Cement-augmented Pedicle Screw Instrumentation Research Articles

Cement Augmented Pedicle Screw Instrumentation in Pediatric Spine Surgery

Osteoporosis in pediatric patients is rare. Osteomalacia and osteoporosis are known to develop in syndromic or neuromuscular scoliosis children. Spinal deformity surgery for pediatric patients with osteoporosis is challenging, associated with pedicle screw (PS) failure and compression fractures. Cement augmentation of PS is one several measures to prevent screw failure. It provides additional pull-out strength to the PS in the osteoporotic vertebra. In 2010-2020, an analysis of pediatric patients who had cement augmentation of PS with a minimum follow-up of 2 years was performed. Radiological and clinical evaluations were analyzed. The study included 7 patients (4 girls, 3 boys) with a mean age of 13 years (range, 10-14 years) and mean follow-up of 3 years (range, 2-3 years). Only 2 patients underwent revision surgery. Total number of cement augmented PSs was 52 with an average of 7 per patient. Only 1 patient had lower instrumented vertebra vertebroplasty. There was no PS pull-out in the cement augmented levels, and there were no neurological deficits or pulmonary cement embolisms. One patient developed a PS pull-out in uncemented levels. Two patients developed compression fractures, one, with osteogenesis imperfecta, in the supra-adjacent levels (upper instrumented vertebra+ 1 and upper instrumented vertebra+ 2), and the other, with neuromuscular scoliosis, in the uncemented segments. In this study, all cement augmented PSs provided satisfactory radiological outcomes without PS pull-out and adjacent vertebral compression fracture. In pediatric spine surgery, in osteoporotic patients with a poor bone purchase, cement augmentation may be used, especially in high-risk patients with osteogenesis imperfecta, neuromuscular scoliosis, and syndromic scoliosis.

Percutaneous Endovascular Retrieval of Large Cement Leakage into the Right Atrium Following Cement-Augmented Pedicle Screw Instrumentation.

Percutaneous Endovascular Retrieval of Large Cement Leakage into the Right Atrium Following Cement-Augmented Pedicle Screw Instrumentation.

Influence of cement-augmented pedicle screws with different volumes of polymethylmethacrylate in osteoporotic lumbar vertebrae over the adjacent segments: a 3D finite element analysis

BackgroundPolymethylmethacrylate (PMMA) is commonly used for cement-augmented pedicle screw instrumentation (CAPSI) to improve the fixation stability and reduce the risk of screw loosening in the osteoporotic thoracolumbar spine. Biomechanical researches have shown that various dose of cement (1-3 ml) can be injected to enhance screw stability. To date, there have been no studies on the relationship between adjacent segment degeneration and the volume of PMMA. This study aimed to explore the influence of CAPSI with different volumes of PMMA in osteoporotic lumbar vertebrae over adjacent segments by using finite element analysis.MethodsSeven different finite element models were reconstructed and simulated under different loading conditions, including (1) an intact model, (2) three single-level CAPSI models with different volumes of PMMA (1, 1.73, and 2.5 ml), and (3) three double-level CAPSI models with different volumes of PMMA (1, 1.73, and 2.5 ml). To improve the accuracy of the finite element analysis, the models of the injectable pedicle screw and bone cement were created by using a three-dimensional scanning machine and the CAPSI patient’s CT data, respectively. The range of motion (ROM), the stress of intervertebral discs, and the stress of facet in the adjacent segment were comparatively analyzed among the different models.ResultsThe ROMs of the different segments were compared with experimental data, with good agreement under the different load conditions (21.3°, 13.55°, 13.99°, and 6.11° in flexion, extension, bending, and rotation at L3-S1 level, respectively). Compared with the intact model, the ROM, disc stresses, and facet stress in adjacent segments were found to be higher in the six operative models. Otherwise, with a larger volume of PMMA injected, the ROM, disc stresses, and facet stress slightly increased at the adjacent segment. However, the differences were insignificant with the biggest difference less than 3.8%.ConclusionsCAPSI could increase the incidence of disk degeneration in the adjacent segment, while within a certain range, different volumes of PMMA provided an approximate impact over the adjacent segment degeneration.

Asymptomatic Pulmonary Cement Embolism after Cement-Augmented Pedicle Screw Instrumentation: A Case Report

Asymptomatic Pulmonary Cement Embolism after Cement-Augmented Pedicle Screw Instrumentation: A Case Report

Cardiac Perforation Caused by Cement Embolus after Cement-Augmented Pedicle Screw Instrumentation: A Case of Report

Cardiac Perforation Caused by Cement Embolus after Cement-Augmented Pedicle Screw Instrumentation: A Case of Report

Effect and potential risks of using multilevel cement-augmented pedicle screw fixation in osteoporotic spine with lumbar degenerative disease

BackgroundThe increase of augmented level and bone cement dose are accompanied by the rising incidence of cement leakage (CL) of cement-augmented pedicle screw instrumentation (CAPSI). But the effect and potential risks of the application of CAPSI to osteoporotic lumbar degenerative disease (LDD) have not been studied in the case of multilevel fixation. This study aimed to investigate the effectiveness and potential complications of using multilevel CAPSI for patients with osteoporotic LDD.MethodsA total of 93 patients with multilevel LDD were divided into the CAPSI group (46 subjects) and the conventional pedicle screw (CPS) group (47 subjects), including 75 cases for three levels and 18 cases for four levels. Relevant data were compared between two groups, including baseline data, clinical results, and complications.ResultsIn the CAPSI group, a total of 336 augmented screws was placed bilaterally. The CL was observed in 116 screws (34.52%). Three cemented screws (0.89%) were found loosened during the follow-up and the overall fusion rate was 93.47%. For perioperative complications, two patients (4.35%) experienced pulmonary cement embolism (PCE), one patient augmented vertebral fracture, and three patients (6.52%) wound infection. And in the CPS group, thirty-three screws (8.46%) suffered loosening in cranial and caudal vertebra with a fusion rate of 91.49%. The operation time and hospital stay of CAPSI group were longer than the CPS group, but CAPSI group has a lower screw loosening percentage (P<0. 05). And in terms of blood loss, perioperative complications, fusion rate, and VAS and ODI scores at the follow-up times, there were no significant differences between the two groups.ConclusionsPatients with osteoporotic LDD underwent multilevel CPS fixation have a higher rate of screw loosening in the cranial and caudal vertebra. The application of cemented pedicle screws for multilevel LDD can achieve better stability and less screw loosening, but it also accompanied by longer operating time, higher incidence of CL, PCE and wound infections. Selective cement augmentation of cranial and caudal pedicle screws may be a worthy strategy to decrease the complications.

Influence of cement-augmented pedicle screw instrumentation in an osteoporotic lumbosacral spine over the adjacent segments: a 3D finite element study

PurposeTo compare the effect of conventional pedicle screw (CPS) and cement-augmented pedicle screw instrumentation (CAPSI) on adjacent segment degeneration (ASD).MethodsA normal male volunteer without a history of spinal disease was selected, lumbar CT data was collected, an intact L3-S1 three-dimensional finite element model was created by software including Mimics, Geomagic, and SolidWorks, and the fixation methods were performed accordingly. A common pedicle screw model and a cement-augmented pedicle screw model of L4–L5 with fusion and internal fixation were constructed. With ANSYS Workbench 17.0, a 500 N load was applied to the upper surface of L3 to simulate the weight of a human body, and a 7.5 N m moment was applied at the neutral point to simulate flexion, extension, left/right bending, left/right rotation of the spine. The peak von Mises stress of intervertebral disc and the range of motion (ROM) on the adjacent segments (L3–4 and L5–S1) were compared.ResultsThe validity of the intact model shows that the ROM of the model is similar to that of a cadaveric study. Compared with the intact model, CPS model and CAPSI model in all motion patterns increased the ROM of adjacent segments. The intervertebral disc stress and the ROM of adjacent segments were found to be higher in the CAPSI model than in the CPS model, especially in L3–4.ConclusionIn general, the biomechanical analysis of an osteoporotic lumbar spine showed that both CPS and CAPSI can increase the ROM and disc stresses of osteoporotic lumbar models, and compared with CPS, CAPSI is more likely to increase the potential risk of adjacent segment degeneration.

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

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

Risk Factors for Adjacent Fractures After Cement-Augmented Thoracolumbar Pedicle Screw Instrumentation.

The aim of our study was to identify factors that influence the occurrence of adjacent fractures in patients with cement-augmented pedicle screw instrumentation. Data were retrospectively collected from medical charts and operative reports for every surgery in which cement-augmented instrumentation was used in our hospital of 4 consecutive years. A total of 93 operations were included and examined for gender, age, T-score, number of fused segments, number of implanted screws, broken screws, loosening of screws, leakage and distribution pattern of cement, pre- and postoperative kyphosis angle, revision surgery and adjacent fractures in follow-up. Categorical data were compared using the χ2 test or by Fisher's exact test, as appropriate. Continuous variables conforming to a normal distribution were compared using Student's t test. Otherwise the Mann-Whitney U test was applied. A P-value of <.05 was considered statistically significant. A trend was defined as a P < .2. The mean age was 68.1 years with a mean T-score of -3.12. Nineteen adjacent fractures occurred during follow-up and the median follow-up was 12 months (range, 1-27). Patients showed a higher risk for adjacent fractures following revision surgery (P = .016). Most fractures occurred superior to the instrumented level (P = .013) and in the first 12 months. Difference of T-score between the group "no adjacent fracture" and the group "adjacent fracture" was 0.7 (P = .138). Another trends were found in greater age (P = .119) and long instrumentations (P = .199). Revision surgeries are associated with a higher risk of adjacent fractures. In these cases, prophylactic kyphoplasty of the superior vertebra should be considered. This study is a retrospective, nonrandomized cohort/follow-up study. 3.

Surgical treatment of scoliosis in osteogenesis imperfecta with cement-augmented pedicle screw instrumentation.

A retrospective study. To report the early postoperative results of scoliosis surgery in osteogenesis imperfecta (OI) patients utilizing all pedicle screw constructs and present a novel cementing technique to increase pedicle screw purchase in the osteoporotic OI spine. Scoliosis surgery utilizing hooks and wire systems have high complication rates in OI. Pedicle screw fixation systems have the biomechanical advantage of 3-column fixation, and cement augmentation of pedicle screws provides additional pull-out strength in the osteoporotic OI spine. The clinical and radiologic results of 10 consecutive OI patients treated with all pedicle screw instrumentation and fusion were retrospectively reviewed. The radiologic data included preoperative and postoperative major curve measurements: major curve Cobb angle, global coronal balance (GCB), apical vertebral translation (AVT), and the lowest instrumented vertebral (LIV) tilt. Operative findings included blood loss, surgery time, and additional procedures. All patients received intravenous pamidronate therapy preoperatively to increase bone mineral density. Ten patients with OI were operated on between 2005 and 2009. Seven had cement-augmented pedicle screw insertion at the proximal and distal foundations. The mean hospital stay was 10±7.5 days (range, 4-27 d) and the average follow-up period was 25.7±13.1 months (range, 14-50 mo). Mean preoperative and postoperative major Cobb angles were 83.7±23.8 and 40.3±14.6 degrees, respectively (48% correction; P<0.05). Mean preoperative and postoperative GCB deviations were 26.7±18.6 and 14.1±13.3 mm, respectively (P=0.097). Mean preoperative and postoperative AVTs were 69.3±29.1 and 29±12.2 mm, respectively (P<0.05). Preoperative and postoperative LIV tilts were 18.5±8.9 and 5.2±3.9 degrees, respectively (P<0.05). At the latest follow-up, the mean major curve Cobb angle was 37.7±13.1 degrees, the GCB deviation was 13.8±5.1 mm, the AVT was 31.7±13.3 mm, and the LIV tilt was 11.3±8.8 degrees. There was no difference between the early postoperative and the latest follow-up major curve Cobb angle, GCB deviation, AVT, or LIV tilt, indicating maintenance of correction. The mean blood loss was 23,75 mL (range, 800-45,00 mL). The mean operative time was 375.4 minutes (range, 262-491 min). The mean postoperative Scoliosis Research Society-22 patient-based outcome scores were 4.6±0.7 (out of 5). There were no instrumentation failures or permanent neurological deficits in this series. Pedicle screw instrumentation in OI scoliosis is safe and effective. Cement augmentation in these patients may help to increase the pedicle pull-out strength and decrease the screw failure rates, especially at the proximal and the distal ends of instrumentation.

Safe surgical technique: cement-augmented pedicle screw instrumentation and balloon-guided kyphoplasty for a lumbar burst fracture in a 97-year-old patient

BackgroundDuring the last few years, an increasing number of unstable thoracolumbar fractures, especially in elderly patients, has been treated by dorsal instrumentation combined with a balloon kyphoplasty. This combination provides additional stabilization to the anterior spinal column without any need for a second ventral approach.Case presentationWe report the case of a 97-year-old male patient with a lumbar burst fracture (type A3-1.1 according to the AO Classification) who presented prolonged neurological deficits of the lower limbs - grade C according to the modified Frankel/ASIA score. After a posterior realignment of the fractured vertebra with an internal screw fixation and after an augmentation with non-absorbable cement in combination with a balloon kyphoplasty, the patient regained his mobility without any neurological restrictions.ConclusionEspecially in older patients, the presented technique of PMMA-augmented pedicle screw instrumentation combined with balloon-assisted kyphoplasty could be an option to address unstable vertebral fractures in “a minor-invasive way”. The standard procedure of a two-step dorsoventral approach could be reduced to a one-step procedure.

Acute Pericarditis Caused by Acrylic Bone Cement After Percutaneous Vertebroplasty

Acute pericarditis caused by foreign material without trauma is rare. In the following case, acrylic bone cement penetrated the right ventricle (RV) after percutaneous vertebroplasty (PVP). A 66-year-old woman presented with chest pain exacerbated by deep inspiration and recumbency. She had received PVP 8 days earlier to treat a vertebral compression fracture. Her chest radiograph showed fractured vertebra filled with bone cement in …