Use Of Polymethylmethacrylate Research Articles

Fe-doped 45S5 bioactive glass compositions impair the metabolic activity and proliferation of metastatic human breast cancer cells in vitro

Many kinds of human tumors, including breast carcinomas, frequently metastasize to the bone, making it prone to pathologic fractures. Surgical management of bone metastases ranges from the resection of metastases to bone repair. Current surgical methods for the repair of bone defects include the use of polymethyl methacrylate (PMMA)-based bone cements. A promising alternative material are bioactive glass (BG) particles that in addition to providing physical stability can also induce bone regeneration. Moreover, BGs doped with Fe2O3may also have a negative impact on tumor cells. Here, we tested the hypothesis that BGs can affect metastatic human breast cancer cells. To this end, we assessed the effects of different BG compositions with and without Fe2O3on metastatic human MDA-MB-231 breast cancer cellsin vitro. We found that all BGs tested impaired the viability and proliferation of breast cancer cells in a concentration-dependent manner. The anti-proliferative effects inversely correlated with BG particle size, and were in general less pronounced in mesenchymal stromal cells (MSCs) that served as a control. Moreover, Fe2O3-doped BGs were more potent inhibitors of tumor cell proliferation and metabolic activity than Fe2O3-free BG. Our data therefore indicate that BGs can affect human breast cancer cells more strongly than MSCs, and suggest that the presence of Fe2O3can potentiate anti-proliferative and anti-metabolic effects of BGs. Fe2O3-doped BGs thus have the potential to be used for the surgical management of metastatic bone lesions, and may in addition to their regenerative properties also allow the local control of bone metastases.

Experimental study of light transmitting concrete with ultra-high content of polymethyl methacrylate

Light Transmitting Concrete (LTC) is an innovative material for crafting unique and sustainable architectural and civil structures. Previous studies primarily utilized optical fibers with diameters below 1.5 mm, which did not exceed 10 % of the volumetric content in concrete. This study aims to develop LTC with ultra-high light transmission capabilities while preserving its mechanical strength. An important innovation is the use of polymethyl methacrylate (PMMA) with larger diameters than normal optical fibers. Specifically, PMMA fibers of 2.0 mm diameter and PMMA tubes of 10–20 mm diameter were employed to increase the spacing between these materials when arranged in an ultra-high volumetric content within the concrete, facilitating easier compaction of the fresh concrete. Experiments of the material's mechanical properties, microstructure, and optical performance were conducted. The findings suggest that although the increased PMMA content might reduce the concrete’s mechanical strength due to a smaller effective cross-sectional area, the LTC still achieves compressive strength exceeding 40 MPa. This underscores the viability of LTC with a substantially higher content of light transmitting functional materials compared to previous studies, while still maintaining a mechanical strength greater than normal concrete. The light transmission efficiency of LTC is nearly directly proportional to its PMMA content, and able to reach up to 30 % of the light source's intensity. Additionally, LTC with PMMA fibers provides uniform light distribution across its surface because of scattering, while LTC with larger-diameter PMMA tubes focuses light around the core areas due to direct lighting.

Does exposure to polymethyl methacrylate bone cement increase the risk of surgical glove failure?

Surgical glove perforation has been linked to a double-fold increased risk of surgical site infection. Infection in the context of arthroplasty can have devastating consequences. In orthopaedics, use of polymethyl methacrylate (PMMA) bone cement is commonplace, and the impact on glove strength and perforation risk is not fully understood. This study aimed to examine the resistance to perforation and thickness of gloves following PMMA exposure, in accordance with the International Organization for Standardization (ISO) standard for glove integrity. Pairs of gloves were separated and randomly sorted into exposure and control groups. Twenty pairs of latex and 40 pairs of polyisoprene gloves were used. Exposure group glove cuffs were in contact with cement from a single surface of the glove for 13 min as cement cured. Force to perforation and glove thickness were tested in accordance with ISO guidelines. Latex gloves were found to have a significantly increased force to perforation following PMMA exposure (10.26 Newtons (N) vs. 9.81 N, P = 0.048). Both polyisoprene under- and over-gloves were shown to have no significant change in strength to perforation post exposure (9.69 N vs. 9.83 N, P = 0.561, and 10.26 N vs. 10.65 N, P = 0.168, respectively). All groups were over the ISO standard minimum strength of 5 N. Exposure of latex and polyisoprene surgical gloves to PMMA bone cement does not appear to increase glove perforation risk and rather may improve natural rubber latex glove strength. This study supports the use of latex and polyisoprene surgical gloves in procedures that involve the handling of PMMA bone cement.

Long-Term Ultrasound Twinkling Detectability and Safety of a Polymethyl Methacrylate Soft Tissue Marker Compared to Conventional Breast Biopsy Markers—A Preclinical Study in a Porcine Model

ObjectiveWe have studied the use of polymethyl methacrylate (PMMA) as an alternative biopsy marker that is readily detectable with ultrasound Doppler twinkling in cases of in vitro, ex vivo, or limited duration in vivo settings. This study investigates the long-term safety and ultrasound Doppler twinkling detectability of a PMMA breast biopsy marker following local perturbations and different dwell times in a 6-mo animal experiment. MethodsThis study, which was approved by our Institutional Animal Care and Use Committee, involved three pigs and utilized various markers, including PMMA (Zimmer Biomet), 3D-printed, and Tumark Q markers. Markers were implanted at different times for each pig. Mesh material or ethanol was used to induce a local inflammatory reaction near certain markers. A semiquantitative twinkling score assessed twinkling for actionable localization during monthly ultrasounds. At the primary endpoint, ultrasound-guided localization of lymph nodes with detectable markers was performed. Following surgical resection of the localized nodes, histomorphometric analysis was conducted to evaluate for tissue ingrowth and the formation of a tissue rind around the markers. ResultsNo adverse events occurred. Twinkling scores of all markers for all three pigs decreased gradually over time. The Q marker exhibited the highest mean twinkling score followed by the PMMA marker, PMMA with mesh, and Q with ethanol. The 3D-printed marker with mesh and PMMA with ethanol had the lowest scores. All wire-localized lymph nodes were successfully resected. Despite varying percentages of tissue rind around the markers and a significant reduction in overall twinkling (p < 0.001) over time, mean PMMA twinkling scores remained clinically actionable at 6 and 5 mo using a General Electric C1-6 probe and 9L-probe, respectively. ConclusionsIn this porcine model, the PMMA marker demonstrates an acceptable safety profile. Clinically actionable twinkling aids PMMA marker detection even after 6 mo of dwell time in porcine lymph nodes. The Q marker maintained the greatest twinkling over time compared to all the other markers studied.

Septic Tibial Shaft Non-Union Treated by One-Step Surgery Using a Custom-Made Intramedullary Antibiotic Cement-Coated Carbon Nail: Case Report, Focus on Surgical Technique and Brief Literature Review

Septic non-union (SNU) represents an insidious complication of open fractures. SNU is defined as a clinical and radiological evidence of cessation of fracture healing after 6-8 months of treatment, associated with persistence of clinical, laboratoristic and radiological signs of infection. The infection is mostly caused by bacteria and when it occurs at the bone fracture site, the healing process slows down and generally the treatment takes place in multiple phases. First a surgical debridement, often with the use of polymethylmethacrylate and local antibiotics, associated with specific systemic antibiotic therapy and a temporary stabilization of the septic non-union. Once the infection is cleared up, the final definitive synthesis is performed. Recently the use of implantable antibiotic medical devices in one step surgery has been introduced with encouraging results and have shown numerous advantages both in terms of management and morbidity for the patient. There are several "pre-formed" devices on the market, which however must be approved by the institution and often have the limit of a high cost in addition to the impossibility of using specific antibiotics. We want to report our experience with a clinical case of a tibial SNU successfully treated by one-step surgery procedure using a custom-made intramedullary antibiotic cement-coated carbon nail. We focus on surgical technique, advantages and pitfalls related to the use of these devices.

Uso de placa de polimetilmetacrilato (PMMA) no tratamento de craniosquise associada à meningocele em uma bezerra girolando: relato de caso

Abstract Most genetic diseases affect purebred animals and are inherited as recessive genes. Cranioschisis refers to dysraphism, which occurs in the midline of the skull due to failure to close the cranial symphysis, which can lead to herniation of the meninges filled with cerebrospinal fluid (meningocele), where there is usually a projection of the meningeal tissue. Diagnosis is performed based on clinical examination, characteristic anatomopathological data, and complementary imaging tests. The surgical approach for correction of cranioschisis is the only described as a therapeutic solution and is indicated in cases in which the cranial synthesis defect does not allow for brain protrusion and there is only the occurrence of meningocele, in addition to the absence of severe signs of neurological alteration. This paper reports a case of the use of polymethylmethacrylate (PMMA) plaque to treat cranioschisis associated with meningocele in a Girolando heifer. The surgical opening of the frontonasal sacculation allowed draining a total liquid content of 488 mL, inspection, and suture of the envelope membrane. APMMA plaque, molded to the bone surface and anchored in the adjacent soft tissue, was used to cover the evidenced frontonasal bone opening. Despite the unfavorable prognosis of the disease, the cranioplasty surgery for the treatment of cranioschisis associated with meningocele using PMMA plaque obtained satisfactory results relative to the quality and maintenance of this animal’s life, evaluated at 19 months postoperatively.

New bone formation using antibiotic-loaded calcium sulfate beads in bone transports for the treatment of long-bone osteomyelitis.

Bone transport is one of the most frequently used techniques for critical-sized bone defects due to trauma or infection. To fill the defect area and avoid the collapse of soft tissues during transport, some authors have described the use of polymethylmethacrylate or absorbable antibiotic carriers in the form of cylindrical blocks. In this article, we present our experience in the treatment of post-traumatic osteomyelitis of the lower and upper limbs, using a bone transport technique with antibiotic-loaded calcium sulfate in the form of beads. Results With the progressive absorption of calcium sulfate, we observed the formation of a bone-like tissue envelope at the periphery of the defect area. Histological analysis and direct visualization during open revision surgery of the docking site in all patients confirmed the presence of newly formed bone tissue with a high presence of osteoblasts and few osteoclasts; no areas of necrosis or signs of infection were observed. This bone envelope maintained the mechanical protective function of the transport path and docking site, and also provided a biological stimulus to avoid the development of necrotic areas and optimize the consolidation phase. Conclusion Bone transport with calcium sulfate beads improves biological and mechanical support and reduces the number of surgeries required.

Outcomes of Cranioplasty after Craniectomy

Objective: Craniectomy is a widely used procedure in neurosurgery that results in more cranioplasties to repair skull defects. The complication rate after cranioplasties seems to be higher than elective craniotomies so this study was conducted to determine the outcome of cranioplasty after craniectomy.&#x0D; Materials &amp; Methods: The patients included in this study had craniectomy and cranioplasty for any indication. Patients included had variables, such as age, sex, underlying pathology, craniectomy and cranioplasty dates, the material used for cranioplasty (autologous bone or methyl methacrylate), and methods of cranioplasty flap fixation (sutures or titanium plates and screws) follow up period and complications.&#x0D; Results: It was concluded that patients in the age group of 41 – 60 years (5 cases), males (7 cases), cranioplasty performed after 6 months (5cases) with autologous bone graft (8cases) were associated with more complications.&#x0D; Conclusion: The overall rate of complications associated with cranioplasties is not negligible, however, early cranioplasty in young patients with the use of polymethyl methacrylate may be associated with less complication rate.&#x0D; Keywords: Decompressive, Craniectomy, Cranioplasty, Autologous, Polymethyl Methacrylate

Pyrolysis and combustion behavior study of PMMA waste from micro-scale to bench-scale experiments

With the increasing use of polymethyl methacrylate (PMMA), there is growing concern about its waste utilization. It is of great significance to study its pyrolysis and combustion behaviors, then a series of experiments were conducted from micro-scale (thermogravimetry, fourier transform infrared spectroscopy and mass spectrometry) to bench-scale (fire propagation apparatus and cone calorimeter). By the micro-scale experiments, the pyrolysis kinetic model was established and kinetic parameters were obtained by coupling the Shuffled Complex Evolution optimization algorithm. Moreover, based on the inferred pyrolysis gases and functional groups, the possible chemical reactions of PMMA pyrolysis from molecular structure were also put forward. By the bench-scale experiments, the pyrolysis and combustion behaviors were further studied by coupling the pyrolysis kinetics and mass/heat transfer process, including mass loss rate, heat release rate and CO2/CO production. The obtained pyrolysis and combustion characteristics by the multi-scale experiments would be helpful for the further energy utilization.

Customized polymethylmethacrylate cranioplasty using a low-cost 3-dimensional printed mold

Introduction. Significant cranial defects result from a decompressive craniectomy following head trauma, malignant brain edema, intracranial hemorrhage, or resection of tumor affected bone. Unrepaired cranial defects are not just a tremendous esthetic problem. The underlying brain is unprotected, prone to injury, and this state can lead to the so-called ?syndrome of the trephined? with mood instability, headaches, and even a neurological deficit. Currently, there is no widely accepted uniform technique of cranial vault shape restoration. Combining 3D technology with the use of polymethylmethacrylate is a challenging field that can bring good functional and aesthetic results and, in the case of smart design, become efficient, low-cost technology. We offer a possible solution to a problem that would be acceptable in neurosurgical practice. Case outline. We present a 37-year-old male patient with a massive hemicranial defect as a consequence of previous decompressive craniectomy following severe craniocerebral injury the previous year. Together with engineers from the appropriate 3D modeling studio, we have designed a two-part mold by laser printing technology using biocompatible advanced polyamide. We made a customized polymethylmethacrylate graft intraoperatively using this mold and achieved good aesthetic results. Conclusion. Reports of 3D printing assisted cranioplasties are growing, describing different techniques and cost- estimation. We hope to introduce a low-cost and simple method for repairing a skull defect.

Analysis of intensification methods for fine dry-ground powder materials

The paper describes the influence of various intensifiers on the material grinding process. The most well-known method for intensifying chip grinding consists in the use of polymethyl methacrylate (PMMA), a high molecular weight polymer additive. It intensifies crushing of steel chips as compared to grinding in the air or in alcohol and reduces the oxygen content in the metal phase, improving the properties of the resulting powder. However, contamination of the powders with polymer degradation products significantly limits the applications of this method for intensifying chip grinding. Based on the data in various studies, gases may be rated as follows in terms of their effect on the disintegration of metal powders: hydrogen &gt; helium &gt; argon &gt; nitrogen &gt; air. When comparing the intensification of fine grinding of metal powders with the use of PMMA and a gaseous medium, it may be concluded that both methods have a common major drawback, which is the contamination of the finished powders with the products of interaction between the grinding intensifiers and the material being ground. In order to improve the disintegration efficiency of metal powders and minimize the negative effect, a wide range of experimental studies will be required, with the grinding of metal waste not only in gaseous, but also in liquid media, as well as with the use of surfactants. A comprehensive study of the effects of various media and surfactants on the grinding kinetics, both when used individually and in combinations, may help identify the best intensifiers that would eliminate the unnecessary contamination of the grinding products.The study was carried out under the grant issued by the Russian Science Foundation (project No. 20-79-10125).

Lung injury in patients age 75 years and older with the use of polymethylmethacrylate fenestrated pedicle screws

Pulmonary complications in patients age 75 years and older who undergo spinal fusion may have catastrophic consequences. The use of augmentation techniques with polymethylmethacrylate (PMMA) have been associated with pulmonary damage. The use of fenestrated pedicle screws augmented with PMMA may increase the risk of lung injury in this population. To investigate whether the use of PMMA-augmented screws is correlated with increased lung injury in patients undergoing instrumented lumbar spinal fusion. A nonrandomized, prospective, case-controlled clinical study was carried out. We included 50 consecutive patients: 25 classifieds as patients who required PMMA-augmented screws in lumbar spinal fusion, and 25 classifieds as control participants because they underwent uncemented instrumented spinal fusion. We compare the incidence of the event, lung damage, in both groups by measuring a series of parameters: arterial blood gas, transesophageal echocardiography, urinary desmosine, and chest radiograph. The epidemiological parameters analyzed were age, sex, body mass index, status as a smoker, and number of cement leaks. Changes in pulmonary damage markers were described in both groups of patients, comparing postsurgery values with baseline values. In control participants, each change was evaluated for the total number of patients. All changes are indicated in this report by mean differences for quantitative variables and by differing proportions for qualitative variables, with 95% confidence intervals provided for all values. There was an increase in postinstrumentation PaO2 (arterial partial pressure of oxygen) in both groups, probably related to the use of mechanical ventilation and recruitment maneuvers. Even though the group that required augmentation had lower baseline levels, the difference between groups was not statistically significant. On transesophageal echocardiographs, we observed scattered small, snowflake-like emboli, and bright echo signals appeared in the right atrium during PMMA injection. Signal density was constant but gradually faded away when PMMA injection ended. No participants in the group without augmentation had radiological complications. Overall, desmosine levels increased in both groups, and the rise was similar in both. There was a slight average increase in urine desmosine levels after instrumentation and progressively continues to rise until 24 hours after instrumentation, with a subsequent decrease at 72 hours. Comparing the two groups, we found no statistically significant differences at any time. We were not able to identify a significant difference in urine desmosine levels associated with the augmentation of with fenestrated pedicle screws with PMMA. Despite comparing patients age 75 years or older with a younger group, we found no clinical, analytical, or gasometric data indicating lung damage in patients who had augmentation.

Evaluation of Temperature Influence on Tensile Strength and Izod Impact Resistance on Poly Methyl Methacrylate (PMMA)

The increasing use of poly methyl methacrylate (PMMA), often replacing tempered glass, is a consequence of its high rigidity, practicality, lightness and transparency. However, current manufacturing standards in the polymer industry recommend specific tests on these materials. The present study aims to mechanically test the properties of poly methyl methacrylate (PMMA) material under conditions that simulate a much more aggressive environment than usual. Infrared spectroscopy (FTIR), thermogravimetric (TG/DTG) tests, Izod impact tests, and scanning electron microscopy (SEM) analysis were performed. The results showed that poly (methyl methacrylate) (PMMA) maintained its tensile mechanical properties up to 105°C. Regarding the impact tenacity, the temperature negatively influenced the performance of this polymer.

Long-term clinical complications associated with the use of polymethyl methacrylate in spinal stabilization of dogs and cats: case series

Vertebral and spinal cord trauma are common conditions in small animal practice and often result in vertebral fractures/luxation (VFL) with concomitant spinal cord laceration, concussion, compression, or ischemia. These lesions have several clinical presentations that may vary from moderate to severe pain and partial to total loss of motor, sensory, and visceral functions, which may result in death or euthanasia. Our purpose is to describe five cases (four dogs and one cat) of complications secondary to the use of bone cement for vertebral stabilization. The patients, between five months and four years of age and weighing between 1.4 and 12.2 kg, were referred to the Small Animal Orthopedics and Traumatology Service of the Veterinary Hospital of the College of Veterinary Medicine and Animal Science of the University of São Paulo. They had a history of post-operatory polymethyl methacrylate (PMMA) reactions (such as drainage or cement exposure due to infection or implant failure) in periods from 9 to 18 months after undergoing spinal osteosynthesis. Surgical implant removal occurred in 80% of the patients (4/5). Complete remission was not observed in the patient with residual implants. The association of pins/screws and PMMA is a versatile osteosynthesis technique and is applicable in all spinal regions. However, delayed complications can occur, which could require additional surgical procedures. Despite the small number of cases included in this study, one can infer that complications related to the use of bone cement in spinal surgery can occur in the long term and should be highlighted during the implant choosing process for vertebral osteosynthesis in small animals.

P0531CONTINUOUS HEMODIAFILTRATION WITH PMMA HEMOFILTER MODULATED COMPLEMENT ACTIVATION AND RENAL DYSFUNCTION IN A SWINE MODEL OF SEPSIS-INDUCED ACUTE KIDNEY INJURY

Abstract Background and Aims Sepsis-induced acute kidney injury (AKI) is a growing health care problem, refractory to conventional treatments. This disease is characterized by an overwhelmed immune response against a primary insult that become responsible for renal dysfunction and poor outcome. Therapeutic strategies based on blood purification have been developed for the treatment of this disease. The use of polymethyl methacrylate (PMMA) membrane hemofilter in continuous hemodiafiltration (CHDF) modality showed better hemodynamic stability and efficient renal support in chronic dialysis maintenance. Here we investigated the efficacy of Hemofeel PMMA membrane (TORAY, Japan) in interfering with Complement activation and renal damage in a swine model of sepsis-induced AKI. Method After 3 hours from LPS infusion, 7 hours of PMMA-CVVH treatment or 7 hours of polysulfone (PSF)-CVVH were performed. Animals were sacrificed after 24h from LPS infusion. Histologic and renal function parameters were analyzed in all pigs. Pentraxin-3 (PTX3) and C5b-9 deposits were assessed on renal biopsies. Systemic Complement activation was evaluated by Wieslab kit. Gene expression profile was obtained from isolated PBMCs by Agilent SurePrint G3 Porcine Gene Expression Microarrays. Genespring and R software were used for the analysis. Results were validated by Real-time PCR. Results Analysis of renal biopsies from septic pigs presented increased interstitial leucocyte infiltrate, extensive collagen deposition and diffuse glomerular thrombi compared to healthy pigs (p&amp;lt;0.05). Confocal analysis showed extensive PTX-3 and C5-b9 deposits at tubulo-interstitial level associated with significant activation of systemic complement classical and alternative pathways (p&amp;lt;0.05). Interestingly, PMMA-CVVH treatment significantly reduced local and systemic complement activation, leucocyte infiltrate and tubule-interstitial fibrosis (p&amp;lt;0.05). On the contrary, no significant improvement was observed by PSF-CVVH treatment. Then, we compared the whole-genome gene expression profiles of swine PBMC. We identified 711 differentially expressed genes comparing PBMC before LPS infusion (LPS T0) and after 24 hours from LPS infusion (LPS T24) and 913 genes comparing gene expression profiles of LPS T24 group with that of septic pigs treated with PMMA-CVVH (PMMA T24 group) (fold change &amp;gt;2 ; false discovery rate &amp;lt;0.05). The most modulated genes were Granzime B, Complement Factor B, Complement Component 4 Binding Protein Alpha, IL-12, SERPINB-1 and TIMP-2 that were closely related to sepsis-induced immunological process. Finally, quantitative PCR confirmed the microarray data indicating that Granzime B and Complement Factor B upregulation in PBMC was significantly hampered by PMMA treatment. Conclusion Our data suggest that LPS induced AKI is characterized by activation of Classical and alternative Complement pathways resulting in significant renal tissue damage. By interfering with complement activation and inflammatory response, PMMA membrane might prevent dysfunctional activation of resident renal cells with prevention of sepsis-induced AKI.

Fabrication process of InGaAs-based nanodiode array using electron-beam lithography technique

Self-switching diode (SSD) is a unipolar two-terminal planar device which has a typical channel in nanoscale dimension. It has shown outstanding properties as a microwave and submillimeter wave rectifier by exploiting its nonlinear current-voltage (I-V) characteristic and intrisically low parasitic capacitance. In detection systems, SSDs are often used with an antenna to form a rectifying antenna (rectenna). The large impedance mismatch between SSD and antenna, due to high resistance of a single SSD, has always hampered the rectenna to achieve good extrinsic rectification performance (e.g., voltage responsivity > 400 V/W). As such, a large array of SSDs connected in parallel is very much desired to reduce the device resistance, and hence minimizing the impedance mismatching issue. In this work, an interdigital structure which can accommodate approximately 2,000 SSDs in parallel has been utilized. The material used was InGaAs/InAlAs heterostructure grown onto an InP substrate. The fabrication of the SSD array has implemented an electron-beam lithography (EBL) technique and the use of polymethyl methacrylate (PMMA) as a masking layer. The fabricated SSD array has shown a typical diode-like I-V characteristic, indicating that EBL method is not only convenient to realize nanoscale electronic devices, but also very practical for large area operations.

Steinmann Pins and Polymethylmethacrylate Repair of Fourth Lumbar Vertebral Fracture and Dorsocranial Luxation in PuppySteinmann Pins and Polymethylmethacrylate Repair of Fourth Lumbar Vertebral Fracture and Dorsocranial Luxation in Puppy

Background: Acute spinal traumas can lead to irreversible damage associated with vascular and inflammatory changes in neural tissue. Since spine and spinal cord traumas have an unfavorable prognosis in small animals, and reports of the use of Steinmann pins and polymethylmethacrylate repair of lumbar vertebra fracture-luxation in puppies are rare in the literature, the present paper aimed to report the surgical treatment of transversal fracture through the body of the fourth lumbar vertebra, with dorsocranial displacement of the caudal fragment by using Steinmann pins and polymethylmethacrylate in a 7-month-old Labrador Retriever male dog.Case: A 7-month-old intact male Labrador Retriever dog, weighing 24.0 kg was attended at School Veterinary Hospital with a history of hit by car and paraplegia of the hind limbs. On neurological examination was observed no proprioception and no deep pain sensitivity on the both pelvic limbs. The lumbar spinal palpation showed intense pain, and the motor function and patellar reflexes were reduced. The values of haematological and biochemical analysis remained within the reference values for the species. Radiographs revealed a transversal fracture through the body of the fourth lumbar vertebra, with dorsocranial displacement of the caudal fragment, and was decided to perform a surgical treatment by open reduction and internal fixation of the fracture. The dog was positioned in ventral recumbency for surgery, and a dorsal midline incision was made from the second lumbar vertebra to the sixth lumbar vertebra. Two crossed 1.5 mm Kirschner wires were placed through the caudal articular facets of the fourth lumbar vertebra to provide initial stability. Two 2.0 mm Steinmann pins were placed at 60° angle of the bodies of the second and fifth lumbar vertebrae, and third and fourth lumbar vertebrae. This procedure was repeated on the other side of the vertebral bodies. Sixty grams of polymethylmethacrylate bone cement was applied and the fixation was checked for stability. Muscular, subcutaneous tissue and skin was closed routinely. The dog was paraplegic without any pain and used a wheelchair to assist in locomotion, although it still had urinary and faecal incontinence; no tail control; and the implants were not removed.Discussion: Lumbar vertebral injuries, as in the present case frequently, occur secondary to severe trauma (e.g. hit by car) and seem to have a characteristic fracture pattern. The patient became paraplegic due to spinal cord injury and failure of sensitivity and elimination of urine and feces which can be associated with progressive destruction of neuronal tissue due to secondary vascular and inflammatory events. The radiographic exam was used to confirm the spinal injury and determine whether by conservative or surgical treatment. The treatment choice is related to the number of fractured compartments, and the presence or not of compression. Fractures in two or more compartments are indicative of surgical treatment, similar as the present case. Use of Steinmann pins was to make a rigid fixing system compared with block plates used for the same function. Use of polymethylmethacrylate may also become a complication due to the infection, for this reason was prescribed an antibiotic for 15 days. This procedure proved to be effective since the dog showed no signs of infection. According to the characteristics of the present case report, the use of Steinmann pins and polymethylmethacrylate for repair of transversal fracture through the body of the fourth lumbar vertebra, with dorsocranial displacement of the caudal fragment provided an effective and practical means of stabilisation, promoting decompression, and thus, improving the patient's quality of life.

Fat embolism syndrome secondary to the use of polymethylmethacrylate in bioplasty: a systematic review

A Revista Brasileira de Cirurgia Plástica é o órgão oficial de divulgação da Sociedade Brasileira de Cirurgia Plástica (SBCP), tem como objetivo registrar a produção científica em Cirurgia Plástica, fomentar o estudo, aperfeiçoamento e atualização dos profissionais da especialidade.

Polymethylmethacrylate patient-matched implants (PMMA-PMI) for complex and revision cranioplasty: analysis of long-term complication rates and patient outcomes

ABSTRACTObjective: Cranioplasty (CP) is associated with high complication rates and patient-matched implants (PMI) are frequently used for CP. However, only limited data are available regarding complication rates of PMI-based CP after complex or failed primary CP. Here we report our experience with the use of polymethylmethacrylate (PMMA) PMI for this purpose.Method: We analyzed all patients with complex or failed primary CP and subsequent implantation of PMMA-PMI between 2010 and 2015 at our institution.Results: A total of 67 patients (29 females, 38 males) with a mean age of 43 years (range: 13–74 years) were included in the study. Primary PMI-CP was performed in 18 patients with destructive or osteolytic bone tumors. Secondary PMI-CP was performed in 49 patients. Complications occurred in 14 patients with an overall complication rate of 21.7% during a mean follow-up of 39.7 ± 23.4 month. Approximately two-thirds of the patients reported a good quality of life after the initial event and subsequent CP. The majority of patients (>90%) was satisfied with the cosmetic result.Conclusion: Surgical CP with PMMA-PMI appears to be a suitable method for patients with failed or complex CP. Complication rates are comparable to those reported for primary CP.

296 Increased Penis Circumference and Quality of Life

Men who believe they have a thin penis produce an unsatisfactory quality of sexual life. This work aims to determine if the increase of the penis in circumference brings gains in the quality of life. To determine if the increase of the circumference of the penis up to 5 cm brought an improvement in the quality of life of the 64 patients attended between 2015 to 2017. In this study, we followed 64 patients who performed the procedure in 2015, and 23 patients (35.94%) answered the questionnaire by email, whatsapp or telephone spontaneously. Among its different therapeutic functions, the use of polymethyl methacrylate (PMMA) for more than two decades has been highlighted in the replacement of lost volumes with the aging and filling of wrinkles and wrinkles. It is considered a permanent biomaterial, although its reliability is widely discussed. The implant used was PMMA (10%) in the 20 ml volume under local anesthesia (xylocaine), 20 days after postectomy and allergy test. Outpatient. After subcutaneous PMMA implantation, the mechanical traction should be used for 30 days. Being the daily use minimum of 6 hours. It should be used at intervals of 1 hour every 2 hours of use.