• Journal of the Korean Society of Radiology
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• v.84 no.2
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• pp.427-440
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• 2023

Purpose This study aimed to investigate the correlation between the fat signal fraction (FF) of the fat-dominant bone tissue of the knee joint, measured using the MRI Dixon method (DIXON) technique, and bone mineral density (BMD). Materials and Methods Among the patients who underwent knee DIXON imaging at our institute, we retrospectively analyzed 93 patients who also underwent dual energy X-ray absorptiometry within 1 year. The FFs of the distal femur metaphyseal (Fm) and proximal tibia metaphyseal (Tm) were calculated from the DIXON images, and the correlation between FF and BMD was analyzed. Patients were grouped based on BMD of lumbar spine (L), femoral neck (FN), and common femur (FT) respectively, and the Kruskal-Wallis H test was performed for FF. Results We identified a significant negative correlation between TmFF and FN-BMD in the entire patient group (r = -0.26, p < 0.05). In female patients, TmFF showed a negative correlation with FN-BMD, FT-BMD, and L-BMD (r = -0.38, 0.28 and -0.27, p < 0.05). In male patients, FmFF was negatively correlated with only FN-BMD and FT-BMD (r = -0.58 and -0.42, p < 0.05). There was a significant difference in the TmFF between female patients grouped by BMD (p < 0.05). In male patients, there was a significant difference in FmFF (p < 0.05). Conclusion Overall, we found that FF and BMD around the knee joints showed a negative correlation. This suggests the potential of FF measurement using DIXON for BMD screening.

• Journal of the Korean Orthopaedic Association
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• v.56 no.5
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• pp.404-412
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• 2021

Purpose: This study examined the degree of cartilage regeneration by performing second-look arthroscopy in a group of patients who underwent high tibial osteotomy and microfractures for unicompartmental osteoarthritis of the medial knee joint and to determine the factors affecting cartilage regeneration. In addition, this study analyzed whether there is a relationship between the degree of cartilage regeneration and functional results. Materials and Methods: From 2007 to 2015, this study evaluated 81 cases who underwent second-look arthroscopy at the time of plate removal after a microfracture and high tibial osteotomy with a minimum two-year follow-up. The degree of femoral cartilage injury before surgery was classified by ICRS (International Cartilage Research Society), and all were grade III and IV. After second-look arthroscopy, cartilage regeneration was classified into a well-regenerated group (grade I, II) and a poorly regenerated group (grade III, IV). The independent factors influencing cartilage regeneration were identified through multivariate logistic regression analysis. In addition, the functional results were compared before and after surgery between the two groups using the Knee Society score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index score (WOMAC). Results: Age, sex, body mass index, postoperative radiologic factors, and preoperative joint condition did not affect the degree of cartilage regeneration significantly. The large cartilage defect (≥2.0 cm²) (p=0.011) and the presence of kissing lesions (p=0.027) were associated with poor cartilage regeneration. No significant difference in the KSS and WOMAC scores was observed between the group with good and poor cartilage regeneration. Conclusion: The presence of a large cartilage defect and kissing lesions is associated with poor cartilage regeneration after high tibial osteotomy and microfracture. On the other hand, the degree of the regenerated cartilage did not show any correlation with the functional outcome.

• Journal of the Korean Orthopaedic Association
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• v.55 no.1
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• pp.54-61
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• 2020

Purpose: Brown tumor is a tumor-like disease that can occur as a linked disease of hyperparathyroidism which can causes osteoporosis, osteitis fibrosa cystica, pathologic fractures. Brown tumor has been reported as a case report, but there is no comprehensive report on the exact diagnosis and principle of management for osseous lesion. The purpose of this study is to report the treatment and results of osseous lesions through 5 cases. Materials and Methods: From February 2004 to May 2015, five cases of Brown tumor were diagnosed in Chosun University Hospital and Chonnam National University Hospital orthopedic department. Medical records and radiographs were reviewed retrospectively. Parathyroid tumors were surgically removed, and surgical treatment and observation were performed for orthopedic osseous lesions. Results: The mean length of the long axis of the symptomatic osseous lesion was 6.2 cm (4.5-9.0 cm). An average of 7.6 (range, 3 to 14) of high uptake osseous lesion showed in whole body bone scan. The absolute value, T-score and Z-score of the vertebrae and proximal femur were adequate for diagnosis of osteoporosis using dual energy X-ray absorptiometry bone mineral density at diagnosis and recovered to normal at the last follow-up. In laboratory tests, serum concentrations of total calcium, ionized calcium, inorganic phosphorus, serum alkaline phosphatase, and parathyroid hormone were helpful to diagnosis and normalized upon successful removal of parathyroid adenoma or cancer. Conclusion: For accurate diagnosis of Brown tumor, it should be accompanied by systemic examination as well as clinical symptoms, laboratory tests and radiologic examination for osseous lesions. And a good prognosis can be expected if the hyperparathyroidism is treated together with the comprehensive treatment of osseous lesions.

• 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 the Korean Orthopaedic Association
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• v.52 no.1
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• pp.83-91
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• 2017

Purpose: To investigate the clinical outcomes of distal hook augmentation using a pedicle screw in thoracolumbar fusion in elderly patients. Materials and Methods: This retrospective multicenter study recruited 20 patients aged 65 years or older, who underwent anterior support and long level posterior fusion in the thoracolumbar junction with a follow-up of one year. To assess the effect of distal hook augmentation, the patients were divided into two groups; the pedicle screw with hook group (PH group, n=10) and the pedicle screw alone group (PA group, n=10). Results: The average age was 72.4 years (65-83 years). The average fusion segment was 4.6 segments (3-6 segments). There were no significant differences in age, sex, causative diseases, bone mineral density of lumbar and proximal femur, number of patients with osteoporosis, and number of fused segments between the two groups (p≥0.05). At 1 year follow-up after surgery, parameters related with distal screw pullout were significantly worse in the PA group. No patients in the PH group had distal screw pullout. However, six patients (60%, 6/10) in the PA group had distal screw pullout. There were no significant differences in the progression of distal junctional kyphosis between the two groups. Conclusion: Distal hook augmentation is an effective procedure in protecting distal pedicle screws against the pullout when long level thoracolumbar fusion was performed in elderly patients aged 65 years or older.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.2
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• pp.163-171
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• 2008

Purpose: We analyze the characteristics of soft tissue sarcomas presented with hematoma, which were misdiagnosed as simple hematoma initially and the proper management were delayed. Materials and Methods: The 7 patients with histologically proven soft tissue sarcoma with hematoma presented since February 1997 were evaluated retrospectively. Neither patient had a medical history of bleeding tendency nor anticoagulant therapy. Two of them had minor traumas. There were 2 men and 5 women. Average follow up period was 58 months. MRI findings, provided treatments and oncologic outcome were reviewed with the reference of related articles. Results: Retrospective review of initial MR images revealed deep seated intramuscular masses with focal solid enhanced nodules at the peripheral margin. The diagnoses were delayed at least 1 month in 3 of them which included 2 cases of simple hematoma evacuation without biopsy initially. After histologic diagnosis of soft tissue sarcoma, wide resections were performed in 4 cases. one patient underwent above knee amputation and the remained 2 patients were managed with wide resection followed by amputation due to local recurrence. At last follow up there were CDF and NED in 2 cases, respectively and AWD in 3 cases. Conclusion: To avoid the delay of diagnosis and treatment of soft tissue sarcomas presented with hematoma, high degree of clinical suspicion, careful analysis of MR images and early biopsy were important.