Bioelectrical impedance analysis (BIA) is currently the most commonly used method in clinical practice to measure body composition. However, the bioelectrical impedance analyzer is not designed according to different countries, races, and elderly populations. Because different races may have different body compositions, a prediction model for the elderly population in Taiwan should be developed to avoid population bias, thereby improving the accuracy of community evaluation surveys. Dual energy X-ray absorptiometry (DXA) was used as a standard method for comparison, and impedance analysis was used for the development of a highly accurate predictive model that is suitable for assessing the body composition of elderly people. This study employed a cross-sectional design and recruited 438 elderly people who were undergoing health examinations at the health management center in the Tri-Service General Hospital as study subjects. Basic demographic variables and impedance analysis values were used in four predictive models, namely, linear regression, random forest, support vector machine (SVM), and eXtreme Gradient Boosting (XGBoost) models, to predict DXA body composition. The data from 354 study subjects were used to develop the predictive model, while the data from 84 study subjects were used to validate the accuracy of the predictive model. The body composition of elderly people as estimated by InBody 720 was highly correlated with that estimated by DXA. The correlation coefficient between InBody 720 and DXA for muscle mass was 0.969, and that for fat mass was 0.935. Consistency analysis results showed that InBody 720 tends to underestimate muscle mass and fat mass. A comparison of the accuracy of the linear regression, random forest, SVM, and XGBoost models showed that the linear regression has the highest accuracy. The correlation coefficient between the new model and DXA for muscle mass and fat mass were 0.977 and 0.978, respectively. The new predictive model can be used to monitor the nutrition status of elderly people and identify people with sarcopenia in the community.

The Hoffa fat pad (infrapatellar fat pad) is a source of post‐traumatic anterior knee pain, and Hoffa disease is a syndrome leading to chronic inflammation of the fat pad. Herein, change in T2* relaxation time of the fat pad was measured in a rodent anterior cruciate ligament transection (ACLX) model in order to (i) examine the causal relationship of anterior cruciate ligament (ACL) deficiency and Hoffa disease and (ii) demonstrate the feasibility of using T2* as an imaging biomarker to monitor disease progression. Three groups of male Sprague Dawley rats (n = 6 each group), received either (i) no intervention; (ii) sham surgery at the right knee; or (iii) right ACLX. T2* relaxation time was measured and histology was examined in the Hoffa fat pad after surgery. At 13 and 18 weeks after surgery, T2* values were significantly higher in the right fat pad than the left (p < 0.001) and significantly higher in the ACLX group than the control and sham groups (p < 0.001). Histology showed fibrosis and degeneration of adipocytes in the right knees of the ACLX group. We conclude that ACL deficiency and Hoffa disease are causally related and that MRI T2* value can serve as an imaging biomarker of Hoffa disease progression. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1348–1355, 2015.

Langerhans cell histiocytosis (LCH), formerly known as histiocytosis X, refers to a spectrum of diseases characterized by idiopathic proliferation of histiocytes that produce either focal (localized LCH) or systemic manifestations (Hand-Schüller-Christian disease and Letterer-Siwe disease). Localized LCH accounts for approximately 60-70 % of all LCH cases. Osseous involvement is the most common manifestation and typically involves the flat bones, along with lesions of the skull, pelvis, and ribs. Localized LCH in bone shows a wide spectrum of clinical manifestations and radiologic features that may mimic those of infections as well as benign and malignant tumors. The diagnostic imaging findings of localized LCH are also diverse and challenging. The penumbra sign is a common and characteristic magnetic resonance imaging (MRI) feature of Brodie's abscess, but is rarely seen in localized LCH. In this report, we describe a case of localized LCH misdiagnosed as Brodie's abscess in a 2-year-old child based on clinical symptoms, laboratory findings, and pre-diagnostic MRI findings (penumbra sign). Therefore, the penumbra sign is not sufficient to clearly establish the diagnosis of Brodie's abscess, and the differential diagnosis of localized LCH should be considered when a child with an osteolytic lesion presents with a penumbra sign.

This study aimed to evaluate the different clinical results and factors associated with cartilage defects in military draftees who underwent different treatments after anterior cruciate ligament (ACL) rupture. Overall, 105 patients who had sustained ACL rupture were military draftees who underwent a conscription examination for physical status assessment from January 2012 to December 2020. Patients were divided into three groups: conservative treatment after ACL rupture, status post-anterior cruciate ligament reconstruction (ACLR), but graft rupture, and status post-ACLR with graft intact. Inter-group comparisons and statistical analyses were performed for age, body mass index (BMI), thigh circumference difference, side-to-side difference in anterior knee translation by KT-2000, meniscus tear, and cartilage defect. Multivariate logistic regression analysis was used to determine the factors associated with cartilage defects. The multivariable regression model showed that BMI (odds ratio OR: 1.303; 95% CI: 1.016–1.672; p = 0.037), thigh circumference difference (OR: 1.403; 95% CI: 1.003–1.084; p = 0.034), tear of lateral meniscus (LM) and medial meniscus (MM) (OR: 13.773; 95% CI: 1.354–140.09; p = 0.027), and graft rupture group (OR: 5.191; 95% CI: 1.388–19.419; p = 0.014) increased the risk of cartilage defects. There was no correlation between cartilage defects and age, KT-2000 difference, tear of LM or MM, or graft intact group. Progression of osteoarthritis was concerned after ACL rupture, and this study identified several factors of post-ACLR graft rupture, greater thigh circumference difference, BMI, and meniscus tear of both LM and MM affecting cartilage defects, which represent early degenerative osteoarthritis changes of the knee. The results of this study should be customized for rehabilitation and military training, especially in military draftees with ACL injuries.

Background and Objectives: Although the ultrasound-guided technique is used in caudal epidural injections, severe complications can happen if ultrasound cannot identify the occurrence of intravascular injection. To determine intraepidural and intravascular injection during caudal epidural injections, we used power Doppler ultrasonography (PDU) when injecting medications into the epidural space. Materials and Methods: This is a retrospective study that enrolled a total of 277 patients with refractory low back pain or degenerative disc from January 2019 to December 2019. The injectate flow of caudal epidural injections was examined with the assistance of PDU and confirmed by fluoroscopy. Four flow patterns were identified by PDU in our study: the “Earthworm sign,” the “Patch sign,” the ”Tubular sign” and the “Absent flow sign.” The accuracy of PDU in identifying intraepidural and intravascular injections was determined by fluoroscopy images recorded during each injection. Results: We evaluated 277 patients (mean age, 68.6 ± 13.2 years; 106 men). The “Patch sign” showed a sensitivity of 88.76% and a specificity of 80% in predicting epidural injection without intravascular injection. The “Earthworm sign” demonstrated a sensitivity of 70% and a specificity of 100% in detecting intravascular injection. The “Tubular sign” showed a specificity of 100% and a sensitivity of 9.4% in predicting successful epidural injection. The absence of a flow signal showed a sensitivity of 1.87% and a specificity of 90% in predicting successful epidural injection. Conclusions: Ultrasound-guided caudal epidural injection can accurately determine intraepidural and intravascular injections with the assistance of PDU and is thus a good alternative technique to fluoroscopy-guided caudal epidural injection.

Utility of magnetic resonance spectroscopy and diffusion-weighted imaging for detecting changes in the femoral head in divers with hip pain at risk for dysbaric osteonecrosis Tsung-Tai Lin, Cheng-Chuan Hu, Yi-Chih Hsu, Chih-Chien Wang, Shih-Wei Chiang, Chao-Ying Wang, Wei-Chou Chang, Guo-Shu Huang