The incidence and risk factors for extensive epidural cement leakage in cement-augmented pedicle screw fixation: a multicenter retrospective study.

INTRODUCTION: In cement-augmented pedicle screw fixation (CAPSF), epidural cement leakage (CL) is a frequently reported complication with the potential for neural injury, especially when it is extensive. To date, there has been no reports discussing basivertebral foramen morphology and pedicle screw placement, which is critical in the analysis of the risk of extensive epidural CL. Thus, this study aimed to identify the incidence and risk factors for extensive epidural CL in osteoporotic patients with CAPSF. MATERIALS AND METHODS: 371 osteoporotic patients using 1898 cement-augmented screws were included. Preoperative computed tomography (CT) was utilized to characterize basivertebral foramen morphology. Following CAPSF, the severity of epidural CL, the implantation position of pedicle screw and cement extension within the vertebral body were determined by postoperative CT. In this study, significant risk factors for extensive epidural CL were identified through logistic regression analysis. RESULTS: There were 19 patients (5.1%) and 32 screws (1.7%) with extensive epidural CL. Nine patients (involving 19 screws) had neurological symptoms. The independent risk factors for patients with extensive epidural CL were decreased BMD and increased number of augmented screws. Significant predictors for extensive epidural CL were a magistral type of basivertebral foramen, more volume of cement injected, solid screw, a shallower screw implantation, and the smaller distance between the tip of the screw and the midline of vertebral body. CONCLUSION: Extensive epidural CL risk was significant in CAPSF when a magistral basivertebral foramen was present; solid screws and more volume of cement were used; and screw tip was implanted shallower or closer to the midline.

The significance of the best puncture side bone cement/vertebral volume ratio to prevent paravertebral vein leakage of bone cement during vertebroplasty: a retrospective study.

OBJECTIVES: To verify the clinical significance of the best puncture-side bone cement/vertebral volume ratio (PSBCV/VV%) and bone cement leakage in paravertebral veins during vertebroplasty. METHODS: This was a retrospective analysis of a total of 210 patients from September 2021 to December 2022, who were divided into an observation group (110 patients) and a control group (100 patients). In the observation group, patients' preoperative computed tomography (CT) data were imported into Mimics software, and the VV was calculated using the three-dimensional (3D) reconstruction function. Then, based on the best PSBCV/VV% of 13.68% determined in a previous study, the optimal PSBCV to be injected during vertebroplasty was calculated. In the control group, vertebroplasty was performed directly using the conventional method. The incidence of cement leakage into paravertebral veins was observed postoperatively in both groups. RESULTS: There were no statistically significant differences (P > 0.05) in the evaluated indicators between the two groups pre- or postoperatively, including the anterior vertebral margin height, mid-vertebral height, injured vertebral Cobb angle, visual analogue scale (VAS) score, and Oswestry Disability Index (ODI). Intragroup comparisons showed improvements in the anterior vertebral height, mid-vertebral height, injured vertebral Cobb angle, VAS score, and ODI after surgery compared with before surgery (P < 0.05). In the observation group, there were 3 cases of cement leakage into the paravertebral veins, for a leakage rate of 2.7%. In the control group, there were 11 cases of cement leakage into the paravertebral veins, for a leakage rate of 11%. The difference in the leakage rate between the two groups was statistically significant (P = 0.016). CONCLUSION: In vertebroplasty, preoperative VV calculations using Mimics software, combined with calculation of the PSBCV according to the best PSBCV/VV% (13.68%), can effectively prevent leakage of bone cement into paravertebral veins and further prevent serious life-threatening complications such as pulmonary embolism.

Percutaneous endoscopic translaminar approach in a patient with pedicle screw malposition and cement leakage.

We present a 79-year-old female patient who had L2-5 dynamic stabilization with cement (Polymethylmethacrylate) injection 6 weeks prior. Due to post-operative right radicular pain, a lumbar CT was scheduled in which a malposition of the right L4 screw and cement leakage was observed. Via a percutaneous translaminar endoscopic approach the leaked cement was removed and the portion of the screw in contact with the nerve root was drilled. With this minimal-invasive procedure, the patient was relieved of her radicular pain.

An independent inter- and intra-observer agreement assessment of Yeom classification for bone cement leakage following vertebroplasty/kyphoplasty.

STUDY DESIGN: An inter- and intra-observer agreement study. BACKGROUND: In recent years, vertebroplasty and kyphoplasty have been widely used in treating osteoporotic vertebral compression fractures (OVCF) though the clinical efficacy of them is still controversial. However, there are also inevitable complications, first and foremost is bone cement leakage (BCL). Yeom classification is commonly used to evaluate BCL. The objective of this study is to assess its reliability and reproducibility, and to explore its clinical application value. METHODS: All 58 patients with BCL following vertebroplasty/kyphoplasty were involved. Six spine surgeons were selected to be evaluators as they were unaware of the identity of the patients and the treatment they received. They classified BCL according to Yeom system, we used kappa (K) to assess the inter- and intra-observer agreement. After 12 weeks, we repeated the analysis. RESULTS: The inter-observer reliability of Yeom classification was substantial with K value of 0.71 (1st assessment) and 0.73 (2nd assessment). The intra-observer reproducibility of Yeom classification was near perfect with K value of 0.88. CONCLUSION: Yeom classification system has substantial inter-observer reliability and near perfect intra-observer reproducibility in BCL following vertebroplasty/kyphoplasty, which can be widely used in clinical care as an appropriate instrument for early observation, mechanism and severity cognition, and prognosis predicting of BCL. Besides, the adding of type M (the mixed type) may improve the classification.

Complications of Percutaneous Vertebroplasty: A Pictorial Review.

Percutaneous vertebroplasty is a minimally invasive treatment technique for vertebral body compression fractures. The complications associated with this technique can be categorized into mild, moderate, and severe. Among these, the most prevalent complication is cement leakage, which may insert into the epidural, intradiscal, foraminal, and paravertebral regions, and even the venous system. The occurrence of a postprocedural infection carries a notable risk which is inherent to any percutaneous procedure. While the majority of these complications manifest without symptoms, they can potentially lead to severe outcomes. This review aims to consolidate the various complications linked to vertebroplasty, drawing from the experiences of a single medical center.

Establishment and validation of a nomogram and web calculator for the risk of new vertebral compression fractures and cement leakage after percutaneous vertebroplasty in patients with osteoporotic vertebral compression fractures.

PURPOSE: The aim of this work was to investigate the risk factors for cement leakage and new-onset OVCF after Percutaneous vertebroplasty (PVP) and to develop and validate a clinical prediction model (Nomogram). METHODS: Patients with Osteoporotic VCF (OVCF) treated with PVP at Liuzhou People's Hospital from June 2016 to June 2018 were reviewed and met the inclusion criteria. Relevant data affecting bone cement leakage and new onset of OVCF were collected. Predictors were screened using univariate and multi-factor logistic analysis to construct Nomogram and web calculators. The consistency of the prediction models was assessed using calibration plots, and their predictive power was assessed by tenfold cross-validation. Clinical value was assessed using Decision curve analysis (DCA) and clinical impact plots. RESULTS: Higher BMI was associated with lower bone mineral density (BMD). Higher BMI, lower BMD, multiple vertebral fractures, no previous anti-osteoporosis treatment, and steroid use were independent risk factors for new vertebral fractures. Cement injection volume, time to surgery, and multiple vertebral fractures were risk factors for cement leakage after PVP. The development and validation of the Nomogram also demonstrated the predictive ability and clinical value of the model. CONCLUSIONS: The established Nomogram and web calculator (https://dr-lee.shinyapps.io/RefractureApp/) (https://dr-lee.shinyapps.io/LeakageApp/) can effectively predict the occurrence of cement leakage and new OVCF after PVP.

Cement leakage in percutaneous vertebroplasty for spinal metastases: a retrospective study of risk factors and clinical outcomes.

OBJECTIVE: The objective of this research was to investigate the risk factors of cement leakage in patients with metastatic spine tumors following percutaneous vertebroplasty (PVP). METHODS: Sixty-four patients with 113 vertebrae were retrospectively reviewed. Various clinical indexes, including age, sex, body mass index (BMI), smoking history, drinking history, chemotherapy history, radiotherapy history, primary cancer, location, other metastases, collapse, posterior wall defects, the laterality of injection, and the injected cement volume were analyzed as potential risk factors. Multivariate analyses were conducted to identify the independent risk factors. RESULTS: The cement leakage was found 64 in 113 treated vertebrae (56.63%), in which the incidence of each type was shown as below: spinal canal leakage 18 (15.93%), intravascular leakage around the vertebrae 11 (9.73%), and intradiscal and paravertebral leakage 35 (30.97%). Tomita classification (P = 0.019) and posterior wall destruction (P = 0.001) were considered strong risk factors for predicting cement leakage in general. The multivariate logistic analysis showed that defects of the posterior wall (P = 0.001) and injected volume (P = 0.038) were independently related to the presence of spinal canal leakage. The postoperative visual analog scale (VAS) and activities of daily living (ADL) scores showed significant differences compared with the pre-operative parameters (P < 0.05). No significant differences were found in every follow-up time between the leakage group and the non-leakage group for pain management and improvement of activities in daily life. CONCLUSION: In our study, Tomita classification and the destruction of the posterior wall were independent risk factors for leakage in general. The defects of the posterior wall and injected volume were independently related to the presence of spinal canal leakage. The PVP procedure can be an effective way to manage the pain.

Correlation analysis of the puncture-side bone cement/vertebral body volume ratio and bone cement leakage in the paravertebral vein in vertebroplasty.

OBJECTIVES: To explore the influencing factors of bone cement leakage in the paravertebral vein after vertebroplasty for the treatment of osteoporotic vertebral compression fractures (OVCFs) and to determine the correlation between the puncture-side bone cement/vertebral body volume ratio and bone cement leakage in the paravertebral vein. METHODS: This was a retrospective analysis of 495 patients (585 vertebral bodies) with OVCFs treated from August 2018 to May 2021 in our hospital. The patients' postoperative CT data were imported into Mimics software, and the three-dimensional(3D) reconstruction function was used to calculate the bone cement volume (BCV), puncture-side bone cement volume (PSBCV), and vertebral body volume (VBV); the bone cement/vertebral body volume ratio (BCV/VCV%) and puncture-side bone cement/vertebral body volume ratio (PSBCV/VCV%) were additionally calculated. Sex, Age, Body mass index(BMI), Bone density, BCV, PSBCV, VBV, BCV/VCV%, and PSBCV/VCV were compared between the leakage group and the non-leakage group. Logistic regression analysis was used to assess the correlations between the factors that statistically significantly differed between the two groups and the presence of leakage in the paravertebral veins. A receiver operating characteristic (ROC) curve was used to determine the diagnostic value of the PSBCV/VCV% and to obtain the optional cut-off value. RESULTS: A total of 102 males and 393 females with an average age of 72.89 (52 ~ 93) years were included in our study. There were 57 cases of cement leakage (59 vertebral bodies) in the paravertebral vein. There were 438 patients (526 vertebral bodies) without paravertebral cement leakage. Univariate analysis showed that the differences in sex, bone density, PSBCV, and PSBCV/VCV% between the two groups were statistically significant (P < 0.05). Logistic regression analysis showed that there were correlations between sex, bone density, and PSBCV/VCV% and the presence of paravertebral cement leakage (P < 0.05). The ROC curve showed that the area under the curve of the PSBCV/VCV% for the diagnosis of cement leakage in the paravertebral vein was greater than 0.65, and P < 0.05, indicating a diagnostic value. The best cut-off point for the diagnosis of paravertebral cement leakage with the PSBCV/VCV% was 13.68%, with a sensitivity of 84.7% and specificity of 37.8%. CONCLUSION: Sex, bone density, and PSBCV/VCV% are risk factors for cement leakage in the paravertebral veins after vertebroplasty for the treatment of OVCFs; the PSBCV/VCV% is strongly associated with paravertebral venous leakage, and the optimal PSBCV/VCV% is 13.68%. When the PSBCV/VCV% exceeds the optimal value, the risk of cement leakage in the paravertebral vein becomes significantly increased.

The combination of radiofrequency ablation and vertebroplasty shows advantages over single vertebroplasty in treating vertebral neoplastic lesions.

OBJECTIVE: To investigate the safety and efficacy of the combination of radiofrequency ablation (RFA) and vertebroplasty versus single vertebroplasty in treating spinal metastases. MATERIALS AND METHODS: The data of 35 patients with vertebral neoplastic lesions who received RFA combined with vertebroplasty (group A, 15 patients with 17 lesions) or single vertebroplasty (group B, 20 patients with 24 lesions) from March 2016 to June 2019 were retrospectively compared. The data of patients' Visual Analogue Scale (VAS) scores prior to the treatments, 1 week, 1 month, 3 months, and 6 months after the treatments, injected cement volume, ratios of cement leakage were compared between the two groups. RESULTS: All procedures were successfully done without severe complications. The VAS scores in group A were decreased more rapidly 1 week after the treatments and remained more stable at 6 months than that in group B (P < 0.05). The cement injected in group A (5.95 ± 1.45 mL, range 4-9.5 mL) was significantly more than that in group B (4.09 ± 0.55 mL, range 3.1-5.5 mL) (P < 0.05). The ratio of vascular cement leakage in group A was significantly lower than that in group B (P < 0.05), while no statistical difference was found in the non-vascular cement leakage (P > 0.05). CONCLUSIONS: Our study shows that the combination of RFA and vertebroplasty has a better analgesic effect with more injected cement and lower rates of venous cement leakage than single vertebroplasty.

Prediction of early vascular cement leakage following percutaneous vertebroplasty in spine metastases: the Peking University First Hospital Score (PUFHS).

BACKGROUND: Cement leakage into venous blood posed significant challenge to surgeons. The aim of the study was to create a Peking University First Hospital Score (PUFHS) which could evaluate the probability of vascular cement leakage among spine metastases patients following percutaneous vertebroplasty. METHODS: The study retrospectively enrolled 272 spine metastases patients treated with percutaneous vertebroplasty. We randomly extracted all enrolled patients as the training or validation group and baseline characteristic comparison was assessed between the two groups. Creation of the PUFHS was performed in the training group and validation of the PUFHS was performed in the validation group. RESULTS: Of all the 272 patients, the total number of included vertebrae was 632 and the median treated levels were 2 per patient. Vascular cement leakage occurred in 26.47% (72/272) of patients. The baseline characteristics were comparable between the two groups (P > 0.05). Three risk predictors (primary cancer types, number of treated vertebrae levels, and vertebrae collapse) were included in the PUFHS. The area under the receiver operating characteristic curve (AUROC) of the PUFHS was 0.71 in the training group and 0.69 in the validation group. The corresponding correct classification rates were 73.0 and 70.1%, respectively. The calibration slope was 0.78 (95% confidence interval[CI]: 0.45-1.10) in the training group and 1.10 (95% CI: 0.73-1.46) in the validation group. The corresponding intercepts were 0.06 (95% CI: - 0.04-0.17) and - 0.0079 (95% CI: - 0.11-0.092), respectively. CONCLUSIONS: Vascular cement leakage is common among spine metastases after percutaneous vertebroplasty. The PUFHS can calculate the probability of vascular cement leakage, which can be a useful tool to inform surgeons about vascular cement leakage risk in advance.

Comparison between vertebroplasty with high or low viscosity cement augmentation or kyphoplasty in cement leakage rate for patients with vertebral compression fracture: a systematic review and network meta-analysis.

PURPOSE: This study aims to determine whether outcomes following vertebroplasty with high viscosity cement are superior to low viscosity cement and non-inferior to kyphoplasty in the setting of vertebral compression fractures. METHODS: We searched for randomized controlled trials and cohort studies assessing cement leakage rate in adult patients with VCFs who underwent vertebroplasty with high (HVCV) or low viscosity cement (LVCV) augmentation, or kyphoplasty (KP) in PubMed, Embase, Ovid, The Cochrane Library, and Web of Science from inception up to December 2019. Two authors extracted data and appraised risk of bias. We performed pairwise meta-analyses in R to compare differences between three treatments and network meta-analysis using frequentist random-effects models for indirect comparison. We used P-score to rate the overall certainty of evidence. The primary outcome was cement leakage rate. RESULTS: Five RCTs and eight cohort studies with 840 patients and a total of 1280 vertebral bodies were included in the systematic review and network meta-analysis. Compared to LVCV, the relative risk for cement leakage following HVCV and KP was 0.42 (95% CI 0.28-0.61) and 0.83 (95% CI 0.40-1.68), respectively. Our pooled results suggested that HVCV (P-score = 0.99) was better than KP (P-score = 0.36) in cement leakage rate. CONCLUSIONS: The present network meta-analysis demonstrated that HVCV may be associated with lower risk of cement leakage among patients with VCFs as compared to other augmentation techniques. Future prospective studies will validate the findings of this analysis and further elucidate the risk of symptomatic cement leakage.

Paraplegia due to intradural cement leakage after vertebroplasty: a case report and literature review.

BACKGROUND: Vertebroplasty (VP) is considered an alternative therapy in an osteoporotic compression fracture that failed conservative treatment. However, cement leakage into the intradural space can cause catastrophic complications. To the best of our knowledge, intradural cement leakage following VP has been reported only in 7 cases. We report here a case of intradural cement leakage following VP with a literature review. CASE PRESENTATION: An 84-year-old female with an L1 osteoporotic fracture underwent percutaneous VP at a local hospital. Immediately after the procedure, she complained of weakness, numbness, and pain in both legs, and her back pain aggravated. She was transferred to our hospital. The initial muscle power was grade 2 for the right leg and grade 4 for the left leg. Computed tomography (CT) scan showed intradural cement leakage from T10 to L2. Magnetic resonance imaging showed an intradural mass lesion. Although we performed total laminectomy with durotomy and removed intradural cement completely, the neurological deficit did not completely recover. The muscle power was grade 3 for the right leg and grade 4 for the left leg at the last follow-up. CONLCUSIONS: If a neurological deficit is found after VP, a CT scan should be taken to confirm the pattern of cement leakage. In case of intradural cement leakage, surgical decompression should be recommended to improve neurological deficit. To prevent intradural cement leakage during the VP, the needle tip should not perforate the medial wall of the pedicle with appropriate viscosity of cement.

The impact of intravertebral cleft on cement leakage in percutaneous vertebroplasty for osteoporotic vertebral compression fractures: a case-control study.

BACKGROUND: The impact of intravertebral cleft (IVC) on cement leakage in percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCFs) has been discussed. However, the results were conflicting, as the study population and cement leakage classification were heterogeneous. The aim of the study was to evaluate the impact of IVC on the incidence of leakage through vein, leakage through cortex as well as general leakage in PVP for OVCFs. METHODS: All patients with OVCFs who underwent PVP between January 2016 and June 2019 at our institution were retrospectively reviewed. Patients were eligible for this case-control study if they were diagnosed as single level fracture in spine. After inclusive and exclusive criteria were met, a total of 139 patients with IVC were enrolled as the study group. Non-IVC controls were matched in a 1:1 ratio in age (within 3 years), sex and fracture severity with patients in study group. Cement leakage were classified into four types [type B (through basivertebral vein), type S (through segmental vein), type-C (through a cortical defect), and type D (intradiscal leakage)], furtherly into two types [venous type (type-B or/and type S) and cortical type (type-C or/and type-D)]. A general leakage rate and a specific leakage rate per each type were compared between both groups. RESULTS: Each group included 139 patients. Groups were homogenous for age, sex, fracture severity, fracture location, fracture type, cement volume, puncture approach and property of cement. Compared with control group, IVC group had a significantly lower rate of type-B (20.9% vs. 31.7%, P = 0.041), type-S (24.5% vs. 52.5%, P = 0.000), and venous type leakage (37.4% vs. 67.6%, P = 0.000), a significantly higher rate of type-C (25.9% vs. 12.2%, P = 0.004), type-D (16.5% vs. 6.5%, P = 0.009), and cortical type leakage (40.3% vs. 16.5%, P = 0.000), no significant difference on the rate of general leakage (67.6% vs. 76.3%, P = 0.109). CONCLUSION: IVC decreased the risk of cement leakage through vein and increased the risk of cement leakage through cortex. However, it had no significant effect on the occurrence of general leakage.

Is unilateral transverse process-pedicle percutaneous kyphoplasty a better choice for osteoporotic thoracolumbar fractures in the old patients?

BACKGROUND: A few reports have shown that unilateral transverse process-pedicle percutaneous kyphoplasty is a good choice for patients with osteoporotic vertebral compression fracture (OVCF). However, this issue remains controversial and the related comprehensive research was lacked. METHODS: A retrospective study was conducted on patients receiving PKP surgery for OVCF. Patients were divided into three groups according to surgical approach. Symptom and radiographical evaluation were performed preoperatively, 1-month postoperatively, 1-year postoperatively and follow-ups. And follow-ups were repeated every year. Visual Analogue Scale Score (VAS), Oswestry Disability Index (ODI) scores, anterior vertebral height, coronal Cobb angle and sagittal Cobb angle was determined and compared among three groups. RESULTS: Totally 447 patients were included with an average age of 76.6 ± 7.2 years old. UTP showed significantly shorter surgical duration (p < 0.001), lower cement volume (p < 0.001) but higher cement leakage proportion (p = 0.044). No significant statistical difference was found in terms of improvement rates among three groups. Besides, it was notable that the a significantly higher coronal Cobb angle was observed in UTP group, and a about 4°coronal correction was found after UTP PKP. CONCLUSION: UTTP PKP could achieve similar symptoms relief and kyphosis correction as UTP and BTP PKP. However, it had shorter surgical time and less radio exposure than BTP PKP, lower risk of cement leakage and higher proportion of bilaterally cement distribution than UTP PKP. It seemed to be a better choice for patients with OVCF. In addition, we found that UTP PKP was especially fit for OVCF patients with asymmetrical vertebral compression.

Basivertebral foramina of true vertebrae: morphometry, topography and clinical considerations.

PURPOSE: Basivertebral foramina (BVF) are openings of the posterior wall of vertebral body (VB) that lead to basivertebral canals (BVC), where homonymous neurovascular bundle courses. BVF and BVC are implicated with spinal fractures, vertebral augmentation and basivertebral nerve radiofrequency ablation. Despite their essential clinical impact, knowledge of BVF precise anatomy is scarce. The current study describes in detail the BVF typical morphological and topographical anatomy, morphometry and variants. METHODS: In total, 1561 dried true vertebrae of 70 Greek spines of known gender and age were examined. BVF number, location, shape and size (in foramina > 1 mm), BVF distance from VB rims and pedicles, as well as VB morphometry (diameters, heights and distance between pedicles) were studied. Ten spines were re-examined by computed tomography and BVC depth and shape were recorded. Correlations and differences were statistically analyzed. RESULTS: C1 lack BVF (3.4%). One BVF was found in 45.1%, two in 36.9%, three in 3.8% and four BVF in 0.6%. Multiple small (< 1 mm) foramina were observed in 10.1%. Asymmetry was detected in 12.3%. C2 and T10-L1 presented typical pattern, whereas C3 and T2 had the greatest variability. BVF were significantly closer to the upper rim in C2 and T10-L4 and to the lower rim in C7-T4, T6-T8 and L5. The mean BVC depth was 12-21.8% of the VB anteroposterior diameter. CONCLUSION: BVF number, shape, size and topography are described, in detail, per vertebral level. The provided morphological classification and the created cumulative BVF topographic graphs should assist in clinical practice and surgery.

Risk factors for cement leakage and nomogram for predicting the intradiscal cement leakage after the vertebra augmented surgery.

BACKGROUND: Vertebral augmentation is the first-line treatment for the osteoporosis vertebral compression fractures. Bone cement leakage is the most common complication of this surgery. This study aims to assess the risk factors for different types of cement leakage and provides a nomogram for predicting the cement intradiscal leakage. METHODS: We retrospectively reviewed 268 patients who underwent vertebral augmentation procedure between January 2015 and March 2019. The cement leakage risk factors were evaluated by univariate analysis. Different types of cement leakage risk factors were identified by the stepwise logistic analysis. We provided a nomogram for predicting the cement intradiscal leakage and used the concordance index to assess the prediction ability. RESULTS: A total of 295 levels of vertebrae were included, with a leakage rate of 32.5%. Univariate analysis showed delayed surgery and lower vertebral compression ratio were the independent risk factors of cement leakage. The stepwise logistic analysis revealed percutaneous vertebroplasty was a risk factor in vein cement leakage; delayed surgery, preoperative compression ratio, and upper endplate disruption were in intradiscal cement leakage; age, preoperative fracture severity, and intravertebral vacuum cleft were in perivertebral soft tissue cement leakage; no factor was in spinal canal cement leakage. The nomogram for intradiscal cement leakage had a precise prediction ability with an original concordance index of 0.75. CONCLUSIONS: Delayed surgery and more vertebral compression increase the risk of cement leakage. Different types of cement leakage have different risk factors. We provided a nomogram for precise predicting the intradiscal cement leakage.

High-viscosity bone cement for vertebral compression fractures: a prospective study on intravertebral diffusion and leakage of bone cement.

BACKGROUND: Bone cement leakage causes severe complication following percutaneous vertebroplasty. This study probed the diffusion and leakage status of bone cement injected within diverged time duration, so as to find the optimal injection time for bone cement. METHODS: A total of 70 patients with osteoporotic vertebral compression fractures with a symptom of low back pain, who underwent treatment at hospital were enrolled in this study. Patients were randomized into three groups: < 180 s, 180-300, and > 300 s of injection time duration from the beginning to the completion of the injection. The scenarios of vertebral bone cement leakage and diffusion were inspected using postoperative CT. RESULTS: The diffusion coefficient was higher in group A than in group B whereas it was higher in group B than in group C, but without statistical significance among the three groups. The leakage rate was without statistical significance among the three groups. The injection time of bone cement was negatively correlated with the diffusion coefficient, at the correlation coefficient of - 0.253. CONCLUSIONS: The diffusion coefficient of high-viscosity bone cement is negatively correlated with the injection time, and the leakage rate of high-viscosity bone cement does not reduce with the prolongation of injection time.

Cement leakage following percutaneous kyphoplasty in a patient after a posterior lumbar fusion: a case report.

BACKGROUND: Percutaneous kyphoplasty (PKP) has become an important minimally invasive surgical technique for fracture stabilization and pain relief in patients with vertebral compression fractures. However, intraspinal cement leakage following PKP is a serious postoperative complication that can lead to morbidity and mortality. CASE PRESENTATION: We describe an uncommon case of epidural leakage of bone cement in an 81-year-old woman who underwent posterior lumbar decompression and fusion from L3-5 4 years prior and had an unremarkable postoperative course. The patient was admitted to Peking Union Medical College Hospital with complaints of muscle weakness and severe low back pain radiating to the left thigh 1 week after PKP of L5 due to an acute osteoporotic compression fracture. Computed tomographic imaging revealed massive leakage of cement into the spinal canal at L5-S1, and therefore, surgical decompression and removal of epidural cement were performed carefully without causing a dural tear. She improved remarkably and no neurologic deterioration was observed in the postoperative period during the one-year follow-up. CONCLUSIONS: We present the rare reported case, to our knowledge, of epidural cement leakage after PKP at the segment of internal fixation and discuss the most likely etiologies and preventive measures for this condition.

Modified kyphoplasty with controllable balloon dilatation for treatment of thoracolumbar osteoporotic vertebral compression fractures.

PURPOSE: To investigate the surgical effects of modified kyphoplasty with controllable balloon dilatation for treatment of thoracolumbar osteoporotic vertebral compression fractures (OVCF). METHODS: From April 2013 to October 2017, a total of 53 patients with thoracolumbar OVCF were treated with controllable balloon percutaneous kyphoplasty (C-PKP). Peri-operative parameters including days from injury to operation, operation time, injected cement volume, cement leakage and complications were collected. Visual analogue scale (VAS) and Cobb angle before and after operation were applied to evaluate surgical effects. Moreover, a total of 53 cases treated with traditional balloon of percutaneous kyphoplasty were retrospectively analyzed and compared with C-PKP in above parameters. RESULTS: C-PKP achieved significant fewer events of cement leakage (type C) than that of traditional PKP (5/53 vs 13/53, p < 0.01). The patients were followed up for 10.8 ± 4.2 months; VAS and Cobb angle of the injured vertebra in both two groups at three days and final follow-up were significantly improved compared with that before surgery (p < 0.05), while there were no significant differences between the two groups regarding the VAS and Cobb angle at corresponding time points (p > 0.05). CONCLUSIONS: C-PKP technology is a safe and efficient way for the treatment of thoracolumbar OVCF, and it can reduce cement leakage.

The cement leakage in cement-augmented pedicle screw instrumentation in degenerative lumbosacral diseases: a retrospective analysis of 202 cases and 950 augmented pedicle screws.

PURPOSE: To evaluate the incidence, type and risk factors of cement leakage (CL) with cement-augmented pedicle screw instrumentation (CAPSI) in degenerative lumbosacral disease. METHODS: Two hundred and two patients using a total of 950 cement-augmented screws were enrolled. CL was classified into three types: type S: leakage via segmental veins; type B: leakage via basivertebral veins; and type I: leakage via pedicle screw instrumentation to paravertebral soft tissue. The age, gender, operation stage (primary or later stage), body mass index, bone mineral density, the number and type of augmented screw, the position of the tip of screw (lateral or internal part of vertebral body), the position of screw (left or right side), the volume of bone cement, location of the augmented vertebra (lumbar or sacrum), the type of CL and complications were recorded. Binary logistic regression correlation was used to analyze risk factors of veins leakage (type S and type B). RESULTS: The CL was observed in 165 patients (81.68%) and 335 screws (35.26%), leakage types of S, B and I were seen in 255 (76.12%), 77 (22.99%), and 30 (8.96%) of screws, respectively. Besides, double or multiple routes of leakage were seen in 27 screws. Number of augmented screw was a risk factor for vein leakage (OR 0.58; 95% CI 0.44-0.77; P = 0.000). Furthermore, the doses of cement (OR 0.79; 95% CI 0.61-0.99; P = 0.038) and the position of screw (OR 0.39; 95% CI 0.29-0.53; P = 0.000) were identified as risk factors for type S, and the doses of bone cement (OR 0.37; 95% CI 0.25-0.54; P = 0.000) and the position of the tip of screw (OR 0.07; 95% CI 0.04-0.13; P = 0.000) were risk factors for type B. CONCLUSIONS: CAPSI bears a high risk of asymptomatic CL, with a higher rate of leakage into segmental veins and basivertebral veins. As is known, more augmented screws and larger doses of cement are risk factors for veins leakage (type S and type B), while the tip of screw approaching to the midline of the vertebral body is another risk factor to type B. Thus, the CL could be reduced by the amelioration of operative techniques and procedures. These slides can be retrieved under Electronic Supplementary Material.