• Journal of the Korean Arthroscopy Society
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• v.16 no.1
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• pp.17-25
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• 2012

Purpose: The aim of this retrospective study was to evaluate the relationship between appearance and size of bone bruise and severity of anterior cruciate ligament (ACL) injury with magnetic resonance imaging (MRI), furthermore, to identify the mechanism of ACL injury by analyzing the footprint of bone bruise. Materials and Methods: Sixty-five subjects who was taken an MRI within 6 weeks after acute ACL injury were studied. All MRI showed ACL injury and associated bone bruises. Bone bruises were analyzed using Costa-Paz classification based on appearance and location and also scored using Kornaat bone bruise grading system based on size and location. The severity of the ACL injury was graded using a 4-point system (ie, grade 0-3) with oblique coronal MRI. Results: There was statistically significant correlation between Costa-Paz classification of bone bruises in lateral femoral condyle and grade of ACL injury. There were more type 2 lesions in partial tear group (grade 1, 2), however, type 3 lesions of Costa-Paz classification in complete tear group (P=0.037). Significant positive correlations were observed between Kornaat total bone bruise score and grade of ACL injury (P=0.014). Most common ACL injury mechanism was pivot shift injury. Other mechanisms were clip valgus injury, phantom foot injury, and hyperextension injury. Conclusion: It is highly suggested that appearance and size of bone bruise is related to severity of ACL injury after acute ACL injury. The foot print of bone bruise provides valuable clues to identify ACL injury mechanism.

• Journal of the Korean Arthroscopy Society
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• v.1 no.1
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• pp.36-40
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• 1997

Anterior Cruciate Ligament (ACL) plays an important biomechanical role for the stability of knee joint. ACL injury often leads to injuries of articular cartilage, menisci, or other supporting structures, and subsequent development of degenerative arthritis. Controversies still exist in the best treatment modalities of ACL injuries. hut the author considers it most important to make the appropriate patient selection for operative reconstruction or nonoperative treatment. and describes the treatment principles of ACL injury, including diagnosis, patient selection and the treatment modalities for successful treatment of ACL injury.

• Journal of the Korean Arthroscopy Society
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• v.1 no.1
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• pp.31-35
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• 1997

MRI(magnetic resonance imaging) is very useful to visualize the anterior cruciate ligament (ACL) injury of the knee. Differential features of ACL injury at MRI according to acute and chronic stage should be evaluated to enable accurate assessment of the integrity or ACL. Distinguishing features of normal anatomy. acute and chronic injuries or ACL at MRI will be reviewed.

• The Journal of Korean Physical Therapy
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• v.31 no.4
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• pp.161-168
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• 2019

Most athletes with anterior cruciate ligament (ACL) ruptures undergo a surgical ACL reconstruction (ACLR) and rehabilitation. On the other hand, controversy still exists because neither a reconstruction nor rehabilitation have been proven to be superior in the management of ACL injury. This study reviewed the success rates of interventions to provide recommendations for the optimal management after an ACL injury. One of the most important considerations after an ACL injury is the timing and type of intervention. At the early stages, which involve the loss of volume and strength of quadriceps femoral muscle, weight bearing (closed kinetic chain) exercises with pain management followed by high velocity resistance exercises in an open kinetic chain environment are recommended to improve the quadriceps function. After that, it is important to apply intensive isokinetic exercise with a lower extension rate. In this case, it is important to apply overload to the muscles and to simultaneously lead the co-contraction of the hamstrings. Standards are essential because the timing and type of interventions are crucial to prevent re-injury and complications, such as osteoarthritis, as well as to confirm the successful outcome of the treatment. Different interventions recommended for ACL damage have yet to reach consensus. Further studies will be needed to observe the effects of the intervention through multidisciplinary approaches.

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.137-142
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• 2005

Purpose: The purpose of this study is to evaluate the results of arthroscopic anterior cruciate ligament(ACL) repair with minimal incision and to review prognostic factors according to ACL tear patterns and the presence of associated injury Materials and Methods: Thirty eight patients (thirty nine knees) with acute ACL tear were given arthroscopic ACL repair between January 2001 and December 2002 and were followed up at least over six months. Intraoperative findings such as ACL tear pattern and the presence of synovial or concomitant medial collateral ligament injuries were recorded. Each knee was then postoperatively re-evaluated with aid of KT-1000 arthrometer and Lachman test and Lysholm score. Results: Postoperative limitation of motion was significant when combined typed ACL tear was present with concurrent medial collateral ligament(MCL) injury. In contrast, in the case where there were sole proximal ACL tear or no evidence of synovial injury, the limitation of motion was not significant. Anterior laxity was significantly associated with the presence of combined typed ACL tear or concurrent synovial injury, but was not significant when there were sole proximal ACL tear. Conclusion: In the case where there is sole proximal ACL tear without concurrent synovial injury, arthroscopic ACL repair can be considered as a treatment modality for the treatment of acute ACL injury.

• 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.

• Biomaterials and Biomechanics in Bioengineering
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• v.3 no.1
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• pp.27-35
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• 2016

Anterior knee pain is a major problem among adolescents and young adults especially those who participates in sports. The most common pathogenesis of anterior knee pain can arise from compression and shear forces in the patellofemoral joint. It is also caused by impingement of infrapatellar fat pad. Fat pad impingement can occur when the fat pad becomes swollen and inflamed due to a direct blow or chronic irritation. As a result, the bottom tip (or inferior pole) of the patella can pinch the fat pad. One of the many causes of swollen fat pad can be secondary to anterior cruciate ligament (ACL) injury. The aim of this study was to compare the infrapatellar fat pad volume in patients with acute ACL injury and a group of age-, gender-, and activity- matched controls with intact ligament. Axial magnetic resonance (MR) images have been performed on 32 patients with torn ACL and 40 control patients. The volume of the fat pad was measured digitally from MR image by using a 3d Reconstruction software, ellipsoidal approximation, and a MATLAB code. The results were compared between patients with torn ACL and control group. Patients with a torn ACL had a significantly larger fat pad than the controls (P=0.01). There was no significant difference between the methods used to measure the infrapatellar fat pad volume (P=0.83-0.87). Thus, lesions of the infrapatellar fat pad is often associated with ACL injury.

• 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 Physical Therapy
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• v.31 no.6
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• pp.339-345
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• 2019

Purpose: The purpose of this study was to identify changes in knee muscle strength after reconstruction of the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL). Methods: Thirteen subjects (males) with anterior ligament injury and ten subjects (males) with posterior ligament injury voluntarily participated in this study. Both groups were evaluated at the pre-and post-reconstruction stages using an isokinetic dynamometer. Peak torque, total work, and the hamstrings to quadriceps (H/Q) peak torque ratio were calculated at angular velocities of 60°/sec and 180°/sec. Statistical analysis was conducted on SPSS 18.0 for Windows using t-tests to compare mean differences. Results: At an angular velocity of 60°/sec, both the ACL and PCL groups showed a significant increase in muscle strength in the flexors and extensors. Muscle strength in the extensors was significantly increased in the PCL group compared to the ACL group. At an angular velocity of 180°/sec, the ACL group showed a significant increase in muscle endurance in the flexors and extensors, and the PCL group showed a significant increase in muscle endurance in the flexors. At angular velocities of 60°/sec and 180°/sec, the H/Q peak torque ratio increased in the ACL group but decreased in the PCL group. Consequently, the H/Q peak torque ratio was significantly different for the two groups. Conclusion: The results suggest that the patients with ACL injury should focus on strengthening the knee extensors and that the patients with PCL injury need to strengthen the knee flexors.