• Journal of Mechanical Science and Technology
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• 제15권7호
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• pp.1041-1050
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• 2001

Control of bone cement volume (PMMA) may be critical for preventing complications in vertebroplasty, the percutaneous injection of PMMA into vertebra. The purpose of this study was to predict the optimal volume of PMMA injection based on CT images. For this, correlation between PMMA volume and textural features of CT images was examined before and after surgery to evaluate the appropriate PMMA amount. The gray level run length analysis was used to determine the textural features of the trabecular bone. Extimation of PMMA volume was done using 3D visualization with semi-automatic segmentation on postoperative CT images. Then, finite element (FE) models were constructed based on the CT image data of patients and PMMA volume. Appropriate material properties for the trabecular bone were assigned by converting BMD to elastic modulus. Structural reinforcement due to the changes in PMMA volume and BMD was assessed in terms of axial displacement of the superior endplate. A strong correlation was found between the injected PMMA volume and the area of the intertrabecular space and that of trabecular bone calculated from the CT images (r=0.90 and -0.90, respectively). FE results suggested that vertebroplasty could effectively reinforce the osteoporotic vertebra regardless of BMD or PMMA volume. Effectiveness of additional PMMA injection tended to decrease. For patients with BMD well lower than 50mg/ml, injection of up to 30% volume of the vertebral body is recommended. However, less than 30% is recommended otherwise to avoid any complications from excessive PMMA because the strength has already reached the normal level.

• Clinics in Shoulder and Elbow
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• 제18권3호
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• pp.138-143
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• 2015

Background: To evaluate the effect of preoperative fatty degeneration of deltoid and teres minor muscles on the clinical outcome in patient with reverse total shoulder arthroplasty (RTSA). Methods: Nineteen patients with RTSA were enrolled. The mean follow-up period was 16.1 months. The fatty degeneration of three distinct parts in each deltoid and the teres minor muscle was measured using a preoperative magnetic resonance imaging. Postoperatively, the muscle strengths for forward elevation (FE), abduction (Abd), and external rotation (ER) were measured using a myometer at the last follow-up. The parameters for clinical outcome were Constant Score (CS) and Korean Shoulder Score (KSS). Results: The number of cases was 10 in group 1 and 9 in group 2. The strength of FE and Abd were significantly higher in group 1 (p<0.001 and p<0.001, respectively), and the strength of ER was not different significantly between two groups (p=0.065). For the clinical outcome, both CS and KSS were higher in group 1 (p=0.002 and p=0.002, respectively). The number of patients in group A was 11, and group B was 8. Although there was not a significant difference in terms of FE and Abd between group A and B (p=0.091, p=0.238), ER was significantly higher in group A (p=0.012). We did not find a significant difference in the clinical scores (CS, p=0.177 and KSS, p=0.238). Conclusions: These findings suggest the importance of a preoperative evaluation of the fatty degeneration of deltoid and teres minor muscles for predicting postoperative strength and clinical outcome.

• Archives of Plastic Surgery
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• 제33권2호
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• pp.233-236
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• 2006

Merkel cell carcinoma is rare skin malignancy originated from epidermal mechanoreceptor of neural origin. The tumor usually affects older individuals at sun exposed area such as head, neck and extremity. Subclinical involvement of regional lymph node is reported frequently at the time of initial treatment. Thus even asymptomatic patients who present with clinically localized tumor should undergo evaluation with computed tomography and lymphangiography. Positron emission tomography(PET) scans can imaging the metabolic difference of malignant tumors. Increased glucose uptake of malignant tumor cells are detected by PET scanner. PET scans can provide qualitative and quantitative informations about systemic metastasis of tumors. Although there are no data that define the efficacy of PET scans in the initial diagnostic evaluation of head and neck cancer, they could be considered. Current standards of treatment of Merkel cell carcinoma is wide surgical excision and regional lymphadenectomy if there are suspicious lymph nodes. The author reported a patient with Merkel cell carcinoma of cheek. Wide surgical excision and postoperative PET/CT was done for evaluation of regional lymph node and distant metastasis. There were two hot-uptakes in patient's neck, so they were considered as metastatic node, but finally they were proved to be tuberculosis lymphadenitis after excision.

• Archives of Plastic Surgery
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• 제40권6호
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• pp.687-696
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• 2013

Background Ischemic preconditioning has been shown to improve the outcomes of hypoxic tolerance of the heart, brain, lung, liver, jejunum, skin, and muscle tissues. However, to date, no report of ischemic preconditioning on vascularized bone grafts has been published. Methods Sixteen rabbits were divided into four groups with ischemic times of 2, 6, 14, and 18 hours. Half of the rabbits in each group underwent ischemic preconditioning. The osteomyocutaneous flaps consisted of the tibia bone, from which the overlying muscle and skin were raised. The technique of ischemic preconditioning involved applying a vascular clamp to the pedicle for 3 cycles of 10 minutes each. The rabbits then underwent serial plain radiography and computed tomography imaging on the first, second, fourth, and sixth postoperative weeks. Following this, all of the rabbits were sacrificed and histological examinations were performed. Results The results showed that for clinical analysis of the skin flaps and bone grafts, the preconditioned groups showed better survivability. In the plain radiographs, except for two non-preconditioned rabbits with intraoperative ischemic times of 6 hours, all began to show early callus formation at the fourth week. The computed tomography findings showed more callus formation in the preconditioned groups for all of the ischemic times except for the 18- hour group. The histological findings correlated with the radiological findings. There was no statistical significance in the difference between the two groups. Conclusions In conclusion, ischemic preconditioning improved the survivability of skin flaps and increased callus formation during the healing process of vascularized bone grafts.

• Journal of Korean Neurosurgical Society
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• 제29권12호
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• pp.1634-1641
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• 2000

Objective : The cerebrospinal fluid(CSF) pulsates within the craniospinal axis in response to rhythmic cerebral blood volume variation during the cardiac cycle. The aim of this study is to characterize the normal and abnormal CSF flow and its waveforms in the cervical spinal subarachnoid space. Methods : The magnetic resonance(MR) images were obtained with 1.5 T(GE Signa, GE Medical Systems, Milwaukee, USA) unit using the 2 dimensional cine PC(phase contrast) sequence with cardiac gating and gradient recalled echo imaging. This pulse sequence yielded 16 quantitative flow-encoded images per cardiac cycle. Sagittal and axial images of the cervical spinal CSF space were obtained, and target sites were analyzed for characteristic CSF flow (TR=50ms, TE=12.5-15ms). The region of interest(ROI) was 1mm 3 in volume. Twenty six persons were included in this study : 10 healthy volunteers and 16 patients with cervical myelopathy. The post-operative cine MR study were also done in five patients. Results : The normal CSF pulsation dynamics in the cervical spine showed discrete systolic and diastolic components. The CSF flow revealed a sine wave pattern, in which the systolic phase was shorter than the diastolic phase(ratio=2 : 3). The patient group revealed decreased amplitudes of the CSF flow and irregularly distored flow waves. The systolic phase was elongated in the ROI above the stenotic level, whereas the diastolic phase was lengthened below the level. In the postoperative images, the abnormal pattern and amplitude were found to be corrected. Conclusion : From these results, the authors believe that the CSF flow study provides valuable informations regarding the extent of cervical stenosis and may be useful for the surgical planning and post-operative evaluation.

• Journal of Korean Neurosurgical Society
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• 제54권4호
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• pp.302-308
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• 2013

Objective : MR perfusion and single photon emission computerized tomography (SPECT) are well known imaging studies to evaluate hemodynamic change between prior to and following superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis in moyamoya disease. But their side effects and invasiveness make discomfort to patients. We evaluated the ivy sign on MR fluid attenuated inversion recovery (FLAIR) images in adult patients with moyamoya disease and compared it with result of SPECT and MR perfusion images. Methods : We enrolled twelve patients (thirteen cases) who were diagnosed with moyamoya disease and underwent STA-MCA anastomosis at our medical institution during a period ranging from September of 2010 to December of 2012. The presence of the ivy sign on MR FLAIR images was classified as Negative (0), Minimal (1), and Positive (2). Regions were classified into four territories: the anterior cerebral artery (ACA), the anterior MCA, the posterior MCA and the posterior cerebral artery. Results : Ivy signs on preoperative and postoperative MR FLAIR were improved (8 and 4 in the ACA regions, 13 and 4 in the anterior MCA regions and 19 and 9 in the posterior MCA regions). Like this result, the cerebrovascular reserve (CVR) on SPECT was significantly increased in the sum of CVR in same regions after STA-MCA anastomosis. Conclusion : After STA-MCA anastomosis, ivy signs were decreased in the cerebral hemisphere. As compared with conventional diagnostic modalities such as SPECT and MR perfusion images, the ivy sign on MR FLAIR is considered as a useful indicator in detecting brain hemodynamic changes between preoperatively and postoperatively in adult moyamoya patients.

• Journal of Korean Neurosurgical Society
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• 제52권5호
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• pp.491-494
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• 2012

We report a rare complication of iatrogenic spinal intradural following minimally invasive extradural endoscopic procedues in the lumbo-sacral spines. To our knowledge, intradural cyst following epiduroscopy has not been reported in the literature. A 65-year-old woman with back pain related with previous lumbar disc surgery underwent endoscopic epidural neuroplasty and nerve block, but her back pain much aggravated after this procedure. Postoperative magnetic resonance imaging revealed a large intradural cyst from S1-2 to L2-3 displacing the nerve roots anteriorly. On T1 and T2-weighted image, the signal within the cyst had the same intensity as cerebrospinal fluid. The patient underwent partial laminectomy of L5 and intradural exploration, and fenestration of the cystic wall was accomplished. During operation, the communication between the cyst and subarachnoid space was not identified, and the content of the cyst was the same as that of cerebrospinal fluid. Postoperatively, the pain attenuated immediately. Incidental durotomy which occurred during advancing the endoscope through epidural space may be the cause of formation of the intradural cyst. Intrdural cyst should be considered, if a patient complains of new symptoms such as aggravation of back pain after epiduroscopy. Surgical treatment, simple fenestration of the cyst may lead to improved outcome. All the procedures using epiduroscopy should be performed with caution.

• Journal of Korean Neurosurgical Society
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• 제54권2호
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• pp.128-131
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• 2013

Transforaminal lumbar interbody fusion (TLIF) is commonly used procedure for spinal fusion. However, there are no reports describing anterior cage dislodgement after surgery. This report is a rare case of anterior dislodgement of fusion cage after TLIF for the treatment of isthmic spondylolisthesis with lumbosacral transitional vertebra (LSTV). A 51-year-old man underwent TLIF at L4-5 with posterior instrumentation for the treatment of grade 1 isthmic spondylolisthesis with LSTV. At 7 weeks postoperatively, imaging studies demonstrated that banana-shaped cage migrated anteriorly and anterolisthesis recurred at the index level with pseudoarthrosis. The cage was removed and exchanged by new cage through anterior approach, and screws were replaced with larger size ones and cement augmentation was added. At postoperative 2 days of revision surgery, computed tomography (CT) showed fracture on lateral pedicle and body wall of L5 vertebra. He underwent surgery again for paraspinal decompression at L4-5 and extension of instrumentation to S1 vertebra. His back and leg pains improved significantly after final revision surgery and symptom relief was maintained during follow-up period. At 6 months follow-up, CT images showed solid fusion at L4-5 level. Careful cage selection for TLIF must be done for treatment of spondylolisthesis accompanied with deformed LSTV, especially when reduction will be attempted. Banana-shaped cage should be positioned anteriorly, but anterior dislodgement of cage and reduction failure may occur in case of a highly unstable spine. Revision surgery for the treatment of an anteriorly dislodged cage may be effectively performed using an anterior approach.

• 대한족부족관절학회지
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• 제14권1호
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• pp.53-57
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• 2010

Purpose: This study was designed to evaluate the clinical and radiographical results of anatomical reconstruction by Chen method for chronic lateral ankle instability. Materials and Methods: Fifteen patients with chronic lateral ankle instability who had undergone anatomical reconstruction of anterior talofibular and calcaneofibular ligaments by Chen method were evaluated retrospectively. Average age of the patients was 31.3 years, and average follow-up period was 15.5 months. Preoperative and postoperative radiographs including varus stress view and magnetic resonance imaging (MRI) were analyzed. The clinical evaluation was performed according to the American Orthopaedic Foot and Ankle Society (AOFAS) scale. Results: Radiographically average talar tilt angle was $15.3^{\circ}$ preoperatively, and the difference with contralateral normal side was $10.1^{\circ}$. At last follow up, talar tile angle and the difference with contralateral side improved to $5.9^{\circ}$ and $1.3^{\circ}$ respectively. AOFAS scale was 66.6 preoperatively and 87.3 postoperatively. In MRI findings, four patients had associated intra-articular lesion such as articular cartilage defect, synovitis and osteoarthritis. The talar tilt angle improvement and AOFAS scale of patients without intra-articular lesion was better than those of four patients with intra-articular lesions. Surgical wound pain occurred in six patients and sural neuropathy in three patients. Conclusion: The anatomical reconstruction by Chen method was an easy and effective procedure for symptomatic chronic lateral ankle instability. Careful operative technique may prevent the surgical wound pain and sural neuropathy.

• Archives of Plastic Surgery
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• 제36권4호
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• pp.497-499
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• 2009

Purpose: Leiomyoma is a rare benign tumor of nonstriated muscles. Leiomyoma is most commonly found in the uterus and rarely occur in the hand. 150 cases of leiomyoma of the hand have been reported in the English literature; however, to the best of our knowledge only four of these have been in children and none were reported in Korean literature. We present a case of leiomyoma in the hand of a 8 - year - old boy, which is a rare site for localization and unusual for age. Methods: A 8 - year - old boy presented with a painless mass on the ulnar side of his thumb. Physical examination revealed a $1.2{\times}1.2cm$ round, rubbery mass that was nontender to palpation. The vascular, sensory, and motor exams were otherwise unremarkable. Further evaluation with CT demonstrated an enhancing mass at dorsoulnar aspect of 1st proximal phalangeal region suggestive of a hemangioma versus other enhancing solid mass. The diagnosis of a leiomyoma was confirmed following surgical excision with histologic evaluation. Results: At 3 months follow - up, the incision was healed, motor and sensory function were intact, and there were full range of motion. Neither recurrence nor postoperative complication were observed. Conclusion: Leiomyoma is a rare tumor of the hand, especially in children. Diagnosing hand tumors in children is more difficult than in adults, hand surgeons should be aware of the diagnostic possibilities based on examination and imaging of a hand tumor ; however, surgical excision with histologic examination is required for definitive diagnosis.