Cement Volume Research Articles

A relevant investigation of the degree of cement diffusion after robot-assisted percutaneous vertebroplasty

The aim of this research was to conduct randomized trials assessing the extent of cement diffusion following robot-assisted percutaneous vertebroplasty (R-PVP) for osteoporotic vertebral compression fractures (OVCF). A total of 96 OVCF patients meeting the inclusion criteria and admitted between January 2023 and November 2023 were included in the study. Among them, 48 patients were assigned to the robotic-assisted PVP group (R-PVP group) and 48 patients were assigned to the traditional PVP group (PVP group). The study examined the differences in age, sex, BMD T-value, fracture segment, preoperative, postoperative, and 3-month postoperative visual analogue scale (VAS) and Oswestry disability index (ODI) pain scores, fluoroscopic dose, frequency of fluoroscopy, volume of bone cement injected, angle of puncture abduction, degree of cement diffusion, and bone cement spillage among the two patient groups. A logistic regression model was employed to analyze the factors influencing the extent of postoperative bone cement diffusion. The findings indicated that the R-PVP group exhibited a significantly larger puncture abduction angle, improved postoperative cement dispersion, increased cement injection volume, and decreased incidence of cement spillage compared to the PVP group. Furthermore, the R-PVP group demonstrated superior outcomes in these aspects, as well as lower intraoperative fluoroscopic frequency and radiation exposure. Additionally, bone density, puncture abduction angle, cement injection volume, and surgical approach were identified as independent factors associated with the extent of postoperative cement dispersion.

Higher bone cement volume in total knee arthroplasty lowers the risk of postoperative radiolucent lines.

>The aim of this multicenter study was to analyze the potential impact of patient demographics and cementation technique towards the development of radiolucent lines (RLLs) in primary total knee arthroplasty (TKA). It was hypothesized that cementation techniques, including higher cement volume, double-layer cementation technique and hardening in full extension, reduce RLL incidence by improving stability, whereas demographic factors such as age, BMI and smoking may increase RLL risk by affecting bone quality and mechanical loading. Altogether, 776 patients (median age: 70.7 years; 39.2% males) underwent TKA at five tertiary orthopaedic centres between 11/2013 and 04/2023. X-rays were analyzed retrospectively for the evaluation of RLLs taken between 6 and 36 months from surgery. RLLs on anterior-posterior and lateral X-rays taken at a median of 14 months (range: 6-36) from primary surgery were evaluated using the Knee Society roentgenographic evaluation and scoring system. Potential associations of demographics and cementation technique on the occurrence of RLLs during follow-up were analyzed with uni- and multivariate logistic regression models. The overall incidence of RLLs around the TKA amounted to 37.4% (n = 290), with the tibial component (29.4%) being more commonly affected than the femoral component (15.0%). Patient age, gender, BMI and smoking habits were not significantly associated with higher incidence of RLLs (p > 0.05). The amount of cement used (odds ratio: 0.99; 95% confidence interval: 0.98-0.99; p = 0.028) was independently associated with a lower incidence of RLLs, irrespective of the double- versus single-layer cementation technique, cement hardening in full extension and time required for the X-ray. No influence of demographic data on the incidence of RLL was found, yet specific cementation techniques appeared beneficial. Future studies with longer follow-up periods are required to provide further insight into the herein-made preliminary findings and to assess potential associations with long-term aseptic loosening rates. Level III, retrospective observational study.

The Risk of Intravenous Cement Leakage and Short-term Outcomes of Selective Cement-augmented Pedicle Screws: A Multicenter Retrospective Study.

Multicenter retrospective cohort study. To evaluate the efficacy and safety of using cement-augmented pedicle screw (CAPS) fixation only for the cephalad and caudal vertebral bodies. Pedicle screw fixation is less effective in patients with low-quality bone. Although CAPS fixation has shown promise in improving stability and reducing screw loosening in such cases, cement leakage can have serious consequences. This study included 65 patients who underwent spinal surgery using CAPS and were followed up for >3 months. Four CAPSs were used in each patient, and 254 CAPSs were included in the analysis. Of the 65 patients, 36.9% showed intravenous cement leakage, and a low bone mineral density (BMD) was associated with a higher risk of cement leakage. The use of a CAPS on the right side was also potentially associated with a higher risk of leakage. However, the shape and location of the leaked cement remained stable over time. Screw loosening occurred in 3.5% of the CAPSs and was associated with a lower cement volume. Cement leakage was related to lower BMD. Using CAPS exclusively at the lower or upper instrumentation levels might minimize the risk of cement leakage in osteoporotic patients.

A contrastive analysis of two bone cement applicators for percutaneous vertebroplasty in the treatment of OVCF: A retrospective study

Background Percutaneous vertebroplasty (PVP) is the mainstream treatment for osteoporotic vertebral compression fractures (OVCF). In order to provide better clinical efficacy and reduce complications, various bone cement applicators are still being developed and gradually applied in clinical practice. However their clinical results are still to be reported. Objective To evaluate the clinical efficacy of the novel spiral cement applicators and the traditional push-rod applicators for the PVP treatment of osteoporotic vertebral compression fractures (OVCF). Methods A retrospective study, from February 2017 to May 2019, was conducted on 107 OVCF patients who received PVP surgeries respectively with spiral applicators (Observation group) and pushrod applicators (Control group). Perioperative indicators, imaging indicators, clinical efficacy, other indicators were collected and compared. Results The follow-up period was two years. The baseline data of the two groups were comparable ( P > 0.05). The anterior edge height and kyphosis angle of the injured vertebrae after surgery compared with before surgery increased significantly in both groups ( P < 0.05). The midline height in the observation group after surgery compared with before surgery increased significantly ( P < 0.05). The kyphosis angle after surgery and these recovery rates of kyphosis angle, the anterior edge height, the midline height, the posterior edge height increased significantly in the observation group compared with the control group ( P < 0.05). VAS and ODI in both groups were significantly lower on the 3rd day and 2nd year after surgery than before surgery, and decreased gradually over time ( P < 0.05). The VAS and ODI on the 3rd day after surgery were significantly lower in the observation group than in the control group ( P < 0.05). The number of fluoroscopy and operation time were significantly lower in the observation group than in the control group ( P < 0.05). The rate of bone cement leakage, bone cement diffusion coefficient and cement volume in the observation group were significantly higher than that of the control group ( P < 0.05). Conclusion The spiral applicator is better than the pushrod applicator in reducing the number of fluoroscopy and operation time, restoring vertebral height, correcting kyphosis, alleviating pain immediately, improving function, and facilitating dispersion of cement, with a higher rate of bone cement leakage.

The shard test and nanoporomechanics reverse classical paradigm of cement hydration being contractive

Le Chatelier in 1887 and Powers in 1947 demonstrated that the volume of nanoscale C-S-H (calcium silicate hydrate) particles formed during hydration is smaller than the combined volume of the reactants-the anhydrous Portland cement and water. Hydration has thus been considered as contractive. An experiment shows that the opposite is true above the nanoscale. The porous skeleton of cement paste expands as the growing C-S-H particles push each other apart, similar to crystal growth pressure. This is significant for high-performance concretes (HPC) with low water-cement ratios (w/c [Formula: see text] 0.4), where chemical self-desiccation lowers pore relative humidity by 40%, compared to just 1% in traditional concretes (w/c [Formula: see text] 0.5). Standard American Society for Testing and Materials (ASTM) C1608 tests, using 10 mm thick water-immersed specimens, show large shrinkage because the half-time of water ingress is many decades, unable to offset shrinkage-causing self-desiccation. The present experiment, using a laser microscopy-topography technique, proves the opposite-expansion, evidenced by measuring the length changes of water-immersed HPC shards 0.5 mm thick in which the diffusion halftime, only about one hour, allows continuous resaturation of pores, canceling self-desiccation. The faster diffusion (halftime of one hour) enables continuous pore resaturation, preventing shrinkage. When sealed with paraffin oil, the shards self-desiccate and shrink. These findings align with studies since 2015, showing that models excluding hydration expansion cannot fit test data across various specimen sizes and sealing conditions. The results suggest that standardized ASTM tests for the so-called chemical shrinkage in modern concretes with very low water-cement ratios are misleading and need revision.

Reuse of sheep wool fibers in the production of ultralightweight foamed concrete: effect of fiber treatment, length, and content on the mechanical properties

Concrete is one of the most widely used materials in the world. Still, its production processes, energy consumption, and high use of raw materials make it one of the most environmentally harmful materials. This study aims to enhance the sustainability of concrete by reducing the amount of binder and incorporating secondary materials into the cementitious matrix. The binder reduction is achieved by using a foaming agent that creates a microporous matrix, significantly decreasing the volume of cement in the material. Additionally, reinforcing the material with sheep wool fiber not only improves its mechanical properties but also gives a new purpose to a commonly discarded secondary material. The research specifically seeks to identify the most effective treatments for sheep wool fiber (including non-treated, salt-treated, lime-treated, NaOH-treated, and surfactant-treated fibers), as well as the optimal fiber length (6, 12, and 20 mm) and content (4.5, 9, and 15 kg/m³) for ultralightweight foamed concrete in terms of mechanical strength. The findings demonstrate excellent compatibility between wool fibers and ultralightweight foamed concrete, with fiber-reinforced samples showing up to a 60% increase in flexural strength and up to a 50% increase in compressive strength. Among the various fiber treatments evaluated, surfactant-treated fibers yielded the best results.

The impact of different courses of osteoporotic vertebral compression fracture on the early efficacy of percutaneous vertebroplasty: a retrospective study.

Percutaneous vertebroplasty (PVP) is a frequently employed technique for treating osteoporotic vertebral compression fracture (OVCF). However, there is still controversy regarding whether PVP with different courses affects clinical efficacy. Therefore, this study aims to investigate the impact of different courses of OVCF on early clinical and radiological outcomes after PVP. OVCF with shorter course can obtain more satisfactory clinical efficacy and radiological results after PVP. A retrospective analysis was conducted on the clinical data of 100 patients undergoing PVP for OVCF. Patients were categorized into early group (n = 37, <2 weeks), intermediate group (n = 35, 2-4 weeks), and late group (n = 28, 4-6 weeks) according to the time from the occurrence of OVCF to undergoing PVP. The visual analogue scale (VAS) and oswestry disability index (ODI) were used to evaluate the clinical effect before, 1 day, and 12 months after surgery. Anterior vertebral height ratio (AVHR) and local kyphosis angle (LKA) were measured on plain radiographs to evaluate the radiographic changes. The cement volume, cement leakage, hospitalization time, new fractures, and outdoor activity (ODA) were compared among the three groups. Compared with preoperative, VAS and ODI of the three groups were significantly improved (p < 0.05). There was no difference in VAS at 1 day and 12 months after surgery among the three groups (3.3 vs. 3.2 vs. 3.2, 1.7 vs. 2.0 vs. 2.0, respectively). ODI was significantly better in the early and intermediate groups at 1 day and 12 months after surgery (33.49% vs. 32.37% vs. 35.24%, 31.86% vs. 30.73% vs. 34.56%, all p < 0.05), and without inter-group differences. Postoperative AVHR and LKA were improved in all three groups (p < 0.05). The improvement of AVHR and LKA at 1 day and 12 months after surgery was more significant in the early and intermediate groups (AVHR: 21.00% vs. 18.52% vs. 26.31%, 21.82% vs. 20.03% vs. 27.75%, LKA: 17.82º vs. 17.61º vs. 20.49º, 19.07º vs. 19.10º vs. 20.80º, all p < 0.05), and without inter-group differences. The cement volume in the late group was less (4.3 ml vs. 4.3 ml vs. 3.2 ml, p < 0.05), but there were no differences in cement leakage and new fractures. Patients in the late group had a longer hospitalization time (5.1d vs. 5.0d vs. 6.4d, p < 0.05) and poorer ODA (5/15/17 vs. 4/17/14 vs. 11/11/6, p < 0.05). OVCF with a course of less than 4 weeks can recover partial vertebral height and improve local kyphosis after PVP. The clinical and radiological outcomes are better than course of more than 4 weeks. We recommend performing PVP within 4 weeks of the occurrence of OVCF. III; retrospective comparative study.

Impact of Intravertebral Clefts Sclerosis on Percutaneous Vertebroplasty Efficacy in Osteoporotic Vertebral Compression Fractures

To investigate the effect of intravertebral cleft sclerosis on the efficacy of percutaneous vertebroplasty (PVP) in osteoporotic vertebral compression fractures (OVCFs). We analyzed 68 OVCF patients with intravertebral clefts treated with PVP from January 2020 to June 2022. Patients were divided into 2 groups based on computed tomography findings: intravertebral clefts sclerosis (IVCs, 36 cases) and intravertebral clefts nonsclerosis (IVCns, 32 cases). Preoperative data included gender, age, bone mineral density, fractured vertebrae distribution, and disease duration. Excluding those with contraindications, all underwent PVP. Operation time, cement injection volume, leakage rate, and distribution patterns were recorded. Outcomes were evaluated using visual analog scale scores, oswestry disability index, anterior vertebral height, and Cobb angle preoperatively, and at 2 days and 1 year postoperatively. The IVCs group had a longer disease duration (P < 0.05). No significant differences in operation time, cement volume, or leakage rate were observed between groups (P > 0.05). Cement distribution was mass-like in IVCs and sponge-like in IVCns (P < 0.05). Both groups showed significant improvements postoperatively (P<0.05), but IVCns had better recovery in anterior vertebral height, Cobb angle, and oswestry disability index (P < 0.05). IVCs affect cement distribution and recovery outcomes, with IVCns achieving better results. Early treatment is advised for OVCF with intravertebral clefts.

Study on Performance and Engineering Application of Novel Expansive Superfine Cement Slurry.

Superfine cement is widely used in building reinforcement and repair, special concrete manufacturing, and environmental protection engineering due to its high toughness, high durability, good bonding strength, and environmental friendliness. However, there are some problems in superfine cement slurry, such as high bleeding rate, prolonged setting time, and consolidated body volume retraction. In this article, on the premise of using the excellent injectability of superfine cement slurry, the fluidity, setting time, reinforcement strength, and volume expansion rate of novel expansive superfine cement slurries with varying proportions were analyzed by adding expansion agent UEA, naphthalene-based water reducer FDN-C, and triisopropanolamine accelerating agent TIPA. The results show that under most mix ratios, the bleeding rate and fluidity of the novel superfine cement slurry initially increase and decrease with rising water-reducing agent dosage. The initial setting time generally decreases with accelerating agent dosage, reaching a minimum value of 506 min, representing a 33.68% reduction compared to the benchmark group (traditional superfine cement). Under normal conditions, the compressive strength of the net slurry consolidation body is positively correlated with expansion agent dosage, achieving maximum strengths of 8.11 MPa at three days and 6.93 MPa at 28 days; these values are respectively higher by 6.7 MPa and 2.6 MPa compared to those in the benchmark group. On the seventh day, the volume expansion rate of the traditional superfine cement solidified sand body ranges from -0.19% to -0.1%, while that for the corresponding body formed from the novel superfine cement is between 0.41% and 1.33%, representing a difference of 0.6-1.43%. After the on-site treatment of water and sand-gushing strata, the core monitor rate of the inspection hole exceeds 70%. The permeability coefficient of the stratum decreases to a range between 1.47 × 10-6 and 8.14 × 10-6 cm/s, resulting in nearly a thousandfold increase in stratum impermeability compared to its original state. Hence, the findings of this research hold practical importance for the future application of such materials in the development of stratum reinforcement or building repair.

A novel mesh algorithm to improve the packing efficiency of irregular-shaped particles in simulating cement paste's microstructure

Irregular-shaped particle packing is important to simulate the cement paste microstructure. However, the efficiency of current packing models is relatively low. This study proposes a novel packing algorithm named the Mesh Optimization Packing (MOP) model inspired by the VOX and extent overlap box (EOB) methods. The MOP model's performance in terms of accuracy, uniformity, and randomness were evaluated. Meanwhile, compared to the Anm model 2.0 and the VOX model, the MOP model excels in simulating the initial microstructure of cement paste with high cement volume fractions. When the cement volume fraction is 56.03 %, the VOX model requires 124.68 h, while the MOP model only takes 18.80 h. By adding uniform-thickness shells to irregular-shaped particles, the MOP model integrates with the HYMOSTRUC3D-E model to simulate the evolution and uniaxial stretching process of the cement paste microstructure. This innovative modelling approach offers a promising solution for future simulations of cement paste microstructure.

Analysis of the Effect of Bone Cement Distribution Patterns on Surgical Outcomes of Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures

Objective: To evaluate the impact of bone cement distribution patterns on the surgical outcomes of percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCF). Methods: Sixty-four patients with OVCF treated at our hospital from January 2022 to December 2023 were included and divided into two groups based on bone cement distribution patterns: the clustered group and the diffuse group. Both groups underwent PVP. We compared the incidence of bone cement leakage, operative time, blood loss, changes in Visual Analog Scale (VAS) pain scores, and Oswestry Disability Index (ODI) scores before and after treatment between the two groups. Results: The number of cases with bone cement leakage was significantly higher in the diffuse group compared to the clustered group (P &lt; 0.05). There were no significant differences between the two groups in terms of volume of bone cement injected, intraoperative blood loss, or surgical time (P &gt; 0.05). Post-treatment, both VAS and ODI scores were lower than pre-treatment scores in both groups, with the diffuse group showing significantly lower scores than the clustered group (P &lt; 0.05). No postoperative adverse complications were observed in either group. Conclusion: PVP is highly effective for treating OVCF. A more uniform distribution of bone cement is associated with a greater reduction in postoperative pain and improved functional outcomes. However, careful attention is needed to prevent bone cement leakage.

Low-carbon cementitious composite incorporated with biochar and recycled fines suitable for 3D printing applications: hydration, shrinkage and early-age performance

In recent years, the construction industry has witnessed significant advancements in concrete technology, particularly with the integration of 3D printing in cement-based materials. While this innovation offers promising opportunities for the sector, the high binder and fine particle content of 3D printing mixes presents a substantial environmental challenge due to their considerable carbon footprint. To mitigate this impact, strategies often involve substituting portions of the binder or aggregate with waste materials. This article presents a comparative analysis of two promising approaches to reducing the carbon footprint of 3D printing concrete mixes by partially replacing cement with biochar and recycled fines. The study examines the effects of these materials on the rheological properties and early-age hydration processes of the 3D printing mix. A reference mix (REF) was established, followed by the development of eight additional mixes, with four incorporating biochar and four incorporating recycled fines, each replacing 1.25%, 2.5%, 5%, and 10% of the cement volume. The findings indicate that recycled fines have a neutral effect on the spread flow diameter of the mixture but increase initial deformations in printed elements. Conversely, biochar, due to its water absorption capacity, reduces fluidity, enhancing buildability by enabling faster printing with minimal initial deformation. Additionally, replacing up to 2.5 vol.% of cement with either material accelerates the normalized heat flow, contributing to a quicker gain in mechanical properties. However, biochar increases shrinkage deformations within the first 12 hours, while recycled fines mitigate them. Importantly, replacing up to 10 vol.% of cement with these materials does not significantly compromise early compressive strength.

Percutaneous kyphoplasty combined with pediculoplasty (PKCPP) augments and internally fixates the severe osteoporotic vertebral fractures: a retrospective comparative study.

Vertebral augmentation (VA) has emerged as a satisfactory and minimally invasive surgical approach for severe osteoporotic vertebral fractures (OVFs). However, treating severe OVFs with advanced collapse, burst morphology with MC injury, posterior wall retropulsion, high degree of osseous fragmentation, pediculo-somatic junction fracture, and large vacuum cleft presents significant challenges. This study aimed to evaluate the effectiveness of percutaneous kyphoplasty combined with pediculoplasty (PKCPP) in reducing refracture, preventing further collapse and bone cement displacement, reconstructing vertebral body (VB) stability, and providing internal fixation of the anterior column (AC), middle column (MC), and the bilateral pedicles. The current study was designed as a retrospective review of clinical and radiologic parameters. From July 2018 to September 2021, ninety-six patients with severe OVFs and without neurological deficit were treated either with simple percutaneous kyphoplasty (simple PKP group, n = 54) or with percutaneous kyphoplasty combined with pediculoplasty (PKCPP group, n = 42). All patients were followed up for at least 1year, and clinical and radiological outcomes were assessed. Surgery duration and bone cement volume were compared between the two groups, as well as analgesic dosage and hospital stay. Anterior wall height (AWH), posterior wall height (PWH), and Cobb angle (CA) were measured and analyzed before and after surgery. The simple PKP group had significantly shorter surgery duration and lower bone cement volume compared to the PKCPP group (P < 0.05). Conversely, the simple PKP group had significantly higher analgesic dosage and longer hospital stay than the PKCPP group (P < 0.05). Both groups showed significant improvements in AWH, PWH, and CA after surgery (P < 0.05). At the final follow-up, the PWH in the simple PKP group was significantly lower than the preoperative measurement (P < 0.05), and the difference in PWH between the two groups was statistically significant (P > 0.05). Moreover, both groups demonstrated a significant reduction in CA after surgery, with the PKCPP group showing a greater reduction compared to the simple PKP group throughout the postoperative period to the final follow-up (P < 0.05). VAS and ODI scores significantly decreased in both groups after surgery (P < 0.05), with no significant difference between the groups at the final follow-up (P > 0.05). However, the PKCPP group achieved better VAS scores than the simple PKP group at postoperative 1day, 1month, and 3months (P < 0.05), and the ODI in the PKCPP group was lower than the simple PKP group at 1month after surgery (P < 0.05). Furthermore, the overall complication rate in the PKCPP group was significantly lower than that in the simple PKP group (P < 0.05). If performed by appropriately trained surgeons, both PKP and PKCPP are safe and effective treatments for patients with severe OVFs. However, PKCPP offers additional benefits in the setting of bothersome fractures, including rapid pain relief, improved spinal stability, satisfactory restoration of vertebral body height, and better correction of kyphotic deformity. These promising results have been tested in a single center but require further confirmation in multiple centers.

Clinical effect analysis of vertebroplasty with high viscosity and standard bone cement for Kummell disease.

This study aims to observe and compare the effects of high-viscosity bone cement versus standard bone cement on the postoperative outcomes of percutaneous vertebroplasty (PVP) in patients with Kummell disease. A retrospective analysis was conducted on 135 patients with Kummell disease who underwent PVP between January 2019 and May 2023. Patients were divided into 2 groups: the high-viscosity group (group H, 63 cases) received high-viscosity bone cement during surgery, while the standard group (group S, 72 cases) received standard bone cement. Surgery duration, bone cement volume, bone cement leakage rate, as well as preoperative and postoperative evaluations using the Visual Analogue Scale (VAS) for pain, Oswestry Disability Index (ODI), anterior vertebral height, and kyphotic Cobb angle were recorded and compared between the 2 groups. In the group H, significant improvements were observed in VAS scores, ODI, anterior vertebral height, and Cobb angle at 24 hours, 3 months, and 1 year postoperatively compared to preoperative values (P < .01). In the group S, VAS scores and ODI showed significant improvement at 24 hours, 3 months, and 1 year postoperatively (P < .01), but there were no significant differences in anterior vertebral height or Cobb angle compared to preoperative values (P > .05). Comparatively, the group H demonstrated superior outcomes in terms of bone cement volume, leakage rate, recovery of anterior vertebral height, and Cobb angle correction at 24 hours, 3 months, and 1 year postoperatively (P < .05). However, there were no significant differences between the 2 groups in terms of surgery duration, VAS scores, and ODI at the same time points (P > .05). PVP is an effective treatment for Kummell disease, providing significant pain relief and improved spinal function. The use of high-viscosity bone cement allows for greater volume infusion, better restoration of vertebral height, and correction of deformities, while also reducing the risk of cement leakage.

Perfecting the pour: A novel co-axial technique with sequential injections for optimising cement delivery during sacroplasty.

Percutaneous sacroplasty is an effective treatment for painful sacral fractures and tumours, however there is no accepted optimal technique for performing this procedure. This study investigated a novel approach to sacroplasty combining co-axial sacral access, sequential cement injections and hypothermic cement manipulation to improve cement delivery. This retrospective study analysed 11 patients who underwent co-axial sacroplasty between April 2023 and March 2024 for treatment of painful insufficiency fractures (n = 5) or malignant sacral tumours (n = 6). All cases were performed using biplane fluoroscopy with conebeam CT navigation for planning and monitoring percutaneous access. Procedural details, technical outcomes, and clinical outcomes including Numerical Rating Scale (NRS) pain and analgesic utilisation on a six-point scale were analysed pre-procedure and at follow-up. Technical success of was achieved in all cases using this technique. The mean injected cement volume was 20.5 ± 6.4 ml. Median pre-procedural NRS pain scores of 8 (IQR 7.25-8) significantly decreased to 0 (IQR, 0-0.25) at follow-up (p <.01). The median preprocedural analgesic utilisation score reduced from 3 (IQR, 2-3) to 0 (IQR, 0-2.5) at follow-up (p <.01). Cement leakage occurred during two cases without associated adverse clinical sequelae. There were no major adverse events. Co-axial sequential injection sacroplasty is a safe and effective technique which allows facilitates controlled delivery of cement. Improved control of cement delivery, including around high-risk structures for cement leakage, offers a potential safety advantage over conventional sacroplasty techniques. Further research comparing technical and clinical outcomes to conventional techniques is warranted.

Eco-Efficient Mortars for Sustainable Construction: A Comprehensive Approach

Cement production is responsible for approximately 7% of global carbon dioxide emissions. Despite our efforts, we have not been able to find a competitive substitute that is both reliable and environmentally friendly. The easiest way to solve the issue is to rationalize resources and try to minimize their use by replacing them with other materials. The current market shortage and reduced initial strength have limited the availability of blends that contain a significant amount of fly ash. Given the current economic, political, and environmental circumstances, it is predicted that a solution may be ternary blends with cement, fly ash, and MTK. Despite being “ancient” materials, there have been no recent global performance assessments. In this context, an investigation was carried out with ternary blend mortars. A significant volume of cement has been replaced with fly ash and metakaolin. The results show that these blends’ performance is promising because they offer a wide range of possibilities for replacing cement, maintaining or even improving its properties. MTK and fly ash’s synergies significantly enhance mechanical performance and durability. Furthermore, the global sustainability analysis shows that ternary blends are 36% more efficient than binary blends of cement and fly ash or metakaolin.

Comparative analysis of percutaneous vertebroplasty and kyphoplasty in the treatment of Stage III Kummell’s disease without neurological symptoms: a retrospective study

ObjectiveThis study analyzes the safety and efficacy of percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) treatments for Stage III Kummell’s disease without neurological symptoms, comparing the advantages and disadvantages of these two minimally invasive surgical methods.MethodsA retrospective analysis was conducted on 53 patients with non-neurological Stage III Kummell’s disease treated with PVP and PKP at our hospital from December 2018 to January 2023. Patients were divided into PVP (25 cases) and PKP (28 cases) groups based on the surgical method. There were no significant differences in general preoperative data between the two groups (all p > 0.05), ensuring comparability. The study compared surgical duration, volume of bone cement injected, distribution pattern of bone cement, rate of bone cement leakage, and preoperative, postoperative, and final follow-up scores of Visual analogue scale(VAS) and Oswestry disability index(ODI). Additionally, relative anterior height of the injured vertebrae, and Cobb angle of deformity, along with their changes at preoperative, postoperative, and final follow-up stages were calculated and analyzed.ResultsNo significant preoperative differences were observed between the groups (p > 0.05). The PKP group had longer surgeries, higher cement volumes (p < 0.001), and lower leakage rates (p < 0.05), with primarily chunky cement distributions versus mixed distributions in the PVP group. No complications other than cement leakage occurred. VAS and ODI scores showed no significant changes at various time points (p > 0.05) but improved significantly from preoperative (p < 0.001). Both groups saw improved vertebral heights and Cobb angles post-surgery (p < 0.05), with more significant improvements in the PKP group (p < 0.05). Over time, both groups experienced gradual vertebral height loss and increased Cobb angles, more pronounced in the PKP group (p < 0.05). At the final follow-up, there were no statistical differences in vertebral height and Cobb angle between the two groups (p > 0.05).ConclusionThe study evaluates the safety and efficacy of PVP and PKP for Stage III Kummell’s disease without neurological symptoms, comparing the merits of both minimally invasive techniques.

Clinical significance of modified unilateral puncture percutaneous vertebroplasty guided by 3D- printed guides in the treatment of osteoporotic vertebral compression fractures: a retrospective study

ObjectiveTo investigate the clinical significance of using 3D printing guides in modified unilateral puncture percutaneous vertebroplasty (PVP) for the treatment of osteoporotic vertebral compression fractures (OVCF), and to explore a new method for preventing paravertebral vein leakage during PVP in conjunction with a previous study of the optimal puncture-side bone cement/vertebral volume ratio(PSBCV/VV%).MethodsThis retrospective study analyzed 99 patients who underwent unilateral puncture PVP between January 2023 and December 2023. Patients were divided into a guide plate group (46 patients) and a conventional group (53 patients). The guide plate group underwent modified unilateral puncture PVP with the guidance of 3D printing guides, while the conventional group underwent unilateral puncture PVP using the conventional pedicle approach. The distribution of bone cement, surgical outcomes, and the occurrence of cement leakage into paravertebral veins were observed in both groups.ResultsThe guide plate group had significantly shorter operating time and required fewer fluoroscopies compared to the conventional group. The amount of bone cement volume (BCV) used in the guide plate group was higher, but the amount of bone cement volume on the puncture side(PSBCV), the PSBCV/VV%, and the rate of paravertebral vein leakage were lower in the guide plate group compared to the conventional group (P < 0.05). Within each group, significant improvements in anterior vertebral margin height, Cobb angle, visual analog scale (VAS) score, and Oswestry Disability Index (ODI) were observed at 1 day and 1 month postoperatively compared to preoperative values (P < 0.05).ConclusionUsing 3D printing guides in modified unilateral puncture PVP is a safe and effective method for treating OVCF. And it has the advantages of short operation time, less fluoroscopy, even distribution of bone cement, and a low rate of paravertebral vein leakage.

Distributed fiber optic temperature and strain sensing in cementing and water injection: Insights to well integrity monitoring and multisensing optical fiber cable design

In this study, we installed two fiber optic cables with different designs into a new well, a soft-flat cable and a stainless-steel cable, for distributed fiber optic sensing in cementing and water injection. The two fiber cables were cemented behind casing and the soft-flat cable was used for temperature sensing in cementing as well as cement curing period. The high-speed Rayleigh scanning successfully visualized the cement front tracking from the combined effects of temperature and pressure changes by cement pumping. The temperature variations in cement curing reveled the cement volume and have the potential to identify defects in annular cement and formation damage caused by cementing. The water injection test for strain sensing was carried out with increasing injection rate from 100 L/min to 200 L/min. Strain profiles from the two fiber cables suggested that the strain responses reveal alternation of sand and silt, and reservoir heterogeneity. The water injection results showed that the measured strains of the two cables matched fairly well and the stainless-steel cable showed a high strain sensitivity responding to injection pressure (1 με/5 kPa). Comparison of strain measurement results of the two cables provided valuable insights for future strain fiber cable design. Strain sensing results also indicated a high capability to capture small pressure changes in the heterogeneous layers. Thus, our results demonstrate the high potential of using strain sensing for leak detection and well integrity monitoring in fluid injections, particularly for the long-term monitoring at CO2 storage site.

EFFECT OF SPINAL FUSION ON BIOMECHANICS OF FACET JOINTS: SYNCHRONIZED SPATIO-TEMPORAL AND MECHANICAL ANALYSIS

ObjectivesUnderstanding lumbar facet joint involvement and biomechanical changes post spinal fusion is limited. This study aimed to establish an in vitro model assessing mechanical effects of fusion on human lumbar facet joints, employing synchronized motion, pressure, and stiffness analysis.Methods and ResultsSeven human lumbar spinal units (age 54 to 92, ethics 15/YH/0096) underwent fusion via a partial nucleotomy model mimicking a lateral cage approach with PMMA cement injection. Mechanical testing pre and post-fusion included measuring compressive displacement and load, local motion capture, and pressure mapping at the facet joints. pQCT imaging (82 microns isotropic) was carried out at each stage to assess the integrity of the vertebral endplates and quantify the amount of cement injected.Before fusion, relative facet joint displacement (6.5 ± 4.1 mm) at maximum load (1.1 kN) exceeded crosshead displacement (3.9 ± 1.5 mm), with loads transferred across both facet joints. After fusion, facet displacement (2.0 ± 1.2 mm) reduced compared to pre-fusion, as was the crosshead displacement (2.2 ± 0.6 mm). Post-fusion loads (71.4 ± 73.2 N) transferred were reduced compared to pre-fusion levels (194.5 ± 125.4 N). Analysis of CT images showed no endplate damage post-fusion, whilst the IVD tissue: cement volume ratio did not correlate with the post-fusion behaviour of the specimens.ConclusionAn in vitro model showed significant facet movement reduction with stand-alone interbody cage placement. This technique identifies changes in facet movement post-fusion, potentially contributing to subsequent spinal degeneration, highlighting its utility in biomechanical assessment.Conflicts of interestNoneSources of fundingThis work was funded by EPSRC, under grant EP/W015617/1.