• The Journal of Korean Physical Therapy
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• v.19 no.6
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• pp.31-36
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• 2007

Purpose: This study compared the thigh circumference and Lysholm scale of a stable and unstable exercise group of patients who had undergone an anterior cruciate ligament reconstruction (ACL reconstruction). Methods: The subjects were patients more than 4 weeks after their ACL reconstruction and could stand on one leg. The patients were divided into a control group with 9 patients performing closed kinetic chain exercises on a stable floor and an experimental group with 10 patients performing closed kinetic chain exercises en an unstable floor. The degree of muscle atrophy was compared by measuring the circumference of the injured thigh before the exercise program, and 3 weeks and 6 weeks after the exercise program. The Lysholm scale was used to assess the function of the knee joint. Results: There was no significant increase in thigh circumference according to the exercise periods in the two groups. However, there was a statistically significant increase before exercises and 6 weeks after the exercises (p<0.05). There were statistically significant differences in the Lysholm scores between the two groups (p<0.05). Conclusion: There were no statistically significant increase in the two groups, but there was a significant difference between before the exercise program and 6 weeks after the exercise program (p<0.05).

• Journal of the Korean Arthroscopy Society
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• v.5 no.2
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• pp.63-68
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• 2001

Purpose : To propose the diagnosis, 'hypertrophy of the anterior cruciate ligament(ACL)', and its clinical, radiological and pathological characteristics. Materials & Method : Since Dec. 1995, we have experienced 10 patients(12 knees) with hypertrophy of the ACL. There were 2 males and 8 females, and the age of the patients ranged from 35 to 67 years. Characteristics of clinical, radiological and pathological findings were analysed. Results : The chief complaint was insidious onset of dull pain on the knee which became worse with activity. The constant physical finding was painful limitation of full extension of the knee. Sagittal MR images showed diffuse swelling of the ACL, similar finding that could be seen in acute ACL tear. Arthroscopically, noted was a marked enlargement of the ACL causing notch impingement. Biopsies of the hypertrophied ACL showed increased collagenous tissue with variable degree of myxoid degeneration. With partial excision of the hypertrophied ACL with or without notchplasty, the symptoms improved in all. Conclusion : Hypertrophy of the ACL, a newly proposed diagnosis, should be considered be determining the cause of the painful knee, and further study should be done about its pathogenesis.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.391-398
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• 2019

The purpose of study is to investigate the difference of the daN force applied during the examination using Telos Device and the degree of fluctuation of anterior cruciate ligament according to the individual differences of the muscles involved in knee stability. The examination was done by the Lachman test using Telos Device and the changes of anterior cruciate ligament were measured by varying the force of 0. 15, 30 daN on each right and left side and the force of 30 daN after the bruce protocol. Computed tomography (CT) was used to measure muscle mass. As a result of measuring the degree of fluctuation of the anterior cruciate ligament according to the change of the force applied to the Telos Device, there was a statistically significant difference in the knee fluctuation when 15 daN and 30 daN were applied on both right and left. Also, it is analyzed that the degree of fluctuation of anterior cruciate ligament varies according to the difference of individual's muscle mass. Therefore, it is considered that the force applied to the Telos Device should be changed according to the difference of individual's muscle mass.

• Korean Journal of Applied Biomechanics
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• v.28 no.3
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• pp.175-180
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• 2018

Objective: Anterior cruciate ligament reconstruction (ACLR) has been considered the primary treatment for anterior cruciate ligament (ACL) injured patient. However, there is little biomechanical evidence regarding bilateral knee joint biomechanics during landing and cutting task after ACLR. Method: Eighteen females with ACLR participated in this investigation. Double leg jump landing (DLJL) and single leg jump cut (SLJC) biomechanics were assessed. Results: During DLJL, the healthy knee showed greater knee valgus angle at initial contact ($^{\circ}$) compared to the injured knee (Injured: $2.93{\pm}2.59$, Healthy: $4.20{\pm}2.46$, t=2.957, p=0.009). There was a significant difference in anterior tibial shear force ($N{\times}N^{-1}$) with greater in the injured knee (Injured: $1.41{\pm}0.39$, Healthy: $1.30{\pm}0.35$, t=2.201, p=0.042). During SLJC, injured knee showed greater knee extension moment ($N^*m{\times}[N^*m]^{-1}$) compared to healthy knee (Injured: $0.51{\pm}0.19$, Healthy: $0.47{\pm}0.17$, t=2.761, p=0.013). However, there was no significant differences between the knees in the other variables. Conclusion: ACLRfemales exhibited a greater knee valgus angle at initial contact and lesser anterior tibial shear force on the healthy knee during double leg jump landing. In addition, ACLR females showed a greater knee extension moment on the injured knee during single leg jump cut.

• Journal of Korean Physical Therapy Science
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• v.10 no.1
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• pp.222-231
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• 2003

The ACL(Anterior cruciate ligament) is the smallest of the four main ligaments of the knee, but it is the primary stabilizer. Injuries have a tendency to occur when the foot is firmly planted and the knee is twisted. Any sports that requires acceleration, change of direction and deceleration can increase the chances of suffering an ACL tear. The incidence of severe knee sprains that involve the ACL are at an all-time high. Since 1980, the number of these injuries have increased at least three-fold. Although the rate of increase has been much less dramatic since the middle 1980s, even the ultra-modem releasable ski binding has not been able to start reducing the incidence of ACL injuries. An ACL injury prevention program developed for downhill skiers by the Vermont Safety Research group emphasized increasing awareness of situations that can potentially result in an ACL injury and pre-planning strategies if events, leading to these situations, begin to fall in place. As part of the above study by Ettlinger et al., an educational prevent program was developed to teach these principles and thus reduce the rate of serious knee injuries. Four thousand instructors and patrol at 20 ski resorts who received the training had a 62% decline in serious knee injuries compared to a similar group that did not receive this training. Whenever you fall, try not to fully straighten your legs. Don't try to get up until you've stopped sliding(unless you are try to avoid an obstacle or other skier). When you're down, stay down. And don't land on your hand. So, if you feel yourself falling: arms forward, ski plates together, hands over knee. Then you will be able to save your ACL.

• 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.12 no.1
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• pp.1-7
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• 2013

This article provides an overview of the current concepts regarding anterior cruciate ligament reconstruction, including anatomy, biomechanics, operative techniques and clinical results. Many techniques have been introduced for ACL reconstruction: single bundle reconstruction, remnant preserving augmentation, and double bundle reconstruction. Each technique has its strong and weak points, and it is not sure which technique is superior than others. It is considered to suggest that rather than to select the same method of surgery in all patients, select the method of reconstruction depending on the characteristics of the individual patient, the state of the residual ligaments and extent of the damage.

• Journal of the Korean Arthroscopy Society
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• v.17 no.1
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• pp.44-49
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• 2013

Purpose: To compare of the results between anterior cruciate ligament (ACL) reconstruction alone and combined with high tibial osteotomy for ACL ruptured knees with varus alignment. Materials and Methods: We retrospectively reviewed 8 cases of ACL reconstruction combined with high tibial osteotomy (Group I) and 13 cases of ACL reconstruction alone (Group II) for varus angulated ACL ruptured knees (from March 2005 to February 2007). Mean age were 34.1 years (range: 20-53) in Group I, 34.9 years (range: 21-50) in Group II. Average follow up period were 22.6 months (range: 12-35) in Group I, 20 months (range: 13-33) in Group II. We analyzed clinical and radiological results. Results: There were no significant differences in clinical and radiologic results between two groups for IKDC scores, Lysholm knee scores, Lachman test, pivot shift test, KT-2000 arthrometer, $30^{\circ}$ and $90^{\circ}$ anterior drawer stress radiographs. Tegner activity scales and Cincinnati knee ligament rating scales were 4.9, 57.9 in Group I, and 5.6, 72.9 in Group II. Group I was statistically lower than Group II for Tegner activity scales and Cincinnati knee ligament rating scales (p<0.05). Conclusion: There were no significant differences in daily living between ACL reconstruction alone and combined with high tibial ostetomy for varus angulated ACL ruptured knees. However, ACL reconstruction combined with high tibial osteotomy could limit sport activity ability.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.2
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• pp.92-99
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• 2003

The prevalence of anterior cruciate ligament (ACL) injury is continuously increased due to sports activities and traffic accident. Simultaneously ACL reconstruction operations are on the increase. Several kinds of autografts and allografts are used in ACL reconstruction. Although ACL reconstruction using an autogenous bone-patellar tendon-bone graft is the good standard, it might have potential morbidity, anterior knee pain and minimal extension loss. To minimize the complications and disadvantages on each graft and to select appropriate graft for each patient, it is necessary to understand the unique characteristics of each graft for biomechanical aspect, morbidity and disadvantage. Selecting the appropriate graft depends on numerous factors including surgeon's preference and experience, patient's activity level and age, extent of ligament injury, tissue availability, and patient's selection for graft .

• Advances in nano research
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• v.13 no.3
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• pp.247-257
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• 2022

Extraordinary properties of nanocomposites make them a primary replacement for many conventional materials. Anterior cruciate ligament (ACL) reconstruction, which is a frequent surgery in sport activities, is one of the fields in which nanocomposites could be utilized. In the present study, the mechanical properties of different porous scaffolds made from graphene nano-composites are presented ad load bearing capacity of these materials is calculated using finite element method. The numerical results are further compared with experimental published data. In addition, several geometrical and material parameters are analyzed to find the best configuration of nanocomposite scaffolds in reconstruction of ACL. Moreover, coating of detoxification chemicals are extremely easier on the nano-structured materials than conventional one. Detoxification potential of nano-composites in the injured body are also discussed in detail. The results indicated that nano-composite could be successfully used in place of auto- and allografts and also instead of conventional metallic screws in reconstruction of ACL.