• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.3
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• pp.321-327
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• 2009

This paper studied the influences of the main design parameter-the expansion angle and the material properties of the self-expansion anterior cruciate ligament fixation device on the contact condition with the bone and the initial stability of the device. Using finite element analysis, the stress distributions of the ring part of the device and the wall of the bone tunnel were calculated. And the micro-migration of the device by the pull-out force was calculated. From the analysis results, it was found that when designing the self-expansion type anterior cruciate ligament fixation device, it is desirable to use the material having higher Young's modulus and to design the fixation device that all wedges uniformly maintain contact with bone to obtain initial stability after operation.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.1
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• pp.15-19
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• 2003

Although the number of anterior cruciate ligament reconstruction is increasing, complications after primary ACL reconstruction are more difficult to determine. Intraoperative and postoperative complications can lead to ultimate failure of a primary reconstructive procedure. Therefore, surgical success in ACL reconstruction requires detailed knowledge and technical advancements about ACL reconstruction. Preoperatively surgeon must pay attention to selection of grafts and methods of fixation, and intraoperatively, attention to the harvest of graft, passage of graft, intraarticuar placement of the graft, notchplasty, proper tensioning of the graft, and others. Postoperative complications must be detected early, including infection, abnormal healing responses, arthrofibrosis, graft rejection, and reflex sympathetic dystrophy. Careful patient selection, appropriate surgical timing, careful surgical technique, and supervised preoperative and postoperative rehabilitation can minimize postoperative complications.

• Journal of the Korean Arthroscopy Society
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• v.1 no.1
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• pp.55-62
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• 1997

Various surgical techniques has been advocated for reconstruction of anterior cruciate ligament using the bone-patella tendon-bone graft. Recently endoscopic technique provides good clinical results, with minimal skin incision, accurate positioning of the graft to the femoral tunnel, and decreasing wear rate of the graft. But the graft-tunnel mismatch remains problematic in endoscopic technique. The purpose of this paper is to described causes of the graft-tunnel mismatch and to provide important steps to prevent or minimize the graft-runnel mismatch following anterior cruciate ligament while using the endoscopic technique. Our guideline for prevention of the graft-tunnel mismatch are as follows: (1) The tunnel should he positioned closely to isometric point as much as possible. (2) Anterior placement of the tunnel should be avoided. (3) The change of graft length should be within 2mm between flexion and extension position.

• Journal of the Korean Arthroscopy Society
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• v.1 no.1
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• pp.81-85
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• 1997

This article describes a modified arthroscopic technique of anterior cruciate ligament (ACL) reconstruction using quadrupled hamstring tendon graft. The autogenous semitendinosus and gracilis grafts are harvested without detachment of the tibial insertion. To obtain longer graft, the accessory tibial insertions of the hamstring tendons are dissected. The EndoButton(Acupex Microsurgical, Andover, MA) is used for femoral fixation and two spiked staples are used for tibial fixation in a belt buckle fashion. Then the residual anterior laxity is restored by additional absorbable interference screw fixations. In this technique. more viable graft is obtained and firmer distal fixation is achieved by preservation of the tibial insertion of hamstring tendons.

• 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.

• 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.6 no.2
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• pp.109-114
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• 2002

Propose : The purpose of this retrospective study was to test the posterior cruciate ligament (PCL index) for diagnosis of a tear of the anterior cruciate ligament (ACL) by means of MR imaging. Materials and Methods : From Mar. 1997 to Feb. 2001, concomitant magnetic resonance imaging (MRI) and knee joint arthroscopy were performed in 56 patients of either pain or instability of the knee. The shortest distance between the femoral and tibial attachment of PCL (X) and the distance from that line to the tip of the arc marked by the PCL (Y) on the sagittal plane images were measured. The quotient of these two parameters (Y/X) defined the PCL index. Results : Using MRI diagnosis, there were 35 patients diagnosed with ACL rupture and 21 patients were ruled out of ACL injury. Using arthroscopy, 32 of the 35 patients diagnosed by MRI showed ACL rupture, and 20 of the 21 patients were ruled out of ACL injury. The mean PCL index was 0.40 in the 33 patients diagnosed with ACL rupture through arthroscopy. The mean PCL index was 0.23 in 23 patients with an uninjured ACL through arthroscopy. In 33 patients with ruptured ACL, this value exceeds 0.31. The index value was 0.31 in 3 patients with uninjured ACL. The value of the index was not above 0.31 with an uninjured ACL. PCL index on MRI had a sensitivity of $91\%$ and a specificity of $94\%$ for determining the status of the anterior cruciate ligament. Conclusion : Injury to the ACL changes the PCL index markedly. In diagnostically unreliable MR images, amelioration of the PCL index could help in the diagnosis of ACL injury.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.3
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• pp.251-258
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• 2012

Purpose : The purpose of this study is to provide an efficient and basis for muscle activity of Quadriceps muscles and balance in anterior cruciate ligament reconstruction patients through unstable surface exercise and stable surface exercise. Methods : This study included 30 anterior cruciate ligament reconstruction patients belonging to A hospital and D orthopedic surgery clinic of province who attended the program for 30 minutes at a time and three times a week for 4 weeks. Of these 15 attended the unstable surface exercise program and 15 the stable surface exercise program. To increase muscle activity (%MVIC) and balance (WPL), the unstable surface exercise. Results : The %MVIC of lower extrmity muscle(RF, VL, VM) increased from before training to after training in the case of the participants who performed the unstable surface exercise, and the whole path length (WPL) decreased from before the training to after the training(p<.05). Conclusion : In conclusion, unstable surface exercise program helps to improve the balancing ability and musle activity in a anterior cruciate ligament recunstruction patients who requires both muscle activity and balance than stable surface exercise program.

• Journal of KIISE
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• v.42 no.10
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• pp.1222-1230
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• 2015

Segmentation of the anterior cruciate ligament (ACL) in knee MRI remains a challenging task due to its inhomogeneous signal intensity and low contrast with surrounding soft tissues. In this paper, we propose a multi-atlas-based segmentation of the ACL in knee MRI with locally-aligned probabilistic atlas (PA) in an iterative graph cuts framework. First, a novel PA generation method is proposed with global and local multi-atlas alignment by means of rigid registration. Second, with the generated PA, segmentation of the ACL is performed by maximum-aposteriori (MAP) estimation and then by graph cuts. Third, refinement of ACL segmentation is performed by improving shape prior through mask-based PA generation and iterative graph cuts. Experiments were performed with a Dice similarity coefficients of 75.0%, an average surface distance of 1.7 pixels, and a root mean squared distance of 2.7 pixels, which increased accuracy by 12.8%, 22.7%, and 22.9%, respectively, from the graph cuts with patient-specific shape constraints.

• Clinics in Orthopedic Surgery
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• v.10 no.4
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• pp.413-419
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• 2018

Background: We aimed to examine the factors that influence synovialization of the grafted tendon after double-bundle anterior cruciate ligament (ACL) reconstruction based on second-look arthroscopic findings. Methods: Out of 205 knees that were treated between August 2008 and May 2016 with double-bundle ACL reconstruction using bio-absorbable cross-pins and Endobuttons for femoral tunnel fixation, we enrolled 65 knees (64 patients) that underwent second-look arthroscopy with hardware removal at 1 year postoperatively. Measured clinical outcomes included the Lysholm score and Tegner activity score that were evaluated preoperatively and during the final follow-up. We analyzed the relationship between synovial coverage and patient age, length of the preserved remnant tissue on the tibial side, type of bundle (anteromedial or posterolateral), type of graft (autograft or allograft), and time from injury to surgery. Results: The area of synovial coverage showed a significant statistical correlation with patient age and the length of the preserved remnant tissue on the tibial side. The average synovial coverage was significantly better for the anteromedial bundle than for the posterolateral bundle, better for the autograft than for the allograft reconstruction, and better when treated in the acute stage than in the chronic stage. However, synovialization of grafted tendon did not correlate to clinical outcomes. Conclusions: While we were able to identify several factors influencing synovialization of the grafted tendon after double-bundle ACL reconstruction, including patient age, length of preserved remnant tissue of the torn ACL, type of bundle, type of graft, and time from injury to surgery, we found no evidence that increased synovialization improves clinical outcomes at 1 year postoperatively.