• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.1
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• pp.29-35
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• 2012

The treatments for spinal canal stenosis are radicular cyst removal, spine fusion, and implantation of an artificial intervertebral disc. Artificial intervertebral discs have been most widely used since the mid-2000s. The study of artificial intervertebral discs has been focused on the analysis of the axial rotation, lateral bending, the degrees of freedom of the disc, and flexion-extension of the vertebral body. The issue of fatigue failure years after the surgery has arisen as a new problem. Hence, study of artificial intervertebral discs must be focused on the fatigue failure properties and increased durability of the sliding core. A finite element model based on an in the artificial intervertebral disc (SB Charit$\acute{e}$ III) was produced, and the influence of the radius of curvature and the change in the coefficient of friction of the sliding core on the von-Mises stress and contact pressure was evaluated. Based on the results, new artificial intervertebral disc models (Models-I, -II, and -III) were proposed, and the fatigue failure behavior of the sliding core after a certain period of time was compared with the results for SB Charit$\acute{e}$ III.

• Journal of Korean Neurosurgical Society
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• v.62 no.5
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• pp.561-566
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• 2019

Objective : Functional outcomes have traditionally been evaluated and compared using subjective surveys, such as visual analog scores (VAS), the Oswestry disability index (ODI), and Short Form-36 (SF-36), to assess symptoms and quality of life. However, these surveys are limited by their subjective natures and inherent bias caused by differences in patient perceptions of symptoms. The Fitbit $Charge^{(R)}$ (Fitbit Inc., San Francisco, CA, USA) provides accurate and objective measures of physical activity. The use of this device in patients after laminectomy would provide objective physical measures that define ambulatory function, activity level, and degree of recovery. Therefore, the present study was conducted to identify relationships between the number of steps taken by patients per day and VAS pain scores, prognoses, and postoperative functional outcomes. Methods : We prospectively investigated 22 consecutive patients that underwent laminectomy for spinal stenosis or a herniated lumbar disc between June 2015 and April 2016 by the same surgeon. When patients were admitted for surgery and first visited after surgery, preoperative and postoperative functional scores were recorded using VAS scores, ODI scores, and SF-36. The VAS scores and physical activities were recorded daily from postoperative day (POD) 1 to POD 7. The relationship between daily VAS scores and daily physical activities were investigated by simple correlation analysis and the relationship between mean number of steps taken and ODI scores after surgery was subjected to simple regression analysis. In addition, Wilcoxon's signed-rank test was used to investigate the significance of pre-to-postoperative differences in VAS, ODI, and SF-36 scores. Results : Pre-to-postoperative VAS (p<0.001), ODI (p<0.001), SF-36 mental composite scores (p=0.009), and SF-36 physical composite scores (p<0.001) scores were found to be significantly different. Numbers of steps taken from POD 1 to POD 7 were negatively correlated with daily VAS scores (r=-0.981, p<0.001). In addition, the mean number of steps from POD 3 to POD 7 and the decrease in ODI conducted one month after surgery were statistically significant (p=0.029). Conclusion : Wearable devices are not only being used increasingly by consumers as lifestyle devices, but are also progressively being used in the medical area. This is the first study to demonstrate the usefulness of a wearable device for checking patient physical activity and predicting pain and prognosis after laminectomy. Based on our experience, the wearable device used to provide measures of physical activity in the present study has the potential to provide objective information on pain severity and prognosis.

• Asian Spine Journal
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• v.12 no.6
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• pp.1043-1052
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• 2018

Study Design: Level III retrospective cross-sectional study. Purpose: To define and characterize the presentation, symptom duration, and patient/surgical risk factors associated with 'post-decompressive neuropathy (PDN).' Overview of Literature: PDN is characterized by lower extremity radicular pain that is 'different' from pre-surgical radiculopathy or claudication pain. Although it is a common constellation of postoperative symptoms, PDN is incompletely characterized and poorly understood. We hypothesize that PDN is caused by an intraoperative neuropraxic event and may develop early (within 30 days following the procedure) or late (after 30 days following the procedure) within the postoperative period. Methods: Patients who consented to undergo lumbar laminectomy with or without an instrumented fusion for degenerative lumbar spine disease were followed up prospectively from July 2013 to December 2014. Relevant data were extracted from the charts of the eligible patients. Patient demographics and surgical factors were identified. Patients completed postoperative questionnaires 3 weeks, 3 months, 6 months, and 1 year postoperatively. Questions were designed to characterize the postoperative pain that differed from preoperative pain. A diagnosis of PDN was established if the patient exhibited the following characteristics: pain different from preoperative pain, leg pain worse than back pain, a non-dermatomal pain pattern, and nocturnal pain that often disrupted sleep. A Visual Analog Scale was used to monitor the pain, and patients documented the effectiveness of the prescribed pain management modalities. Patients for whom more than one follow-up survey was missed were excluded from analysis. Results: Of the 164 eligible patients, 118 (72.0%) completed at least one follow-up survey at each time interval. Of these eligible patients, 91 (77.1%) described symptoms consistent with PDN. Additionally, 75 patients (82.4%) described early-onset symptoms, whereas 16 reported symptoms consistent with late-onset PDN. Significantly more female patients reported PDN symptoms (87% vs. 69%, p=0.03). Patients with both early and late development of PDN described their leg pain as an intermittent, constant, burning, sharp/stabbing, or dull ache. Early PDN was categorized more commonly as a dull ache than late-onset PDN (60% vs. 31%, p=0.052); however, the difference did not reach statistical significance. Opioids were significantly more effective for patients with early-onset PDN than for those with late-onset PDN (85% vs. 44%, p=0.001). Gabapentin was most commonly prescribed to patients who cited no resolution of symptoms (70% vs. 31%, p=0.003). Time to symptom resolution ranged from within 1 month to 1 year. Patients' symptoms were considered unresolved if symptoms persisted for more than 1 year postoperatively. In total, 81% of the patients with early-onset PDN reported complete symptom resolution 1 year postoperatively compared with 63% of patients with late-onset PDN (p=0.11). Conclusions: PDN is a discrete postoperative pain phenomenon that occurred in 77% of the patients who underwent lumbar laminectomy with or without instrumented fusion. Attention must be paid to the constellation and natural history of symptoms unique to PDN to effectively manage a self-limiting postoperative issue.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.450-457
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• 2019

Objective : Anterior cervical discectomy and fusion (ACDF) is commonly used surgical procedure for cervical degenerative disease. Among the various intervertebral spacers, the use of allografts is increasing due to its advantages such as no harvest site complications and low rate of subsidence. Although subsidence is a rare complication, graft collapse is often observed in the follow-up period. Graft collapse is defined as a significant graft height loss without subsidence, which can lead to clinical deterioration due to foraminal re-stenosis or segmental kyphosis. However, studies about the collapse of allografts are very limited. In this study, we evaluated risk factors associated with graft collapse. Methods : We retrospectively reviewed 33 patients who underwent two level ACDF with anterior plating using allogenous bone graft from January 2013 to June 2017. Various factors related to cervical sagittal alignment were measured preoperatively (PRE), postoperatively (POST), and last follow-up. The collapse was defined as the ratio of decrement from POST disc height to follow-up disc height. We also defined significant collapses as disc heights that were decreased by 30% or more after surgery. The intraoperative distraction was defined as the ratio of increment from PRE disc height to POST disc height. Results : The subsidence rate was 4.5% and graft collapse rate was 28.8%. The pseudarthrosis rate was 16.7% and there was no association between pseudarthrosis and graft collapse. Among the collapse-related risk factors, pre-operative segmental angle (p=0.047) and intra-operative distraction (p=0.003) were significantly related to allograft collapse. The cut-off value of intraoperative distraction ${\geq}37.3%$ was significantly associated with collapse (p=0.009; odds ratio, 4.622; 95% confidence interval, 1.470-14.531). The average time of events were as follows: collapse, $5.8{\pm}5.7months$; subsidence, $0.99{\pm}0.50months$; and instrument failure, $9.13{\pm}0.50months$. Conclusion : We experienced a higher frequency rate of collapse than subsidence in ACDF using an allograft. Of the various preoperative factors, intra-operative distraction was the most predictable factor of the allograft collapse. This was especially true when the intraoperative distraction was more than 37%, in which case the occurrence of graft collapse increased 4.6 times. We also found that instrument failure occurs only after the allograft collapse.

• The Journal of Korean Medicine
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• v.44 no.2
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• pp.20-33
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• 2023

Objectives: This study is designed to statistically analyze the features of patients who visited to Department of Acupuncture and Moxibustion at OO Korean Medicine Hospital for 3 years. Methods: This study retrospectively analyzed the medical records of patients at Department of Acupuncture and Moxibustion at OO Korean Medicine Hospital using IBM SPSS ver. 27.0 for Windows. Results: 1. In the analysis of the total number of patients, those in their 30s accounted for the highest percentage, male patients had a higher rate. 2. In the analysis of KCD-8 code, spinal stenosis and fractures in areas other than the spine were the most common in the 70s and older, and cervical sprains were the most common in other. 3. In the analysis of the number of hospitalizations, patients classified as illness or higher age had more re-hospitalization than patients classified as injury or lower age in first-time care. 4. In the analysis of hospitalization duration, patients classified as illness, female or higher age had longer hospitalization duration than patients classified as accident, male or lower age in first-time care. Conclusion: We expect that the results of this study would be used as reference materials for analyzing medical consumption condition of Department of Acupuncture and Moxibustion.

• Journal of the Korean Orthopaedic Association
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• v.54 no.3
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• pp.203-210
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• 2019

The aim of this review was to evaluate minimally invasive lateral lumbar interbody fusion on the latest update. Lumbar interbody fusion was introduced recently. This study performed, a literature review of the indications, clinical outcomes, fusion rate, and complications regarding recently highlighted minimally invasive lateral lumbar interbody fusion. The indications of lateral lumbar interbody fusion are similar to the conventional anterior and posterior interbody fusion in degenerative lumbar diseases. In particular, lateral lumbar interbody fusion is an effective minimally invasive surgery in spinal stenosis, degenerative spondylolisthesis, degenerative adult deformity, degenerative disc disease and adjacent segment disease. In addition, the clinical outcomes and fusion rates of lateral lumbar interbody fusion are similar compared to conventional lumbar fusion. On the other hand, non-specific complications including hip flexor weakness, nerve injury, vascular injury, visceral injury, cage subsidence and pseudohernia have been reported. Lateral lumbar interbody fusion is a very useful minimally invasive surgery because it has advantages over conventional anterior and posterior interbody fusion without many of the disadvantages. Nevertheless, nonspecific complications during lateral lumbar interbody fusion procedure remain a challenge to be improved.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.115-120
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• 2011

Purpose: To examine the feasibility of the treatment planning for minimizing carotid artery dose in the radiotherapy of early glottic cancer. Materials and Methods: From 2007 to 2010, computed tomography simulation images of 31 patients treated by radiotherapy for early glottic cancer were analyzed. The virtual planning was used to compare the parallel-opposing fields (POF) with the modified oblique fields (MOF) placed at angles to exclude the ipsilateral carotid arteries. Planning target volume (PTV), irradiated volume, carotid artery, and spinal cord were analyzed at a mean dose, $V_{35}$, $V_{40}$, $V_{50}$ and with a percent dose-volume. Results: The beam angles were arranged 25 degrees anteriorly in 23 patients and 30 degrees anteriorly in 8 dose-volume of carotid artery shows the significant difference (p<0.001). The mean doses of carotid artery were 38.5 Gy for POF and 26.3 Gy for MOF and the difference was statistically significant (p=0.012). Similarly, $V_{35}$, $V_{40}$, and $V_{50}$ also showed significant differences between POF and MOF. Conclusion: The modified oblique field was respected to prevent a carotid artery stenosis and reduce the incidence of a stroke based on these results.

• Journal of the Korean Orthopaedic Association
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• v.55 no.5
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• pp.411-417
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• 2020

Purpose: This paper reports the short-term clinical and radiological results of unilateral biportal endoscopic decompression (UBE) to prove its efficacy. Materials and Methods: Twenty patients who received unilateral biportal endoscopic far-lateral decompression (UBEFLD) were analyzed statistically using the visual analogue scale (VAS), modified Macnab criteria and Oswestry Disability Index (ODI) clinically. Radiologically, their intervertebral angle (IVA), percentage slip, disc height index (DHI) and foraminal height index (FHI) were analyzed pre- and postoperatively. Results: The VAS scores were 6.20 preoperatively, which improved to 2.05, 1.75 and 1.45 at postoperative one month, three months and one year, respectively (p<0.001). The modified macnab criteria in both the good or excellent category was 70.0%, 80.0% and 85.0% at postoperative one month, three months and one year, respectively (p=0.034). The ODI improved from 59.8% preoperatively to 35.8%, 33.2%, and 17.1% at postoperative one month, three months, and one year, respectively (p<0.001). The IVA was increased 0.40±0.88 after a surgery (p=0.057). Percentage slip was increased 0.19% after surgery (p=0.134). The DHI changed from 0.49 preoperatively to 0.62 postoperatively (p=0.359), and the FHI changed from 0.71 preoperatively to 0.79 postoperatively (p<0.001). Conclusion: UBEFLD displayed satisfactory results. Such a result highlights the potential of UBEFLD as an excellent alternative to spinal fusion or microscopic surgery.

• Journal of Korean Medicine Rehabilitation
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• v.23 no.4
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• pp.213-223
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• 2013

Objectives Low back pain (LBP) is one of the most common reason for people in Korea to visit Korean medical institutions. To assess actual amounts of use in the treatment of LBP in Korean medicine and to provide objective base line data for policy decision making, research regarding the current state of LBP patients' treatment in Korean medical institutions are in need. Methods The current study was designed as a retrospective chart review to investigate descriptive characteristics of LBP patients. The clinical records of 304 patients who were hospitalized for the treatment of LBP in Korean rehabilitation medicine inpatient clinics of five different Korean medicine hospitals were analyzed. The percentage of patient characteristics such as sex, age, average duration of admission, insurance type, diagnosed LBP related disease code, and rates of interventions applied were assessed. Results 1. The female sex was significantly predominant among patients with LBP : 105 patients (34.5%) were male and 199 patients (65.5%) were female. Percentage of the patients' age appeared as followed : 76 people (25.0%) were in their 50s, 64 people (21.1%) were in their 40s, 51 people (16.8%) were in their 30s, 37 people (12.2%) were in their 60s, and 33 people (10.9%) were in their 70s. Approximately half of the total LBP patients investigated were older than 50. 2. The average duration of admission was 16.2 days. Approximately one third (30.3%) of the patients were hospitalized for 8 to 14 days. 3. Female patients tended to stay admitted in hospitals slightly longer than male patients. Elderly (age 60~79) patients stayed in hospitals longer (17.8 days) compared to younger (age 20~39) patients (13.5 days). 4. More than half of the patients (171 cases, 56.3%) had their hospital bills covered with automobile insurance. 40.1% (122 cases) of the patients had medical insurance to cover their hospital bills. The average duration of admission of patients who had automobile insurance was 14.2 days, while that of the patients who had medical insurance was 18.4 days. 5. "Sprain and strain of the lumbar spine and pelvis" was the most commonly used (195 cases, 64.1%) disease code in patients with LBP. Patients diagnosed as "lumbar and other intervertebral disc disorders with radiculopathy" required the longest admission duration (22.1 days). 6. Herbal medication was applied to all of the patients during admission. Acupuncture was applied to all of the patients except one case diagnosed as spinal stenosis. Physical therapy, cupping therapy, moxibustion therapy, chuna therapy, and pharmacopuncture therapy were applied to 94.7, 92.8, 85.2, 83.9, and 49.7% of the patients, respectively. 7. There were certain differences among Korean medicine hospitals in terms of the LBP patients' duration of admission, type of insurance, frequency of the disease code use, type of intervention applied. Conclusions It is thought that the current study can be used as reference data in assessing the current state of LBP treatment in Korean rehabilitation medicine and a basis for future research. Provided improvements of certain limitations of the current study in future researches, such data would act as better base line data in policy decision making.