Search

Objectives: In Korea, an average of 258 workers claim compensation for their noise-induced hearing loss (NIHL) on an annual basis. Indeed, hearing disorder ranks first in the number of diagnoses made by occupational medical check-ups. Against this backdrop, this study analyzed the impact of 19 types of noise-generating machines and equipment on the sound pressure levels in workplaces and NIHL occurrence based on a 2009 national survey on work environments. Methods: Through this analysis, a series of statistical models were built to determine posterior probabilities for each worksite with an aim to present risk ratings for noise levels at work. Results: It was found that air compressors and grinding machines came in first and second, respectively in the number of installed noise-generating machines and equipment. However, there was no direct relationship between workplace noise and NIHL among workers since noise-control equipment and protective gear had been in place. By building a logistic regression model and neural network, statistical models were set to identify the influence of the noise-generating machines and equipment on workplace noise levels and NIHL occurrence. Conclusion: This study offered NIHL prevention measures which are fit for the worksites in each risk grade.

Category: Midfoot/Forefoot; Hindfoot Introduction/Purpose: Evaluation of plain radiographs is of fundamental importance in the diagnosis and treatment planning of foot and ankle disorders. These assessments are essential, but can be difficult for the following reasons: First, many angles must be measured using various reference lines. Second, there may be inter-observer differences in the measurements. Consistent and standardized measurement methods are required to increase the efficiency and accuracy of radiographic readings. Several recent studies have reported good results using deep learning (DL) models for medical image analysis. It is expected that efficiency and accuracy can be increased through radiographic readings using DL. This study aims to develop a DL model that recognizes the bones of the foot and ankle in plain radiographs and automatically measures angles frequently used for diagnosis. Methods: The DL model was developed using two architectures: segmenting objects by locations (SOLO) for bone segmentation and Global Universal U-Net (GU2Net) for reference line detection. The angles measured were hallux valgus angle (HVA) and 1st- 2nd intermetatarsal angle (IMA) on anterior-posterior (AP) X-ray; calcaneal pitch angle (CPA) and lateral Meary's angle (LMA) on lateral X-ray. Only data obtained from external test set were used for statistical analysis to evaluate the model's performance. The test set used a total of 558 images collected from January 2022 to September 2022. Angles measured by the DL model were compared with angles measured manually by human researchers. The intraclass correlation coefficient (ICC) was used to evaluate the accuracy of angle measurements. The error between the angle measured by the DL model and the angle measured by human researchers was evaluated using root mean square error (RMSE) and mean absolute difference (MAE). Results: As shown in the attached table, the ICCs of HVA were 0.957 (right) and 0.933 (left). The ICCs of IMA were 0.881 (right) and 0.902 (left). The ICCs of LMA were 0.895 (right) and 0.937 (left). The ICCs of CPA were 0.918 (right) and 0.868 (left). All ICCs were greater than 0.8, indicating excellent correlations between angles measured with the DL model and angles measured manually (ground truth). For RMSE and MAE, the left IMA was the smallest (1.50 and 1.16, respectively), and the right LMA was the largest (4.50 and 2.47, respectively). Conclusion: The DL model in our study was able to perform various angle measurements in both AP and lateral X-rays with considerable accuracy. Through additional model training and development, it is expected that it will be useful for analyzing various foot and ankle disorders such as hallux valgus, flatfoot, pes cavus and other alignment deformities.

Category: Sports; Ankle Introduction/Purpose: The clinical features of chronic lateral ankle instability (CLAI) consist of mechanical and functional instability. Mechanical instability can be identified by physical examination of the injured anterior talofibular ligament laxity and can be treated with surgical ligament repair. Functional instability is more related to the patient's subjective symptoms due to decreased muscle strength, range of motion (ROM), coordination, and proprioception. In a previous report, ankle instability recurred in 16% after the modified Broström procedure (MBP) despite postoperative rehabilitation. Functional instability should be treated along with mechanical instability. We hypothesized that applying preoperative physiotherapy (prehabilitation) to patients with CLAI would improve postoperative functional recovery. We designed and performed a structured prehabilitation protocol for CLAI patients scheduled for MBP and investigated postoperative effects. Methods: Between March 2021 and December 2022, 28 patients were prospectively enrolled. Patients were randomly assigned to prehabilitation group (P) or non-prehabilitation group (N). Fourteen patients were enrolled in group P, and they started a 4-week prehabilitation protocol that continued the physiotherapy until 6 weeks postoperatively. Group N included 14 patients who received the same protocol of physiotherapy only for 6 weeks after surgery. The physiotherapy protocol consisted of peroneal muscle strengthening using Thera-band, gastro-soleus stretching, bipedal calf raises, single limb stance, step down with single limb, and box hop/quadrant hop. Outcome measurement was performed 1 day before MBP, 4 weeks and 6 weeks after surgery. The visual analogue scale, AOFAS ankle hindfoot scale, Karlsson scale, Foot and Ankle Ability Measure (FAAM-activities of daily living: ADL and FAAM-sports), Lower Extremity Functional Scale (LEFS), and ankle ROM were investigated. All data were statistically analyzed. Results: The mean ages were 27.0 ± 8.46(P), 29.7 ± 7.54(N), and there were 4 (28.6%, P) and 6 (42.9%, N) males. There were no statistical differences between the two groups in age and gender distribution. As shown in the attached table comparing clinical outcomes between the two groups, AOFAS ankle hindfoot scale, Karlsson scale, FAAM-ADL, and LEFS 1 day before MBP were statistically significantly higher in group P than in group N. Compared to group N, group P improved ankle inversion and eversion 1 day before MBP (p < 0.05 each). Although there was no statistical significance, the mean of Karlsson scale, FAAM-ADL subscale, FAAM-sports subscale, and LEFS were all maintained higher in group P than in group N from before MBP to 6 weeks after surgery. Conclusion: Our findings demonstrated the importance of functional recovery along with mechanical stability in the treatment of CLAI. Functional scores tended to be maintained higher in group P than in group N from preoperative to postoperative follow-up period. However, the number of participants included in our study was relatively small at 28. Larger studies with long-time follow- up will be needed. In conclusion, a structured prehabilitation may improve functional recovery when performing MBP for CLAI.

Abstract In this study, we aimed to evaluate the association between general and central obesity, and their changes with risk of knee osteoarthritis (OA) using retrospective cohort data collected from the Korean National Health Insurance Service. We studied 1,139,463 people aged 50 and over who received a health examination in 2009. To evaluate the association between general and/or central obesity and knee OA risk, a Cox proportional hazard models were used. Additionally, we investigate knee OA risk according to the change in obesity status over 2 years for subjects who had undergone health examinations for 2 consecutive years. General obesity without central obesity (HR 1.281, 95% CI 1.270–1.292) and central obesity without general obesity (HR 1.167, 95% CI 1.150–1.184) were associated with increased knee OA risk than the comparison group. Individuals with both general with central obesity had the highest risk (HR 1.418, 95% CI 1.406–1.429). This association was more pronounced in women and younger age group. Remarkably, the remission of general or central obesity over two years was associated with decreased knee OA risk (HR 0.884; 95% CI 0.867–0.902; HR 0.900; 95% CI 0.884–0.916, respectively). The present study found that both general and central obesity were associated with increased risk of knee OA and the risk was highest when the two types of obesity were accompanied. Changes in obesity status have been confirmed to alter the risk of knee OA.

Abstract We aimed to determine whether knee OA is associated with CVD risk and all-cause death and to evaluate whether the association differs by exercise behavior. We used Korea National Health Insurance Service (KNHIS) database and included 201,466 participants (7572 subjects diagnosed with knee OA) who underwent health screening between 2009 and 2015. Those who had been diagnosed with knee OA or CVD before the index year were excluded. Cox proportional hazard models were used after adjusting for sociodemographic and CVD risk factors to evaluate the association between knee OA and CVD risk and all-cause death. Stratification analysis was further performed to determine the effect of exercise behavior on this relationship. During a median follow-up of 7.06 ± 2.24 years, 8743 CVD (2510 MI and 6553 stroke) cases developed. Individuals with knee OA had increased risks of CVD [hazard ratio (HR) 1.26, 95% confidence interval (CI) 1.15–1.38], myocardial infarction (MI) (HR 1.20, 95% CI 1.00–1.44), and stroke (HR 1.29, 95% CI 1.16–1.43) compared with those without knee OA. Those with knee OA who did not exercise had an increased risk of CVD (HR 1.25, 95% CI 1.11–1.40), whereas no significant increased CVD risk was observed in those with knee OA who exercised at least once a week (HR 1.11, 95% CI 0.96–1.28). There was no association between knee osteoarthritis and all-cause death. Knee OA was independently associated with an increased risk of CVD. Lack of exercise might have a synergistic adverse effect on the association between knee OA and CVD.

Abstract Enchondroma is the most common bone tumor in the hand. While standard surgical procedure is intra-lesional excision and bone grafting, there is a dispute between allogeneic bone, autogenous bone, and synthetic bone substitute grafting. Diverse adjuvant treatments have been introduced to reduce recurrence, but results are mixed with controversies. Meanwhile, whether existing descriptive classification could predict treatment outcome remains unclear. Thus, we reviewed patients with solitary enchondroma of the hand who underwent simple curettage followed by allogeneic cancellous bone chip impaction grafting. Eighty-eight patients with more than 5 years of follow-up were enrolled. Demographic data, local recurrence, and complications were reviewed. Duration of consolidation and the difference according to Takigawa classification were assessed. Range of motion (ROM), and functional scores were also evaluated. There were 51 women and 37 men, with a mean age of 37.9 years. Mean follow-up was 10.2 years. Recurrence occurred only in one patient. There was no complication. Mean postoperative total active motions of fingers and thumb were 239° and 132.9°. Mean modified Disabilities of the Arm, Shoulder, Hand score, and Musculoskeletal Tumor Society Score were 1.63, and 99.2 at the last follow-up. Consolidation, ROM, and functional scores according to Takigawa classification showed no significant differences. This study suggests that simple curettage with impaction grafting of allogeneic cancellous bone chip is a feasible method for treating solitary enchondromas involving short tubular bone of the hand with good long-term outcomes. Postoperative recurrence and complication rates were very low. Radiographic and clinical results were good regardless of the previous radiological classification.

It is important to estimate the exact depth from 2D images, and many studies have been conducted for a long period of time to solve depth estimation problems. Recently, as research on estimating depth from monocular camera images based on deep learning is progressing, research for estimating accurate depths using various techniques is being conducted. However, depth estimation from 2D images has been a problem in predicting the boundary between objects. In this paper, we aim to predict sophisticated depths by emphasizing the precise boundaries between objects. We propose a depth estimation network with encoder–decoder structures using the Laplacian pyramid and local planar guidance method. In the process of upsampling the learned features using the encoder, the purpose of this step is to obtain a clearer depth map by guiding a more sophisticated boundary of an object using the Laplacian pyramid and local planar guidance techniques. We train and test our models with KITTI and NYU Depth V2 datasets. The proposed network constructs a DNN using only convolution and uses the ConvNext networks as a backbone. A trained model shows the performance of the absolute relative error (Abs_rel) 0.054 and root mean square error (RMSE) 2.252 based on the KITTI dataset and absolute relative error (Abs_rel) 0.102 and root mean square error 0.355 based on the NYU Depth V2 dataset. On the state-of-the-art monocular depth estimation, our network performance shows the fifth-best performance based on the KITTI Eigen split and the eighth-best performance based on the NYU Depth V2.

Transtibial amputation is the preferred strategy for treating a diabetic foot with an infection and necrosis. However, if a tibial intramedullary nail was previously inserted into the ipsilateral lower extremity, the nail must be removed to perform the transtibial amputation. In this special situation, the removal of the tibial intramedullary nail can cause various complications after transtibial amputation. We present a case and surgical technique report of a 46-year-old male with an uncontrolled diabetic foot with tibial intramedullary nail insertion. With the nail and ankle fixed by distal interlocking screws, a below-knee amputation was performed by removing the nail and the amputated limb together. This surgical method is expected to reduce postoperative complications such as infections and patella instability after the amputation of a diabetic foot.

TiNi shape memory alloy was used to recover the shape of transformed objects using its shape memory effect. This shape memory effect plays an important role inside metal matrix composite. A composite using shape memory alloy has a large advantage that can control crack initiation and propagation, when compared with other composites due to the shape memory effect of shape memory alloy under high temperature. In this study, TiNi/Al6061 and TiNi/2024 shape memory composites were fabricated by the hot press method, and a fatigue test was performed to evaluate the fatigue damage for the shape memory composites under room temperature and high temperature. The relationship of the crack growth rate and the stress intensity factor for these shape memory composites were clarified at both temperature conditions. The delay effect of crack propagation due to shape memory alloy was also evaluated under high temperature. In addition, an acoustic emission technique was used to evaluate the crack initiation and the control of crack propagation by shape memory effect under fatigue test nondestructively. The relationship between AE parameter and the degree of fatigue damage of the shape memory composites was discussed. [ABSTRACT FROM AUTHOR]