• Journal of the Korean Society of Radiology
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• v.8 no.2
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• pp.57-63
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• 2014

This study aims to find out the standardized test criteria regarding patients with the anterior cruciate ligament damage by identifying the degree of the flexion gap of femur and tibia upon bending of the anterior cruciate ligament in order to carry out the accurate test of such impairment. On the standardized test method and judgement criteria upon the anterior cruciate ligament test using Telos, it has been shown that there was no significant difference in the results according to the position of a fixed roller in the anterior cruciate ligament test for normal patients. However, in a test for patients who had undergone the anterior cruciate ligament reconstruction, it has been shown that the measured values of the anterior cruciate ligament tended to be pushed when the position of a fixed roller was less than 1cm in the test according to the position of a fixed roller of Telos (less than 1cm, more than 3cm), and this was statistically significant. The anterior cruciate ligament test (knee stress test) is a limited method used in orthopedics and rehabilitation medicine, and there have been no standardized test guidelines available yet although numerous ligament measurement tests have been performed. In addition, since the measured values are often different depending on testers even on the test that is expected to give the same result, the reproducibility of the test is still low. Accordingly, it is considered that the criteria for the anterior cruciate ligament test need to be established, and this would contribute to the accuracy of the diagnosis through the accurate test and standardized measurements.

• 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 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.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.2
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• pp.134-140
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• 2005

Purpose: We evaluated the effectiveness of temporary using the extendible external fixator (EF) for lengthening of soft tissue that contracture caused by tumor prosthesis removal in the treatment of complications after limb salvage surgery like deep infection and loosening. Materials and Methods: Five patients six cases were included who underwent extendible EF (Dyna-extor(r)). EF was applied after insertion of half pin to the proximal and distal bone of defect area. EF lengthening started at third day of post-operation, above 2-3 mm per day in the range of no neurological sign. Results: The treatment area was three in femur and two in tibia. Mean age when the time of EF apply was 22.2 years old (range 15-29), but its primary limb salvage operation had done in 13.4 years old (range 9-19), therefore mean times of interval between initial tumor prosthesis reconstruction and temporary EF apply was 8.8 years (range 3-14). One patient had EF for 150 days with 7.2 cm lengthening. Others 5 cases of 4 patients had EF for mean 37 days (range 25-50) and mean soft tissue lengthening was 5.8 cm. Three patients underwent re-insertion of tumor prosthesis and two patients underwent knee fusion as final operation and showed no evidence of infection through mean 22 months follow up period. Conclusion: Temporary using of extendible EF is an effective method for correction of leg shortening which occurred by soft tissue contracture in the complications of limb salvage operation or their treatment process, and it could be provide easily application of tumor prosthesis and knee fusion as final operation.

• The Journal of the Korean bone and joint tumor society
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• v.10 no.1
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• pp.1-12
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• 2004

Purpose: The current study was performed to analyze the oncological and functional results, and the patient, the limb and the prosthesis survival of osteosarcoma around the knee in children according to the treatment options. Materials and Methods: From 1982 to 2002, 63 patients with osteosarcoma around the knee underwent surgical treatments before 16 years of age. Surgical treatment options were amputation, endoprosthetic replacement, and implantation of low heat-treated autogenous bone graft after wide resection of tumor. The mean age of patients was 11.5 years (4.4~16), and the mean follow-up period was 6.1 years (2.1~16.8). All patients had neoadjuvant and adjuvant chemotherapy. All endoprosthses were extendible types. Anatomical locations of osteosarcoma were distal femur in 40 patients, and proximal tibia in 23 patients. As regard to Enneking stage, 4 patients had stage $II_A$, 50 patients had stage $II_B$, and 9 patients had stage III tumors. Results: The 5 year survival rate of stage $II_B$ patients was 72.7% in amputation, 83.7% in endoprosthesis, and 100% in low heat-treated autogenous bone graft. The 5 year survival rate of salvaged limb was 84.4% in endoprosthesis, and 80% in low heat-treated autogenous bone graft. The survival rate of prosthesis was 92.7% at 5 years, 67.4% at 10 years in endoprosthesis, and 75% at 5 years in low heat-treated autogenous bone graft. Mean functional outcome scores were 8.7 points in amputation, 20.6 points in endoprosthesis, and 16 points in low heat-treated autogenous bone graft. Distant metastasis occurred 15.8% in amputation, 27% in endoprosthesis and local recurrence occurred 8.1% in endoprosthesis, 14.3% in low heat-treated autogenous bone graft. Major complications happened 26.3% in amputation, 35.1% in endoprosthesis, and 28.6% in low heat-treated autogenous bone graft. Conclusion: Limb salvage procedure had functionally better results than amputation in children with osteosarcoma around the knee. Reconstruction with endoprosthesis after resection of tumor had good results in children as adults. In certain circumstances as too small bone for endoprosthesis or minimal bony destruction or too skeletally immature patient, low heat-treated autogenous bone graft may be a good treatment option. Low heat-treated autogenous bone graft may be considered as not only a substitute for endoprosthesis but also a temporary method before endoprosthesis.

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.2
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• pp.99-109
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• 2023

Purpose: CT scan makes up for the weak point of the nuclear medicine image having a low resolution and also were used for attenuation correction on image reconstruction. Recently, many studies try to make use of CT images additionally, one of them is to measure the bone mineral density(BMD) using Quantitative CT(QCT) software. BMD exams are performed to scan lumbar and femur with DXA(Dual-Energy X-Ray Absorptiometry) in order to diagnose bone disease such as osteopenia, osteoporosis. The purpose of this study is to identify the usefulness of QCT_BMD analyzed with low dose CT images on L-spine Bone SPECT/CT comparing with DXA_BMD. Materials and Methods: Fifty five women over 50 years old (mean 66.4 ± 9.1) who took the both examinations(L-spine Bone SPECT/CT with SIEMENS Intevo 16 and DXA scan with GE Lunar prodigy advance) within 90 days from April 2017 to July 2022, BMD, T-score and disease classification were analyzed. Three-dimensional BMD was analyzed with low dose CT images acquired on L-spine Bone SPECT/CT scan on Mindways QCT PRO^TM software and two-dimensional BMD was analyzed on DXA scan. Basically, Lumbar 1-4 were analyzed and the patients who has lesion or spine implants on L-spine were excluded for this study. Pearson's correlation analysis was performed in BMD and T-score, chi-square test was performed in disease classification between QCT and DXA. Results: On 55 patients, the minimum of QCT_BMD was 18.10, maximum was 166.50, average was 82.71 ± 31.5 mg/cm³. And the minimum of DXA-BMD was 0.540, maximum was 1.302, average was 0.902 ± 0.201 g/cm², respectively. The result shows a strong statistical correlation between QCT_BMD and DXA_BMD(p<0.001, r=0.76). The minimum of QCT_T-score was -5.7, maximum was -0.1, average was -3.2 ± 1.3 and the minimum of DXA_T-score was -5.0, maximum was 1.7, average was -2.0 ± 1.3, respectively. The result shows a statistical correlation between QCT T-score and DXA T-score (p<0.001, r=0.66). On the disease classification, normal was 5, osteopenia was 25, osteoporosis was 25 in QCT and normal was 10, osteopenia was 25, osteoporosis was 20 in DXA. There was under-estimation of bone decrease relatively on DXA than QCT, but there was no significant differences statistically by chi-square test between QCT and DXA. Conclusion: Through this study, we could identify that the QCT measurement with low dose CT images QCT from L-Spine Bone SPECT/CT was reliable because of a strong statistical correlation between QCT_BMD and DXA_BMD. Bone SPECT/CT scan can provide three-dimensional information also BMD measurement with CT images. In the future, rather than various exams such as CT, BMD, Bone scan are performed, it will be possible to provide multipurpose information via only SPECT/CT scan. In addition, it will be very helpful clinically in the sense that we can provide a diagnosis of potential osteoporosis, especially in middle-aged patients.

• Journal of the Korean Arthroscopy Society
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• v.9 no.1
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• pp.51-55
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• 2005

Purpose: To compare the stability and clinical result after anterior cruciate ligament reconstructed knee after graft fixation using Intrafix in tibial tunnel with or without additional tibial post fixation. Materials and Methods: We analyzed 37 cases which were treated with four-strand hamstring tendon autograft during the period from May 2002 to January 2003. The grafts were fixed with Rigidfix system (Mitek Product, Johnson and Johnson, USA) in femur tunnel and Intrafix system (Mitek Product, Johnson and Johnson, USA) in tibial tunnel. After tibial fixation, additional tibial post fixation was done, which was determined by the serial case number prospectively. Patients were followed for average of fourteen months(range, thirteen to twenty-five months) At the time of final follow-up, patients were evaluated in terms of Lachman test, pivot shift test, Lysholm scores, IKDC (International Knee Documentation Committee) assessment, side-to-side KT-1000 maximum-manual arthrometer differences. Results: At last follow-up, Lysholm score was average 93.1(range: 65 to 98), IKDC assessment revealed that 26 cases had score of A, 10 cases had score of B and 1 case had score of C. The average maximum-manual KT-1000 arthrometer side ?to-side difference was 2.5 mm$(0{\sim}6mm)$. There was one case in which the Lachman test was graded as 2+ and four cases in which the Lachman test was graded as 1+ and the remaining thirty-two cases were normal by Lachman test. One case had a 2+ pivot-shift, and 2 cases had a 11 pivot-shift. The remaining 34 knees were normal on pivot -shift testing. The average maximum-manual KT-1000 arthrometer side-to-side difference was average 2.8 mm$(0{\sim}6mm)$ in Intrafix only group and average 2.2 mm$(0{\sim}4mm)$ in additional fixation group (P>0.05). Conclusion: Without additional tibial fixation, the stability of the anterior cruciate reconstructed knee with hamstring graft which was fixed with Intrafix was restored.