• Journal of Korean Foot and Ankle Society
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• v.12 no.1
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• pp.14-19
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• 2008

Purpose: We tried to understand the effects of the derotational closing wedge Akin osteotomy during the operation for the hallux valgus with pronation of great toe. Materials and Methods: Eighty five patients who had undergone Akin osteotomy among the eighty seven patients who had been treated with Scarf osteotomy with hallux valgus were included in this study. Derotational supination was added on the medial closing wedge Akin osteotomy at the base of proximal phalanx and it was secured with K-wire, headless screw or staple. We measured and analyzed pre- and post-operative hallux primus valgus angle and hallux pronational rotatory angle. Results: The hallux primus valgus angle improved an average of $14{\pm}2.98$ degrees to $-1{\pm}1.68$ degrees with the hallux pronational rotatory angle respectively from $24.8{\pm}7.64$ degrees to $4.7{\pm}4.22$ degrees. Conclusions: After the metatarsal osteotomy for the treatment of the hallux valgus with the pronation of great toe, derotational closing wedge Akin osteotomy can give us a belief that it can correct the hallux primus valgus angle and hallux pronational rotatory angle also and it can be a helpful method for minimizing the recurrence rate of the hallux valgus deformity.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1-6
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• 2003

In this paper, we design a wedge type rail clamp which can protect container crane from wind with constant clamping force regardless of the operating period. When we design wedge type rail clamp. it is important to determine the angle of wedge and analyze a contact condition of roller and wedge so that we might develop a rail clamp with variable capacity. Therefore, this paper suggest a process to decide wedge angles within feasible range which could be obtained using load analysis and FEA of wedge type rail clamp.

• Journal of Korean Foot and Ankle Society
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• v.8 no.1
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• pp.64-70
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• 2004

Purpose: We compared the result of a proximal metatarsal closed wedge osteotomy and soft tissue procedure with a modified chevron osteotomy and soft tissue procedure in the treatment of hallux valgus. Materials and Methods: Between March 1999 and February 2003, we performed proximal metatarsal closed wedge osteotomy and soft tissue procedure on 17 feet (12 patients), and modified chevron osteotomy and soft tissue procedure on 12 feet (9 patients). Results: According to Mayo clinic forefoot scoring system (FFSS), group 1, with proximal metatarsal closed wedge osteotomy, shows 67.2 points postoperatively and group 2, with modified chevron osteotomy, shows 68.5 points postoperatively. In group 1, the average correction of hallux valgus angle and intermetatarsal angle was 20.8 degrees and 4.8 degrees, respectively. In group 2, the average correction of hallux valgus angle and intermetatarsal angle was 19.9 degrees and 4.7 degrees, respectively. The average shortening was 3.15 mm in group 1 and 1.38 mm in group 2. Conclusion: We obtained relatively good clinical and radiographic result in this study. The effect on shortening of the first metatarsal was greater in the proximal metatarsal closed wedge osteotomy than modified chevron osteotomy, but the metatarsal shortening did not related with metatarsalgia. So, both techniques seems optimal surgical treatment for hallux valgus deformity.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.149-157
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• 2002

This paper is to investigate collapse mechanisms of CFRP(Carbon Fiber Reinforced Plastics)composite tubes and to evaluate collapse characteristics on the change of interlaiminar number and ply orientation angle of outer under static and impact axial compression loads. When a CFRP composite tube is crushed, static/impact energy is consumed by friction between the loading plate and the splayed fronds of the tube, by fracture of the fibers, matrix and their interface. These are associated with the energy absorption capability. In general, CFRP tube with 6 interlaminar number(C-type), absorbed more energy than other tubes(A, B, D-types). The maximum collapse load seemed to increase as the interlaminar number of such tubes increases. The collapse mode depended upon orientation angle of outer of CFRP tubes and loading status(static/impact). Typical collapse modes of CFRP tubes are wedge collapse mode, splaying collapse mode and fragmentation collapse mode. The wedge collapse mode was shown in case of CFRP tubes with 0° orientation angle of outer under static and impact loadings. The splaying collapse mode was shown in only case of CFRP tubes with 90°orientation angle of outer under static loadings, however in Impact tests those were collapsed in fragmentation mode .

• Journal of Korean Neurosurgical Society
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• v.38 no.4
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• pp.255-258
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• 2005

Objective : Lumbar lordotic curve on L4 to S1 level is important in maintaining spinal sagittal alignment. Although there has been no definite report in lordotic value, loss of lumbar lordotic curve may lead to pathologic change especially in degenerative lumbar disease. This study examines the changes of lumbar lordotic curve after posterior lumbar interbody fusion with wedge shape cage. Methods : We studied 45patients who had undergone posterior lumbar interbody fusion with wedge shape cage and screw fixation due to degenerative lumbar disease. Preoperative and postoperative lateral radiographs were taken and one independent observer measured the change of lordotic curve and height of intervertebral space where cages were placed. Segmental lordotic curve angle was measured by Cobb method. Height of intervertebral space was measured by averaging the sum of anterior, posterior, and midpoint interbody distance. Clinical outcome was assessed on Prolo scale at 1month of postoperative period. Results : Nineteen paired wedge shape cages were placed on L4-5 level and 6 paired same cages were inserted on L5-S1 level. Among them, 18patients showed increased segmental lordotic curve angle. Mean increased segmental lordotic curve angle after placing the wedge shape cages was $1.96^{\circ}$. Mean increased disc height was 3.21mm. No cases showed retropulsion of cage. The clinical success rate on Prolo's scale was 92.0%. Conclusion : Posterior lumbar interbody fusion with wedge shape cage provides increased lordotic curve, increased height of intervertebral space, and satisfactory clinical outcome in a short-term period.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.12 no.2
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• pp.1-10
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• 2006

The purpose are to assess the efficacy of a contact lateral-wedged insole with strapping on the femorotibial angle in patients with varus deformity osteoarthritis of the knee after treatment period. 25 outpatients with knee osteoarthritis (OA) were randomized to be treated with a contact lateral-wedge insole with strapping. Standing radiographs were used to analyze the femorotibial angle for each subject. The result of repeated two-way ANOVA's reveled that a contact lateral-wedged insole with strapping produced significantly differences in the femorotibial angle between groups after treatment period (P<0.05). and repeated one-way ANOVA's reveled that it produced significantly differences in the femorotibial angle between experimental groups after treatment period (P<0.05). We suggest that these results may be beneficial for manufacturing foot orthotic devices, such as wedged insoles, to control medial and later compartment forces in the knee varus-valgus deformity.

• Journal of Mechanical Science and Technology
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• v.14 no.6
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• pp.690-698
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• 2000

The laminar boundary layer flow and heat transfer of anisotropic fluids in the vicinity of a wedge have been examined with constant surface temperature. The similarity variables found by Falkner and Skan are employed to reduce the stream wise-dependence in the coupled nonlinear boundary layer equations. The numerical solutions are presented using the fourth-order Runge - Kutta method and the distribution of velocity, micro-rotation, shear and couple stresses and temperature across the boundary layer are plotted. These results are also compared with the corresponding flow problems for Newtonian fluid over wedges. It is found that for a constant wedge angle, the skin friction coefficient is lower for micropolar fluid, as compared to Newtonian fluid. For the case of the constant material parameter K, however, the magnitude of velocity for anisotropic fluid is greater than that of Newtonian fluid. The numerical results also show that for a constant wedge angle with a given Prandtl number, Pr = I, the effect of increasing values of K results in increasing thermal boundary layer thickness for anisotropic fluid, as compared with Newtonian fluid. For the case of the constant material parameter K, however, the heat transfer rate for anisotropic fluid is lower than that of Newtonian fluid.

• Progress in Medical Physics
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• v.12 no.2
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• pp.125-131
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• 2001

We was investigate the dosimetric characteristics of the virtual wedge and it compared to the conventional fixed wedge. Also we was evaluate the quality factor of the experimental multi-channel dosimetry system for virtual wedge. Recently virtual wedge technique and wedge fraction methods are available through the computer controlled asymmetric collimator or the independent jaw in medical linear accelerator for radiation therapy. The dosimetric characteristics are interpreted by radiation field analyzer RFA-7 system and PTW-UNIDOS system. Experimental multi-channel dosimetry system for virtual wedge was consists of the electrometer, the solid detector and array phantom. The solid detectors were constructed using commercially diodes for the assessment of quality assurance in radiotherapy. And it was used for the point dose measuring and field size scanning. The semiconductor detector and ion chamber were positioned at a dmax, 5 cm, 10 cm, 20 cm depth and its specific ratio was determined using a scanning data. Wedge angles in fixed and virtual type are compared with measurements in water phantom and it is shown that the wedge angle 15$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$were agree within 1$^{\circ}$ degree in 6, 10 MV photon beams. In PDD and beam flatness, experimental multi-channel disimetry system was capable of reproduceing the measured values usually to within $\pm$2.1% the statistical uncertainties of the data. It was used to describe dosimetric characteristics of virtual wedge in clinical photon beams. Also we was evaluate optimal use of the virtual wedge and improve the quality factor of the experimental multi-channel dosimetry system for virtual wedge.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.12 no.1
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• pp.44-50
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• 2006

The purpose of this study is to assess the radiographic effects of normal person with contact laterally wedged insoles with strapping of varying elevations. Eight person who were randomized into group according to their birth dates and wedge elevation, participants wore contact laterally wedged insoles with strapping with elevation of 9, 15, 21mm. Standing radiographs were used to analyze the femorotibial angle for each subject, The result of repeated measures ANOVA's reveled that laterally wedged insoles with strapping of varying elevations produced significantly the femorotibial angle. The degree of change in femorotibial angle with the insole with strapping was effected by the tilt of the lateral wedge(P<0.05). We suggest that these results may be beneficial for manufacturing foot orthotic devices, such as wedged insoles, to control medial and later compartment forces in the knee varus-valgus deformity.

• The KSFM Journal of Fluid Machinery
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• v.9 no.3 s.36
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• pp.22-28
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• 2006

The discharge coefficient in segmental wedge haying ninety degrees yeller angle for the five kinds of opening ratio with differential pressure taps located at both upstream and downstream of one diameter of pipe was measured. Main purpose of this work is placed on specifying the characteristic of discharge coefficient of a segmental wedge used as a primary element of flow metering devices, and suggestion for the fixed location of pressure taps useful. Although the range of the opening ratio over this work is more expanded than previous studies. The opening ratios of segmental wedge, namely 0.3, 0.4, 0.5, 0.6 and 0.7 were investigated. The Reynolds number based on the spool inside diameter ranges from 12,000 to 380,000.