Jai Hyung Park

Graft bending angle is correlated with femoral intraosseous graft signal intensity in anterior cruciate ligament reconstruction using the outside-in technique.

BACKGROUND The purposes of this study were as follows: 1) to determine the correlation between the bending angle of the anterior cruciate ligament (ACL) graft at the femoral tunnel and the magnetic resonance imaging (MRI) signal intensity of the ACL graft and 2) to analyze the difference in the MRI signal intensity of the reconstructed ACL graft in different areas of the graft after single-bundle hamstring autograft ACL (SB ACL) reconstruction using an outside-in (OI) technique with bone-sparing retro-reaming. METHODS Thirty-eight patients who underwent SB ACL reconstruction with the hamstring tendon autograft using the OI technique were enrolled in this study. All patients were assessed using three-dimensional computed tomography (CT) to evaluate femoral tunnel factors, including tunnel placement, tunnel length, tunnel diameter, and femoral tunnel bending angle. At a mean of 6.3±0.8months after surgery, 3.0-T MRI was used to evaluate the graft signal intensity using signal/noise quotient for high-signal-intensity lesions. RESULTS Among various femoral tunnel factors, only the femoral tunnel bending angle in the coronal plane was significantly (p=0.003) correlated with the signal/noise quotient of the femoral intraosseous graft. The femoral intraosseous graft had significantly (p=0.009) higher signal intensity than the other graft zone. Five cases (13.2%) showed high-signal-intensity zones around the femoral tunnel but not around the tibial tunnel. CONCLUSION After ACL reconstruction using the OI technique, the graft bending angle was found to be significantly correlated with the femoral intraosseous graft signal intensity, indicating that increased signal intensity by acute graft bending might be related to the maturation of the graft. LEVEL OF EVIDENCE This was a retrospective comparative study with Level III evidence.

Management of Blood Loss in Hip Arthroplasty: Korean Hip Society Current Consensus

The volume of hip arthroplasty is stiffly increasing because of excellent clinical outcomes, however it has not been shown to decrease the incidence of transfusions due to bleeding related to this surgery. This is an important consideration since there are concerns about the side effects and social costs of transfusions. First, anemia should be assessed at least 30 days before elective hip arthroplasty, and if the subject is diagnosed as having anemia, an additional examination of the cause of the anemia should be carried and steps taken to address the anemia. Available iron treatments for anemia take 7 to 10 days to facilitate erythropoiesis, and preoperative iron supplementation, either oral or intravenous, is recommended. When using oral supplements for iron storage, administer elemental iron 100 mg daily for 2 to 6 weeks before surgery, and calculate the dose using intravenous supplement. Tranexamic acid (TXA) is a synthetic derivative of the lysine component, which reduces blood loss by inhibiting fibrinolysis and clot degradation. TXA is known to be an effective agent for reducing postoperative bleeding and reducing the need for transfusions in primary and revision total hip arthroplasties. Patient blood management has improved the clinical outcome after hip arthroplasty through the introduction and research of various agents, thereby reducing the need for allogeneic blood transfusions and reducing the risk of transfusion-related infections and the duration of hospitalizations.

Evaluation of Selective Bundle Injury to the Anterior Cruciate Ligament: T2-Weighted Fast Spin-Echo 3-T MRI With Reformatted 3D Oblique Isotropic (VISTA) Versus 2D Technique

OBJECTIVE The purpose of this study was to compare the diagnostic utility of oblique sagittal and oblique coronal 3D volume isotropic turbo spin-echo acquisition (VISTA) images with that of 2D fast spin-echo (FSE) T2-weighted images in the diagnosis of selective bundle tears of the anterior cruciate ligament (ACL). MATERIALS AND METHODS This retrospective study included 56 patients who underwent 2D FSE and 3D VISTA 3-T MRI of the knee before arthroscopic procedures. Images obtained with the two sequences were interpreted by two musculoskeletal radiologists independently, and the results were analyzed with the surgical diagnosis as the reference. RESULTS Among the 56 patients with suspected ACL injury, the arthroscopic records revealed 14 cases (25%) of complete tear, four cases (7%) of selective posterolateral bundle tear, and three cases (5%) of selective anteromedial bundle tear. The contrast-to-noise ratio between the ACL and joint fluid for 3D VISTA was 1.97 times as high as that for 2D FSE (p < 0.001). The entire width evaluation and margin sharpness scores for 2D FSE were significantly higher than those for 3D VISTA for both readers (p < 0.05). No significant differences were found in sensitivity, specificity, or accuracy of 2D FSE and 3D VISTA in the diagnosis of selective ACL tears (p > 0.05). CONCLUSION The diagnostic utility of oblique sagittal and oblique coronal 3D VISTA sequences was similar to that of 2D FSE sequences in the MRI diagnosis of selective bundle tear of the ACL, but the image quality of 3D VISTA was inferior to that of 2D FSE.

Analysis of the Korean Orthopedic In-Training Examination: The Hip and Pelvis Section

Purpose The purpose of this study was to analyze the questions in the hip and pelvis section of the Korean Orthopaedic In-Training Examination (KOITE). Materials and Methods We analyzed all KOITE questions pertaining to hip and pelvis surgery between 2010 and 2014. A thorough analysis of the contents was performed after categorizing as tested topics, imaging modalities used, taxonomic classification, and recommended references. We also analyzed the scores of the hip and pelvis section of the KOITE. Results Seventy-five of five-hundred questions (weight, 15.0%) were related to the hip and pelvis. Trauma including fracture and dislocation (26/75, 34.7%) was asked more commonly than disease and basics. The description-only questions (65/75, 86.7%) were the most frequently asked. According to taxonomic classification, taxonomy 3 (decision; 39/75, 52.0%) was most frequently asked. Campbells Operative Orthopedics (52/75, 69.3%) was the reference that covered most of the questions. Conclusion This analysis of the hip and pelvis section of KOITE could be used for resident training programs in teaching hospitals.

A cohort study of incident microalbuminuria in relation to HOMA-IR in Korean men

BACKGROUND Despite the previous studies showing the relationship between microalbuminuria and insulin resistance, longitudinal effect of insulin resistance on development of microalbuminuria is not clearly identified in non-diabetic population. METHODS One thousand six hundred three non-diabetic Korean men without microalbuminuria in 2005 had been followed up for the development of microalbuminuria until 2010. Microalbuminuria was evaluated by urine-albumin creatinine ration, and insulin resistance was evaluated by homeostasis model assessment of insulin resistance (HOMA-IR). Cox proportional hazards model was used to estimate the risk for microalbuminuria according to the tertile of HOMA-IR. RESULTS During 5465.8 person-y of average follow-up, microalbuminuria developed in 76 (4.7%) participants. Incidence of microalbuminuria increased in proportion to the level of HOMA-IR (tertile 1: 3.0%, tertile 2: 4.1%, tertile 3: 7.1%, P<0.001). When the 1st tertile of HOMA-IR was set as reference, hazard ratios and 95% confidence interval were 1.15 (0.56-2.35) and 2.07 (1.05-4.09) for those in the 2nd and 3rd tertiles of HOMA-IR, even after adjusting multiple covariates, respectively (P for linear trend=0.054). CONCLUSIONS Increased insulin resistance was a predictor of microalbuminuria in Korean men.

Incidental risk for diabetes according to serum ferritin concentration in Korean men

BACKGROUND Despite accumulating evidence suggesting the clinical association between serum ferritin concentrations and diabetes, it is not clearly identified in other ethnic groups besides western population. This study analyzed a longitudinal relationship between serum ferritin concentration and the risk for diabetes in non-diabetic Korean men. METHODS This study was composed of a cohort of 30,002 non-diabetic Korean men who participated in medical health check-up program in 2005. They were divided into 4 groups according to their baseline ferritin concentrations (first quartile-fourth quartile) and monitored until 2010. Their incidences and hazard ratios of diabetes were compared among 4 groups according to their baseline ferritin concentrations. RESULTS While 2655 cases of diabetes newly developed during follow-up, incidence of diabetes increased proportionally to the baseline serum ferritin concentrations. In Cox-proportional hazard model, hazard ratios for diabetes also independently increased according to the baseline serum ferritin concentrations [quartile 1: 1.00 (reference), quartile 2: 1.00 (0.87-1.12), quartile 3: 1.13 (1.00-1.29), quartile 4: 1.18 (1.04-1.34), respectively]. CONCLUSIONS Increased ferritin concentration was associated with increased risk for diabetes in Korean men. These findings suggest the clinical significance of serum ferritin concentration in the development diabetes.

Three-dimensional scapular dyskinesis in hook-plated acromioclavicular dislocation including hook motion

BACKGROUND The purpose of this study is to analyze the 3-dimensional scapular dyskinesis and the kinematics of a hook plate relative to the acromion after hook-plated acromioclavicular dislocation in vivo. Reported complications of acromioclavicular reduction using a hook plate include subacromial erosion and impingement. However, there are few reports of the 3-dimensional kinematics of the hook and scapula after the aforementioned surgical procedure. METHODS We studied 15 cases of acromioclavicular dislocation treated with a hook plate and 15 contralateral normal shoulders using computed tomography in the neutral and full forward flexion positions. Three-dimensional motion of the scapula relative to the thorax during arm elevation was analyzed using a computer simulation program. We also measured the distance from the tip of the hook plate to the greater tuberosity, as well as the angular motion of the plate tip in the subacromial space. RESULTS Decreased posterior tilting (22° ± 10° vs 31° ± 8°) in the sagittal plane and increased external rotation (19° ± 9° vs 7° ± 5°) in the axial plane were evident in the affected shoulders. The mean values of translation of the hook plate and angular motion against the acromion were 4.0 ± 1.6 mm and 15° ± 8°, respectively. The minimum value of the distance from the hook plate to the humeral head tuberosity was 6.9 mm during arm elevation. CONCLUSIONS Acromioclavicular reduction using a hook plate may cause scapular dyskinesis. Translational and angular motion of the hook plate against the acromion could lead to subacromial erosion. However, the hook does not seem to impinge directly on the humeral head.

How can MRI change the treatment strategy in apparently isolated greater trochanteric fracture

INTRODUCTION The purpose of this study was to evaluate the proportion of greater trochanter (GT) fractures with occult extension to the intertrochanteric region on magnetic resonance imaging (MRI) among apparently isolated GT fractures and to investigate the use of MRI for formulating a treatment strategy in patients with isolated GT fractures. PATIENTS AND METHODS This retrospective cohort study reviewed 37 patients with isolated GT fractures on plain radiography. Surgical or conservative treatment was decided according to MRI findings. We divided patients into 3 groups according to the extension of the fracture line. In group 1, the fracture line was within the lateral one-third in the coronal plane. In group 2, the fracture line extended from the lateral one-third to the medial one-third. In group 3, the fracture line extended over the medial one-third and/or to the medial cortex of the femur. Conservative treatment was performed in groups 1 and 2, and surgical treatment was performed in group 3. The clinical results, radiography findings, and MRI findings were investigated. RESULTS MRI revealed hidden intertrochanteric fractures (groups 2 [n = 10] and 3 [n = 4]) in 38% of apparently isolated GT fractures on radiography. No displacement was found in groups 1 (n = 23) and 2. Of the 4 patients in group 3, 3 were treated surgically and achieved good functional results and 1 refused to undergo surgery and finally developed complete intertrochanteric fracture. This patient presented 5 days later with increased hip pain, and radiography demonstrated displacement of the fracture, prompting surgical intervention. CONCLUSIONS The evaluation of apparently isolated GT fractures using MRI can be useful to diagnose the extent of the occult fracture and determine the treatment strategy.

Roles of Exosome-Like Vesicles Released from Inflammatory C2C12 Myotubes: Regulation of Myocyte Differentiation and Myokine Expression

Background/Aims: The complicated differentiation processes of cells in skeletal muscle against inflammation that induce muscle atrophy are not fully elucidated. Given that skeletal muscle is a secretory organ, we evaluated the effects of inflammation on myogenic signals and myokine expression, and the roles of inflammatory exosomes released by myotubes in myogenic differentiation. Methods: Inflammation was induced by treatment of fully differentiated C2C12 myotubes with a cytokine mixture of TNF-α and INF-γ. Exosome-like vesicles (ELVs) were isolated from conditioned media of control or inflamed myotubes and incubated with myoblasts. The expression of molecular switches that contribute to myogenic differentiation, including several kinases, their downstream targets, and myokines, were evaluated using immunoblot analysis in inflamed myotubes and in myoblasts treated with ELVs. Results: Inflammation activated molecular mechanisms contributing to muscle atrophy, including AMPK, p-38 MAPK and JNK, while inhibiting Akt-mediated myogenic signals. In addition, inflammation induced myostatin expression with suppression of a myostatin-counteracting myokine, decorin. Well-characterized ELVs released from inflamed myotubes induced myoblast inflammation and inhibited myogenic mechanisms while stimulating atrophic signals. Conclusion: Inflammation of skeletal muscle induces muscle atrophy via multiple mechanisms, including the regulation of myokines and kinases. Inflammatory ELVs are likely to contribute to inflammation-induced muscle atrophy.

Comparison of two-dimensional fast spin echo T2 weighted sequences and three-dimensional volume isotropic T2 weighted fast spin echo (VISTA) MRI in the evaluation of triangular fibrocartilage of the wrist

OBJECTIVE To compare image quality of three-dimensional volume isotropic T2 weighted fast spin echo (3D VISTA) and two-dimensional (2D) T2 weighted images (T2WI) for evaluation of triangular fibrocartilage (TFC) and to investigate whether 3D VISTA can replace 2D T2 WI in evaluating TFC injury. METHODS This retrospective study included 69 patients who received wrist MRIs using both 2D T2 WI and 3D VISTA techniques for assessment of wrist pathology, including TFC injury. Two radiologists measured the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) of the two sequences. The anatomical identification score and diagnostic performance were independently assessed by two interpreters. The diagnostic abilities of 3D VISTA and 2D T2 WI were analysed by sensitivity, specificity and accuracy for diagnosing TFC injury using surgically or clinically confirmed diagnostic reference standards. RESULTS 17 cases (25%) were classified as having TFC injury. 2 cases (12%) were diagnosed surgically, and 15 cases (88%) were diagnosed by physical examination. 52 cases (75%) were diagnosed as having intact TFC. 8 of these cases (15%) were surgically confirmed, while the others were diagnosed by physical examination and clinical findings. The 3D VISTA images had significantly higher SNR and CNR values for the TFC than 2D T2 WI images. The scores of 3D VISTAs total length, full width and sharpness were similar to those of 2D T2 WI. We were unable to find a significant difference between 3D VISTA and 2D T2 WI in the ability to diagnose TFC injury. CONCLUSION 3D VISTA image quality is similar to that of 2D T2 WI for TFC evaluation and is also excellent for tissue contrast. 3D VISTA can replace 2D images in TFC injury assessment. Advances in knowledge: 3D VISTA image quality is similar to that of 2D T2 WI for TFC evaluation and is also excellent for tissue contrast. 3D VISTA can replace 2D images in TFC injury assessment.