• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.4 s.247
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• pp.457-464
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• 2006

The anterior cruciate ligament (ACL) is liable to a major injury that often results in a functional impairment requiring surgical reconstruction. The success of reconstruction depends on such factors as attachment positions, initial tension of ligament and surgical methods of fixation. The purpose of this study is to find isometric positions of the substitute during flexion/extension. The distance between selected attachments on the femur and tibia was computed from a set of measurements using a 6 degree-of-freedom magnetic sensor system. A three-dimensional knee model was constructed from CT images and was used to simulate length change during knee flexion/extension. This model was scaled for each subject. Twenty seven points on the tibia model and forty two points on the femur model were selected to calculate length change. This study determined the maximum and minimum distances to the tibial attachment during flexion/extension. The results showed that minimum length changes were $1.9{\sim}5.8mm$ (average $3.6{\pm}1.4mm$). The most isometric region was both the posterosuperior and anterior-diagonal areas from the over-the-top. The proposed method can be utilized and applied to an optimal reconstruction of ACL deficient knees.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.4 s.247
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• pp.435-441
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• 2006

The anterior cruciate ligament(ACL) is an important stabilizer of knee joint. The ACL injury of knee is common and a serious ACL injury leads to ligament reconstruction surgery. Gait analysis is essential to identify knee condition of patients who display abnormal gait. The purpose of this study is to evaluate and classify knee condition of ACL deficient patients using a nonlinear dynamic method. The nonlinear method focuses on understanding how variations in the gait pattern change over time. The experiments were carried out for 17 subjects(l2 healthy subjects and five subjects with unilateral deficiency) walking on a motorized treadmill for 100 seconds. Three dimensional kinematics of the lower extremity were collected by using four cameras and KWON 3D motion analysis system. The largest Lyapunov exponent calculated from knee joint flexion-extension time series was used to quantify knee stability. The results revealed the difference between healthy subjects and patients. The deficient knee was significantly unstable compared with the contralateral knee. This study suggests an evaluation scheme of the severity of injury and the level of recovery. The proposed Lyapunov exponent can be used in rehabilitation and diagnosis of recoverable patients.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.1
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• pp.6-14
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• 2003

The goal of rehabilitation after ACL reconstruction are return the patient to a reinjury level of activity with stable joint, removing pivot shift phenomenon, preservation of meniscus, restoration of range of motion, and minimize patello-femoral complication. The ACL reconstruction should avoid immediate surgery. The preoperative phase emphasizes two important factors. (1) The patient should have a resolution of knee swelling, a return of full ROM, and a normal gait. (2) The patient should be mentally prepared for the operation and subsequent rehabilitation. The postoperative rehabilitation program emphasizes extension, closed kinetic chain function exercises. The regular follow-up is important.

• Journal of Korean Orthopaedic Sports Medicine
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• v.7 no.2
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• pp.142-145
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• 2008

Forefoot injuries are common in runners or martial art athletes, but due to the anatomical stability, collateral ligament injury of the hallucal interphalangeal joint has been rarely reported. We report a college Taekwondo athlete with chronic varus instability of the hallucal interphalangeal joint due to chronic lateral collateral ligament rupture. The patient had been treated with lateral ligament reconstruction and achieved good clinical outcome.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.164-171
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• 2006

Anterior cruciate ligament(ACL) injury of the knee is common and a serious ACL injury leads to ligament reconstruction surgery. Gait analysis is used to identify the result of surgery. The purpose of this study is to numerically evaluate and classify knee condition of patients through the chaos analysis. Experiments were carried out for 13 subjects (8 healthy subjects, 5 ACL deficient patients) walking on a treadmill. Sagittal kinematic data of the right lower extremity were collected by using a 3D motion analysis system. The recorded gait patterns were digitized and then coordinated by KWON3D. The largest Lyapunov exponent from the measured knee angular displacement time series was calculated to quantify local stability. It was found that the Lyapunov exponent becomes larger as the knee condition becomes worse. This study suggested a method of the severity of injury and the level of recovery. The proposed method discerns difference between healthy subjects and patients.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.2 no.1
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• pp.37-44
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• 2009

Prolotherapy, the technology for strengthening lax ligaments, has found increased acceptance in recent years. Prolotherapy involves the injection of the irritant solutions into the weakened or stretched ligaments which are a source of chronic pain. This induces an inflammatory response which mimics the normal repair sequence. Various musculoskeletal disorders of lower extremities such as degenerative arthrtitis, ligament and tendon injuries can be treated with prolotherapy. Prolotherapy is a very good, powerful nonsurgical conservative treatment in various musculoskeletal disorders. Ultrasound exam is very useful to find and confirm the exact location of disorders and check the progress in prolotherapy practices.

• Investigative Magnetic Resonance Imaging
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• v.17 no.3
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• pp.239-242
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• 2013

Anomalies of the medial meniscus are rare and difficult to diagnose clinically. Among these anomalies, anomalous insertion of the medial meniscus into the anterior cruciate ligament is rare. Most of the reported cases had no relation to clinical symptoms and were found incidentally during arthroscopy. We report a rare case of anomalous insertion of the medial meniscus into the anterior cruciate ligament with a brief review of the literature.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.143-153
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• 1998

Platelet-derived growth factor(PDGF) and lipopolysaccharide(LPS) may be the important regualtors of bone metabolism Exogenous PDGF is recognized to have a stimulating effect on bone resorption in organ culture but to stimulate the formation of new bone ultimately. LPS is known to be a stimulating agent on the osteoclastic activity. The purpose of this study was to evaluate the effects and the interaction of PDGF and LPS on periodontal ligament(PDL) cells which have important roles in bone remodeling. Cultured human periodontal ligament cells were tented with various concentration or PDGF and/or LPS. The cellular viability was measured by Microtitration(MTT) assay according to the lapse time of culture. The obtained results were as follows: 1. The viability of PDL cells was not different from the con01 in 0.1ng/ml of PDGF, but was significantly increased to be over the level of control in 1ng/ml of PDGF at the second day of culture, and in 10ng/m1 of PDGF at the second and the third day of culture. 2. The cellular viability was decreased in $0.5{\mu}g/ml$ or $5{\mu}g/ml$ LPS at the third day of culture. 3. Incubation with both 1ng/ml or 10ng/ml of PDGF and $0.5{\mu}g/ml$ of $5{\mu}g/ml$ of LPS resulted in the increased cellular viability at the third day, which was greater than LPS only treated group. It was greater than even the control group in 10ng/m1 of PDGF. From the above findings, we could summarize that the admixture of PDGF and LPS could not less increase the viability of the human periodontal ligament cells than PDGF only.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.679-685
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• 2010

Many animal models of osteoarthritis (OA) have been developed, aimed at understanding the long-term progression of OA and difficulty of identifying patients in the initial stage of the disease. In canines, coxofemoral luxation and hip dysplasia are common orthopedic ailments related to OA in the hip joint. Transecting the ligament of the head of the femur (LHF) aids in diagnosis of coxofemoral joint OA. Presently, mobility of this joint was increased by transected LHF in 10 mature, 2-3-year-old (average $2.57{\pm}0.20$ years), healthy male beagles. The animals were normally gaited 1-week post-operatively. During the experimental period, examinations including X-ray, complete blood count and serum chemistry were unremarkable. Proteomic examination revealed protein alterations in synovial fluid, with significant increases in Vitamin D-binding protein precursor (ANOVA, p < 0.004) and Kinogen-1 (ANOVA, p < 0.039). Both proteins correlated with arthritis.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.439-455
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• 1994

The purpose of this study was to investigate the distribution of nerves in the periodontal ligament of a dog's primary teeth by each developing stage. The distribution of nerves in the periodontal ligament were investigated by means of immunohistochemistry for detection of neurofilament protein (NFP). The results were as follows: The NFP-immunoreactive nerve fibers were found to be densely distributed in the apical third of the periodontal ligament, while they were sparse in the coronal two third, in both primary and permanent teeth. In generally the density of distribution and degree of arborization of nerve fibers in periodontal ligament of primary teeth revealed a poor appearance compared with that of permanent teeth. Periodontal ligament in anterior teeth showed more abundant nerve innervation than posterior teeth, and the periodontal ligament of the bifurcation area in posterior teeth roots were not observed to have nerve fiber. The density of nerve distribution in the periodontal ligament of primary teeth was reduced according to the physiological root resorption and nerve fibers were not observed in the surrounding area on the root of the exfoliation stage in primary teeth. The distribution of nerve fibers in mucogingival tissue, was poor innervated according to the aging of the dogs. A more abundant distribution of nerve fiber was represented in the lingual mucogingival tissue than in the labial side. Most of the nerve endings in the periodontal ligament of primary teeth showed a tree-like appearance. However, the typical Ruffini-like nerve endings were not observed.