• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.5
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• pp.517-523
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• 2011

Anterior cruciate ligament (ACL) injuries are treatedwith surgical reconstruction. Although ACL consists of two functional bundles, only the anteromedial bundle is surgically reconstructed, and the effect of the reconstruction of the posterolateral bundle is unknown. The purpose of this study is to investigate the role of the posterolateral bundle and the effect of double-bundle reconstruction during single-leg landing. A 3D dynamic knee with various ACL reconstructed models was created using MRI, and single-leg landing motion was simulated using in-vivo human experimental data. The results showed that the lateral shift of the tibial insertion of the anteromedial bundle and the posterolateral bundle of the ACL constrain the tibial internal rotation more efficiently than a single anteromedial bundle can. In addition, double-bundle ACL reconstruction is less sensitive to inaccuracies in the tibial tunnel placement.

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.222-231
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• 2005

Purpose: This article describes a double-bundle ACL reconstruction technique using a five-strand hamstring tendon autograft with conventional anteromedial bundle reconstruction and additional posterolateral bundle reconstruction. Operative technique: For the tibial tunnel, the conventional single tunnel technique is performed and for the femoral tunnel, the double tunnel technique is performed with the anteromedial and posterolateral bundle. After minimal notchplasty, the anteromedial femoral tunnel is prepared with leaving one milimeter of posterior femoral cortex within the over-the-top, which if positioned at the 11-o'clock orientation for the right knee or at the 1-o'clock position for the left knee. The posterolateral femoral tunnel that is located 5 to 7 mm superior to the inner margin of the lateral meniscus anterior horn at $90^{\circ}$ of flexion is prepared with tile outside-in technique using a 4.5 cannulated reamer. The graft material for the double bundle reconstruction is made of the conventional four-strand hamstring autograft in the anteromedial bundle and of a single-strand semitendinosus tendon in the posterolateral bundle. The anteromedial bundle is fixed with using a rigid fix system on the femoral side and the posterolateral bundle is fixed to tie with the miniplate from the outside femur. Then, with the knee in $10^{\circ}\;to\;20^{\circ}$ of flexion, a bioabsorbable screw is simultaneously applied to achieve tibial fixation with tensioning of both bundles. Conclusion: A double bundle reconstruction with five-strand hamstring autograft, which is designed with a favorable conventional anteromedial bundle and an additional posterolateral bundle to restore rotation stability, seems to be a very effective method for the treatment for ACL instabilities.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.195-199
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• 2002

This article is to report a new technique for reconstruction of the anteromedial and posterolateral bundles of anterior cruciate ligament by separate tensioning and fixation of the each bundle. Method : Tibial and femoral tunnels were made with conventional technique of anterior cruciate ligament reconstruction. Tibial tunnel was enlarged $5\~7$ mm in anterior-posterior direction to make oval it in cross section. When preparing the Achilles tendon allograft, bone plug portion was trimmed as the conventional technique. The tendinous portion was trimmed as two separate bundles by dividing the tendinous portion longitudinally, so the graft is shaped like 'Y'. The bone plug portion of allograft was inserted into the femoral tunnel and fixed with absorbable cross pins. Two ligamentous portionss of the distal part of the grafts were tensioned separately at the external orifice. Anteromedial bundle was fastened under maximum tension with the knee flexed 90 degrees by post-tie method. The posterolateral bundle was fixed by the same technique with the knee in full extension. Then, an absorbable interference screw was inserted between the two bundles upto the upper end of the tibial tunnel, to get more initial rigidity of the reconstructed graft as well as to locate the two bundles in more anatomic position.

• Journal of the Korean Arthroscopy Society
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• v.12 no.2
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• pp.112-117
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• 2008

Purpose: Double-bundle reconstruction of anterior cruciate ligament(ACL) has the advantage of restoring the isometry and original function of ACL. The purpose of this study is to evaluate the clinical results following double-bundle reconstruction of ACL using autogenous hamstring grafts through an accessory anteromedial portal. Materials and Methods: From January 2005 to July 2006, sixty patients(52 males, 8 females) underwent double-bundle ACL reconstruction using autogenous hamstring tendons..The mean age was 31.7 years($20{\sim}51$ years). The mean follow up period was 13.4 months($12{\sim}16$ months). We made a horizontal-oblique skin incision just medial to tibial tuberosity and harvested semitendinosus and gracilis tendon. Tibial tunnel for posterolateral bundle was made near its anatomical position. By modifying an anatomic reconstruction of ACL by Yasuda et al., we made a femoral tunnel for posterolateral bundle through accessory anteromedial portal. Tunnels for anteromedial bundle were made with conventional method. We reconstructed anteromedial bundle with semitendinosus tendon and posterolateral bundle with gracilis tendon. Clinical results at last follow up were evaluated by range of motion, extent of anterior displacement(KT-1000 arthrometer), pivot-shift test. Functional evaluation of clinical outcomes were evaluated by Lysholm score and modified Feagin Scoring System. Results: There was no limitation of motion of knee joint at last follow up. Mean side to side difference of anterior displacement of tibia by KT-1000 arthrometer was improved from 8.4 mm preoperatively to 1.7 mm postoperatively(p<0.05). Average Lysholm score was improved from 64.1 preoperatively to 92.2 postoperatively(p<0.05). In modified Feagin Scoring System, 90% of cases were rated as good or excellent. Conclusion: Double-bundle reconstruction of ACL using autogenous hamstring grafts through accessory anteromedial portal results in good clinical outcomes.

• 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.

• 대한관절경학회:학술대회논문집
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• 2009.10a
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• pp.130-130
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• 2009

• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.128-133
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• 2012

Purpose: This study examined the relationship between graft appearance on follow-up magnetic resonance imaging (MRI) and knee stability after double bundle anterior cruciate ligament (ACL) reconstruction. Materials and Methods: For each patient, 1.5 tesla MRI's were obtained. The signal intensity of grafts was divided into 3 grades by Sononda's classification. The course of grafts was divided into two patterns: straight and curved. We assessed Lachman test, KT 2000 arthrometer and anterior drawer stress radiograph using Telos$^{(R)}$ in $30^{\circ}$ knee flexion for anterior stability and evaluated pivot shift test for rotatory stability. The correlation between graft appearance on MRI and the results of knee stability tests was evaluated. Results: The anteromedial (AM) graft was evaluated as being grade 1 in 66.7%, grade 2 in 26.7%, and grade 3 in 6.7% of the cases and the posterolateal (PL) graft was assessed as being grade 1 in 63.3%, grade 2 in 33.3%, and grade 3 in 3.3% of the cases according to the signal intensity. The AM graft was evaluated as being straight in 83.3% and curved in 16.7% of the cases, and the PL graft was assessed as being straight in 86.7% and curved in 13.3% of the cases according to the course. The course of AM graft was correlated with the results of anterior stability tests and the course of PL graft was correlated with the result of rotatory stability test. However, the signal intensity of grafts was not correlated with the results of anterior stability and rotatory stability tests. Conclusion: The course of AM is correlated with anterior stability and the course of PL is correlated with rotatory stability on follow-up MRI after double bundle ACL reconstruction.

• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.160-166
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• 2012

Purpose: The aim of this study was to determine the patterns of the stress distribution within the reconstructed anterior cruciate ligament (ACL) double bundles in response to an anterior tibial load and rotatory load at $45^{\circ}$ flexed knee model by use of a 3-dimensional finite element analysis (FEM). Materials and Methods: The $0^{\circ}$ and $45^{\circ}$ flexed 3-D knee model were reconstructed based on the high resolution computed tomography (CT) images from the right knee of a healthy male subject. To simulate double bundle ACL reconstruction, in $0^{\circ}$ analytic model, four 7 mm diameter tunnels were created at the center of each anteromedial (AM) and posterolateral (PL) footprints on the femur and tibia. The grafts were inserted into the corresponding bone tunnels and then reconstructed knee model was flexed to $45^{\circ}$. As a next step, the 5 mm anterior tibial load and internal rotational load of $10^{\circ}$ were applied on the final Computer aided design (CAD) model. And then stress patterns of each bundle were assessed using a finite element analysis. Results: In response to the 5 mm of anterior tibial load, the AM bundle showed increased stresses around the tibial and femoral attachment sites; especially in the anterior aspect of the bundle. In the PL bundle, the highest stress concentration was also noticed on the anterior aspect of the bundle. Under $10^{\circ}$ internal rotational load, the stress concentration was predominant around the anterior aspect of the tibial attachment site within the AM bundle. The PL bundle also showed highest stress concentration on the anterior aspect of the bundle. Conclusion: Although the stress patterns were not identical among the AM and PL bundle, there were common trends in the stress distribution. The stress concentration was predominant on the anterior aspect of both bundles in response to the anterior tibial load and rotatory load.

• Journal of the Korean Arthroscopy Society
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• v.15 no.2
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• pp.132-139
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• 2011

The concept of double-bundle ACL reconstruction was introduced recently to restore the anatomical and biomechanical functions of the native ACL. According to anatomical and biomechanical studies, the separate reconstruction of anteromedial and posterolateral bundle expect to increase the overall postoperative stability and clinical results compared to single-bundle ACL reconstruction. But there is still a lack of available clinical outcome studies with sufficient follow-up to demonstrate the real advantages of double-bundle ACL reconstruction. The purpose of this article is to review the evidence to support double-bundle technique and to address controversies existing over the usefulness of this technique.

• Journal of the Korean Arthroscopy Society
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• v.12 no.3
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• pp.198-204
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• 2008

Purpose: The purpose of this study is to analyze the merits and demerits of double bundle reconstruction and achieve improvements hereafter, by comparing the results of double bundle and single bundle reconstruction using tibialis anterior allograft. Materials and Methods: Twenty seven patients were divided to undergo either double bundle(n=14) or single bundle(n=13) reconstruction with tibialis anterior allograft tendon. The evaluation methods were AP laxity with KT-2000 arthrometer, isokinetic knee strength measurements, pivot-shift test, IKDC subjective score, Lysholm knee score, Tegner activity score, radiographic evaluations with postoperative MRI, and second look arthroscopy. Results: Lysholm knee score and Tegner activity score were significantly better in double bundle reconstruction. In pivot-shift test, single bundle reconstruction was evaluated as grade 0 in 10 of the knees, grade 1 in 1, and grade 2 in 2. Double bundle reconstruction was evaluated as grade 0 in 13, and grade 2 in 1. In second look arthroscopy, single bundle was evaluated as excellent in 6 of the knees, fair in 7, anteromedial bundle of double bundle reconstruction was excellent in 13 and fair in 1, and posterolateral bundle was excellent in 4, fair in 9, and poor in 1. There were no significant differences in other evaluations. Conclusion: Favorable outcome may be expected with double bundle reconstruction of ACL. However there are still need for improvement in terms of reconstruction technique and rehabilitation protocol to reduce PL bundle injury.