A novel classification of cement distribution patterns based on plain radiographs associated with cement filling rate and relevance to the clinical results of unipedicle vertebroplasty.

INTRODUCTION: Cement distribution pattern following unipedicle percutaneous vertebroplasty (UVP) for osteoporotic vertebral compression fractures (OVCFs) has been reported in association with clinical results. The present retrospective study aimed to classify the bone cement distribution types following UVP and investigate the differences in clinical efficacy and related complications. MATERIALS AND METHODS: We retrospectively reviewed the medical records of the patients with single-segment OVCFs who underwent UVP. Cement distribution patterns were divided into the diffuse, block, double band, and single band types according to the plain radiographs and further by cement filling rate (CFR) based on a three-dimension reconstruction of post-operative CT. The cutoff values of CFR were > 34% for the diffuse, block between 34 and 20%, and each band of the double or single band < 20%. Clinical efficacy and related complications were compared among the four cement distribution types 24 h after the operation and the last follow-up. RESULTS: A total of 155 patients with an average follow-up time of 20.3 months were included. The diffuse type included 26 patients; block, 87; double band, 18; and single band, 24. The VAS and ODI after operation improved significantly in all four groups. The diffuse and block types had similar clinical results. The clinical outcomes in the single band group were the poorest at the last follow-up. The patients with single band type also had the highest rates of body re-collapse and revision surgery for the index level. CONCLUSION: Diffuse and block groups can better maintain the height of the vertebral body and reduce the risk of vertebral body recompression. The single band has the poorest results, and intraoperative immediate contralateral vertebroplasty was highly recommended.

Effect of different cement distribution in bilateral and unilateral Percutaneous vertebro plasty on the clinical efficacy of vertebral compression fractures.

BACKGROUND: The ramifications of osteoporotic fractures and their subsequent complications are becoming progressively detrimental for the elderly population. This study evaluates the clinical ramifications of postoperative bone cement distribution in patients with osteoporotic vertebral compression fractures (OVCF) who underwent both bilateral and unilateral Percutaneous Vertebroplasty (PVP). OBJECTIVE: The research aims to discern the influence of bone cement distribution on the clinical outcomes of both bilateral and unilateral Percutaneous Vertebroplasty. The overarching intention is to foster efficacious preventive and therapeutic strategies to mitigate postoperative vertebral fractures and thereby enhance surgical outcomes. METHODS: A comprehensive evaluation was undertaken on 139 patients who received either bilateral or unilateral PVP in our institution between January 2018 and March 2022. These patients were systematically classified into three distinct groups: unilateral PVP (n = 87), bilateral PVP with a connected modality (n = 29), and bilateral PVP with a disconnected modality (n = 23). Several operational metrics were juxtaposed across these cohorts, encapsulating operative duration, aggregate hospital expenses, bone cement administration metrics, VAS (Visual Analogue Scale) scores, ODI (Oswestry Disability Index) scores relative to lumbar discomfort, postoperative vertebral height restitution rates, and the status of the traumatized and adjacent vertebral bodies. Preliminary findings indicated that the VAS scores for the January and December cohorts were considerably reduced compared to the unilateral PVP group (P = 0.015, 0.032). Furthermore, the recurrence of fractures in the affected and adjacent vertebral structures was more pronounced in the unilateral PVP cohort compared to the bilateral PVP cohorts. The duration of the procedure (P = 0.000) and the overall hospitalization expenses for the unilateral PVP group were markedly lesser than for both the connected and disconnected bilateral PVP groups, a difference that was statistically significant (P = 0.015, P = 0.024, respectively). Nevertheless, other parameters, such as the volume of cement infused, incidence of cement spillage, ODI scores for lumbar discomfort, post-surgical vertebral height restitution rate, localized vertebral kyphosis, and the alignment of cement and endplate, did not exhibit significant statistical deviations (P > 0.05). CONCLUSION: In juxtaposition with unilateral PVP, the employment of bilateral PVP exhibits enhanced long-term prognostic outcomes for patients afflicted with vertebral compression fractures. Notably, bilateral PVP significantly curtails the prevalence of subsequent vertebral injuries. Conversely, the unilateral PVP cohort is distinguished by its abbreviated operational duration, minimal invasiveness, and reduced overall hospitalization expenditures, conferring it with substantial clinical applicability and merit.

TiRobot-assisted percutaneous kyphoplasty in the management of multilevel (more than three levels) osteoporotic vertebral compression fracture.

PURPOSE: To compare the effectiveness of TiRobot-assisted kyphoplasty with that of the traditional fluoroscopy-assisted approach in treating multilevel osteoporotic vertebral compression fractures. METHODS: In this retrospective study, we collected data from 71 patients (TiRobot-assisted group, n = 39; fluoroscopy-assisted group, n = 32) with multilevel osteoporotic vertebral compression fracture treated with unilateral traditional TiRobot-assisted or fluoroscopy-assisted percutaneous kyphoplasty. The operative time, infusion volume, length of stay (LOS), hospital expenses, visual analog scale (VAS), Oswestry Disability Index (ODI), radiation exposure, puncture deviation, anterior height of diseased vertebrae, local kyphotic angle, bone cement distribution, and bone cement leakage were compared between the TiRobot- and fluoroscopy-assisted groups. RESULTS: Of the 257 treated vertebrae, the average amount of bone cement injected in the TiRobot-assisted (142 vertebrae) and fluoroscopy-assisted (115 vertebrae) groups was 4.6 mL and 4.5 mL, respectively. The VAS score was significantly lower in the TiRobot-assisted group at 24 hours post-operatively (p = 0.006). The X-ray frequency was 34.7 times in the TiRobot-assisted group and 51.7 times in the fluoroscopy-assisted group (p < 0.001). In addition to the operative time, cumulative radiation dose for the surgeon and patient was significantly lower in the TiRobot-assisted group. The hospital expenses of the TiRobot-assisted group were significantly higher (p < 0.001). The puncture deviation and bone cement distribution were better in the TiRobot-assisted group (p < 0.001). Bone cement leakage was found in 18 and 29 cases in the TiRobot- and fluoroscopy-assisted groups, respectively (p = 0.010). One patient in the fluoroscopy-assisted group experienced radiculopathy due to a misplaced puncture but recovered in three months. No radiculopathy was observed in the TiRobot-assisted group. CONCLUSIONS: TiRobot-assisted percutaneous multilevel kyphoplasty is more accurate and has smaller radiometry, a more uniform bone cement distribution, and lower bone cement leakage. This method was therefore accurate and safe.

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.

The effect of bone cement distribution on the outcome of percutaneous Vertebroplasty: a case cohort study.

BACKGROUND: To analyze the effect of different types of bone cement distribution after percutaneous vertebroplasty (PVP) in patients with osteoporotic vertebral compression fracture (OVCF). METHODS: One hundred thirty seven patients with single level OVCF who underwent PVP were retrospectively analyzed. The patients were divided into two groups according to bone cement distribution. Group A: bone cement contacted both upper and lower endplates; Group B: bone cement missed at least one endplate. Group B was divided into 3 subgroups. Group B1: bone cement only contacted the upper endplates; Group B2: bone cement only contacted the lower endplates; Group B3: bone cement only located in the middle of vertebral body. The visual analogue scale (VAS) score at 24 h post operation and last follow-up, anterior vertebral height restoration ratio (AVHRR), anterior vertebral height loss ratio (AVHLR), local kyphotic angle change and vertebral body recompression rate were compared. RESULTS: 24 h post operation, the pain of all groups were significantly improved. The average follow-up time was 15.3 ± 6.3 (6-24) months. At last follow-up, the VAS score of group A was lower than that of group B. There were 14 cases (10.2%) of adjacent vertebral fracture, 5 cases (8.6%) in group A and 9 cases (11.4%) in group B. There were 9 cases (6.6%) of cement leakage, 4 cases (6.9%) in group A and 5 cases (6.3%) in group B. At last follow-up, there were 16 cases (11.7%) of vertebral body recompression, including 3 cases (5.2%) in group A and 13 cases (16.5%) in group B. There was no significant difference in AVHRR between two groups. Local kyphotic angle change was significant larger in group B. At last follow-up, AVHLR in group B was higher than that in group A. Analysis in subgroup B revealed no significant difference in VAS score, local kyphotic angle change, vertebral recompression rate, AVHRR or AVHLR. CONCLUSIONS: If the bone cement fully contacted both the upper and lower endplates, it can better restore the strength of the vertebral body and maintain the height of the vertebral body, reduce the risk of the vertebral body recompression and long-term pain.

Biomechanical study of different bone cement distribution on osteoporotic vertebral compression Fracture-A finite element analysis.

Purpose: This study aimed to compare the biomechanical effects of different bone cement distribution methods on osteoporotic vertebral compression fractures (OVCF). Patients and methods: Raw CT data from a healthy male volunteer was used to create a finite element model of the T12-L2 vertebra using finite element software. A compression fracture was simulated in the L1 vertebra, and two forms of bone cement dispersion (integration group, IG, and separation group, SG) were also simulated. Six types of loading (flexion, extension, left/right bending, and left/right rotation) were applied to the models, and the stress distribution in the vertebra and intervertebral discs was observed. Additionally, the maximum displacement of the L1 vertebra was evaluated. Results: Bone cement injection significantly reduced stress following L1 vertebral fractures. In the L1 vertebral body, the maximum stress of SG was lower than that of IG during flexion, left/right bending, and left/right rotation. In the T12 vertebral body, compared with IG, the maximum stress of SG decreased during flexion and right rotation. In the L2 vertebral body, the maximum stress of SG was the lowest under all loading conditions. In the T12-L1 intervertebral disc, compared with IG, the maximum stress of SG decreased during flexion, extension, and left/right bending and was basically the same during left/right rotation. However, in the L1-L2 intervertebral discs, the maximum stress of SG increased during left/right rotation compared with that of IG. Furthermore, the maximum displacement of SG was smaller than that of IG in the L1 vertebral bodies under all loading conditions. Conclusions: SG can reduce the maximum stress in the vertebra and intervertebral discs, offering better biomechanical performance and improved stability than IG.

Comparison of the Clinical Efficacy and Bone Cement Distribution Difference Between Kummell's Disease and Osteoporotic Vertebral Compression Fracture After Percutaneous Kyphoplasty.

BACKGROUND: Kummell's disease (KD) and osteoporotic vertebral compression fracture (OVCF) are commonly found in patients with osteoporosis. Several studies have been conducted on bone cement distribution in OVCF or KD; a comparison between the 2 diseases is rarely reported. OBJECTIVES: To compare the clinical efficacy and bone cement distribution difference between KD and OVCFs after percutaneous kyphoplasty (PKP). STUDY DESIGN: This was a retrospective, nonrandomized controlled study. SETTING: Department of Orthopedics from an affiliated hospital. METHODS: From January 2018 to December 2020, 61 patients who underwent PKP surgery for single KD or OVCF and met the inclusion criteria were retrospectively reviewed. All patients were assigned to 2 groups: the KD group and the OVCF group. Clinical and radiologic characteristics, including the bone cement volume, leakage, bone cement dispersion scale, anterior vertebral height (AVH), median vertebral height (MVH), posterior vertebral height (PVH), Cobb angle and Visual Analog Scale (VAS) were analyzed and compared using Mimics three-dimensional (3D) reconstruction images and 3D reconstruction computed tomography, preoperatively, postoperatively, and 2 years after the operation, respectively. The correlations between the bone cement dispersion scale and the VH improvement rate (VHIR), VH change rate (VHCR), VAS improvement rate (VASIR), and follow-up VAS improvement rate (f-VASIR) were also evaluated. RESULTS: The mean follow-up time was 24.0 months. Postoperative VH, Cobb angle, vertebra volume, and VAS score were significantly improved in the 2 groups (P < 0.05). There was no statistical difference in postoperative parameters between the 2 groups. While a strong positive correlation between VHIR and bone cement dispersion scale was observed in the OVCF group (P < 0.01), no significant correlation between VHIR and bone cement dispersion scale was found in the KD group. There was no correlation between VASIR and bone cement dispersion scale in both groups. Compared with postoperation, VH was lower in both groups in later follow-up, and the difference between the 2 groups was statistically significant (P < 0.05). VH, VAS, f-VASIR, and VHCR had a worse manifestation in the KD group than in the OVCF group. However, no significant correlation was found between VHCR, f-VASIR, and bone cement dispersion scale in the 2 groups. LIMITATIONS: This study was limited by the non-randomized design, small sample size, and lack of a comprehensive follow-up period. CONCLUSIONS: Although there was no significant difference in the bone cement distribution and early clinical efficacy between KD and OVCF patients under the same surgical plan and surgeon, OVCF patients exhibited better long-term radiologic and clinical outcomes.

Biomechanical Study of Porcine Osteoporotic Vertebral Compression Fracture Model Strengthened by Trajectory-Adjustable Bone Cement Filling Device.

OBJECTIVE: To establish a porcine osteoporotic vertebral compression fracture model and compare the impact of unilateral vertebroplasty using trajectory-adjustable bone cement filling device to traditional surgical tools on vertebral biomechanics. METHODS: Twenty-four fresh adult porcine vertebrae were used to establish an osteoporotic vertebral compression fracture model. The specimens were divided into 4 groups (A, B, C, and D), each consisting of 6 vertebrae. Group A served as the control group without vertebral augmentation (percutaneous vertebroplasty [PVP]). Patients in Group B underwent unilateral PVP using conventional surgical tools, while patients in Group C underwent bilateral PVP using the same tools. In Group D, patients underwent unilateral PVP with a trajectory-adjustable bone cement filling device. Postoperative X-ray examinations were performed to assess cement distribution and leakage. The compressive stiffness and strength of each spinal unit were evaluated using an electronic mechanical testing machine. RESULTS: In Groups B, C, and D, the percentages of total cement distribution area were 32.83 ± 3.64%, 45.73 ± 2.27%, and 47.43 ± 3.51%, respectively. The values were significantly greater in Groups C and D than in Group B (P < 0.05), but there was no significant difference between Groups C and D (P > 0.05). The stiffness after vertebral augmentation in Groups B, C, and D was 1.04 ± 0.23 kN/mm, 1.11 ± 0.16 KN/mm, and 1.15 ± 0.13 KN/mm, respectively, which were significantly greater than that in Group A (0.46 ± 0.06 kN/mm; P < 0.05). The ultimate compressive strengths in Groups B, C, and D were 2.53 ± 0.21 MPa, 4.09 ± 0.30 MPa, and 3.99 ± 0.29 MPa, respectively, all surpassing Group A's strength of 1.41 ± 0.31 MPa. Additionally, both Groups C and D demonstrated significantly greater ultimate compressive strengths than Group B did (P < 0.05). CONCLUSIONS: A trajectory-adjustable bone cement filling device was proven to be an effective approach for unilateral vertebroplasty, restoring the biomechanical properties of fractured vertebrae. Compared to traditional surgical tools, this approach is superior to unilateral puncture and yields outcomes comparable to those of bilateral puncture. Additionally, the device ensures a centrally symmetrical distribution pattern of bone cement, leading to improved morphology.

Static study and numerical simulation of the influence of cement distribution in the upper and lower adjacent vertebrae on sandwich vertebrae in osteoporotic patients: Finite element analysis.

Objective: We analyzed the influence of the location of the upper and lower cement on the sandwich vertebrae (SV) by computer finite element analysis. Materials and Methods: A finite element model of the spinal segment of T11-L1 was constructed and 6 mL of cement was built into T11 and L1 simultaneously. According to the various distributions of bone cement at T11 and L1, the following four groups were formed: (i) Group B-B: bilateral bone cement reinforcement in both T11 and L1 vertebral bodies; (ii) Group L-B: left unilateral reinforcement in T11 and bilateral reinforcement in L1; (iii) Group L-R: unilateral cement reinforcement in both T11 and L1 (cross); (iv) Group L-L: unilateral cement reinforcement in both T11 and L1 (ipsilateral side). The maximum von Mises stress (VMS) and maximum displacement of the SV and intervertebral discs were compared and analyzed. Results: The maximum VMS of T12 was in the order of size: group B-B < L-B < L-R < L-L. Group B-B showed the lowest maximum VMS values for T12: 19.13, 18.86, 25.17, 25.01, 19.24, and 20.08 MPa in six directions of load flexion, extension, left and right lateral bending, and left and right rotation, respectively, while group L-L was the largest VMS in each group, with the maximum VMS in six directions of 21.55, 21.54, 30.17, 28.33, 19.88, and 25.27 MPa, respectively. Conclusion: Compared with the uneven distribution of bone cement in the upper and lower adjacent vertebrae (ULAV), the uniform distribution of bone cement in the ULAV reduced and uniformed the stress load on the SV and intervertebral disc. Theoretically, it can lead to the lowest incidence of sandwich vertebral fracture and the slowest rate of intervertebral disc degeneration.

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.

Analysis of optimal volume fraction percentage and influencing factors of bone cement distribution in vertebroplasty using digital techniques.

PURPOSE: To explore the optimal volume fraction percentage (VF%) and influencing factors of bone cement distribution in percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCF) using digital techniques. PATIENTS AND METHODS: From January 2019 to February 2021, 150 patients with 0VCF who underwent PVP surgery in our hospital were analyzed. Based on postoperative X-ray and CT, the spatial distribution score of the intravertebral cement was calculated and the patients were divided into two groups: 0-7 were divided into group A; 8-10 were divided into group B. The general data of the two groups of patients were compared, and Mimics three-dimensional reconstruction images were used to measure the cement dispersion volume (CDV), vertebral body volume (VBV), and VF%. Factors affecting bone cement distribution were included in a multifactorial logistic regression analysis to construct a receiver operating characteristic (ROC) curve, calculate a cut-off value for the extensive distribution of bone cement, and analyze the correlation between bone cement distribution scores and VF%. RESULTS: There were 60 patients in group A and 90 patients in group B. Univariate analysis showed that bone mineral density (BMD), cement leakage, CDV, and VF% were significantly lower in group A than in group B (p < 0.05). Multivariate logistic regression analysis showed that BMD and VF% were independent influencing factors on bone cement distribution. The area under the curve (AUC) of VF% was 84.7%, and the cut-off value for extensive distribution of bone cement was 28.58%, which corresponded to a sensitivity and specificity of 72.2% and 91.7%, respectively. There was a strong correlation between the cement distribution score and VF% (r = 0.895, p < 0.001). CONCLUSION: BMD and VF% were important independent influencing factors of bone cement distribution. Extensive bone cement distribution can be achieved when the VF% reaches 28.58%.

[Effects of different puncture levels in bilateral percutaneous vertebroplasty on distribution of bone cement and effectiveness of osteoporotic thoracolumbar compression fractures].

Objective: To investigate the effects of different puncture levels on bone cement distribution and effectiveness in bilateral percutaneous vertebroplasty for osteoporotic thoracolumbar compression fractures. Methods: A clinical data of 274 patients with osteoporotic thoracolumbar compression fractures who met the selection criteria between December 2017 and December 2020 was retrospectively analyzed. All patients underwent bilateral percutaneous vertebroplasty. During operation, the final position of the puncture needle tip reached was observed by C-arm X-ray machine. And 118 cases of bilateral puncture needle tips were at the same level (group A); 156 cases of bilateral puncture needle tips were at different levels (group B), of which 87 cases were at the upper 1/3 layer and the lower 1/3 layer respectively (group B1), and 69 cases were at the adjacent levels (group B2). There was no significant difference in gender, age, fracture segment, degree of osteoporosis, disease duration, and preoperative visual analogue scale (VAS) score, and Oswestry disability index (ODI) between groups A and B and among groups A, B1, and B2 ( P>0.05). The operation time, bone cement injection volume, postoperative VAS score, ODI, and bone cement distribution were compared among the groups. Results: All operations were successfully completed without pulmonary embolism, needle tract infection, or nerve compression caused by bone cement leakage. There was no significant difference in operation time and bone cement injection volume between groups A and B or among groups A, B1, and B2 ( P>0.05). All patients were followed up 3-32 months, with an average of 7.8 months. There was no significant difference in follow-up time between groups A and B and among groups A, B1, and B2 ( P>0.05). At 3 days after operation and last follow-up, VAS score and ODI were significantly lower in group B than in group A ( P<0.05), in groups B1 and B2 than in group A ( P<0.05), and in group B1 than in group B2 ( P<0.05). Imaging review showed that the distribution of bone cement in the coronal midline of injured vertebrae was significantly better in group B than in group A ( P<0.05), in groups B1 and B2 than in group A ( P<0.05), and in group B1 than in group B2 ( P<0.05). In group A, 7 cases had postoperative vertebral collapse and 8 cases had other vertebral fractures. In group B, only 1 case had postoperative vertebral collapse during follow-up. Conclusion: Bilateral percutaneous vertebroplasty in the treatment of osteoporotic thoracolumbar compression fractures can obtain good bone cement distribution and effectiveness when the puncture needle tips locate at different levels during operation. When the puncture needle tips locate at the upper 1/3 layer and the lower 1/3 layer of the vertebral body, respectively, the puncture sites are closer to the upper and lower endplates, and the injected bone cement is easier to connect with the upper and lower endplates.

Clinical outcomes with second injection after insufficient bone cement distribution in unilateral kyphoplasty for osteoporotic vertebral compressive fracture: a cohort retrospective study.

BACKGROUND: Bone cement distribution is an important factor affecting pain relief and long-term prognosis of osteoporotic vertebral compression fracture (OVCF) treated with vertebral augmentation. Unilateral percutaneous kyphoplasty (PKP) is the most common procedure, and insufficient bone cement distribution is more common than bilateral PKP. However, effective remedies are remain lack. In this study, sufficient cement distribution was achieved by adjusting the working channel followed by second cement injection as a remedy in cases with insufficient cement distribution, and the purpose was to evaluate the clinical outcomes by a retrospective cohort study. METHODS: From July 1, 2017 to July 31, 2020, OVCF patients treated with unilateral PKP were included in this retrospective cohort study. According to the bone cement distribution (insufficient cement distribution was confirmed when the cement did not exceed the mid line of the vertebral body in frontal film or/and the cement did not contact the upper/lower vertebral endplates in the lateral film.) and whether second injection was performed during surgery, the patients were divided into three groups. Insufficient group: patients with insufficient cement distribution confirmed by fluoroscopy or postoperative x-ray. Second injection group: patients with insufficient cement distribution was found during the procedure, and second injection was performed to improve the cement distribution. CONTROL GROUP: patients with sufficient cement distribution in one injection. The Primary outcome was cemented vertebrae re-collapse rate. The secondary outcomes included operative time, radiation exposure, cement leakage rate, VAS, ODI, and adjacent vertebral fracture rate. RESULTS: There are 34 cases in insufficient group, 45 cases in second injection group, and 241 cases in control group. There was no significant difference in baseline data and follow-up time among the three groups. PRIMARY OUTCOME: The injured vertebrae re-collapse rate of insufficient group was significantly higher than that of second injection group (42.22% vs 20.59%, P = 0.000) and control group (42.22% vs. 18.26%, P = 0.000). Kaplan-Meier survival analysis showed that there was no significant difference in the survival time between second injection group and control group (P = 0.741, Log-rank test), both of which were significant less than that in insufficient group (P = 0.032 and 0.000, respectively). SECONDARY OUTCOMES: There was no significant difference in VAS score and ODI after operation between second injection group and control group, both of which were superior to those in insufficient group (P = 0.000). At the final follow-up, there was no significant difference in VAS and ODI among the three groups (P > 0.05). The operation time of second injection group was significantly higher than that of insufficient group (53.41 ± 8.85 vs 44.18 ± 7.41, P = 0.000) and control group (53.41 ± 8.85 vs 44.28 ± 7.22, P = 0.000). The radiation exposure of the second injection group was significantly higher than that of insufficient group (40.09 ± 8.39 vs 30.38 ± 6.87, P = 0.000) and control group (40.09 ± 8.39 vs 31.31 ± 6.49, P = 0.000). The cement leakage rate of second injection group (20.59%) was comparable with that of insufficient group (24.44%) and control group (21.26%) (P = 0.877). The length of hospital stay of the second injection group (4.38 ± 1.72) was comparable with that of insufficient group (4.18 ± 1.60) and control group (4.52 ± 1.46) (P = 0.431). CONCLUSIONS: When cement distribution is insufficient during unilateral PKP, second injection may relieve early pain, reduce the incidence of cemented vertebral re-collapse and adjacent vertebral fracture, without increasing the cement leakage rate, although this procedure may increase the operation time and radiation exposure.

Optimizing percutaneous vertebroplasty: extra-facet puncture for osteoporotic vertebral compression fractures.

PURPOSE: To assess the safety and efficacy of the extra-facet puncture technique applied in unilateral percutaneous vertebroplasty (PVP) for treating osteoporotic vertebral compression fractures. METHODS: Demographics (age, gender, body mass index and underlying diseases) were recorded for analyzing. Visual analog scale (VAS) and Oswestry Disability Index (ODI) scores as well as their corresponding minimal clinically important difference (MCID) were used to evaluate clinical outcomes. The segmental kyphotic angle, the vertebral compression ratio and bone cement distribution pattern were evaluated by the plain radiographs. The facet joint violation (FJV) was defined by the postoperative computed tomography scan. Binary logistic regression analysis was performed to investigate relationships between multiple risk factors and residual back pain. RESULTS: VAS and ODI scores in both traditional puncture group and extra-facet puncture group were significantly decreased after PVP surgery (p < 0.05). However, no significant difference was observed between the two groups according to VAS and ODI scores. The proportion of patients achieving MCID of VAS and ODI scores was higher in extra-facet puncture group as compared to traditional puncture group within a month (p < 0.05). Finally, multivariate logistic regression analysis showed that FJV (odds ratio 16.38, p < 0.001) and unilateral bone cement distribution (OR 5.576, p = 0.020) were significant predictors of residual back pain after PVP surgery. CONCLUSIONS: Extra-facet puncture percutaneous vertebroplasty can decrease the risk of FJV and it also has the advantage of more satisfied bone cement distribution.

Comparison of Unilateral and Bilateral Percutaneous Kyphoplasty for Bone Cement Distribution and Clinical Efficacy: An Analysis Using Three-Dimensional Computed Tomography Images.

BACKGROUND: Percutaneous kyphoplasty (PKP) is an effective treatment for osteoporotic vertebral compression fractures (OVCF). Comparisons of different approaches have previously focused primarily on x-rays. Three-dimensional (3D) computed tomography (CT) enables better imaging evaluation of bone cement distribution. OBJECTIVES: To compare the CT imaging parameters and clinical efficacies of unilateral and bilateral PKP. STUDY DESIGN: This was a prospective, nonrandomized controlled study. SETTING: Department of Orthopedics from an affiliated hospital. METHODS: Seventy-two single-level OVCF patients who underwent 3D CT between 2018 and 2020 were evaluated prospectively. All patients underwent PKP and were assigned to 2 groups: unilateral PKP and bilateral PKP. Imaging outcomes were assessed by determining the cement volume, leakage, dispersion index, vertebral height (VH) and the cement volume of the noninjected and injected sides. Clinical outcomes were evaluated using the Visual Analog Scale (VAS). The correlations between the bone cement volume or dispersion index and the VAS, VH improvement rate (VHIR), or bone cement leakage were also evaluated. RESULTS: The mean follow-up time was 17.1 months. The postoperative VH and VAS in both groups were significantly improved (P < 0.05). However, there were no statistically significant differences in the cement volume, leakage or dispersion index, VH, or VAS between the 2 groups. No statistically significant differences in the cement volume or VH were found between the noninjected and injected sides within the unilateral group. The operative time was significantly shorter in the patients who underwent unilateral PKP. Unilateral PKP in which the bone cement did not cross the midline had a higher VAS compared with bilateral PKP. Both the bone cement volume and dispersion index displayed a positive correlation with the VHIR, but no correlation with the VAS or bone cement leakage. LIMITATIONS: This study was limited by the nonrandomized design, small sample size, and short follow-up period. CONCLUSIONS: While unilateral PKP was as effective as bilateral PKP, it had a shorter operation time. However, the bilateral PKP approach might be followed when bone cement is distributed in only one side following the unilateral PKP procedure.

[Effect of bone cement distribution on the clinical outcome of unilateral transpedicular puncture for spinal osteoporotic fractures].

OBJECTIVE: To investigate the effects of different bone cement morphology distribution on the clinical efficacy of unilateral percutaneous vertebroplasty(PVP) for spinal osteoporotic fractures. METHODS: The clinical data of 66 patients with osteoporotic vertebral compression fractures received unilateral PVP treatment from January 2019 to April 2020 were retrospectively analyzed. There were 16 males and 50 females, including 83 vertebral bodies, 45 thoracic vertebrae and 38 lumbar vertebrae, and 55 patients with single-segment, 6 double-segment, 4 three-segment and 1 four-segment. The age ranged from 60 to 93 years with an average of (76.83±8.65) years. The included patients were admitted to hospital 1 to 10 days after onset, and were diagnosed by anteroposterior and lateral X-rays, MRI and bone density examination before surgery. According to the shape of bone cement in postoperative X-ray, the patients were divided into O-shaped group (28 cases) and H-shaped group (38 cases). In O-shaped group, the bone cement presented agglomeration mass distribution in the affected vertebra in postoperative X-ray while the bone cement presented disseminated honeycomb distribution in the affected vertebrae in H-shaped group. Bone cement injection volume was collected in two groups. The intraoperative bone cement leakage and postoperative adjacent vertebral fractures were observed. The VAS of the two groups before operation and 1 day, 1 month, 6 months and 1 year after operation were compared;and ODI of the two groups 1 day, 6 months and 1 year after operation were compared. The kyphosis angle and anterior height of the affected vertebrae were measured before operation and 1 week, 1 year after operation. RESULTS: All 66 patients completed 1-year follow-up, and all patients healed well at the puncture site after surgery. There were 1 case and 8 cases of bone cement leakage in O-shaped group and H-shaped group during surgery respectively (P<0.05), but no serious complications occurred. One case occurred adjacent vertebral fracture in both groups during one-year follow-up (P>0.05). There was no statistical significance in injection amount of bone cement between the two groups (P>0.05). The VAS scores of O-shaped group and H-shaped group were 7.89±0.79, 2.75±1.08, 0.46±0.58, 0.36±0.49 and 8.00±1.04, 2.58±1.15, 0.53±0.56, 0.42±0.50 before operation, 1 day, 6 months, 1 year after operation respectively, and there was no statistical significance(P>0.05), and the VAS scores were 0.96±0.58 and 1.18±0.83 at 1 month after operation respectively, with statistical significance(P<0.05). The ODI scores of O-shaped group and H-shaped group were 12.43±3.78, 10.00±2.46, 8.43±1.50 and 12.11±3.68, 9.53±2.35, 8.32±1.51 at 1 day, 6 months and 1 year after surgery respectively, and there was no statistical significance between the two groups(P>0.05). There were no statistical significance in kyphotic angles and anterior height before surgery and 1 week, 1 year after surgery between two groups (P>0.05). CONCLUSION: No matter the distribution of bone cement is O-shape or H-shape, it can achieve good clinical effect, and the prognosis effect is equivalent. Therefore, when performing unilateral puncture PVP surgery, it is not necessary to deliberately increase the puncture angle of the puncture needle in order to achieve the full diffusion of the affected vertebrae, so as to reduce the risk of damaging important structures and bone cement leakage.

Effect of cement distribution type on clinical outcome after percutaneous vertebroplasty for osteoporotic vertebral compression fractures in the aging population.

Objective: The study aimed to investigate the effect of the type of bone cement distribution on clinical outcomes following percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCF) in the elderly. Methods: Retrospective analysis of 160 patients diagnosed with OVCF who underwent PVP treatment from March 2018 to December 2020. Based on the kind of postoperative bone cement distribution, bone cement was classified as types I, II, III, IV, and V. Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Cobb angle, anterior vertebral height ratio, refracture rate of injured vertebrae, and incidence of adjacent vertebral fractures were compared for the five types before and after three days, and one year of operation. Results: VAS and ODI at three days and one year postoperative were significantly lower than those preoperative (P < 0.05) for all five distribution types. VAS and ODI for types I, II, and III were lower at one year postoperatively than for types IV and V (P < 0.05). There was no significant difference in Cobb angle and anterior vertebral body height ratio between preoperative and three days postoperative groups (P < 0.05); however, there were significant differences between three days and one-year postoperative and preoperative groups (P < 0.05). Following one year of surgery, the Cobb angle and the anterior vertebral height ratio of types IV and V were significantly different from those of types I, II, and III (P < 0.05), and there was a statistically significant difference between types IV and V (P < 0.05). In terms of the incidence of injured vertebral refractures and adjacent vertebral fractures, the evenly distributed types I, II, and III were significantly lower than the unevenly distributed types IV and V, and the incidence of type V was higher (P < 0.05). Conclusions: The clinical efficacy of cement distribution following PVP of types I, II, and III is better than that of types IV and V, which can better relieve pain with long-lasting efficacy and minimize the occurrence of refractures of injured vertebrae and adjacent vertebral body fractures.

Clinical Outcomes of Fracture Haemorrhage Aspiration for Percutaneous Vertebroplasty in Treating Osteoporotic Vertebral Compression Fractures.

BACKGROUND: A retrospective study aimed to introduce a new method for improving the diffusion degree of bone cement and to observe its clinical efficacy in percutaneous vertebroplasty treating osteoporotic vertebral compression fractures (OVCFs). METHODS: From January 2019 to March 2020, a total of 83 patients were enrolled and reviewed. The patients were divided into two groups according to the operation method. The clinical and radiographic parameters were recorded and compared between these two groups. Those who received percutaneous vertebroplasty with haemorrhage aspiration were recorded as group A (n=42). In group A, the haemorrhage in the vertebral fracture was aspirated compared with conventional percutaneous vertebroplasty. Patients who underwent conventional percutaneous vertebroplasty were classified as group B (n=41). RESULTS: Visual analogue scale (VAS) values and Oswestry Disability Index (ODI) scores showed no significant difference between the two groups preoperatively, postoperatively or at the final follow-up (FU) (P>0.05). The intraoperative VAS score (bone cement injection) in group A was significantly lower than that in group B (3.83±0.79 vs 5.44±1.32, P < 0.01). The local kyphotic angle (LKA) (final follow-up), LKA loss, fractured vertebral anterior height loss (FVAHL) and anterior vertebral height loss ratio (AVHLR) were significantly lower in group A than in group B. The anterior vertebral height ratio (AVHR) at the final FU in group A was higher than that in group B (P=0.013). The distribution of bone cement was significantly different (P=0.034). By analysing the distribution pattern of bone cement, it was found that the values of LKA loss, FVAHL and AVHLR were superior in the type A bone cement distribution to those in types B and C. CONCLUSION: Compared with traditional surgical methods, bone haemorrhage aspiration could improve the diffusion degree of bone cement and reduce the height loss and deformity of injured vertebrae. This method provides a feasible new scheme for improving the dispersion of bone cement.

[Therapeutic effect and imaging study of directional bone cement guide for the treatment of thoracolumbar vertebral compression fractures].

OBJECTIVE: To evaluate the therapeutic effects and bone cement distribution of unilateral percutaneous kyphoplasty (PKP) with oriented bone cement injector for thoracolumbar osteoporotic vertebral compression fractures (OVCFs). METHODS: The clinical data of 211 patients (211 vertebrae) with thoracolumbar osteoporotic compression fractures underwent PKP between July 2016 to July 2018 were retrospectively analyzed. All punctures were performed unilaterally:102 patients in observation group used oriented bone cement injector including 30 males and 72 females with an average age of (68.4±8.9)years old; 109 patients in regular group used traditional bone cement injector including 32 males and 77 females with an average age of (70.4±9.2) years old. The two groups were compared in terms of duration of operation, cement volume, visual analogue scale(VAS), Oswestry Disability Index(ODI), distribution of bone cement, bone cement leakage and Cobb angle modified rate. RESULTS: There were no significant difference in gender, age and fracture vertebra between the two groups(P>0.05). No significant difference was found between two groups in duration of operation, cement volume, VAS, ODI and Cobb angle(P>0.05). In observation group, 10 cases occurred cement leakages, with leakage rate of 9.80%; and in regular group, 11 cases occurred cement leakage, with leakage rate of 10.09%. There was no significant difference in the cement leakage rate between two groups(P>0.05). In observation group, proportion rate of I-IV degree in cement distribution was 60.78%, 19.61%, 9.80%, 9.80%, respectively; while 39.45%, 22.93%, 22.93%, 14.68% in regular group. The I degree of cement cross-filling rate was better in observation group than in regular group(P<0.05). There was no significant difference between two groups in II degree distribution rate of bone cement(P>0.05). From T10 to L5, I degree bone cement distribution rate of both groups showed decline trend. The I degree cement cross-filling rate in L1-L5 was 50% in observation group and 30.23% in regular group(P<0.05). CONCLUSIONS: Oriented bone cement injector can control the direction of bone cement dispersion and achieve effective distribution of bilateral bone cement using unilateral puncture and satisfactory surgical results. It is feasible and effective for unilateral PKP treatment of OVCFs.

[Application of three-dimensional CT and image classification in percutaneous vertebraplasty for osteoporotic vertebral compression fractures].

OBJECTIVE: To explore the application of three-dimensional CT and image classification in the treatment of osteoporotic vertebral compression fracture(OVCFs) by percutaneous vertebroplasty(PVP). METHODS: A total of 90 patients with OVCFs who were treated with PVP in Linqu People's Hospital of Shandong Province from April 2016 to March 2018 were selected as subjects. There were 31 males and 59 females, aged from 63 to 84 years old. Bone mineral density measurements were performed in all patients to confirm the presence of osteoporosis and imaging examinations were performed to confirm the presence of vertebral fractures. The fracture area was determined by MRI fat surpressed image before operation and three-dimensional modeling was performed to calculate the volume of fracture area. Three dimensional CT imaging of bone cement in fracture area was performed after PVP and the volume ratio of bone cement in fracture area was calculated by computer aided design software, by which patients were divided into groups for study. Forty-one patients whose volume ratio of bone cement in fracture area less than 50% are control group and the rest of 90 patients are observation group. Visual analogue scale (VAS) and Oswestry Disability Index(ODI) were collected in two groups before operation and 1 day, 3 months after operation. The amount of bone cement was recorded after operation. RESULTS: All operations were successful. There were 3 cases of cement leakage in control group and 4 cases in observation group. All patients had no obvious clinical symptoms. After continuous observation and follow-up for 3 months, no complications such as adjacent vertebral fracture, infection, bone cement displacement were found. There was no significant difference in bone cement doses and bone cement leakage between two groups(P>0.05). There was no significant difference in preoperative VAS and ODI between two groups(P>0.05). All VAS and ODI obviously decreased(P<0.05) at 1 day after operation and in observation group the decrease was more significant (P<0.05). At 3 months after operation there was no significant difference between two groups. This may have been due to basically healing of vertebral fractures at 3 months after surgery and the pain was no longer significantly related. CONCLUSIONS: PVP can significantly improve clinical symptoms of OVCFs and bone cement filling in fracture area is the key to the short-term effect of PVP.