Bone Cement Injection Research Articles

THE FIXATION EFFECT OF DIFFERENT TYPES OF SCREWS IN THE WHOLE OSTEOPOROTIC LUMBAR VERTEBRAE: AN FEA STUDY

Purpose: The aim of this study is to explore how pedicle screws (PSs) and cortical bone trajectory (CBT) screws differ in fixation strength when implanted in L1–L5 with osteoporosis, providing support for choosing implants and trajectories in spine internal fixation surgeries. Methods: We filtered 30 lumbar segments out from CT images of eight osteoporotic participants and simulated PS or CBT screw implantation in each segment, generating 60 vertebra-screw assembly FE models. To evaluate the fixation effect, we performed a pull-out force test simulation in each model and analyzed the maximal pull-out force, pull-out stiffness, and equivalent stress of vertebrae and screws. Results: The maximal pull-out force of PS and CBT screws in L1–L5 was in the range of 905–1552 (N) and 587–1012 (N), while the pull-out stiffness was in the range of 1990–2617 (N/mm) and 1007–1681 (N/mm). The fixation strength of PS in L4 and L5 was higher ([Formula: see text]), while in L1–L3 PS and CBT screws are similar ([Formula: see text]). The maximal stress of vertebrae and screws when PS was pulled at 0.25[Formula: see text]mm was larger than that of CBT screws. Conclusions: For patients with moderate osteoporosis, it is recommended to insert PS into L4 and L5 to attain better fixation strength, but vertebrae are more prone to fracture. Consequently, under severe osteoporosis, the implantation of CBT screws should be considered first. Bone cement injection may be necessary to consolidate the screw-vertebrae interface with osteoporosis.

Combined Application of Grid Body Surface Locator and Preemptive Analgesia in Daytime Vertebroplasty.

Objective To explore the clinical advantages of grid body surface locator combined with preemptive analgesia in the treatment of osteoporotic lumbar fractures in daytime vertebroplasty. Methods A retrospective study was conducted on 120 patients who underwent lumbar vertebroplasty in the Department of Orthopedics of General Hospital of Northern Theater Command from January 2017 to January 2020. According to the preoperative planning and analgesic mode of treatment, they were divided into the daily operation experimental group and the traditional mode control group. Prone positioning of a patient under anesthetic is safe of ensuring optimum surgical access for many procedures, providing that the risks are fully understood. The general baseline data, intraoperative fluoroscopy times and operation time, bone cement injection volume, bone cement permeability, VAS score before operation, 1 day, and 3 months after operation, and the recovery of anterior vertebral height before and after operation were analyzed. Results There was no statistically significant difference in the preoperative general data between the two groups. One day after operation, the VAS score of the experimental group was lower than that of the control group, but there was no difference after 3 months. The permeability of bone cement in the experimental group was lower than that in the control group, the height of anterior edge of injured vertebra was better than that in the control group, and the operation time was less than that in the control group. Conclusion The daytime operation experimental group can significantly alleviate postoperative pain, increase the amount of bone cement injection, and reduce the permeability of bone cement through preoperative planning of puncture path and key puncture points, combined with advanced labor pain, but there is no significant difference in long-term pain relief.

Epidemiological and clinical characteristics analysis of 681 cases of thoracolumbar osteoporotic vertebral compression fractures

To investigate the epidemiological and clinical characteristics of patients with thoracolumbar osteoporotic vertebral compression fracture (OVCF) treated by percutaneous vertebroplasty (PVP). The clinical and imaging data of 681 patients with thoracolumbar OVCF treated with PVP between January 2017 and December 2021 were collected. The epidemiological and clinical characteristics of the patients with thoracolumbar OVCF in single center were summarized from the aspects of demographic distribution (mainly including gender, age), fracture characteristic analysis [including pathological segments, bone mineral density, and body mass index (BMI)], and operation related results (including the distribution of unilateral and bilateral puncture and bone cement injection, postoperative effectiveness analysis and refracture). Of the 681 patients, 134 (19.68%) were male and 547 (80.32%) were female, with a male-to-female ratio of 1∶4.08. The age ranged from 53 to 105 years, with an average of 75.3 years. The age group of 60-90 years old had the largest number of patients (91.04%); the high incidence age group of men was 70-90 years old (13.95%), and that of women was 60-80 years old (72.98%). A total of 836 vertebrae were involved, and the morbidity of thoracolumbar vertebrae (T 11-L 1) was the highest (56.34%, 471/836). The main type of fracture was compression fracture (92.58%, 774/836) and Kümmell disease (7.42%, 62/836). There were 489 cases (71.81%) of osteoporosis, including 66 males and 423 females, with a male-to-female ratio of 1∶6.42. There was significant difference in distribution of bone mineral density between male and female groups ( Z=-5.810, P<0.001). BMI showed 206 cases (30.25%) of underweight, 347 (50.95%) cases of normal, 58 cases (8.52%) of overweight, 42 cases (6.17%) of obese, and 28 cases (4.11%) of extremely obese. The difference in BMI distribution between male and female groups was significant ( Z=-2.220, P=0.026). Of 836 vertebral bodies, 472 (56.46%) were punctured unilaterally and 364 (43.54%) bilaterally. Most of the vertebral bodies (49.88%, 417/836) were injected with 5.0-6.9 mL bone cement, and most of them were distributed in thoracolumbar and lumbar vertebral bodies (T 11-L 3). The visual analogue scale (VAS) score and Oswestry disability index (ODI) of patients with unilateral puncture and bilateral puncture significantly improved at 6 months after operation ( P<0.001), and also the difference was significant between the two groups in the difference of pre- and post-operation ( P<0.001). There were 628 cases (92.22%) with the first occurrence of OVCF, and 53 cases (7.78%) with two or more times of OVCF, all of which were female patients, and 26 cases (49.06%) occurred in the adjacent segment of the previous PVP operation. Female were more than male in OVCF patients. Thoracolumbar vertebral body has the highest morbidity. Patients with low BMI are more likely to have osteoporosis, and patients with high BMI have a higher risk of compression fracture. The amount of bone cement injected through bilateral puncture was greater than that through unilateral puncture.

A finite element analysis on different bone cement forms and injection volumes injected into lumbar vertebral body in percutaneous kyphoplasty

BackgroundTo investigate the stress changes between different bone cement forms and injection volumes in adjacent vertebrae after percutaneous kyphoplasty (PKP) by establishing a three-dimensional finite element model of osteoporosis.MethodsA male healthy volunteer was selected. CT of scans L1 to L3 vertebrae were imported into Mimics 21.0 software.The vertebral model of osteoporosiswas established based on previous literature reference. The models were divided into three groups: unilateral, bilateral integration and bilateral separation groups, with each group injecting 2 ml, 4,ml and 6 ml of bone cement, respectively. In all models, a vertical compressive load of 500 N, anterior flexion/posterior extension, left/right bending, and left/right rotation were applied with a moment of 7.5 N/m, of which 85% was applied to the anterior mid-column and 15% to the posterior column. The stress changes between adjacent vertebrae under different conditions were calculated.ResultsAfter percutaneous kyphoplasty was applied to the L2 vertebral body, some differences can be found between the effects of different cement injection volumes and cement morphology on adjacent structures. There was no major difference between the groups when the bone cement injection volume was 2 ml. When the amount of bone cement injected was 4 ml, the bone cement morphology of the bilateral integration group (BIG) produced less stress between adjacent vertebral bodies. The minimum stress was 14.95 MPa in the L3 vertebral body in posterior extension. Whereas the stress levels on adjacent intervertebral structures, BIG shaped bone cement shows some superiority. In addition, the adjacent vertebrae and intervertebral structures are subjected to less stress during left and right rotation.ConclusionsThe present finite element study suggested that bilateral integration bone cement is a suitable form of cement injection, and when the injection volume is 4 ml, reduces stress on adjacent segments by approximately 15% while maintaining the stability of the injected vertebral body.

Vertebral augmentation: an overview.

Vertebral compression fractures (VCFs) are a common pathologic process seen in 30-50% of individuals over the age of 50years. Historically, VCFs were first treated with nonsurgical management while vertebral augmentation was reserved for severe cases resulting in deformity or significant disability. Current treatment algorithms based on established appropriateness criteria have changed recommendations towards supporting early vertebral augmentation for the VCFs causing the most clinically difficulty and taking into account the degree of vertebral body height loss, kyphotic deformity, and the degree of clinical progression. Percutaneous vertebroplasty (PVP) involves injecting primarily polymethacrylate (PMMA) bone cement directly into the cancellous bone of the vertebral body. There is recent literature showing the effectiveness of PVP including data comparing vertebroplasty to sham treatment. Vertebroplasty evolved into balloon kyphoplasty (BKP) where a balloon is first inserted into the vertebral body to create a cavity and reduce the fracture followed by an injection of bone cement. Both PVP and BKP have been shown to be significantly more effective at treatment of VCFs compared to nonsurgical management. The benefits shown in the literature have been demonstrated randomized control trials, cohort matched trials, post-market trials, registries, and many other data sources with approximately 250 manuscripts produced per year dedicated to the topic of vertebral augmentation.

Biomechanical evaluation of percutaneous cement discoplasty by finite element analysis

BackgroundPercutaneous cement discoplasty (PCD) is a minimally invasive treatment for degenerative lumbar spine disease, but the relationship between decompression effect on the nerve root and different doses of bone cement is uncertain.PurposeTo investigate the indirect decompression effect of cement with different doses on nerve roots and the biomechanical changes on the spine during PCD using finite element analysis (FEA).MethodsFEA was adapted to analyze the mechanical changes in the lumbar vertebrae before and after the application of PCD.CT scan images of adult males were utilized to establish a finite element model of the lumbar vertebral body using mimics and Pro/E software. The images were divided into four models: the normal model (normal, model N), the disc degeneration model (high, model H), the intervertebral disc injected with 3 mL of bone cement (model H1), and the intervertebral disc injected with 5 mL of bone cement (model H2). All models were analyzed using the ABAQUS6.14.2 software. The normal physiological movements were simulated, and the mechanical changes in the lumbar vertebrae were observed prior to and after the cement filling application.ResultsThe stress of the nerve root in model H was the largest. The nerve root stress in the model H2 was the smallest during flexion, extension, left bending, right bending, left rotation, and right rotation at 90%, 44%, 25%, 56%, 56%, and 51% of the normal benchmark, respectively. After the injection of bone cement, the nerve root stress is reduced. The greater the amount of cement, the lesser the nerve root stress. The motion was reduced in models H, H1, and H2, and there were differences between models H1 and H2. Cartilage endplate stress was less in model H2 than in model H1.ConclusionsThe nerve root stress increased after degeneration and decreased after intervertebral height recovery through cement injection, resulting in a significant indirect decompression effect.The stress of the nerve root decreased with the increase in the amount of cement injection.

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

To investigate the effects of different bone cement morphology distribution on the clinical efficacy of unilateral percutaneous vertebroplasty(PVP) for spinal osteoporotic fractures. 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. 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). 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.

Comparison of Unipedicular and Bipedicular Percutaneous Kyphoplasty for Kummell's Disease.

Objective:To compare the clinical efficacy of unipedicular and bipedicular percutaneous kyphoplasty (PKP) for Kummell’s disease.Methods:A retrospective study was performed to review 40 patients with stage I and II Kummell’s disease who underwent PKP in our hospital from January 2015 to June 2018. Based on the transpedicular approach of PKP, those patients were randomly divided into unipedicular group (n = 19) and bipedicular group (n = 21). Operative time, bone cement injection volume and cement leakage rate were compared in the two groups. Pre- and post-operative visual analogue score (VAS), local kyphotic angle and average vertebral height were also evaluated.Results:All patients underwent surgery successfully. Compared with preoperative condition, VAS was significantly decreased at 1 day after operation and the last follow-up in both groups (P < .05), and local kyphotic angle and average vertebral height were restored markedly (P < .05). Operative time of both groups had no significant difference (P > .05). Bone cement injection volume was larger in bipedicular group (P < .05). At 1 day after operation and the last follow-up, the local kyphotic angle and average vertebral height in bipedicular group were restored better than those in unipedicular group (P < .05). There were 4 cases of cement leakage in both groups, with leakage rates of 21.1% and 19.0%, respectively, and the difference was not significant (P > .05).Conclusion:Both unipedicular and bipedicular PKP are effective for treating patients with stage I and II Kummell’s disease, while postoperative pain relief and imaging results in bipedicular group were better than those in unipedicular group.

Pathological Clinical Analysis and Imaging Manifestations for Spinal Bone Tumors Based on Cement Injection.

In order to explore the imaging manifestations and pathological characteristics of spine tumors, this article explores the clinical diagnosis and treatment methods through multi-sample case analysis with the support of imaging, and proposes a targeted treatment method that uses a special PVP needle with a beveled puncture surface for puncture. Moreover, this article uses the supporting PVP syringe for bone cement injection, develops a health status questionnaire, and adopts a scoring method for comprehensive assessment. The purpose of this article is to show that through the combination of preoperative radiotherapy and postoperative bracing, bone cement injection to treat vertebral tumors can immediately obtain satisfactory pain relief. Finally, through case analysis and image performance, we can see that the method proposed in this article has a certain effect.

A novel bone cement injector augments Chinese osteoporotic lumbar pedicle screw channel: a biomechanical investigation

BackgroundThe study aimed to (1) create a series of pedicle injectors with different number of holes on the sheath especially for the Chinese elderly patients and (2) further investigate the effects of the injectors on the augmentation of pedicle screw among osteoporotic lumbar pedicle channel.MethodsThis study used the biomechanical test module of polyurethane (Pacific Research Laboratory Corp, USA) to simulate the mechanical properties of human osteoporotic cancellous bone. The bone cement injectors were invented based on anatomical parameters of lumbar pedicle in Chinese elderly patients. Mechanical test experiments were performed on the bone cement injectors according to the three groups, namely, a local augmentation group, a full-length augmentation group, and a control group. The local augmentation group included three subgroups including 4-hole group, 6-hole group, and 8-hole group. All holes were laterally placed. The full-length augmentation group was a straight-hole injector. The control group was defined that pedicle screws were inserted without any cement augmentation. Six screws were inserted in each group and the maximum insertion torque was recorded. After 24 h of injecting acrylic bone cement, routine X-ray and CT examinations were performed to evaluate the distribution of bone cement. The axial pull-out force of screws was tested with the help of the material testing system 858 (MTS-858) mechanical tester.ResultsThe bone cement injectors were consisted of the sheaths and the steel rods and the sheaths had different number of lateral holes. The control group had the lowest maximum insertion torque as compared with the 4-hole, 6-hole, 8-hole, and straight pore groups (P < 0.01), but the differences between the 4-hole, 6-hole, 8-hole, and straight pore groups were no statistical significance. The control group had the lowest maximum axial pull-out force as compared with the other four groups (P < 0.01). Subgroup analysis showed the 8-hole group (161.35 ± 27.17 N) had the lower maximum axial pull-out force as compared with the 4-hole group (217.29 ± 49.68 N), 6-hole group (228.39 ± 57.83 N), and straight pore group (237.55 ± 35.96 N) (P < 0.01). Bone cement was mainly distributed in 1/3 of the distal end of the screw among the 4-hole group, in the middle 1/3 and distal end of the screw among the 6-hole group, in the proximal 1/3 of the screw among the 8-hole group, and along the long axis of the whole screw body in the straight pore group. It might indicate that the 8-hole and straight-hole groups were more vulnerable to spinal canal cement leakage. After pullout, bone cement was also closely connected with the screw without any looseness or fragmentation.ConclusionsThe bone cement injectors with different number of holes can be used to augment the pedicle screw channel. The pedicle screw augmented by the 4-hole or 6-hole sheath may have similar effects to the straight pore injector. However, the 8-hole injector may result in relatively lower pull-out strength and the straight pore injector has the risks of cement leakage as well as cement solidarization near the screw head.

Comparison of Therapeutic Effects of PVP and PKP Combined With Triple Medication on Mild and Moderate Osteoporotic Vertebral Compression Fracture in the Elderly.

ObjectiveTo compare and analyze the therapeutic effect of percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) combined with triple therapy on elderly patients with mild to moderate osteoporotic vertebral compression fractures (OVCF).MethodsA total of 114 cases of elderly patients with mild to moderate osteoporotic vertebral compression fractures were identified as research subjects in our hospital from January 2017 to January 2018, and a total of 136 vertebrae were included. The patients who underwent PVP operation were included as the control group with 67 injured vertebrae, and the patients who underwent PKP operation were included as the experimental group with 69 injured vertebrae.ResultsThe operation time and bone cement injection volume of the experimental group were significantly higher than the control group. The visual analog scale (VAS) scores of the two groups at 3 months and 6 months after operation were lower than those before operation, with lower VAS scores observed in the experimental group at 3 months and 6 months after operation. The anterior height of the vertebral body in the experimental group was higher than that of the control group. The experimental group outperformed the control group in the incidence of postoperative complications. The postoperative Oswestry dysfunction index (ODI) scores of the two groups were lower before the operation, in which the experimental group had lower scores than the control group (P < 0.05).ConclusionPVP and PKP combined with postoperative triple therapy can achieve a promising analgesic effect. PKP has a higher volume of bone cement injection volume, and a lower incidence of complications, which gives rise to a better vertebral body recovery height than that of PVP, with rapid postoperative body function recovery and good quality of life.

Different Associated Aspects That Influence Complication Rates on Clinical PKP Surgery Using Smart Medical Big Data.

Osteoporotic vertebral compression fractures are on the rise in modern society due to the aging population, and this often results in painful symptoms and kyphotic abnormalities in patients. Bone cement was injected into the vertebral body to reinforce the vertebral body and restore most of the damaged vertebrae's natural height. Percutaneous kyphoplasty is the name given to this type of procedure (PKP). Bone cement leakage has been linked to several problems, according to the research. Neurological problems might arise if bone cement leaks into the spinal canal or the nerve root canal during surgery. As a result, PKP surgeons must now deal with the issue of reducing bone cement leakage. Using smart medical big data, this paper examines a sample of PKP operations and then examines different associated aspects that influence complication rates in order to better advice clinical PKP surgery use. There were 172 vertebral bodies in total in 72 patients receiving PKP surgery at a Chinese hospital that were examined by smart medical big data for vertebral degeneration and fusion. Bone cement leakage and variations in preoperative average anterior vertebral column height, preoperative Cobb angle, and the volume of injected bone cement were considered when dividing the patients into leakage and nonleakage groups; then, we figure out what is causing the bone cement to leak. Five patients experienced lung-related problems out of the 18 vertebral bodies with bone cement leaking that were selected for study. That leakage rate was 10.5%. The differences between the two groups in terms of vertebral compression and bone cement injection were statistically significant based on a single-factor analysis. Bone cement leakage in PKP surgery has been linked to the amount of bone cement injected and whether the vertebral body's peripheral wall was injured, according to multivariate analysis. Lung-related problems are more common in patients with a prior history of illness. Osteoporotic vertebral compression fractures can be successfully treated with percutaneous kyphoplasty. An important risk factor for bone cement extravasation in PKP surgery is the amount of bone cement injected, as well as its viscosity and whether damage to the vertebral body's peripheral wall has occurred.

The role of surgery in the treatment of metastatic bone tumor.

Surgery for bone metastasis has two primary goals-palliative care to relieve pain, instability and paralysis, and tumor resection for curing the disease. Oncologically en bloc resection, followed by a reconstruction of the bone defect is the treatment of choice in single bone metastasis from renal cell carcinoma or thyroid cancer. Bone metastases may occur in the extremities, pelvis, or spine, and different resection and reconstruction methods depend on the regional anatomy. For instance, multiple options are available for reconstruction of the pelvis, especially for the acetabulum, including anatomical reconstruction using custom-made implants or recycled autologous bone grafting when a long-term prognosis is expected. Recently, for the spine, total en bloc spondylectomy is extensively performed despite the initial limitations of surgical invasiveness, such as blood loss. Principally, palliative surgery aims to maintain lasting bony stability with minimal surgical invasiveness. Intramedullary nails and plate fixation are frequently used in the extremities but the postoperative failure rate is relatively high. Therefore, surgeons should consider the use of long intramedullary nails and long-type stems for endoprosthesis reconstruction along with cement fixation to reduce the failure rate. Although short-term complications, such as dislocation, have been observed with endoprosthesis reconstruction, it is stable in the long-term follow-up. Percutaneous bone cement injection into the spine and pelvis is also effective and less invasive.

Effects of Location and Volume of Intraosseous Cement on Adjacent Level of Osteoporotic Spine Undergoing Kyphoplasty: Finite Element Analysis

Kyphoplasty (KP) is a surgery used to reduce pain and increase stability by injecting medical bone cement into broken vertebrae. The purpose of this study was to determine the ideal amount of cement and injection site by analyzing forces with the finite element method. We modeled the anatomical structure of the vertebra and injected the cement at T12. By increasing the amount of cement from 1 cc to 22 cc, stress applied to T11 and L1 cortical was calculated. In addition, stress applied to the adjacent KP level was calculated with different injection sites (medial, anterosuperior, posterosuperior, anteroinferior, and posteroinferior). After 5 cc cement was inserted, adjacent end plate stress was analyzed. In this study, break point adjacent bone stress according to the capacity of cement was bimodal. Flexion/extension and lateral bending conditions showed similar break points (11.5-11.7 cc and 18.5-18.6 cc, respectively). When cement injection was changed, front under and back under had the highest stress values among various parts, whereas the center position showed the lowest stress value. With increasing amount of bone cement, stress on the upper and lower end plates of the cemented segment increased significantly. Thus, increasing cement amount to be more than 11.5 cc has a potential risk of adjacent fracture. Centrally injected bone cement can lower the risk of adjacent fracture after percutaneous KP.

Evaluation of Intraosseous Pressure during Pelvic Percutaneous Cement Injection: An In Vitro Study in Swine.

A minimally invasive procedure for symptomatic pelvic bone metastasis is a feasible option for advanced cancer patients, and bone cement injection plays an essential role. Pulmonary embolism caused by thrombus, fat, or tumor emboli is a major complication related to bone cement injection, and increasing intraosseous pressure is a predisposing factor. This study aimed to quantify the degree of pressure change in the pelvic bone during percutaneous bone cement injection and investigate whether there is a significant decrease in intraosseous pressure when a decompressive route is additionally established. Bone cement injection into the acetabulum of swine pelvises by simulating the actual surgical procedure in terms of the injection method, bone cement, and surgical instruments was performed while recording the intraosseous pressure. Twenty swine pelvises were used and grouped into a decompression group and a non-decompression group. Bone cement injection and pressure measurement were conducted in the same way in both groups, but an additional decompressive route was established for each pelvis in the decompression group. Continuous variables were compared using the Mann-Whitney test. The mean amount of injected bone cement was 19.8 mL and 20.3 mL and the mean speed of bone cement injection was 0.14 mL/sec and 0.12 mL/sec in the decompression group and the non-decompression group, respectively. The mean peak intraosseous pressures was 10.5 kPa with decompression and 37.8 kPa without decompression, and the difference was statistically significant (p < 0.01). Intraosseous pressure during bone cement injection into swine pelvises was similar to that during vertebroplasty or kyphoplasty. When the additional decompression route was established, the intraosseous pressure decreased to one third the level.

Robot-Assisted Bone Cement Injection.

In this article, assistance to bone cement injection is studied, with a focus on vertebroplasty, a procedure dedicated to the treatment of vertebral compression fractures. A robotic system that can remotely be operated at pressures up to 140 bar is presented. It improves cement polymerization control, combining a cold passive exchanger that slows down the cement curing in the syringe and an active exchanger that controls the injected cement temperature. The cement remote injection uses a rate control teleoperation strategy with force feedback to help monitoring the cement state. In addition to laboratory assessments, cadaver experiments were performed to illustrate the satisfactory operation of the whole system.

Application of Curved Diffusion Needle in unilateral percutaneous vertebroplasty

To evaluate the effectiveness of Curved Diffusion Needle in unilateral percutaneous vertebroplasty (PVP) by compared with bilateral PVP. A clinical data of 93 patients with osteoporotic vertebral compression fracture (OVCF) treated with PVP between January 2020 and January 2021 was retrospectively analyzed, including 47 patients underwent unilateral PVP assisted with Curved Diffusion Needle (unilateral group) and 46 patients underwent bilateral PVP (bilateral group). There was no significant difference in gender, age, cause of injury, time from injury to operation, T value of bone mineral density, AO classification, distribution of injured vertebrae, and preoperative visual analogue scale (VAS) score, Oswestry disability index (ODI), relative height of injured vertebrae, and Cobb angle between the two groups ( P>0.05). The operation time, the amount of bone cement injection, the incidence of bone cement leakage, the bone cement diffusion distribution, VAS score, ODI, the relative height of injured vertebrae, and Cobb angle were recorded and compared between the two groups. All operations successfully completed. The operation time was significantly shorter in unilateral group than in bilateral group ( t=-13.936, P=0.000), and the amount of bone cement injection was significantly less in unilateral group than in bilateral group ( t=-13.237, P=0.000). The incidence of bone cement leakage in unilateral group was 19.14%, which was significantly lower than that in bilateral group (39.13%) ( χ 2=4.505, P=0.034). The score of bone cement distribution in unilateral group was 7.0±1.3, of which 41 cases were excellent and 6 cases were well. The score of bilateral group was 7.4±0.8, of which 43 cases were excellent and 3 cases were well. There was no significant difference in score and grading of bone cement distribution between the two groups ( t=-1.630, P=0.107; Z=-1.013, P=0.311). All patients were followed up and the follow-up time was 3-10 months (mean, 6.5 months) in unilateral group and 3-10 months (mean, 6.1 months) in bilateral group. The VAS score, ODI, the relative height of injured vertebrae, and Cobb angle at 24 hours after operation and last follow-up were significantly better than those before operation in the two groups ( P<0.05). There were significant differences in all indicators between 24 hours after operation and last follow-up ( P<0.05). There was no significant difference in all indexes between the two groups ( P>0.05) at the same time point after operation. During follow-up, there was no complication such as contralateral vertebral collapse, refracture, adjacent vertebral fracture, or local kyphosis in the two groups. Unilateral PVP assisted with Curved Diffusion Needle for OVCF is beneficial to the distribution of bone cement, which can not only achieve similar effectiveness to bilateral PVP, but also achieve shorter operation time, less bone cement injection, and lower risk of bone cement leakage.

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

BackgroundA 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).MethodsFrom 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).ResultsVisual 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.ConclusionCompared 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.

Treatment of Kümmell’s disease following the occurrence of osteoporotic vertebral compression fracture

Background: The incidence of osteoporotic vertebral compression fracture (OVCF) is increasing with the increase in the elderly population. Kümmell’s disease following OVCF occurrence is not a rare complication and is frequently associated with severe pain or neurologic deficit with progressive kyphotic deformity. Kümmell’s disease initially meant post-traumatic delayed vertebral collapse, but now it is also termed nonunion, osteonecrosis, or intravertebral vacuum cleft, all of which suggest the disruption of the healing process.Current Concepts: The major pathogenesis of Kümmell’s disease is a vascular compromise caused by mechanical stress or intravascular pathology. The key radiologic sign to diagnose Kümmell’s disease is the presence of intravertebral vacuum cleft, observed using simple X-ray, computed tomography, or magnetic resonance imaging. Magnetic resonance imaging is the most useful diagnostic tool showing gas or fluid signals. The risk factors for the progression of Kümmell’s disease after OVCF include middle-column injury, confined low signal intensity on T2-weighted image, posterior wall combined fracture, kyphotic angle &gt;10°, and a height loss &gt;15%. Its treatment can be broadly classified as conservative treatment, bone cement injection, and surgical treatment. The appropriate treatment method is selected based on the pain intensity, neurological symptoms, and the severity of the kyphotic deformity.Discussion and Conclusion: Kümmell’s disease usually develops along with osteoporosis. Therefore, the treatment should be focused on relief from symptoms associated with Kümmell’s disease and osteoporosis. It is recommended that an anabolic agent should be administered after the diagnosis of Kümmell’s disease, regardless of the treatment modality.

Overview of research work of Prof. Chu on two medical devices

Surgical procedures are relatively common and procedures for broken bones often involve intramedullary nailing to repair the bone and keep it stable. However, there are challenges associated with the process and Professor Woeichyn Chu, who is a distinguished professor based within the Department of Biomedical Engineering at the National Yang Ming Chiao Tung University in Taiwan, is developing a medical device to help surgeons overcome these challenges, benefiting patients and clinicians. The device is called iMET (intra-medullary endo-transilluminating) and came about after Woeichyn Chu spoke with his brother, Dr William Chu, General Orthopedic Department, Cheng Hsin General Hospital, Taiwan, about some of the challenges relating to intramedullary nailing which led the brothers to begin working together to develop a medical device to help target distal locking holes in intramedullary nailing procedures. The iMET device that the brothers are developing is designed to improve target aiming accuracy and reduce dose absorption concerns. In the process, it will save significant time, effort and money. As well as benefiting patients and clinicians, iMET also reduces X-ray fluoroscopy time, which has health benefits for all involved. Woeichyn Chu and his brother are also developing a device called iKypho, which applies negative pressure during bone cement injection in percutaneous vertebroplasty surgeries. iKypho reduces bone cment leakage risks when using low viscosity cement and reducing the costs associated with high viscosity bone cement.