• Korean Journal of Applied Biomechanics
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• v.33 no.2
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• pp.45-51
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• 2023

Objective: The aim of this study was to examine the effect of strength training targeting medial quadriceps/hamstrings and non-targeting strength training on dynamic balance. Method: A total of 51 healthy subjects were randomly assigned to control, targeting strength training, or non-targeting training groups. To measure the dynamic balance, the star excursion balance test (SEBT) was performed before and after training. The SEBT parameters were compared using repeated measures ANOVA, and post-hoc paired t test at a significance level of 0.05. Results: Greater anterior (p= .011), anteromedial (p= .001), medial (p< .001), lateral (p< .001), and anterolateral (p= .001) reach distances were found between pre- and post-training in the strength training targeting medial thigh muscles group. Only greater lateral reach distance was found after non-targeting strength training (p= .029). In addition, no differences were found for any SEBT scores in the control group. Conclusion: Strength training targeting medial quadriceps and hamstrings can improve the dynamic balance, thereby it positively affected in lower extremity injury risk, whereas non-targeting strength training rarely changes the dynamic balance.

• Journal of the Korean Orthopaedic Association
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• v.55 no.4
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• pp.281-293
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• 2020

An anterior cruciate ligament (ACL) reconstruction is one of the most frequent surgical procedures in the knee joint, but despite the better understanding of anatomy and biomechanics, surgical reconstruction procedures still fail to restore rotational stability in 7%-16% of patients. Hence, many studies have attempted to identify the factors for rotational laxity, including the anterolateral ligament (ALL), but still showed controversies. Descriptions of the ALL anatomy are also confused by overlapping nomenclature, but it is usually known as a distinctive fiber running in an anteroinferior and oblique direction from the lateral epicondyle of the femur to the proximal anterolateral tibia, between the fibular head and Gerdy's tubercle. The importance of the ALL as a secondary restraint in the knee has been emphasized for successful ACL reconstructions that can restore rotational stability, but there is still some controversy. Some studies reported that the ALL could be a restraint to the tibial rotation, but not to anterior tibial translation. On the other hand, some studies reported that the role of ALL in rotational stability would be limited as a secondary structure because it bears loads only beyond normal biomechanical motion. The diagnosis of an ALL injury can be performed by a physical examination, radiology examination, and magnetic resonance imaging, but it should be assessed using a multimodal approach. Recently, ALL was considered one of the anterolateral complex structures, as well as the Kaplan fiber in the iliotibial band. Many studies have introduced many indications and treatment options, but there is still some debate. The treatment methods are introduced mainly as ALL reconstructions or lateral extra-articular tenodesis, which can achieve additional benefit to the knee stability. Further studies will be needed on the indications and proper surgical methods of ALL treatment.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.1
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• pp.41-47
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• 2010

Purpose: To compare the obliquity of femoral tunnels prepared with transtibial (TT) versus anteromedial portal technique (AM) using x-ray in single-bundle anterior cruciate ligament (ACL) reconstruction. Materials and Methods: Among one-hundred thirty two patients who were undergoing ACL reconstruction from January 2007 to December 2009, thirty patients using TT and twenty patients using AM, those who had single-bundle ACL reconstruction, were evaluated with plain radiographs including anteroposterior, intercondylar notch and lateral view to compare the obliquity of bone tunnels. Results: The mean coronal obliquity of femoral tunnel for TT was $71^{\circ}$ (range; $65^{\circ}{\sim}77^{\circ}$), while for AM was $51^{\circ}$ (range; $39^{\circ}{\sim}60^{\circ}$) and the mean sagittal obliquity of femoral tunnel for TT was $22.7^{\circ}{\pm}7.8$, while for AM was $30.2^{\circ}{\pm}6.9$, their differences between them were statistically significant (P<0.05). However, there were no differences between two techniques on the tibial tunnel obliquity in coronal and sagittal plane. Conclusion: Anterior cruciate ligament reconstruction using AM portal technique allows more horizontally oriented and divergent femoral tunnel compared to that of transtibial technique. This seems to enable the graft placement into the femoral footprint and preserve the posterior cortical wall.

• Journal of Korean Orthopaedic Sports Medicine
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• v.8 no.2
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• pp.95-101
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• 2009

Purpose: The purpose of this study was to determine how many of our patients who had had anterior cruciate ligament (ACL) reconstruction returned to their previous levels of sports and to identify why not doing so. Material and Methods: We evaluated 43 knees with a minimum of two years follow-up among whom undergoing 109 ACL reconstruction from September 2003. The mean age of patients was 26 years (17 to 45 years) Clinical results was evaluated according to the Lysholm Knee scores, Tegner activity score, subjective IKDC questionnaires, objective IKDC evaluation form and KT-1000 arthrometer. Results: The overall clinical results demonstrated significant improvement at the final follow-up comparing to preoperative data (P<0.05). Among 43 patients, 25 patients (58%) returned to their previous level of sports and 18 patients (42%) did not. Of whom, 11 patients (61%) were not able to return to sports due to fear to re-injury and 7 patients (39%) suffered from instability and pain. The differences in the Lysholm Scores, KT-1000 arthrometer and subjective IKDC in the 3 groups of patients by ANOVA test were found to be statistically significant (P<0.001). Although there is no difference in objective IKDC and KT-1000 arthrometer, the difference was observed in Tegner activities, subjective IKDC obtained by those who returned to sport and those who had fear to reinjury (P<0.001). Conclusion: This study showed that a quater of patients could not return to their previous level of sport after ACL reconstruction because of fear to reinjury. We thought that not only improving the technique of ACL reconstruction and systemic rehabilitation but also considering psychological factor of patients could allow more patients to return to the previous level of sports.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.1
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• pp.28-36
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• 2003

Purpose: To determine and to compare the effects of cyclic loading on the fixation strength of different femoral fixation methods in ACL reconstruction. Materials and Methods: Biomechanical test using an Instron(R) machine (Model No.5569. Mass, U.S.A) were carried out to compare the pull out strength of six different femoral fixation techniques after a cyclic loading in 72 Yorkshire pig knees. The graft-bone complex was cyclically loaded between 30N and 150N at 50 mm/min rate for 1000 cycles and maximal tensile testing was performed. A preload of 30N was applied to the graft along the axis of the tunnel 15 minutes. ANOVA and the Duncan multiple comparison test was used for the statistical analysis. Results: The mean maximum tensile strength of femoral fixation before and after the cyclic loading test were 1003.4$\pm$145N and 601.1$\pm$154N in hamstring-LA screw(R) group, 595.5$\pm$104N and 360.7$\pm$56N in hamstring-Bioscrew(R) group, 1431.7$\pm$135N and 710.7$\pm$114N in hamstring-Semifix(R) group, 603.6$\pm$54N and 459.1$\pm$46N in hamstring-Endobutton(R) fixation group, 1067.4$\pm$145 and 601.8$\pm$134N in the BPTB-Titanium interference screw group, and 987.1$\pm$168N and 588.7$\pm$124N in the BPTB-Bioscrew(R) group. And these data illustrated that cyclic loading reduces the maximum tensile strength by 40 $\%$, 39 $\%$, 50 $\%$, 24 $\%$, 44 $\%$, 40 $\%$ respectively. Conclusions: With the results of these experiments it should be emphasized that rehabilitation exercises after anterior cruciate ligament reconstruction should be executed with precaution as the repetitive flexion and extension of the knee would compromise the maximum tensile strength of the graft tendon.

• Journal of the Korean Arthroscopy Society
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• v.7 no.1
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• pp.58-62
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• 2003

Purpose : The purpose of this study was to investigate the incidence, location, type and treatment of meniscal injury associated with acute anterior cruciate ligament (ACL) tears Material and Methods: From Mar. 1997 to Feb. 2002, we reviewed 73 cases of acute ACL tear. There were 66 males and 7 females. The average age at the time of surgery was 33 year old (range, 16-62 years). The common causes of meniscal injury were sports injuries (45 cases) and traffic accidents (19 cases). In 45 sports injuries, thirty four cases were soccer injuries. All patients had undergone arthroscopic evaluation. We analyzed incidence, type, location, and treatment of meniscal injuries, especially those of soccer injuries. Results : Foully eight (57 sites) out of 73 had meniscal tears : Of these injuries, tears of lateral meniscus (26 cases, $54.2\%$) were more common than medial meniscus. Posterior horn of the meniscus was the most common location (52 cases, $91.2\%$) and radial tears were the most common type (15 cases, $26.3\%$). Thirty eight cases $(66.7\%)$ were treated by partial menisectomy. In soccer injuries, twenty eight (33 sites) out of 34 had meniscal tears. and tears of lateral meniscus (17 cases, $60.7\%$) were more common. Posterior horn of the meniscus was the most common location (30 cases, $90.9\%$) and radial tears were the most common type (9 cases, $27.3\%$). Twenty two cases $(66.7\%)$ were treated by partial menisectomy. Conclusions : Lateral meniscal tears in the setting of an acute ACL insufficiency are more common than medial meniscal tears. The findings in the this study would be helpful in clinical diagnosis and subsequent treatment decisions in patients with an acute ACL tears.

• Investigative Magnetic Resonance Imaging
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• v.11 no.1
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• pp.27-32
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• 2007

Purpose : To evaluate the mucoid degeneration (MD) of the anterior cruciate ligament (ACL) of the knee by correlation of MRI findings with pathology, in the patients with osteoarthritis (OA). Materials and Methods : This study included 17 patients (mean 68.8 years old) who underwent preoperative MRI. In proton density-weighted sagittal and coronal images ACLs were evaluated for the thickness and signal intensity (SI). Total knee replacement arthroplasty was performed and the pathologic findings of ACL were evaluated. MD was classified as 3 grades according to the degenerated amount in microscopy. Thickness and SI was evaluated as normal or increased on MRI. Results : All of the 4 patients who showed thickened ACL showed increased SI on MRI. All of the 8 patients with increased SI of the ACL on MRI had MD in the ACL. However, remained 9 patients also had MD, in spite of their normal thickness and SI on MRI. Calcification was seen in 5 patients. Conclusion : Eight cases who showed ACL thickening or increased SI on MRI were well correlated with MD, however, because the other nine cases who showed normal thickness and normal SI of ACL on MRI also showed MD in pathology, normal MRI finding should not exclude the possibility of MD of ACL.

• Journal of the Korean Arthroscopy Society
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• v.8 no.2
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• pp.75-81
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• 2004

Purpose: Recent development and advances in arthroscopic surgical techniques for Anterior Cruciate Ligament(ACL) reconstruction have led to the ideal location for the etric point from 10 o'clock (in right knee) and 13:30 (in left knee) to 10:30 (in right knee) and 14 o'clock (in left knee) in the frontal plane. This study was performed to compare operative methods and the radiologic results of femoral tunnels made through the tibial tunnel(trans-tibial approach) and the anteromedial portal. Material and Methods: From January 2003 to May 2004, one-hundred reconstructions of anterior cruciate ligament were performed. Group I (femoral tunnel through tibial tunnel) was composed of 50 cases and group ll (femoral tunnel through anteromedial portal) was consisted of 50 cases. The study was performed to compare the radiographic results of femoral tunnels made through the tibial tunnel and the anteromedial portal and operative methods. Results: In operative methods at Group II, femoral tunnel was made more easily at isometric point than Group I, a good visual field was achived because 100$^{\circ}$ flxion of knee, they can be reduced risk of posterior cortical breakage and tunnel-graft mismatching and decreased divergence of femoral interference screw in radiology (P<0.05). The angle between femoral tunnel and longitudinal axis of ACL wae increased at Group ll. Conclusion: Aanteromedial portal technique was more useful in ACL reconstruction for femoral tunnel toward 10 o'clock to10:30(in right) or 1:30 to 2 o'clock(in left).

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.154-161
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• 2005

Purpose: to describe the histologic appearance of the type III bone bruise in knees which had sustained an acute anterior cruciate ligament (ACL) rupture. Materials and Method: Twenty-five patients who sustained acute ACL rupture were prospectively enrolled in this study. On MRI, 14 patients demonstrated type III bone bruise on lateral femoral condyle, and 11 patients didn't demonstrated bone bruise. Arthroscopic evaluation and biopsy of the articular cartilage and subchondral bone wert performed before ACL reconstruction. Histologic and immunohistochemical evaluations were done. Results: There was no difference between the bone bruise and control group in the hematoxylin-eosin staining for cell distribution, Masson's trichrome staining for collagen and immunohistochemical staining for type I and type II collagen (p>0.05). But in the safranin-O staining for glycosaminoglycan distribution, the bone bruise group had an evidence of decreased staining at the superficial and middle layers, compared with the control group (p<0.05). We also found fatty change of bone marrow in calcified zone of the bone bruise group with safranin-O staining. Conclusion: We suggest that the type III bone bruise found on MRI indicates a substantial damage to normal articular cartilage homeostasis, and may induce further damage of the articular cartilage.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.2
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• pp.91-97
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• 2010

Purpose: The purpose of this study was to evaluate the results of treatment for longitudinal meniscal tear in ACL rupture patients by clinical evaluation and $2^{nd}$ look arthroscopy. Materials and Methods: Among the patients who underwent surgery due to ACL rupture and longitudinal meniscal tear between 2002~2009, 32 patients were selected for the study. The patients were devided into three groups; group 1 had repair, group 2 had partial menisectomy due to impossible to repair, group 3 had conservative treatment due to stable meniscus. Comparative retrospective analysis was applied with KT 1000 arthrometer, Lysolm' score, Tegner activity score, IKDC subjective score, and $2^{nd}$ look arthroscopy. Results: Lysolm' score, Tegner activity score, IKDC subjective score showed no statistical difference in all three groups. KT-1000 side to side difference improved from 6.2, 6.15, 6.38 before surgery to 2.56, 2.49, 2.58 after surgery in group 1, 2, and 3, respectively. In group 1, second-look arthroscopy revealed complete healing in 12 patients, incomplete healing without any clinical symptoms in 2, and healing failure in 1. In group 2, second-look arthroscopy showed partial regeneration on margin of meniscectomy. In group 3, second-look arthroscopy revealed complete healing in 2 patients, while 4 showed incomplete healing so that have repaired. Conclusion: In the study, the outcome was better when the stable longitudinal meniscal tear on posterior horn with ACL rupture had active treatment.