• 한국소음진동공학회논문집
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• 제24권6호
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• pp.452-461
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• 2014

Two stroke low speed diesel engines that have many advantages such as high thermal efficiency and durability have been widely used for marine engine. However, it is also true that many problems have occurred due to the high explosion pressure and severe operating environment. Especially problems of shaft damage etc. intensively occurred due to the phenomenon of crankshaft exceeding the allowable stress, including the shaft vibration of the engine model in the early stage. In this study, the crankshaft fracture phenomenon of early engine model was evaluated and analyzed by using up-to-date torsional vibration calculation program and measurement instrument. And this was numerically shown.

• 한국기계가공학회지
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• 제7권4호
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• pp.102-108
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• 2008

This study investigates the fatigue life and the damage possibility of cam shaft by the fatigue tool of Ansys. Among nonconstant fatigue loads, the case of 'SAE Bracket History' which is severest at the variation of load tends to be most unstable. The maximum relative damage in case of 'SAE Bracket History' is occurred near the average stress '0' and this case can be shown to have the possibility to take more damage than other cases. The case of 'Sample History' which becomes a little slow at the variation of load tends to be most stable. But there is most damaged possibility of 5% as 7 times at the range of mean stress from 0Pa to -104MPa and amplitude stress from 0MPa to 104MPa than the case of 'SAE Bracket History' or 'SAE Transmission'.

• Clinics in Shoulder and Elbow
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• 제19권1호
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• pp.8-14
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• 2016

Background: The purpose of this study was to investigate the difference between two nailing approaches of intramedullary screw fixation, the retrograde nailing versus the anterograde nailing, on the radiological and clinical outcomes in patients with clavicle shaft fractures. Methods: From April 2002 to August 2014, we enrolled a total of 22 patients with clavicle shaft fractures to participate in this study. Twelve patients received retrograde intramedullary nailing and 10 received anterograde nailing. The average duration of follow-up was 12 months. In all the patients, we took follow-up radiographs of the anteroposterior and the axial views to assess the postoperative radiological outcomes. We measured the visual analogue scale (VAS) score, American Shoulder and Elbow Surgeons (ASES) score, and the range of motion (ROM). Results: Clinically, we did not find a statistically significant difference in the retrograde group and the anterograde group in terms of the duration to bone union, the VAS score the ASES score and the ROMs. Radiologically, we found that the difference in the clavicle shortening of the affected arm and the unaffected arm did not show a statistically significant difference at the immediate postoperative assessment. we found that the difference in the clavicle shortening of the affected arm between the immediate postoperative and the final follow-up value did not show a statistically significant difference. Conclusions: We found that both the retrograde nailing and the anterograde nailing gave a favorable outcome for clavicle shaft fractures. Although we saw evidence of clavicle shortening after intramedullary screw fixation, this was not a factor that influenced clinical outcome.

• 대한견주관절학회:학술대회논문집
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• 대한견주관절학회 2002년도 학술대회
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• pp.121-122
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• 2002

• 대한견주관절학회:학술대회논문집
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• 대한견주관절학회 2009년도 제17차 학술대회
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• pp.161-161
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• 2009

To prevent distraction and varus deformity between the humeral head and shaft, tension band sutures placed between the head of the interlocking screw and the rotator cuff, and we recommend using nonabsorbable sutures. We describe our simple procedure to overcome these difficulties in tension band suturing after reducing a proximal humerus fracture to maintain the reduction.

• 대한족부족관절학회지
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• 제5권1호
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• pp.18-22
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• 2001

Most of Danis-Weber type B fracture has an oblique fracture plane proximal posteriorly to distal anteriorly. In these cases, the lateral plate has become widely accepted. However some limitation to the use of the lateral plate exist. The plate must be bent accurately and the screws in the distal fragment must be unicortical to avoid penetration into the joint, predisposing it to poor fixation in the osteoporotic bone. In 1982, Brunner and Weber introduced the antiglide plate for fixation of the shaft oblique fracture of the distal fibula, but it has not widely used. The author reviewed 21 cases treated by antiglide plate fixation from March, 1995 to March, 1999 which could be follow-up more than 1 year. We analysed the result radiographically and clinically using Ankle-Hindfoot scale(100 % total) of the American Orthopedic Foot and Ankle Society. The results obrained were as follows: 1. All fracture were united at average 8 weeks clinically and radiographically. 2. According to the Ankle- Hindfoot scale, 8 cases were above 90 points, 11 cases were beet ween 80 and 89 points and two cases were below 80 points. 3. One case had an injury to intermediate dorsal cutaneous nerve.

• Clinics in Shoulder and Elbow
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• 제24권2호
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• pp.72-79
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• 2021

Background: A midshaft clavicle fracture is a common fracture that typically responds well to open reduction and internal fixation (ORIF). However, refracture can occur after implant removal (IR). This study aimed to analyze the rate of refracture and related factors after removal of the locking compression plate (LCP) for displaced midshaft clavicle fractures. Methods: We retrospectively reviewed the medical records of 201 patients who had undergone ORIF with LCP for midshaft clavicle fractures after IR after bony union from January 2011 to May 2018 at our institute. We evaluated basic demographic characteristics and radiographic parameters. All patients were treated with an LCP for primary fracture. The patients were divided into two groups: a refracture group that experienced a second fracture within 1 year after IR and a no-fracture group. Results: There were four cases (1.99%) of refracture; three were treated conservatively, while one was treated surgically. All patients achieved bony union. The average interval between refracture and IR was 64 days (range, 6-210 days). There was a significant difference in classification of fractures (AO Foundation/Orthopaedic Trauma Association [AO/OTA] classification) between the two groups. However, other patient demographics and radiographic measurements between refracture and IR, such as bone diameter, showed no significant difference between the two groups. Conclusions: This study showed that one in 50 patients suffered from refracture after removal of the LCP. Thus, if patients desire IR, the surgeon should explain that there is a relatively higher possibility of refracture for cases with simple or segmental fractures than for other types of fracture.

• Clinics in Shoulder and Elbow
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• 제25권4호
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• pp.304-310
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• 2022

Background: The Boileau classification distinguishes three surgical neck fracture patterns: types A, B, and C. However, the reproducibility of this classification on plain radiographs is unclear. Therefore, we questioned what the interobserver agreement and accuracy of displaced surgical neck fracture patterns is categorized according to the modified Boileau classification. Does the reliability to recognize these fracture patterns differ between orthopedic residents and attending surgeons? Methods: This interobserver study consisted of a randomly retrieved series of 30 plain radiographs representing clinical practice in a level 1 and a level 2 trauma center. Radiographs were included from patients (≥18 years) who sustained an isolated displaced surgical neck fracture if they were taken ≤1 week after initial injury. A ground truth was established by consensus among three senior orthopedic surgeons. All images were assessed by 17 orthopedic residents and 17 attending orthopedic trauma surgeons. Results: Agreement for the modified Boileau classification was fair (κ=0.37; 95% confidence interval [CI], 0.36-0.38) with an accuracy of 62% (95% CI, 57%-66%). Comparison of interobserver variability between residents and attending surgeons revealed a significant but clinically irrelevant difference in favor of attending surgeons (0.34 vs. 0.39, respectively, Δκ=0.05, 95% CI, 0.02-0.07). Conclusions: The modified Boileau classification yields a low interobserver agreement with an unsatisfactory accuracy in a panel of orthopedic residents and attending surgeons. This supports the hypothesis that surgical neck fractures are challenging to categorize and that this classification should not be used to determine prognosis if only plain radiographs are available.

• Biomaterials and Biomechanics in Bioengineering
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• 제5권1호
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• pp.11-23
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• 2020

Total hip prosthesis is used for the patients who have hip fracture and are unable to recover naturally. To de-sign highly durable prostheses one has to take into account the natural processes occurring in the bone. Finite element analysis is a computer based numerical analysis method which can be used to calculate the response of a model to a set of well-defined boundary conditions. In this paper, the static load analysis is based, by se-lecting the peak load during the stumbling activity. Two different implant materials have been selected to study appropriate material. The results showed the difference of maximum von Misses stress and detected the frac-ture of the femur shaft for different model (Charnley and Osteal) implant with the extended finite element method (XFEM), and after the results of the numerical simulation of XFEM for different was used in deter-mining the stress intensity factors (SIF) to identify the crack behavior implant materials for different crack length. It has been shown that the maximum stress intensity factors were observed in the model of Charnley.

• Journal of Trauma and Injury
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• 제29권3호
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• pp.76-81
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• 2016

Purpose: The purpose of this study was to compare the data comprehensively including not only the clinical and radiographic outcomes but some parameters related to operation between the minimally invasive plate osteosynthesis (MIPO) technique and intramedullary nailing (IMN) for treatment of segmental tibia shaft fractures. Methods: We conducted a retrospective study of 31 patients (mean age, 49.3 years, range, 27-74 years), with a mean follow-up of 14.1 months (range, 12-19 months) with acute segmental tibial fractures (AO 42-C2) who underwent either surgical treatment of MIPO or IMN. In accordance with the Gustilo-Anderson classification, 11 were type I, 5 were type II, and 15 were type III. Initial compartment syndrome was confirmed in 2 cases. Results: There were no statistically significant differences in terms of the patient demographic data between the two groups. The time to definitive fixation was longer in the MIPO group (mean $13.7{\pm}10.9days$; range, 2-27) than in the intramedullary group (mean $5.4{\pm}9.6days$; range, 0-35) with statistically significant difference (p=0.002). Bony union was observed in most of cases but except 5 cases of nonunion were diagnosed (3 in the MIPO vs 2 in IMN, p=0.188). The average bone healing time was 27.1 weeks (10 to 56 weeks) in MIPO group and 23.2 weeks (13 to 66 weeks) in IMN group, respectively (p=0.056). Overall complications were 5 cases in MIPO group and 2 cases in the IMN group. Difference in LEFS was not statistically significant between both groups (p=0.824). Conclusion: This study showed that segmental tibia shaft fractures treated with both MIPO and intramadullary nailing was challenging with relatively high complication rate. A well planned sequential strategy with keeping the soft tissue and personality of fracture in mind is utmost significant as much as the choice of surgical modalities.