both groups, but gradually decreased over time, and the degree of correction was significantly higher in the spongy group than in the block group. The change of local kyphosis and loss of vertebral body height were also less severe in the spongy group at the last follow-up. CONCLUSIONS: Compared with blocky group, spongy group can better maintain the height of the vertebral body, correct local kyphosis, reduce the risk of the vertebral body recompression, long-term pain and restore functions.

Prophylactic vertebral augmentation in patients with intra-disc leakage after kyphoplasty.

BACKGROUND: A uperior adjacent vertebral fracture (SAVF) is a common complication after kyphoplasty. Intra-disc leakage is a significant risk factor of SAVF. However, to date, no studies on the prevention of SAVF after intra-disc leakage have been conducted. This study sought to evaluate the clinical outcome of prophylactic vertebral augmentation in high-risk patients, and explore the other risk factors of SAVF. METHODS: Of 2,571 patients who received kyphoplasty, 82 with intra-disc leakage were retrospectively enrolled in the study, and divided into 2 groups based on whether they had a superior level of prophylactic vertebral augmentation. To ensure that any possible early complications were examined, there was a minimum follow-up period of 12 months. RESULTS: The pre-operation parameters were comparable between the 2 groups. In the non-prophylactic group, 9 of 59 (15.3%) patients had SAVF superior to the level of intra-disc leakage. Of these 9 SAVF cases, 8 fractures (88.9%) occurred within 6 months after surgery. Overall, 14 (23.7%) patients developed a new fracture. In the prophylactic group, no patients had a SAVF (0.0%), but 3 (13.0%) had remote fractures (P=0.047 and 0.284). No complications were associated with vertebral augmentation. Further, the risk factor analysis showed that patients with comorbidities and a history of corticoid use had a higher risk of fracture compared with patients with none of these risk factor [odds ratios: 12.0, 95% confidence interval (CI): 1.0-143, and 34.3, 95% CI: 3.2-364.5, respectively]. CONCLUSIONS: Prophylactic vertebral augmentation can prevent SAVF without complications. Patients with comorbidities and a history of corticoid use had a higher risk of SAVF compared with patients without corticoid use. Thus, we recommend prophylactic vertebral augmentation in the selected high-risk patients.

Overcorrection of fractured vertebrae increases the incidence of adjacent fractures after balloon kyphoplasty: A retrospective study.

PURPOSE: To investigate whether the correction amount by balloon kyphoplasty (BKP) is associated with the incidence of adjacent vertebral fractures (AVF). METHODS: Data from 61 patients without and 25 patients with AVF were analyzed. A linear regression model was used between vertebral instability and corrected angle or height to divide patients into the overcorrection and undercorrection groups. RESULTS: Vertebral fractures overcorrected for instability led to a higher incidence rate of AVF [42.4% and 46.9% with overcorrection vs. 10.7% and 13.3% with undercorrection for angle and height, respectively]. CONCLUSIONS: Overcorrection of fractured vertebrae may associate with the increased incidence of AVF.

A study on the relationship between the rate of vertebral body height loss before balloon kyphoplasty and early adjacent vertebral fracture.

BACKGROUND: The number of patients with an osteoporotic vertebral compression fracture, which is often accompanied by lower back pain and restrained activities, is growing. Balloon kyphoplasty involves the inflation of a balloon to restore height and reduce kyphotic deformity before stabilization with polymethylmethacrylate. However, there is a great deal of debate about whether balloon kyphoplasty also increases fracture morbidity by either inducing or facilitating subsequent adjacent vertebral fractures. OBJECTIVE: To evaluate the relationship between the rate of vertebral body height loss before balloon kyphoplasty and the etiology of early adjacent vertebral fracture after augmentation. METHODS: A total of 59 patients with osteoporotic vertebral compression fractures who underwent kyphoplasty were enrolled. This study defined early adjacent segmental fractures as new fractures occurring within three months after surgery. This study included the rate of vertebral body height loss. RESULTS: Early adjacent vertebral fractures were diagnosed in nine (15%) of the 59 patients. The patients were divided into two groups, with and without adjacent vertebral fractures. There was no significant difference in terms of age, body mass index, bone mineral density, local kyphotic angle, Cobb's angle, cement volume, cement leakage, and percent height restored between the groups with fractures and without fractures. There was a statistically significant difference between the two groups in the rate of vertebral body height loss. The rate of vertebral body height loss was significantly higher in the fracture group than in the without fracture group. CONCLUSIONS: A high rate of vertebral body height loss increased the risk of early adjacent vertebral fractures after balloon kyphoplasty.