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1.
Global Spine J ; : 21925682231218729, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38015818

RESUMO

STUDY DESIGN: Retrospective Study. OBJECTIVES: Minimally invasive endoscopic spinal surgery is gaining popularity, but our understanding of the lumbar spine's microvascular geometry relies heavily on cadaver studies and textbook illustrations. Additionally, inconsistent nomenclature of vessels in the literature hampers effective communication among surgeons. This study aims to improve the clarity and comprehensibility of the lumbar spinal microvascular geometry under endoscopic view. METHODS: The study included 400 patients who underwent endoscopic spinal surgery for lumbar spinal canal stenosis and foraminal stenosis. The surgeries were performed by an experienced surgeon using either the interlaminar or transforaminal approach. Endoscopic video recordings were further analyzed to map the microvascular geometry and common bleeding foci. The observed results were cross-referenced with existing literature to reconstruct a comprehensive view of the vascular anatomy. RESULTS: The transforaminal approach commonly encounters bleeding foci originating from the major branches of the segmental lumbar artery and the emissary veins within the foramen. The interlaminar approach primarily encounters bleeding foci from the muscle vessels in the dorsal lamina, which are believed to be located near the ends of the three main branches. In the intracanal region, epidural vessels form a rotary loop above the disc, which can contribute to most of the bleeding during discectomy. CONCLUSIONS: This study provides a comprehensive understanding of the microvascular anatomy in the lumbar spine during endoscopic spinal surgery. Recognizing the geometry will help surgeons anticipate and control bleeding, reducing the risk of complications. The findings contribute to the improvement of surgical techniques and patient safety in endoscopic spinal surgery.

2.
BMC Musculoskelet Disord ; 24(1): 426, 2023 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-37244983

RESUMO

BACKGROUND: The NASS guideline cannot recommend any of the surgical treatment options toward adult isthmic spondylolisthesis (AIS) since 2014. After the introduction of endoscopic decompression, instead of treating the spondylolysis itself, treatment can specifically target the refractory radicular pain developed during the degeneration progress without devastating the peripheral soft tissue. However, we noticed that endoscopic transforaminal decompression seems to be less effective in AIS compared to other types of degenerative spondylolisthesis. Thus, we came up with a novel craniocaudal interlaminar approach, utilizing the proximal adjacent interlaminar space to perform bilateral decompression and observed the pathoanatomy of pars defect directly and tried to identify the cause of decompression failure. METHODS: From January 2022 to June 2022, 13 patients with AIS underwent endoscopic decompression via the endoscopic craniocaudal interlaminar approach and were followed up for at least 6 months. Visual Analogue Scale, Oswestry Disability Index and MacNab scores were recorded to monitor patients' clinical recovery. All endoscopic procedures were recorded and reviewed to illustrate the pathoanatomy. RESULTS: Four patients required minor revision via the same technique. One of them required it due to incomplete isthmic spur resection, two due to neglected disc protrusion, and the other due to root subpedicular kinking in higher grade anterolisthesis. All patients' clinical condition improved significantly subsequently. After reviewing the endoscopic video, we have observed that the hook-like, ragged spur originating from the isthmic defect extends beyond the region around the foramen. Instead, it extends proximally into the adjacent lateral recess, resulting in impingement along the fracture edge above the index foramen and, in some cases, even in the extraforaminal area. CONCLUSIONS: The broad spanning isthmic spur extending to the proximal adjacent lateral recess might be the reason why the transforaminal approach yielded less satisfactory results due to the incomplete decompression result from approach related restriction. Our study demonstrated an optimistic outcome by applying decompression from the upper level. Therefore, we propose that the craniocaudal interlaminar approach might be a better route for decompression in adult isthmic spondylolisthesis.


Assuntos
Estenose Espinal , Espondilolistese , Humanos , Adulto , Espondilolistese/complicações , Espondilolistese/diagnóstico por imagem , Espondilolistese/cirurgia , Descompressão Cirúrgica/métodos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Endoscopia/métodos , Resultado do Tratamento , Estenose Espinal/cirurgia , Estudos Retrospectivos
3.
Medicina (Kaunas) ; 58(7)2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35888592

RESUMO

Background and Objectives: The boost dose to the tumor bed after whole breast irradiation (WBI) can be divided into sequential boost (SEQ) and simultaneous integrated boost (SIB). SIB using modern radiation therapy (RT) techniques, such as volumetric modulated arc therapy, allow the delivery of a highly conformal dose to the target volume and has a salient ability to spare at-risk organs. This study aimed to compare the radiation dose delivered to the heart and lungs according to boost technique and tumor bed location. Materials and Methods: RT planning data of 20 patients with early-stage left-sided breast cancer were used in this study. All patients were treated with volumetric modulated arc therapy after breast-conserving surgery with a sentinel lymph node biopsy. For each patient, two different plans, whole breast irradiation with simultaneous integrated boost (WBI-SIB) and sequential boost after WBI (WBI-SEQ), were generated. To compare the dose received by each organ at risk (OAR), dose-volume histogram data were analyzed. The mean dose (Dmean) and volume of each organ that received x Gy (Vx) were calculated and compared. Results: For the heart, the V10 was lower for the WBI-SIB plan than for the WBI-SEQ plan (5.223 ± 1.947% vs. 6.409 ± 2.545%, p = 0.008). For the left lung, the V5 was lower in the WBI-SIB plan than for the WBI-SEQ plan (27.385 ± 3.871% vs. 32.092 ± 3.545%, p < 0.001). The Dmean for the heart and left lung was lower for the WBI-SIB plan than for the WBI-SEQ plan (heart: 339.745 ± 46.889 cGy vs. 413.030 ± 52.456 cGy, p < 0.001; left lung: 550.445 ± 65.094 cGy vs. 602.270 ± 55.775 cGy, p < 0.001). Conclusions: The WBI-SIB plan delivered lower radiation doses to the heart and left lung than the WBI-SEQ plan in terms of Dmean and low-dose volume in hypofractionated RT of early-stage left-sided breast cancer patients. Furthermore, a large radiation dose per day may be advantageous, considering the radiobiologic aspects of breast cancer. Long-term follow-up data are needed to determine whether the dosimetric advantages of the WBI-SIB plan can lead to clinically improved patient outcomes and reduced late side effects.


Assuntos
Neoplasias da Mama , Neoplasias Unilaterais da Mama , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Pulmão/patologia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias Unilaterais da Mama/radioterapia , Neoplasias Unilaterais da Mama/cirurgia
4.
Med Phys ; 48(9): 5327-5342, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34224166

RESUMO

PURPOSE: Recently, high-precision radiotherapy systems have been developed by integrating computerized tomography or magnetic resonance imaging to enhance the precision of radiotherapy. For integration with additional imaging systems in a limited space, miniaturization and weight reduction of the linear accelerator (linac) system have become important. The aim of this work is to develop a compact medical linac based on 9.3 GHz X-band RF technology instead of the S-band RF technology typically used in the radiotherapy field. METHODS: The accelerating tube was designed by 3D finite-difference time-domain and particle-in-cell simulations because the frequency variation resulting from the structural parameters and processing errors is relatively sensitive to the operating performance of the X-band linac. Through the 3D simulation of the electric field distribution and beam dynamics process, we designed an accelerating tube to efficiently accelerate the electron beam and used a magnetron as the RF source to miniaturize the entire linac. In addition, a side-coupled structure was adopted to design a compact linac to reduce the RF power loss. To verify the performance of the linac, we developed a beam diagnostic system to analyze the electron beam characteristics and a quality assurance (QA) experimental environment including 3D lateral water phantoms to analyze the primary performance parameters (energy, dose rate, flatness, symmetry, and penumbra) The QA process was based on the standard protocols AAPM TG-51, 106, 142 and IAEA TRS-398. RESULTS: The X-band linac has high shunt impedance and electric field strength. Therefore, even though the length of the accelerating tube is 37 cm, the linac could accelerate an electron beam to more than 6 MeV and produce a beam current of more than 90 mA. The transmission ratio is measured to be approximately 30% ~ 40% when the electron gun operates in the constant emission region. The percent depth dose ratio at the measured depths of 10 and 20 cm was approximately 0.572, so we verified that the photon beam energy was matched to approximately 6 MV. The maximum dose rate was measured as 820 cGy/min when the source-to-skin distance was 80 cm. The symmetry was smaller than the QA standard and the flatness had a higher than standard value due to the flattening filter-free beam characteristics. In the case of the penumbra, it was not sufficiently steep compared to commercial equipment, but it could be compensated by improving additional devices such as multileaf collimator and jaw. CONCLUSIONS: A 9.3 GHz X-band medical linac was developed for high-precision radiotherapy. Since a more precise design and machining process are required for X-band RF technology, this linac was developed by performing a 3D simulation and ultraprecision machining. The X-band linac has a short length and a compact volume, but it can generate a validated therapeutic beam. Therefore, it has more flexibility to be coupled with imaging systems such as CT or MRI and can reduce the bore size of the gantry. In addition, the weight reduction can improve the mechanical stiffness of the unit and reduce the mechanical load.


Assuntos
Elétrons , Aceleradores de Partículas , Simulação por Computador , Imageamento por Ressonância Magnética , Imagens de Fantasmas
5.
Rev Sci Instrum ; 92(2): 024103, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33648097

RESUMO

A compact X-band linear accelerator (LINAC) system equipped with a small and lightweight magnetron was constructed to develop a high-precision image-guided radiotherapy system. The developed LINAC system was installed in an O-ring gantry where cone-beam computed tomography (CBCT) was embedded. When the O-arm gantry is rotated, an x-ray beam is stably generated, which resulted from the stable transmission of radio frequency power into the X-band LINAC system. Quality assurance (QA) tests, including mechanical and dosimetry checks, were carried out to ensure safety and operation performance according to the American Association of Physicists in Medicine's TG-51, 142, an international standard protocol established by accredited institutions. In addition, delivery QA of the radiotherapy planning system was conducted to verify intensity-modulated radiotherapy techniques. Therefore, it was demonstrated that the developed X-band LINAC system mounted on the O-arm gantry proved to be valid and reliable for potential use in CBCT image-guided radiation therapy.


Assuntos
Aceleradores de Partículas/instrumentação , Radioterapia/instrumentação , Rotação , Desenho de Equipamento
6.
Biomed Res Int ; 2020: 8815432, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33381586

RESUMO

Interbody fusion is a common surgical technique for diseases of the lumbar spine. Biportal endoscopic-assisted lumbar interbody fusion (BE-LIF) is a novel minimally invasive technique that has a long learning curve, which can be a barrier for surgeons. Therefore, we analyzed the learning curve in terms of operative time and evaluated the outcomes of BE-LIF. A retrospective study of fifty-seven consecutive patients who underwent BE-LIF for degenerative lumbar disease by a single surgeon from January 2017 to December 2018 was performed. Fifty patients underwent a single-level procedure, and 7 underwent surgery at two levels. The mean follow-up period was 24 months (range, 14-38). Total operative time, postoperative drainage volume, time to ambulation, and complications were analyzed. Clinical outcome was measured using the Oswestry Disability Index (ODI), Visual Analog Scale (VAS) score for back and leg pain, and modified Macnab criteria. The learning curve was evaluated by a nonparametric regression locally weighted scatterplot smoothing curve. Cases before the stable point on the curve were designated as group A, and those after the stable point were designated group B. Operative time decreased as the number of cases increased. A stable point was noticed on the 400th day and the 34th case after the first BE-LIF was performed. All cases showed improved ODI and VAS scores at the final follow-up. Overall mean operative time was 171.74 ± 35.1 min. Mean operative time was significantly lower in group B (139.7 ± 11.6 min) compared to group A (193.4 ± 28.3 min). Time to ambulation was significantly lower in group B compared to group A. VAS and ODI scores did not differ between the two groups. BE-LIF is an effective minimally invasive technique for lumbar degenerative disease. In our case series, this technique required approximately 34 cases to reach an adequate performance level.


Assuntos
Endoscopia , Curva de Aprendizado , Vértebras Lombares/cirurgia , Fusão Vertebral , Idoso , Competência Clínica , Endoscopia/efeitos adversos , Endoscopia/educação , Endoscopia/métodos , Endoscopia/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias , Estudos Retrospectivos , Fusão Vertebral/efeitos adversos , Fusão Vertebral/educação , Fusão Vertebral/métodos , Fusão Vertebral/estatística & dados numéricos , Resultado do Tratamento
7.
J Orthop Surg Res ; 15(1): 557, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33228753

RESUMO

BACKGROUND: Although literature provides evidence regarding the superiority of surgery over conservative treatment in patients with lumbar disc herniation, recurrent lumbar disc herniation (RLDH) was the indication for reoperation in 62% of the cases. The major problem with revisional lumbar discectomy (RLD) is that the epidural scar tissue is not clearly isolated from the boundaries of the dura matter and nerve roots; therefore, unintended durotomy and nerve root injury may occur. The biportal endoscopic (BE) technique is a newly emerging minimally invasive spine surgical modality. However, clinical evidence regarding BE-RLD remains limited. We aimed to compare the clinical outcomes after performing open microscopic (OM)-RLD and BE-RLD to evaluate the feasibility of BE-RLD. METHODS: This retrospective study included 36 patients who were diagnosed with RLDH and underwent OM-RLD and BE-RLD. RLDH is defined as the presence of herniated disc material at the level previously operated upon in patients who have experienced a pain-free phase for more than 6 months. BE-RLD was performed as follows: two independent surgical ports were made inside the medial pedicular line of the target segment and on the intact upper and lower laminas. Peeling off the soft tissue from the vertebral lamina helps to easily identify the traversing nerve root and the recurrent disc material without dealing with the fibrotic scar tissue. Clinical outcomes were obtained using a visual analog scale (VAS) and the modified Macnab criteria before and at 2 days, 2 and 6 weeks, and 3, 6, and 12 months after surgery. RESULTS: The data of 20 and 16 patients who underwent OM-RLD and BE-RLD, respectively, were evaluated. The demographic and perioperative data were comparable between the groups. During the year following the surgery, in the BE-RLD group, the VAS scores at each point were significantly improved over the baseline and remained improved up to 2 weeks after surgery (p < 0.05); however, no statistical difference between the two groups was observed after 6 weeks of surgery (p > 0.05). According to the modified Macnab criteria on the follow-up, the excellent or good satisfaction rates reported at 2 weeks, 6 weeks, 6 months, and 12 months after surgery were 81.25%, 81.25%, 75%, and 81.25%, respectively, in the BE-RLD group, and 50%, 75%, 75%, and 80%, respectively, in the OM-RLD group. CONCLUSION: BE-RLD yielded similar outcomes to OM-RLD, including pain improvement, functional improvement, and patient satisfaction, at 1 year after surgery. However, faster pain relief, earlier functional recovery, and better patient satisfaction were observed when applying BE-LRD. TRIAL REGISTRATION: Retrospectively registered.


Assuntos
Discotomia/métodos , Endoscopia/métodos , Deslocamento do Disco Intervertebral/cirurgia , Vértebras Lombares/cirurgia , Adulto , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
8.
Spine (Phila Pa 1976) ; 45(20): E1349-E1356, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32969993

RESUMO

STUDY DESIGN: A prospective study. OBJECTIVE: To evaluate the change in cervical epidural pressure (CEP) during biportal endoscopic lumbar discectomy (BELD). SUMMARY OF BACKGROUND DATA: In percutaneous uniportal endoscopic lumbar discectomy, irrigation fluid (IF) introduced into the spinal canal during surgery can compress the thecal sac, and act as a potential risk for neurological complications by disturbing cerebrospinal fluid (CSF) circulation and increasing intracranial pressure. METHODS: Thirty consecutive patients, who underwent BELD, which was performed under automated pump system, an infusion pressure of 30 mmHg were enrolled. The change in CEP on C7-T1 level was measured. CEP was measured in each of the five phases of the procedure (1st phase-making surgical portals; 2nd phase-creating a workspace; 3rd phase-performing neural decompression and discectomy; 4th phase-factitious increase of pressure by clogging the outflow; 5th phase-dismission from fluid irrigation system). Neurological complications and independent risk factors were evaluated. RESULTS: In the final 27 patients, changes in CEP during surgery were similar. The baseline CEP was 14.8 ±â€Š2.8 mmHg, and the mean CEP in the 3rd phase 18.8 ±â€Š5.1 mmHg was not significantly higher. In the 4th phase, however, the CEPs rose with linear correlation as the pressure increased. In the 5th phase, the elevated CEP returned to baseline in 2.5 ±â€Š5.6 minutes. No patient had neurological complications. No statistically significant risk factors were observed. CONCLUSION: In BELD, which is performed to allow continuous lavage with infusion pressure set to 30 mmHg, CEP does not increase beyond the physiological range. Therefore, BELD may be considered as a potentially safe technique. LEVEL OF EVIDENCE: 4.


Assuntos
Discotomia , Endoscopia , Espaço Epidural/fisiopatologia , Vértebras Lombares/cirurgia , Adulto , Idoso , Descompressão Cirúrgica , Discotomia Percutânea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pescoço/cirurgia , Procedimentos Neurocirúrgicos , Pressão , Estudos Prospectivos , Segurança , Estenose Espinal/cirurgia , Irrigação Terapêutica , Resultado do Tratamento , Adulto Jovem
9.
Biomed Res Int ; 2020: 4801641, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32695815

RESUMO

BACKGROUND: Symptomatic postoperative spinal epidural hematoma (PSEH) is a devastating complication that could develop after lumbar decompression surgery. PSEH can also develop after biportal endoscopic spine surgery (BESS), one of the recently introduced minimally invasive spine surgery techniques. Gelatin-thrombin matrix sealant (GTMS) is commonly used to prevent PSEH. This study aimed at analyzing the clinical and radiological effects of GTMS use during BESS. METHODS: A total of 206 patients with spinal stenosis who underwent decompression by BESS through a posterior interlaminar approach from October 2015 to September 2018 were enrolled in this study. Postoperative magnetic resonance imaging (MRI) was performed in all patients for evaluation of PSEH. Patients in whom GTMS was not used during surgery were assigned to Group A, and those in whom GTMS was used were classified as Group B. In the clinical evaluation, the visual analog scale (VAS) of the leg and back, Oswestry Disability Index (ODI), and modified MacNab criteria were used. The incidence rate and degree of dural compression of PSEH on postoperative MRI were measured. RESULTS: The average age of the patients was 68.1 ± 11.2 (42-89) years. The overall incidence rate of PSEH was 20.9% (43/206). The incidence rates in Groups A and B were 26.4% and 13.6%, respectively, showing a significant difference (p = 0.023). The VAS-leg and ODI improvement was significantly different depending on the intraoperative use of GTMS. However, there was no statistically significant difference between the two groups in terms of the VAS-back improvement. Groups A and B showed "good" and "excellent" rates according to the modified MacNab criteria in 79.4% and 87.6% of patients, respectively, showing statistically significant difference (p = 0.049). In Group A, two patients underwent revision surgery due to PSEH, while none in Group B had such event. CONCLUSION: Intraoperative use of GTMS during BESS may be related to reduction in the occurrence rate of PSEH. Specifically, patients with GTMS appliance showed marked decrease in the occurrence of PSEH and had better clinical outcomes.


Assuntos
Descompressão Cirúrgica , Endoscopia , Gelatina/farmacologia , Hematoma Epidural Espinal/etiologia , Vértebras Lombares/cirurgia , Imageamento por Ressonância Magnética , Complicações Pós-Operatórias/etiologia , Trombina/farmacologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Hematoma Epidural Espinal/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico por imagem , Reoperação , Resultado do Tratamento
10.
Australas Phys Eng Sci Med ; 42(3): 811-818, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31410839

RESUMO

The nondestructive dosimetry achieved with electron paramagnetic resonance (EPR) dosimetry facilitates repetitive recording by the same dosimeter to increase the reliability of data. In precedent studies, solid paraffin was needed as a binder material to make the lithium formate monohydrate (LFM) EPR dosimeter stable and nonfragile; however, its use complicates dosimetry. This study proposes a newly designed pure LFM EPR dosimeter created by inserting LFM into a 3D-printed container. Dosimetric characteristics of the LFM EPR dosimeter and container, such as reproducibility, linearity, energy dependence, and angular dependence, were evaluated and verified through a radiation therapy planning system (RTPS). The LFM EPR dosimeters were irradiated using a clinical linear accelerator. The EPR spectra of the dosimeters were acquired using a Bruker EMX EPR spectrometer. Through this study, it was confirmed that there is no tendency in the EPR response of the container based on irradiation dose or radiation energy. The results show that the LFM EPR dosimeters have a highly sensitive dose response with good linearity. The energy dependence across each photon and electron energy range seems to be negligible. Based on these results, LFM powder in a 3D-printed container is a suitable option for dosimetry of radiotherapy. Furthermore, the LFM EPR dosimeter has considerable potential for in vivo dosimetry and small-field dosimetry via additional experiments, owing to its small effective volume and highly sensitive dose response compared with a conventional dosimeter.


Assuntos
Formiatos/química , Impressão Tridimensional , Radiometria , Radioterapia , Espectroscopia de Ressonância de Spin Eletrônica , Elétrons , Fótons , Planejamento da Radioterapia Assistida por Computador , Reprodutibilidade dos Testes
11.
Asian Spine J ; 13(2): 334-342, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30959588

RESUMO

Biportal endoscopic spinal surgery (BESS) is a minimally invasive spinal surgery, which is basically similar to microscopic spinal surgery in terms of the use of floating technique and technically similar to conventional percutaneous endoscopic spinal surgery in terms of the use of endoscopic or arthroscopic instruments. Using two independent portals (viewing and working) and maintaining a certain distance from the bony and neural structures allow closer access to the target lesion through a panoramic view by free handling of the scope and instruments rather than through a fixed view by docking into the Kambin's triangle. Minimally invasive surgery allows for reduced dissection and inevitable muscle injury, preserving stability and reducing risks of restabilization. The purpose of fusion surgery is the same as that of the three surgical techniques stated above. Its wider range of view helps to overcome limitations of conventional endoscopic spinal surgery and to supplement the weak points of microscopic spinal surgery, such as limited working space in a tubular retractor and difficulty in accessing the contralateral area. This technique provides an alternative to unilateral or bilateral decompression of lumbar central spinal stenosis, foraminal stenosis, low-grade spondylolisthesis, and adjacent segment degeneration. Early clinical outcomes are promising despite potential for complications, such as dural tearing and postoperative epidural hematoma, similar to other procedures. Merits of BESS include decreased postoperative infection rate due to continuous irrigation throughout the procedure and decreased need for fusion surgery for one- or two-level lumbar stenosis by wide sublaminar and foraminal decompression with minimal sacrifice of stabilizing structures.

12.
PLoS One ; 12(9): e0185082, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28926610

RESUMO

OBJECTIVE: Various methods for radiation-dose calculation have been investigated over previous decades, focusing on the use of magnetic resonance imaging (MRI) only. The bulk-density-assignment method based on manual segmentation has exhibited promising results compared to dose-calculation with computed tomography (CT). However, this method cannot be easily implemented in clinical practice due to its time-consuming nature. Therefore, we investigated an automatic anatomy segmentation method with the intention of providing the proper methodology to evaluate synthetic CT images for a radiation-dose calculation based on MR images. METHODS: CT images of 20 brain cancer patients were selected, and their MR images including T1-weighted, T2-weighted, and PETRA were retrospectively collected. Eight anatomies of the patients, such as the body, air, eyeball, lens, cavity, ventricle, brainstem, and bone, were segmented for bulk-density-assigned CT image (BCT) generation. In addition, water-equivalent CT images (WCT) with only two anatomies-body and air-were generated for a comparison with BCT. Histogram comparison and gamma analysis were performed by comparison with the original CT images, after the evaluation of automatic segmentation performance with the dice similarity coefficient (DSC), false negative dice (FND) coefficient, and false positive dice (FPD) coefficient. RESULTS: The highest DSC value was 99.34 for air segmentation, and the lowest DSC value was 73.50 for bone segmentation. For lens segmentation, relatively high FND and FPD values were measured. The cavity and bone were measured as over-segmented anatomies having higher FPD values than FND. The measured histogram comparison results of BCT were better than those of WCT in all cases. In gamma analysis, the averaged improvement of BCT compared to WCT was measured. All the measured results of BCT were better than those of WCT. Therefore, the results of this study show that the introduced methods, such as histogram comparison and gamma analysis, are valid for the evaluation of the synthetic CT generation from MR images. CONCLUSIONS: The image similarity results showed that BCT has superior results compared to WCT for all measurements performed in this study. Consequently, more accurate radiation treatment for the intracranial regions can be expected when the proper image similarity evaluation introduced in this study is performed.


Assuntos
Neoplasias Encefálicas/radioterapia , Planejamento da Radioterapia Assistida por Computador/normas , Algoritmos , Osso e Ossos/anatomia & histologia , Osso e Ossos/diagnóstico por imagem , Encéfalo/anatomia & histologia , Encéfalo/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/normas , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
13.
Yonsei Med J ; 54(3): 720-5, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23549821

RESUMO

PURPOSE: The purpose of this study is to evaluate the relationship between the angle formed between the proximal most screw through the locking compression plate-proximal lateral tibia (LCP PLT) and the joint line, and to evaluate if this angle can be used intraoperatively as an assessment tool to determine normal alignment of the tibia in the coronal plane. MATERIALS AND METHODS: There are two parts to this study: in the first part, LCP PLT was applied to 30 cadaveric adult tibia. The angle between the joint line and the proximal most screw was measured and termed as the 'joint screw angle' (JSA). In the second part, 56 proximal tibial fractures treated with LCP PLT were retrospectively studied. Two angles were measured on the radiographs, the medial proximal tibial angle (MPTA) and the JSA. Their relationship was analyzed statistically. RESULTS: The average JSA was 1.16 degrees in the anatomical study. Statistical analysis of the clinical study showed that the normal MPTA had a direct correlation with an acceptable JSA. CONCLUSION: We therefore conclude that the JSA can be used intraoperatively to assess the achievement of a normal coronal axis.


Assuntos
Parafusos Ósseos , Procedimentos Ortopédicos/métodos , Fraturas da Tíbia/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Fraturas da Tíbia/diagnóstico por imagem
14.
Eur J Orthop Surg Traumatol ; 23(2): 233-7, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23412457

RESUMO

BACKGROUND: The authors evaluated results and hardware-related complications after the fixation of Danis-Weber (D-W) types A and B lateral malleolus fractures using a 3.5-mm T-shaped locking compression plate (T-LCP) for distal radius. METHODS: Twenty-six patients with Danis-Weber type A or B lateral malleolar fractures treated between January 2001 and February 2008 were included in this study. Mean age of the patients was 52.6 (28-77) years. All patients were treated using a 3.5-mm T-shaped locking plate for distal radius fractures. The distal fragment was fixed with at least 2 locking screws more. Ankle motion was allowed early after surgery. The authors evaluated serial radiographs, range of motion, skin irritation, and AOFAS scores at final follow-ups. RESULTS: All fractures united during follow-up. Eight cases were of D-W type A, and 18 were of D-W type B. A mean number of three screws were placed at the distal fragment (2-4). There were 6 cases (23.1%) of implant irritation over the operative site, but no other complications were encountered. At final follow-ups, the AOFAS score of affected ankles was 97.1 ± 4.4. CONCLUSION: T-LCP use for type A or B lateral malleolar fractures resulted in low hardware-related complications and produced good results at follow-up.


Assuntos
Fraturas do Tornozelo , Placas Ósseas , Fixação Interna de Fraturas/instrumentação , Adulto , Idoso , Parafusos Ósseos , Feminino , Fixação Interna de Fraturas/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
Korean J Urol ; 53(8): 569-72, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22950003

RESUMO

PURPOSE: The aim of this study was to analyze the outcomes of immediate primary repair (IPR) compared with delayed repair (DR) after initial suprapubic cystostomy. MATERIALS AND METHODS: We reviewed the records of 60 patients with bulbous urethral disruption after blunt trauma from February 2001 to March 2011. Seventeen patients who presented in an acute injury state underwent IPR; 43 patients underwent DR after the initial suprapubic cystostomy. None of the patients had undergone previous urethral manipulation. We compared the outcomes, including stricture, impotence, and incontinence, between the two management approaches. We also measured the time to spontaneous voiding, the duration of suprapubic diversion, and the number of days spent in the hospital. RESULTS: The median follow-up was 20.5 months (range, 13 to 59 months; mean, 23.3 months). Among 17 patients in the IPR group, strictures developed in 2 patients (11.7%), and among 53 patients in the DR group, strictures developed in 8 patients (18.6%, p=0.709). The incidences of impotence and incontinence were similar in both groups (17.6% and 0% in the IPR group vs. 27.9% and 4.6% in the DR group, p=0.520 and 1.000, respectively). The time to spontaneous voiding and the duration of suprapubic diversion were significantly shorter in the IPR group (average 27.3 and 33.4 days, respectively) than in the DR group (average 191.6 and 198.1 days, respectively; p<0.001 and <0.001). CONCLUSIONS: IPR may provide comparable outcomes to DR and allow for shorter times to spontaneous voiding and reduce the duration of suprapubic diversion.

16.
Arch Orthop Trauma Surg ; 132(1): 51-6, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21833785

RESUMO

BACKGROUND: LCP-DF (locking compression plate-distal femur) has been introduced as an anatomically pre-shaped plate that does not require further contouring. However, the LCP-DF was developed based on skeletal measurements in Caucasians. It is unknown whether the LCP-DF fits Asians. OBJECTIVE: The purpose of this study was to assess the conformity of the LCP-DF in Asian adult femurs and also to determine the matching pattern of this anatomically pre-shaped LCP-DF in normal Asian adult femurs and the clinical implications of the matching pattern. METHODS: Sixty adult cadaver femurs were obtained from 41 male and 19 female cadavers with an average age of 63 years (31-95). An 11-hole LCP-DF was applied to the lateral surface of the distal femur according to the contour. Any mismatches between the bone and the plate were recorded. Then the distance from the inner surface of the plate to the cortex was measured at the sites of mismatch. C-arm AP image of the distal femur was taken and the angle between the distal most locking screw and the joint line was measured, and it was named as joint screw angle (JSA). RESULTS: Mismatch was found at the level of proximal 4-5 holes of the plate with an average distance of 11.36 mm (range 0-32 mm) at the tip of the plate. Otherwise, the overall conformity of the LCP-DF was good. The average JSA was 2.15 ± 1.78° (ranged from 0° to 5°). CONCLUSION: A rather consistent pattern of mismatch was found at the proximal part of the 11-hole LCP-DF. An attempt to fit the plate to the bone at this level may cause valgus malalignment at the fracture site.


Assuntos
Povo Asiático , Mau Alinhamento Ósseo/etiologia , Placas Ósseas , Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas/instrumentação , Desenho de Prótese/efeitos adversos , Adulto , Parafusos Ósseos , Feminino , Fraturas do Fêmur/etnologia , Fêmur/anatomia & histologia , Fêmur/lesões , Fêmur/cirurgia , Humanos , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos
17.
Arch Orthop Trauma Surg ; 132(2): 233-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22015645

RESUMO

With the introduction of 3.5 anatomically pre-shaped plates, the rafting screw technique is gaining popularity in recent years for the management of lateral tibial plateau fractures with articular depression. To gain access to the depressed articular fragments, the split fragment is hinged open laterally. We elevate the depressed articular fragments to the normal level. The defect below is filled with bone graft or its substitutes. We then close the split fragment and apply rafting screws either through the screw holes of the plate or separately above the plate rather in a blind fashion. We therefore cannot be sure that the rafting screws are supporting the specific elevated fragments. For this reason some surgeons place the rafting screws from within and then close the lateral fragment over the screws. This so-called embedded rafting screw technique carries the risk of difficulty in removal, especially in case of an infection. Here we describe the inside out rafting technique to tackle this problem.


Assuntos
Fios Ortopédicos , Fixação Interna de Fraturas/instrumentação , Fixação Interna de Fraturas/métodos , Fraturas da Tíbia/cirurgia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
18.
Arch Orthop Trauma Surg ; 132(5): 671-6, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22072191

RESUMO

INTRODUCTION: Persistent ulnar-sided wrist pain after treatment of triquetral dorsal chip fracture even after union is a matter of concern. There could be various reasons for this persistent pain like arthritis, instability, fractures and non-union. We correlate our findings of physical examination and wrist arthroscopy as triangular fibrocartilage complex injury to be one of the causes of this persistent pain. PATIENTS: Six subjects who had persistent ulnocarpal joint pain and tenderness after triquetral dorsal chip fracture, despite 2 months of conservative treatment, were subjected to physical tests. If the physical examination yields positive results, then magnetic resonance imaging followed by arthroscopic treatment was performed. The six patients were then evaluated using the visual analogue scale, the Mayo modified wrist score, and the grip strength test. RESULTS: Triangular fibrocartilage complex (TFCC) injury was observed in all six cases and partial TFCC resection and synovectomy were performed. Analysis of the visual analogue scale, Mayo modified wrist score, and grip strength test data revealed statistically significant improvements (P < 0.05). CONCLUSION: In addition to several causes reported in the published literature, TFCC injury can be a cause of persistent ulnar pain after treatment of triquetral dorsal chip fracture. Arthroscopic partial TFCC resection can be considered to be a suitable treatment for such cases.


Assuntos
Artroscopia , Fraturas Ósseas/terapia , Fibrocartilagem Triangular/lesões , Fibrocartilagem Triangular/cirurgia , Piramidal/lesões , Traumatismos do Punho/diagnóstico , Adulto , Fraturas Ósseas/complicações , Força da Mão , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Medição da Dor , Exame Físico
19.
Clin Orthop Surg ; 3(1): 62-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21369480

RESUMO

BACKGROUND: A second staged operation using temporary bridging external fixation (TBEF) has been widely used in patients with periarticular complex fracture, yet few papers have been published on the related complications. The purpose of this study was to report the complication rate and pitfalls directly related to TBEF through a retrospective study and to suggest some solutions. METHODS: Fifty-nine cases that were treated by using TBEF were studied among 195 periarticular complex fractures. We retrospectively collected the clinical and radiological data and then the study data was evaluated for 1) cases with unsatisfactory restoration of length, 2) cases with deep infection caused by half pins invading the zone of definitive fixation, and 3) neurovascular injuries related to half pins. RESULTS: Complications were observed in 7/59 cases (11%). Problems related to the achievement of length were observed in one case of distal tibia fracture and 2 cases of distal femur fracture. Half pin related infection was observed in 2 cases of distal femur fracture. Neurovascular injury (medial calcaneal nerve injury in a distal tibia fracture) was observed in 2 cases. Among 7 complications, four were related to using TBEF in distal femur fracture. This is because the abundant leg muscles have strong deforming force and infection might be increased due to frequent irritation by the half pins. CONCLUSIONS: TBEF is a simple procedure with several advantages. However, complications might be observed if certain principles are not followed. It is thought that many complications due to TBEF can be reduced if the half pins are not inserted in the zone of injury, restoration of length is fully achieved and the neurovascular characteristics are carefully considered. In particular, much more caution is needed in the distal femur, which has abundant muscles surrounding it.


Assuntos
Fixadores Externos/efeitos adversos , Fraturas do Fêmur/cirurgia , Fixação de Fratura/efeitos adversos , Fraturas Cominutivas/cirurgia , Infecção da Ferida Cirúrgica/etiologia , Fraturas da Tíbia/cirurgia , Adulto , Idoso , Feminino , Fixação de Fratura/métodos , Humanos , Desigualdade de Membros Inferiores/etiologia , Masculino , Pessoa de Meia-Idade , Traumatismos dos Nervos Periféricos , Estudos Retrospectivos , Adulto Jovem
20.
Arch Orthop Trauma Surg ; 131(4): 535-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21221613

RESUMO

Most of the clinical studies on the results of MIPO (minimally invasive plate osteosynthesis) with the use of anatomically preshaped locking plates for the complex distal femoral fractures have shown favorable results. In the application of bridge plating, placement of lag screws to the butterfly fragments is usually not recommended because it may make the whole construct too stiff. Recently, problems of nonunion related to excessive stiffness after MIPO using a locked plate were reported but the only solution suggested was reoperation with a bone graft. We herein report a case of nonunion after MIPO of the distal femoral fracture where we applied a concept of "dynamization of the plate-bone construct" to make it less stiff and in turn to get fracture healing with bridging callus formation. A 58-year-old woman sustained a simple oblique fracture of the distal femur (AO-OTA 33A1). We performed MIPO procedure using a locking compression plate-distal femur. To get the alignment, we have placed a conventional screw across the fracture line through the dynamic compression unit (DCU) of the combination hole. Postoperative radiographs revealed 7-8 mm gap across the entire fracture surface which was not obvious on the intra-operative C-arm images. Radiographs taken 6 months after operation showed almost no callus formation with shuttle marginal resorption. We interpreted the situation that the construct was too stiff to allow motion across the fracture site due to the lag screw. We thought we have used it as a reduction screw but it acted as a lag screw, preventing motion at the fracture site. Given this analysis, we have only taken the lag screw out to make the construct less stable. It caused the situation of absolute stability with a significant gap to turn into the one of relative stability with acceptable gap. Fracture has solidly healed with bridging callus formation 6 months after lag screw removal under local anesthesia. We would like to call this strategy as "dynamization" of the locked plating.


Assuntos
Placas Ósseas , Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas/métodos , Fenômenos Biomecânicos , Parafusos Ósseos , Desenho de Equipamento , Feminino , Fluoroscopia , Humanos , Articulação do Joelho/fisiopatologia , Pessoa de Meia-Idade , Amplitude de Movimento Articular
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