• 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.

• Journal of the Korean Arthroscopy Society
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• v.16 no.1
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• pp.34-39
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• 2012

Purpose: This study performed to compare degree of joint stiffness and clinical results between early and delayed reconstruction of acute anterior cruciate ligament (ACL) injuries. Materials and Methods: Thirty-four Patients who underwent ACL reconstruction between March 2008 and October 2010 enrolled this study. We divided the patient into 2 groups, early reconstruction group underwent surgery before a week, delayed reconstruction group underwent surgery after 3 weeks, before 6 weeks. All the patients underwent aggressive joint motion exercise till surgery and enrolled post operative rehabilitation program including self exercise. We checked range of motion, the Lachman test, the pivot shift test, the Lysholm score, the International Knee Documentation Committee (IKDC) score and the Tegner score to evaluate the results. Results: At the final follow up. The Lysholm score was 91.82 in the early group and 94.83 in the delayed group. All the cases were rated above B (near normal) on IKDC score (P=0.217, P=0.845). The Tegner score was 6.7 in the early reconstruction group and 7.1 in the delayed group (P=0.840), there was no difference between the groups for the range of motion (P=0.873, P=0.873), no complication such as deep vein thrombosis or infection, no difference in the Lachman test, pivot shift test (P=0.606, P=0.118). Conclusion: We could obtain satisfactory clinical results in both the early and delayed reconstruction groups of acute ACL injuries. Therefore, the early reconstruction of ACL performed before a week could be one of the treatment options for acute ACL injury.

• 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 the Korean Arthroscopy Society
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• v.3 no.1
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• pp.40-43
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• 1999

Arthroscopic anterior cruciate ligament(ACL) reconstruction using four-strand hamstring tendon with looping around transfixing screw in femoral tunnel requires osteointegration between the grafted tendon and bone for stability of the knee. Authors have experienced a histologic finding of osteointegration between the grafted autogenous hamstring tendon and bone in femoral tunnel after arthroscopic ACL reconstruction. A patient received arthroscopic ACL reconstruction with autogenous four strand hamstring tendon for the ACL injury. Traumatic re-rupture of mid-substance of ACL graft was developed at thirteenth week after operation. During the procedures of arthroscopic revision at fifteenth week after initial ACL reconstruction, biopsy was performed at the site of interface between grafted tendon and bone in femoral tunnel. Integration between the grafted tendon and bone was evident by demonstrating the continuity of collagen fiber between bond and tendon. This histologic finding and the low incidence of early graft failure suggest that free tendon autograft attached to bone by looping around a transfixing screw in femoral tunnel undergoes adequate osteointegration between 12 and 15 weeks after surgery and authors thought that insertion of bone chip into the femoral tunnel would accelerate osteointegration procedure.

• 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.

• Knee surgery & related research
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• v.30 no.4
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• pp.341-347
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• 2018

Purpose: Tunnel widening following anterior cruciate ligament (ACL) reconstruction is commonly observed. Graft micromotion is an important contributing factor. Unlike fixed-loop devices that require a turning space, adjustable-loop devices fit the graft snugly in the tunnel. The purpose of this study is to compare tunnel widening between these devices. Our hypothesis is that the adjustable-loop device will create lesser tunnel widening. Materials and Methods: Ninety-eight patients underwent ACL reconstruction from January 2013 to December 2014. An adjustable-loop device was used in 54 patients (group 1) and a fixed-loop device was used in 44 patients (group 2). Maximum tunnel widening at 1 year was measured by the L'Insalata's method. Functional outcome was measured at 2-year follow-up. Results: The mean widening was 4.37 mm (standard deviation [SD], 2.01) in group 1 and 4.09 mm (SD, 1.98) in group 2 (p=0.511). The average International Knee Documentation Committee score was 78.40 (SD, 9.99) in group 1 and 77.11 (SD, 12.31) in group 2 (p=0.563). The average Tegner-Lysholm score was 87.25 (SD, 3.97) in group 1 and 87.29 in group 2 (SD, 4.36) (p=0.987). There was no significant difference in tunnel widening and functional outcome between the groups. Conclusions: The adjustable-loop device did not decrease the amount of tunnel widening when compared to the fixed-loop device. There was no significant difference in outcome between the two fixation devices. Level of Evidence: Level 3, Retrospective Cohort.

• Journal of the Korean Arthroscopy Society
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• v.2 no.1
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• pp.80-84
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• 1998

The isometric position for the graft is important in the anterior cruciate ligament reconstruction surgery. It is well known that the femoral position is more critical than tibial side. But, there is few deciding method of proper graft position after the anterior cruciate ligament reconstruction surgery. So we planned to evaluate the ideal femoral isometric position with 6 adult cadavaric femurs and exact radiographs. After the insertion of femoral interference screw on ideal isometric position, we obtained roentgenograms of true lateral view and 10, 20, 30, 45 degree internal and external rotation views. Then we measured the shortest distance from the posterior cortical margin of lateral femoral condyle to posterior border of interference screw on the radiographs. We also measured true distance between posterior cortical margin of lateral femoral condyle to the posterior margin of femoral tunnel after cutting of distal femur. Based on this study, we could not determine the permissible rotation degree of radiographs. But we concluded that if the distance between posterior cortical margin of lateral femoral condyle and posterior border of interference screw ranges 4.5-6.5mm on the lateral view, the femoral position is considered as a relatively ideal isometric good position.

• 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.

• 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 Arthroscopy Society
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• v.14 no.1
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• pp.13-19
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• 2010

Purpose: To evaluate and compare the postoperative knee stability and functional scores between single- and double- bundle anterior cruciate ligament (ACL) reconstruction at a minimum 2 years follow-up. Materials and Methods: 56 patients (group T) with ACL injury in one knee were recruited with 27 allocated to the double bundle ACL reconstruction group (group D) and 29 to the single bundle ACL reconstruction group (group S). Clinical outcomes including Lysholm knee scores, Tegner activity scores, Lachman and pivot shift test results, and radiographic stabilities were also compared between two groups. Results: Clinical outcomes including Lysholm knee and Tegner activity scores were similar in the two groups at 2 years follow-up. Furthermore, stability results of Lachman test, pivot shift test, and radiological findings failed to reveal any significant inter-group differences. Conclusion: Double bundle ACL reconstruction does not produce better in clinical outcomes and postoperative stabilities.