• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.26-32
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• 2006

Purpose: We evaluated the result of the degree of reduction and anterior instability after arthroscopic treatment of tibial spine fractures. Materials and Methods: Thirty-two cases of tibial spine fractures treated with arthroscopic procedure could be evaluated and the mean follow-up period was $18\;(12{\sim}48)$ months. Evaluations included Lachman test, rotatory instability examination and side to side difference (SSD) using KT-2000 arthrometer. The degree of radiologic reduction was classified as accurate reduction, anterior elevation and reduction failure, according to which the degree of anterior instability was measured. Results: There were twenty three cases (71%) of accurate duction, eight cases (25%) of anterior elevation and one case (4%) of education failure. Eight (29%) of twenty eight cases with pull-out method showed anterior elevation. The SSDs of the accurate reduction and the anterior elevation group were 2.0 mm and 2.8 mm, respectively showing no significant difference. However, the percent age of grade 0 Lachman test and SSD less than 3 mm of the accurate reduction group were significantly higher. Conclusion: Accurate reduction is important in reducing anterior instability especially in unstable fractures. Therefore, arthroscopic pull-out method should be performed with great caution to avoid anterior elevation of the fracture fragment.

• Journal of Trauma and Injury
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• v.29 no.4
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• pp.204-208
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• 2016

For an orthopaedic surgeon, the critical decisions to either amputate or salvage a limb with severe crushing injury with progressive ischemic change due to arterial rupture or occlusion can become a clinical dilemma at the Emergency Department (ED). And reperfusion injury is one of the fetal complications after vascular reconstruction. The authors present a case which was able to save patient's life by rapid vessel ligation at bedside to prevent severe reperfusion injury. A 43-year-old male patient with no pre-existing medical conditions was transported by helicopter to Level I trauma center from incident scene. Initial result of extended focused assessment with sonography for trauma (eFAST) was negative. The trauma series X-rays at the trauma bay of ED showed a multiple contiguous rib fractures with hemothorax and his pelvic radiograph revealed a complex pelvic trauma of an Anterior Posterior Compression (APC) Type II. Lower extremity computed tomography showed a discontinuity in common femoral artery at the fracture site and no distal run off. Surgical finding revealed a complete rupture of common femoral artery and vein around the fracture site. But due to the age aspect of the patient, the operating team decided a vascular repair rather than amputation even if the anticipated reperfusion time was 7 hours from the onset of trauma. Only two hours after the reperfusion, the patient was in a state of shock when his arterial blood gas analysis (ABGA) showed a drop of pH from 7.32 to 7.18. An imminent bedside procedure of aseptic opening the surgical site and clamping the anastomosis site was taken place rather than undergoing a surgery of amputation because of ultimately unstable vital sign. The authors would like to emphasize the importance of rapid decision making and prompt vessel ligation which supply blood flow to the ischemic limb to increase the survival rate in case of profound reperfusion injury.

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.145-155
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• 2000

Orientation data of discontinuities are of paramount importance for rock slope stability studies because they control the possibility of unstable conditions or excessive deformation. Most orientation data are collected by using linear sampling techniques, such as borehole fracture mapping and the detailed scanline method (outcrop mapping). However, these data, acquired by the above linear sampling techniques, are subjected to bias, owing to the orientation of the sampling line. Even though a weighting factor is applied to orientation data in order to reduce this bias, the bias will not be significantly reduced when certain sampling orientations are involved. That is, if the linear sampling orientation nearly parallels the discontinuity orientation, most discontinuities orientation data which are parallel to sampling line will be excluded from the survey result. This phenomenon can cause serious misinterpretation of discontinuity orientation data because critical information is omitted. In the case study, orientation data collected by using the borehole fracture mapping method (vertical scanline) were compared to those based on orientation data from the detailed scanline method (horizontal scanline). Differences in results for the two procedures revealed a concern that a representative orientation of discontinuities was not accomplished. Equal-area, polar stereo nets were used to determine the distribution of dip angles and to compare the data distribution fur the borehole method versus those for the scanline method.

• Journal of Trauma and Injury
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• v.23 no.2
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• pp.57-62
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• 2010

Purpose: This study analyzed the characteristics of stable pelvic bone fractures with intra-abdominal solid organ injury. Methods: Medical records were retrospectively reviewed from January 2000 to December 2009 of patients with stable pelvic bone fractures. A stable pelvic bone fracture according to Young's classification is defined as a lateral compression type I and antero-posterior compression type I. Subjects were divided into two groups, one with (injured group) and one without (non-injured group) intra-abdominal solid organ injury, to evaluate the dependences of the characteristics on the presence of an intra-abdominal solid organ injury. Data including demographics, mechanism of injury, initial hemodynamic status, laboratory results, Revised Trauma Score (RTS), Abbreviated Injury Scale (AIS), Injury Severity Score (ISS), amount of transfusion, admission to intensive care unit (ICU), and mortality were analyzed. Results: The subjects were 128 patients with a mean age of 42 years old, of whom were 67 male patients (52.3%). The injured group had 21 patients(16.4%), and the most frequent injured solid organ was the liver. Traffic accident was the most common mechanism of injury and lateral compression was the most common type of fracture in all groups. Initial systolic blood pressure was lower in the injured group, and the ISS was greater in the injured group. Arterial pH was lower in the injured group, and shock within 24 hours after arrival at the emergency department was more frequent in the injured group. Transfused packed red blood cells within 24 hours were 8 patients(38.1%) in the injured group and 11 patients(10.3%) in the non-injured group. Conservative treatment was the most common therapeutic modality in all groups. Stay in the ICU was longer in the injured group, and three mortalities occurred. Conclusion: There is a need to decide on a diagnostic and therapeutic plan regarding the possibility of intra-abdominal solid organ injury for hemodynamically unstable patients with stable pelvic bone fractures and for patients with stable pelvic bone fractures along with multiple associated injuries.

• Journal of Korean Neurosurgical Society
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• v.62 no.1
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• pp.96-105
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• 2019

Objective : The aims in the management of thoracolumbar spinal fractures are not only to restore vertebral column stability, but also to obtain acceptable alignment of the thoracolumbar junction (T-L junction) to prevent complications. However, insufficient surgical correction of the thoracolumbar spine would be likely to cause late progression of abnormal kyphosis. Therefore, we identified the surgical factors that affected unfavorable radiologic outcomes of the thoracolumbar spine after surgery. Methods : This study was conducted in a single institution from January 2007 to December 2013. A total of 98 patients with unstable thoracolumbar spine fracture were included. In these patients, fixation was done through transpedicular screws with rods by three surgical patterns. We reviewed digital radiographs and analyzed the images preoperatively and postoperatively during follow-up visits to compare the change of the thoracolumbar Cobb angle with radiologic parameters and clinical outcomes. The unfavorable radiologic group was defined as the patients who were measured as having greater than 20 degrees of thoracolumbar Cobb angle on the last follow-up, or who underwent kyphotic progression of thoracolumbar Cobb angle greater than 10 degrees from the immediate postoperative state to final follow-up, or who had overt instrument failure with/without additional surgery. We assessed the risk factors that affected the unfavorable radiologic outcomes. Results : We had 43 patients with unfavorable radiologic outcomes, including 35 abnormal thoracolumbar alignments and 14 instrumental failures with/without additional surgery. The multivariate logistic regression test showed that immediate postoperative T-L junction Cobb angle less than 10.5 degrees was a statistically significant risk factor, as well as the presence of osteoporosis (p=0.017 and 0.049, respectively). Conclusion : Insufficient correction of thoracolumbar kyphosis was considered to be a major factor of an unfavorable radiological outcome. The spinal surgeon should consider that having a T-L junction Cobb angle larger than 10.5 degrees immediately after surgery could result in an unfavorable radiological outcome, which is related to a poor clinical outcome.

• Structural Engineering and Mechanics
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• v.58 no.3
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• pp.515-532
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• 2016

The elastoplastic response of functionally graded material (FGM) beams resting on a nonlinear elastic foundation to an eccentric axial load is investigated by using the finite element method. The FGM is assumed to be formed from ceramic and metal phases with their volume fraction vary in the thickness direction by a power-law function. A bilinear elastoplastic behavior is assumed for the metallic phase, and the effective elastoplastic properties of the FGM are evaluated by Tamura-Tomota-Ozawa (TTO) model. Based on the classical beam theory, a nonlinear finite beam element taking the shift in the neutral axis position into account is formulated and employed in the investigation. An incremental-iterative procedure in combination with the arc-length control method is employed in computing the equilibrium paths of the beams. The validation of the formulated element is confirmed by comparing the equilibrium paths obtained by using the present element and the one available in the literature. The numerical results show that the elastoplastic post-buckling of the FGM beams is unstable, and the post-buckling strength is higher for the beams associated with a higher ceramic content. Different from homogeneous beams, yielding in the FGM beam occurs in the layer near the ceramic layer before in the layer near metal surface. A parametric study is carried out to highlight the effect of the material distribution, foundation support and eccentric ratio on the elastoplastic response of the beams.

• Journal of Trauma and Injury
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• v.31 no.1
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• pp.12-15
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• 2018

Rib fixations for flail chest or displaced rib fractures are not a new technique. However, reports on rib fixations involving costal cartilage fractures are very few and surprisingly there are no reports of internal fixations involving only the costal cartilage in the English literature. The diagnosis is difficult and the necessity of the procedure may be quite controversial. Placing plates in screws into the costal cartilage alone may seem unstable and easily dislodged or stripped through the cartilage. We report a 31-year-old male scuba diver instructor who underwent rib fixations over his 7th and 8th costal cartilage ribs for severe pain. The procedure was done with conventional plates and screws. He had the plates and screws removed 2 months later due to lingering pain, but with them removed he is now quite happy with the results without pain. The procedure for fixation of painful overlapped costal cartilage is quite simple and can be done with the usual conventional methods, fixating plate and screws directly over the cartilage alone without fixation over the bony rib.

• Tunnel and Underground Space
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• v.11 no.4
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• pp.301-310
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• 2001

Gypsum blocks with sixteen flaws have been prepared and tested in uniaxial compression. Results from these experiments are compared with observations from the same material with two and three flaws. The results indicate that the cracking pattern observed in specimens wish multiple flaws is analogous to the pattern obtained in specimens with two and three flaws such as initiation and propagation of wing, and secondary cracks and coalescence. Wing cracks initiate at an angle with the flaw and propagate in a stable manner towards the direction of maximum compression. Secondary cracks initiate and propagate in a stable manner. As the load is increased, secondary cracks may propagate in an unstable manner and produce coalescence. Two types of secondary cracks are observed: quasi-coplanar, and oblique secondary cracks. Coalescence is produced by the linkage of two flaws: wing and/or secondary cracks. From the sixteen flaws test, four types of coalescence are observed. Observed types of coalescence and initiation stress of wing and secondary crackle depend on flaw geometries, such as spacing, continuity, flaw inclination angle, ligament angle, and steppings.

• Journal of Korean Neurosurgical Society
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• v.54 no.2
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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.

• Journal of Trauma and Injury
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• v.22 no.2
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• pp.248-253
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• 2009

Purpose: Hemodynamically unstable pelvic fractures represent therapeutic challenges for the trauma team. The authors of this article have studied the clinical profiles of the angiographic intervention population at the emergency department during four years (2005~2009) to develop clinical guidelines for preventing deaths due to multiple trauma and for predicting the prognosis during initial evaluation. Methods: We performed a retrospective review of 34 patients who had undergone angiographic interventions at the emergency department and compared the differences in clinical variables between survivors and non-survivors. Results: Representative values were compared between survivors and non-survivors : RTS (revised trauma score) 7.006 (6.376~7.841) vs. 6.128 (4.298~6.494), PRC (packed red cell) units 5.5 (2.0~11.0) vs. 15 (8.0~18.5), and lactate (mmol/L) 3.0 (1.0~7.0) vs. 8.5 (3.5~10.5). RTS (p<0.01) and PRC units before angiographic interventions (p=0.01) and lactate (p=0.02) had correlations to the final outcomes. Conclusion: The availability of an angiographic suite and persistent hypotension after adequate fluid resuscitation for pelvic trauma are good indications of angiographic intervention for pelvic hemorrhage.