• Title/Summary/Keyword: ligament

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The Mechanical Sensitivity at Interfaces between Bone and Interbody Cage of Lumbar Spine Segments (Lumbar spine 의 뼈와 Interbody cage의 접촉면에서 기계공학적 민감성 고찰)

  • Kim Y.
    • Journal of Biomedical Engineering Research
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    • v.21 no.3 s.61
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    • pp.295-301
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    • 2000
  • It is known that among many factors, relative micromotion at bone/implant interfaces can hinder bone ingrowth into surface pores of an implant. Loading conditions, mechanical properties of spinal materials, friction coefficients at the interfaces and geometry of spinal segments would affect the relative micromotion and spinal stability. A finite clement model of the human lumbar spine segments (L4-L5) was constructed to investigate the mechanical sensitivity at the interfaces between bone and cage. Relative micromotion. Posterior axial displacement. bone stress, cage stress and friction force were predicted in changes of friction coefficients, loading conditions. bone density and age-related material/geometric properties of the spinal segments. Relative micromotion (slip distance in a static loading means relative micromotion in routine activity) at the interfaces increased significantly as the mechanical properties of cancellous bone, annulus fibers or/and ligaments decrease or/and as the friction coefficient at the interfaces decreases. The contact normal force at the interfaces decreased as cancellous bone density decreases or/and as the friction coefficient increases A significant increase of slip distance at anterior annulus occurred with an addition of torsion to compressive preload. Relative micromotion decreased with an increase of disc area. In conclusion. relative micromotion, stress response. Posterior axial displacement and contact normal force are sensitive to the friction coefficient of the interfaces, bone density, loading conditions and age-related geometric/material changes.

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Comparative Analysis on Disc Resorption Rate of Lumbar Disc Herniation Patients after Korean Medicine Treatment and Predictive Factors Associated with Disc Resorption (요추 추간판 탈출증 환자의 한의치료 후 디스크 흡수율 비교 및 흡수에 영향을 주는 요인 분석 연구)

  • Kim, Yong-Hyeon;Lee, Ju-Young;Kim, Kwang-Hwi;Kim, Tae-Yeon;Lee, Tae-Geol;Lee, Sang-Woon;Chu, Hui-Yeong;Jeong, Hui-Gyeong
    • Journal of Korean Medicine Rehabilitation
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    • v.28 no.4
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    • pp.33-41
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    • 2018
  • Objectives The purpose of this study is to analyze the effects of Korean Medicine treatment on lumbar disc herniation (LDH) and predictive factors associated with disc resorption by magnetic resonance imaging (MRI). Methods A retrospective study was carried out in 79 lumbar disc herniation patients who had visited Haeundae Jaseng Hospital of Korean Medicine. Patients' diagnosis was based on MRI. MRI was performed on two or more occasions and patients were received Korean Medicine treatment within the period. The volume of each herniated disc was measured three-dimensionally and patient characteristics, interval between MRIs, herniated disc level, disc herniation type, disc migration, intactness of posterior longitudinal ligament (PLL), initial volume of herniated disc, modic change, disc resorption rate were statistically analyzed. Results The mean volumes of herniated discs before Korean Medicine treatment and after Korean Medicine treatment were 1,547.81±598.15mm31,547.81±598.15mm3 and 947.06±335.28mm3947.06±335.28mm3, respectively. The mean resorption rate was 35.7±16.335.7±16.3. Disc extent, intactness of PLL and initial volume of herniated discs were significantly correlated with resorption rate (p=0.003, p=0.001 and p=0.024, respectively). Conclusions Korean Medicine treatment is an effective conservative treatment for lumbar disc herniation. Factors such as disc migration, intactness of PLL, initial volume of herniated disc have a significant association with disc resorption rate.

The Effect of Mineral Trioxide Aggregate on the Production of Growth Factors and Cytokine by Human Periodontal Ligament Fibroblasts (Mineral trioxide aggregate (MTA)가 치주인대 섬유아세포에서 분비되는 cytokine과 성장인자 TGF-β1, FGF-2 발현에 미치는 영향)

  • Kwon, Ji-Yoon;Lim, Sung-Sam;Baek, Seung-Ho;Bae, Kwang-Shik;Kang, Myung-Hoe;Lee, Woo-Cheol
    • Restorative Dentistry and Endodontics
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    • v.32 no.3
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    • pp.191-197
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    • 2007
  • Mineral trioxide aggregate (MTA) would influence healing of periapical tissues by modulating the production of growth factors and cytokines from PDL fibroblasts, however, the studies are insufficient. Therefore, the purpose of this study was to monitor the expression of transforming growth factor-beta1 (TGFβ1)(TGFβ1), fibroblast growth factor-2 (FGF-2), and interleukin-6 (IL-6) from PDL fibroblasts in the presence of MTA. The human PDL fibroblasts were seeded onto the set MTA or IRM at a level of 1×1051×105 cells per unit well, and further incubated for 6, 12, 24, and 48 hours. The levels of TGFβ1TGFβ1, FGF-2 and IL-6 from the supernatant were measured by enzyme-linked immunosorbent assay (ELISA) The data were analyzed using one-way ANOVA. The level of TGFβ1TGFβ1 was down-reg ulated when the cells were grown in the presence of MTA except at 6 hours. The levels of FGF-2 release were significantly suppressed when PDL fibroblasts were grown in the presence of MTA or IRM at all time intervals (p < 0.05). The expressions of IL-6 from MTA treated co)Is were comparable to those of untreated control cells throughout the observation periods. We presume that this material inhibits the stimulatory function of growth factors on granulation tissue formation and in turn, it promotes the healing process modulated by other bone-remodeling cells.

THE VERIFICATION OF THE MTT ASSAY ON THE VIABILITY OF PERIODONTAL LIGAMENTAL CELLS IN RAT MOLARS THROUGH THE HISTOLOGIC EXAMINATION (쥐치아 치근면의 치주인대세포의 활성도를 평가하는 방법으로 MTT검색법의 적절성에 대한 조직학적인 검증)

  • Kim, Hyun-Ki;Kim, Eui-Seoung;Choi, In-Bok;Kim, Jin;Lee, Seung-Jong
    • Restorative Dentistry and Endodontics
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    • v.28 no.5
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    • pp.385-391
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    • 2003
  • The purpose of this study is to examine the viability of PDL cells in rat molars by using MTT assay and to verify the MTT assay through the histologic observation. Thirty of Sprague-Dawley white female rats of 4-weeks old with a body weight of about 100 grams were used. Groupings are as follows : Immediate Group : Positive control group(n=10)-after extraction immediately. Dried Group : Negative control group(n=10)-after drying for an hour under warm dry. ViaSpan® Group : 1hour ViaSpan® group(n=10)-after storing in ViaSpan®at4C for 1hour. Ten teeth of each group were treated as same as above and replanted to the original socket of experimental animals. After two weeks of replantation. all the experimental animals were sacrificed. And after fixation, extracted maxillary jaw was dimineralized. After it was embedded in paraffin. serial section by 5μm was carried out and for construction of specimen, hematoxylin-eosin dye was used. The mean MTT measurement of immediate group(positive control) is 2.81 and the mean measurement of dried group(negative control) is 0.98 which is significantt differnt(P<0.05), The mean measurement of ViaSpan® group is 2.65 and there is significant difference between dried group and ViaSpan® group(P<0.05), However, there is no difference between immediate group and ViaSpan® group. The average resorption points of immediate group is 3.03 points. In the dried group, average 6.44 points resorption and 2.68 points showed resorption in the ViaSpan® group. Unlike with MTT assay, there was no significant difference between the immediate group and ViaSpan® group. The usage of MTT assay as a viable cell marker may give us a better indication of the maintenance of periodontal ligament cell vitality.

Debridement Arthroplasty using Posteromedial Approach in Elbow Joint with Pain and Bony Limitation of Motion (동통과 골성 운동 제한이 있는 주관절에서 후내측 도달법을 이용한 변연 절제 관절 성형술)

  • Cheon, Sang-Jin;Lee, Dong-Ho;Cha, Seung-Han;Kim, Hui-Taek;Suh, Jeung-Tak
    • Clinics in Shoulder and Elbow
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    • v.12 no.1
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    • pp.67-75
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    • 2009
  • Purpose: This study evaluated the clinical outcomes of debridement arthroplasty using the posteromedial approach in elbow joints with pain and bony limitation of motion. Materials and Methods: This study involved 16 elbows in 16 patients with pain and bony limitation of motion, which were treated by debridement arthroplasty using the posteromedial approach from March 2005 to March 2008. The mean follow up period was 27.6 (13~52) months. The clinical outcomes were analyzed using the Visual Analogue Scale(VAS) for pain scale, the preoperative and postoperative range of motion and the Mayo Elbow Performance Scores(MEPS). Results: The VAS was decreased significantly from a preoperative mean of 4.5 to a postoperative mean 1.1 (p<0.001). The average arc of motion improved significantly from 61.6(0 90) preoperatively to 109.4(80120) postoperatively (p<0.001). The MEPS also improved significantly from 59.4 to 85.6 postoperatively (p<0.001). There were no complications, such as hematoma and elbow instability. Conclusion: Debridement arthroplasty using the posteromedial approach is a useful surgical procedure in the elbow joint with pain and bony limitation of motion, where all compartments can be debrided, the ulnar nerve can be manipulated easily and damage to the medial collateral ligament can be minimized.

A STUDY ON COMPARISON OF VARIOUS KINDS OF CLASSII AMALGAM CAVITIES USING FINITE ELEMENT METHOD (유한요소법을 이용한 수종 2급 아말감 와동의 비교연구)

  • Seok, Chang-In;Um, Chung-Moon
    • Restorative Dentistry and Endodontics
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    • v.20 no.2
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    • pp.432-461
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    • 1995
  • The basic principles in the design of Class II amalgam cavity preparations have been modified but not changed in essence over the last 90 years. The early essential principle was "extension for prevention". Most of the modifications have served to reduce the extent of preparation and, thus, increase the conservation of sound tooth structure. A more recent concept relating to conservative Class II cavity preparations involves elimination of occlusal preparation if no carious lesion exists in this area. To evaluate the ideal ClassII cavity preparation design, if carious lesion exists only in the interproximal area, three cavity design conditions were studied: Rodda's conventional cavity, simple proximal box cavity and proximal box cavity with retention grooves. In this study, MO amalgam cavity was prepared on maxillary first premolar. Three dimensional finite element models were made by serial photographic method. Linear, eight and six-nodal, isoparametric brick elements were used for the three dimensional finite element model. The periodontal ligament and alveolar bone surrounding the tooth were excluded in these models. Three types model(B option, Gap option and R option model) were developed. B option model was assumed perfect bonding between the restoration and cavty wall. Gap option model(Gap distance: 2μm) was assumed the possibility of play at the interface simulated the lack of real bonding between the amalgam and cavity wall (enamel and dentin). R option model was assumed non-connection between the restoration and cavty wall. A load of 500N was applied vertically at the first node from the lingual slope of the buccal cusp tip. This study analysed the displacement, 1 and 2 direction normal stress and strain with FEM software ABAQUS Version 5.2 and hardware IRIS 4D/310 VGX Work-station. The results were as followed. 1. Rodda's cavity form model showed greater amount of displacement with other two models. 2. The stress and strain were increased on the distal marginal ridge and buccopulpal line angle in Rodda's cavity form model. 3. The stress and strain were increased on the central groove and a part of distal marginal ridge in simple proximal box model and proximal box model with retention grooves. 4. With Gap option, Rodda's cavity form model showed the greatest amount of the stress on distal marginal ridge followed by proximal box model with retention grooves and simple proximal box model in descending order. 5. With Gap option, simple proximal box model showed greater amount of stress on the central groove with proximal box model with retention grooves. 6. Retention grooves in the proximal box played the role of supporting the restorations opposing to loads.

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Gender Dfferences in Ground Reaction Force Components

  • Park, Sang-Kyoon;Koo, Seungbum;Yoon, Suk-Hoon;Park, Sangheon;Kim, Yongcheol;Ryu, Ji-Seon
    • Korean Journal of Applied Biomechanics
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    • v.28 no.2
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    • pp.101-108
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    • 2018
  • Objective: The aim of this study was to investigate gender differences in ground reaction force (GRF) components among different speeds of running. Method: Twenty men (age=22.4±1.6years, mass=73.4±8.4kg, height=176.2±5.6cm) and twenty women (age=20.7±1.2years, mass=55.0±8.2kg, height=163.9±5.3cm) participated in this study. All participants were asked to run on an instrumented dual belt treadmill (Bertec, USA) at 8, 12, and 16 km/h for 3 min, after warming up. GRF data were collected from 30 strides while they were running. Hypotheses were tested using one-way ANOVA, and level of significance was set at p-value <.05. Results: The time to passive peaks was significantly earlier in women than in men at three different running speeds (p<.05). Further, the impact loading rates were significantly greater in women than in men at three different running speeds (p<.05). Moreover, the propulsive peak at 8 km/h, which is the slowest running speed, was significantly greater in women than in men (p<.05), and the vertical impulse at 16 km/h, which is the fastest running speed, was significantly greater in men than in women (p<.05). The absolute anteroposterior impulse at 8 km/h was significantly greater in women than in men (p<.05). In addition, as the running speed increased, impact peak, active peak, impact loading rate, breaking peak, propulsive peak, and anteroposterior impulse were significantly increased, but vertical impulse was significantly decreased (p<.05). Conclusion: The impact loading rate is greater in women than in men regardless of different running speeds. Therefore, female runners might be exposed to the risk of potential injuries related to the bone and ligament. Moreover, increased running speeds could lead to higher possibility of running injuries.

Analysis of Mechanical Properties and Stress Crack Behavior of HOPE Geomembranes by Laboratory Installation Damage Test (실내 시공시 손상시험에 의한 HDPE 지오멤브레인의 기계적 특성 및 응력균열거동 해석)

  • Khan, Belas Ahmed;Park, Ju-Hee;Kim, Sung-Hee;Chang, Yong-Chai;Oh, Tae-Hwan;Lyoo, Won-Seok;Jeon, Han-Yong
    • Polymer(Korea)
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    • v.35 no.3
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    • pp.203-209
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    • 2011
  • Two smooth and textured surfaced HDPE geomembranes (GMs) were cut into dumbbell shape and notched where depth of the notch produced a ligament thickness of 10% to 90% of the nominal thickness with the specimen at 10% interval. A series of laboratory simulation test for installation damage were carried out at different loading cycles on HDPE GMs in accordance with ISO 10722 test method and the effect of number of loading cycle on installation damage was compared. It was found that yield stress and elongation at yield point decreased gradually as the notch depth was increased. Both installation damaged and notched, GMs were used to understand stress crack behavior and this behavior was observed through NCTL test at 50±1C at different yield stresses immerging in pH 4 and pH 12 buffer solutions. Over 35% tensile load, GMs became vulnerable to stress cracking. Both damaged and notched GMs showed the same trend. Especially, notched GMs showed less strength than installation damaged GMs at every stress cracking test condition.

Reconstruction of Soft Tissue Defects after Snake Bites (뱀교상 후 발생한 연부조직 결손의 재건)

  • Lee, Jang Hyun;Jang, Soo Won;Kim, Cheol Hann;Ahn, Hee Chang;Choi, Matthew Seung Suk
    • Archives of Plastic Surgery
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    • v.36 no.5
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    • pp.605-610
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    • 2009
  • Purpose: Substantial tissue necrosis after snake bites requiring coverage with flap surgery is extremely rare. In this article, we report 7 cases of soft tissue defects in the upper and the lower extremities caused by snake bites, which needed to be covered with flaps. Among the vast mass of publications on snake bites there has been no report that focuses on flap coverage of soft tissue defects due to snake bite sequelae. Methods: Seven cases of soft tissue defects with tendon, ligament, or bone exposure after snake bites were included. All patients were males without comorbidities, the average age was 35 years. All of them required coverage with a flap. In 6 cases, the defect was localized on the upper extremity, in one case the lesion was on the lower extremity. Local flaps were used in 6 cases, one case was covered with a free flap. The surgical procedures included one kite flap, one cross finger flap and digital nerve reconstruction with a sural nerve graft, one reverse proximal phalanx island flap, one groin flap, one adipofascial flap, one neurovascular island flap, and one anterolateral thigh free flap. The average interval from injury to flap surgery was 23.7 days. Results: All flaps survived without complication. All patients regained a good range of motion in the affected extremity. Donor site morbidities were not observed. The case with digital nerve reconstruction recovered a static two point discrimination of 7 mm. The patient with foot reconstruction can wear normal shoes without a debulking procedure. Conclusion: The majority of soft tissue affection after snake bites can be treated conservatively. Some severe cases, however, may require the coverage with flap surgery after radical debridement, especially, if there is exposure of tendon, bone or neurovascular structures. There is no doubt that definite coverage should be performed as soon as possible. But we also want to point out that this principle must not lead to a premature coverage. If the surgeon is not certain that the wound is free of necrotic tissue or remnants of venom, it is better to take enough time to get a proper wound before flap surgery in order to obtain a good functional and cosmetic result.

Effect of 840 nm Light-Emitting Diode(LED) Irradiation on Monosodium Iodoacetate-Induced Osteoarthritis in Rats (흰쥐의 MIA 유발 무릎 뼈관절염에 대한 840 nm LED의 효과)

  • Jekal, Seung-Joo;Kwon, Pil-Seung;Kim, Jin-Kyung;Lee, Jae-Hyoung
    • Journal of the Korean Society of Physical Medicine
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    • v.9 no.2
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    • pp.151-159
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    • 2014
  • PURPOSE: The purpose of this study was to evaluate whether light-emitting diodes (LED) irradiation could be effective in a noninvasive, therapeutic device for the treatment of osteoarthritis(OA). METHODS: Twenty-four male Sprague-Dawley rats were divided into four groups: Vehicle control (saline); monosodium iodoacetate-injection (MIA); LED irradiation after MIA injection (MIA-LED); indomethacin-treatment after MIA injection (MIA-IMT). OA was induced by intra-articular injection of 3 mg MIA through the patellar ligament of the right knee. Vehicle control rats were injected with an equivalent volume of saline. The LED was irradiated for 15 min/day for a week after 7 days of MIA treatment. To compare with the effect of LED irradiation, the indomethacin was administrated 20 mg/kg twice a week orally after 7 days of MIA treatment. Knee joints were removed and fixed overnight in 10% neutral buffered formalin and decalcified by EDTA for 2 week before being embedded in paraffin. The assessment of OA induction were monitored by knee movement and radiographic finding. Histologic analysis were performed following staining with hematoxylin and eosin, safranin O-fast green, or toluidine blue, picrosirius red, and histologic changes were scored according to a modified Mankin system. Apoptotic cell in tissue sections was detected using TUNEL method. RESULTS: Radiographic examination could not show the differences between the MIA-treated and the MIA-LED-treated rats. In the histologic analysis, however, LED irradiation prevented cartilage damage and subchondral bone destruction, and significantly reduced mononuclear inflammatory cell infiltration and pannus formation. LED irradiation also reduced apoptosis of cartilage cells, but it prevented apoptosis of infiltrated inflammatory cells in synovium. In addition, LED irradiation showed an increase of collagen production in the meniscus. CONCLUSION: These results suggest that the 840 nm LED irradiation would be a suitable non-thermal phototherapy for the treatment of OA, as a cartilage protection and anti-inflammatory modality.