An air blow gun is one of the most common pneumatic tools found at industrial sites and entrances of mountain trails in South Korea. It is used for spraying high-pressure air to dust off surfaces and clothes, and to inject air into tubes. There have been many reported cases of injuries and deaths associated with air blow guns. The victim died by placing the nozzle of an air blow gun, installed on an outdoor sports field, into her nose, and pulling the trigger. An autopsy ascribed her death to pneumothorax. Numerous accidents associated with air blow guns have been reported in the media. However, the use of an air blow gun has not been the subject of a suicide case study in forensic literature. To our knowledge, this is the first case report on suicide using an air blow gun. Stronger public safety warnings stressing the potentially fatal outcomes from careless usage of air blow guns are required.

Purpose: To develop a 3D magnetic resonance fingerprinting (MRF) method for application in high resolution knee cartilage PD, T1 , T2 mapping. Materials and Methods: A novel 3D acquisition trajectory with golden-angle rotating radial in kxy direction and interleaved echo planar imaging (EPI) acquisition in the kz direction was implemented in the MRF framework. A centric order was applied to the interleaved EPI acquisition to reduce Nyquist ghosting artifact due to field inhomogeneity. For the reconstruction, singular value decomposition (SVD) compression method was used to accelerate reconstruction time and conjugate gradient sensitivity-encoding (CG-SENSE) was performed to overcome low SNR of the high resolution data. Phantom experiments were performed to verify the proposed method. In vivo experiments were performed on 6 healthy volunteers and 2 early osteoarthritis (OA) patients. Results: In the phantom experiments, the T1 and T2 values of the proposed method were in good agreement with the spin-echo references. The results from the in vivo scans showed high quality proton density (PD), T1 , T2 map with EPI echo train length (NETL = 4), acceleration factor in through plane (Rz = 5), and number of radial spokes (Nspk = 4). In patients, high T2 values (50-60 ms) were seen in all transverse, sagittal, and coronal views and the damaged cartilage regions were in agreement with the hyper-intensity regions shown on conventional turbo spin-echo (TSE) images. Conclusion The proposed 3D MRF method can acquire high resolution (0.5 mm3 ) quantitative maps in practical scan time (~ 7 min and 10 sec) with full coverage of the knee (FOV: 160 × 160 × 120 mm3 ).

Purpose: To develop a 3D magnetic resonance fingerprinting (MRF) method for application in high resolution knee cartilage PD, T1 , T2 mapping. Materials and Methods: A novel 3D acquisition trajectory with golden-angle rotating radial in kxy direction and interleaved echo planar imaging (EPI) acquisition in the kz direction was implemented in the MRF framework. A centric order was applied to the interleaved EPI acquisition to reduce Nyquist ghosting artifact due to field inhomogeneity. For the reconstruction, singular value decomposition (SVD) compression method was used to accelerate reconstruction time and conjugate gradient sensitivity-encoding (CG-SENSE) was performed to overcome low SNR of the high resolution data. Phantom experiments were performed to verify the proposed method. In vivo experiments were performed on 6 healthy volunteers and 2 early osteoarthritis (OA) patients. Results: In the phantom experiments, the T1 and T2 values of the proposed method were in good agreement with the spin-echo references. The results from the in vivo scans showed high quality proton density (PD), T1 , T2 map with EPI echo train length (NETL = 4), acceleration factor in through plane (Rz = 5), and number of radial spokes (Nspk = 4). In patients, high T2 values (50-60 ms) were seen in all transverse, sagittal, and coronal views and the damaged cartilage regions were in agreement with the hyper-intensity regions shown on conventional turbo spin-echo (TSE) images. Conclusion The proposed 3D MRF method can acquire high resolution (0.5 mm3 ) quantitative maps in practical scan time (~ 7 min and 10 sec) with full coverage of the knee (FOV: 160 × 160 × 120 mm3 ).

To date, family medicine and internal medicine fields have been responsible for defining, researching, and development of treatments for sarcopenia, focusing mainly on diabetes and metabolic diseases. Therefore, application of current guidelines for diagnosis of sarcopenia which differ according to continent to patients with hip fractures in the orthopedic field is difficult. The purpose of this review was to understand the recent consensus on the definition and diagnosis of sarcopenia and to highlight the importance of research and future research opportunities on the management of sarcopenia in patients with hip fractures by orthopedic surgeons. The global prevalence of sarcopenia in patients with hip fractures is statistically significant. Despite establishment of various therapeutic and diagnostic criteria for osteoporosis in the clinical field, there are no clear, useful diagnostic criteria for sarcopenia in the clinical field. In particular, few studies on the evaluation and treatment of sarcopenia in patients with hip fractures have been reported. In addition, the quality of life of postoperative patients with hip fractures could be significantly improved by development of precise assessment for muscle regeneration and rehabilitation in the operating room.

Background: The objective of this study was to analyze the direct medical expenses of a vertebral fracture cohort (VC) and a matched cohort (MC) over 5 years preceding and following the fracture, analyze the duration of the rise in medical expenses due to the fracture, and examine whether the expenses vary with age group, utilizing a national claims database. Methods: Subjects with vertebral fractures and matched subjects were chosen from the National Health Insurance Service Sample cohort (NHIS-Sample) of South Korea. Patients with vertebral fractures were either primarily admitted to acute care hospitals (index admissions) or those who received kyphoplasty or vertebroplasty during the follow-up period (2002–2015). A risk-set matching was performed using 1 : 5 random sampling to simulate a real-world situation. Individual-level direct medical expenses per quarter were calculated for 5 years prior and subsequent to the vertebral fracture. In this analysis using a comparative interrupted time series design, we examined the direct medical expenses of a VC and an MC. Results: A total of 3,923 incident vertebral fracture patients and 19,615 matched subjects were included in this study. The mean age was 75.5 ± 7.4 years, and 69.5% were women. The mean difference in medical expenses between the two groups increased steadily before the fracture. The medical expenses of the VC peaked in the first quarter following the fracture. The cost changes were 1.82 times higher for the VC than for the MC (95% confidence interval, 1.62–2.04; p < 0.001) in the first year. Subsequently, there were no differential changes in medical expenses between the two groups (p > 0.05). In the < 70-year subgroup, there were no differential changes in medical expenses between the two groups (p > 0.05). However, in the ≥ 80-year subgroup, the cost changes for the VC were higher than those for the MC up to 5 years after time zero. Conclusions Based on our study results, we suggest that health and medical policies for vertebral fractures should be designed to last up to approximately 1 year after the fracture. Health policies should be differentiated according to age group.

Total joint arthroplasty (TJA) is a surgical procedure, in which parts of damaged joints are removed and replaced with a prosthesis. The main indication of TJA is osteoarthritis, and the volume of TJA is rising annually along with the increase of aged population. Hip and knee are the most common joints, in which TJAs are performed. The TJA prosthesis is composed of metal, plastic, or ceramic device. Even though TJA is the most successful treatment for end-stage osteoarthritis, it is associated with various complications, and periprosthetic joint infection (PJI) is the most serious complication after TJA. With the increasing volume of TJAs, there is a simultaneous rise in the incidence of PJI. Contamination of the surgical wound and the adherence of bacteria to the surface of prosthetic component represent the initial step in the pathogenesis of PJI. The main sources of the contamination are 1) patient's own flora, 2) droplets in the operation room air, and 3) surgical gloves and instruments. Even though modern techniques have markedly reduced the degree of contamination, TJAs cannot be done in completely germ-free conditions and some degree of contamination is inevitable in all surgical procedures. However, not all contamination leads to PJI. It develops when the burden of contamination exceeds the immune threshold or the colony forming units (CFUs) and various factors contribute to a decrease in the CFU level. Surgeons should be aware of the germ burden/CFU concept and should monitor sources of contamination to maintain the germ burden below the CFU to prevent PJI.

Purpose: This study examined the bony morphological changes to analyze the factors affecting bony union in the treatment of elderly femoral shaft fractures with varus bowing using piriformis fossa insertion intramedullary nailing. Materials and Methods: This study included 26 patients over 60 years of age, who were admitted for femoral shaft fractures between January 2005 and December 2014 and treated with piriformis fossa insertion intramedullary nailing. Age, sex, height, weight, bone mineral density, injury mechanism, fracture type, diameter and length of the nail, postoperative lengthening of the femur, postoperative change in varus angle, contact between the lateral and anterior cortex, and the gap between the fracture line and the bony union were checked. The patients were divided into a varus group and nonvarus group, as well as a bone union group and nonunion group. Logistic regression analysis was performed to analyze the factors affecting nonunion. Results: The patients were classified into 11 in the varus group and 15 in the non-varus group and 24 in the union group and 2 in the nonunion group. The varus group showed a larger increase in leg length and varus angle reduction than the non-varus group (p<0.05). The union group had more contact with the lateral cortical bone than that of the nonunion group (p<0.05). The factor affecting bone union in regression analysis was contact of the lateral cortical bone (p<0.05). Conclusion Treatment of a femoral shaft fracture in elderly patients with a varus deformity of the femur using piriformis fossa insertion intramedullary nail increases the length of the femur and decreases the varus deformity. For bony union, the most important thing during surgery is contact of the lateral cortical bone with the fracture site.

Background: The purpose of this study was to investigate the change in the incidence rate, length of hospital stay (LOS), in-hospital mortality rate, and surgical method of hip fractures during the coronavirus disease 2019 (COVID-19) pandemic in South Korea where lockdown restrictions were not implemented. Methods: We calculated the expected values of the incidence of hip fractures, in-hospital mortality and LOS of hip fracture patients in 2020 (COVID period) based hip fracture database of the Korean National Health Insurance Review and Assessment (HIRA) during a 9-year period from 2011 to 2019 (pre-COVID period). A generalized estimating equation model with Poisson distribution and logarithmic link function was used to estimate adjusted annual percent change (PC) of incidence rate and 95% confidence intervals (CIs). Then, we compared the annual incidence, in-hospital mortality rate and LOS in 2020 with the expected values. Results: The overall incidence rate of hip fracture in 2020 was not significantly different from the expected value (PC, −5%; 95% CI, −13 to 4; P = 0.280). In women, the incidence rate of hip fracture in age groups over 70 years was smaller than the predicted value (P < 0.001). The in-hospital mortality rate was not significantly different from the expected value (PC, 5%; 95% CI, −8 to 19; P = 0.461). The mean LOS was larger than the expected value by 2% (PC, 2%; 95% CI, 1 to 3; P < 0.001). In intertrochanteric fracture, the proportion of internal fixation was smaller than the predicted value by 2% (PC, −2%; 95% CI, −3 to −1; P < 0.001), and that of hemiarthroplasty was larger than the predicted value by 8% (PC, 8%; 95% CI, 4 to 14; P < 0.001). Conclusions In 2020, the incidence rate of hip fracture did not significantly decrease, and inhospital mortality rate did not significantly increase compared to the expected rates, which were projected based on the HIRA hip fracture data from 2011 to 2019. Only LOS increased slightly.

Purpose: The purpose of this study was to compare patients who had undergone spine surgery (SS) and hip arthroplasty surgery (HAS) and to analyze how medical policies drawn from “The Evaluation of the Appropriate Use of Prophylactic Antibiotics” have affected length of hospital stay (LOS), direct medical costs (DMC), and the duration of antibiotics use in Korea. Materials and Methods: This retrospective nationwide study identified subjects from the Korean National Health Insurance Review and Assessment Service database from January, 2011 to December, 2018. Evaluation of HAS (control group) was implemented in 2007, and that for SS (case group) was conducted for the first time in 2014 (intervention time). In our comparative interrupted time series analysis, we compared DMC, LOS, and use of antibiotics between both groups. Results: 177468 patients who underwent SS and 89372 patients who underwent HAS were included in the study. In 2016, DMC increased for HAS, compared to SS, by 1.03 times (p=0.041). However, cost changes during other observational periods for SS were not higher than those for HAS (p>0.05). SS incurred a reduced LOS of 3% in the first 2 years (p<0.05). Thereafter, LOS changes in SS were not smaller than those in HAS. A decrease in the usage of total antibiotics and broad spectrum antibiotics was observed for 5 years. Conclusion This medical policy was effective in terms of reducing usage and duration of antibiotics use, especially in the first 2 years after the implementation of the policy.

Background: The objective of our study was to analyze the postoperative direct medical expenses and hospital lengths of stay (LOS) of elderly patients who had undergone either hemiarthroplasty (HA) or total hip arthroplasty (THA) for femoral neck fractures and to determine the indication of THA by comparing those variables between the 2 groups by time. Methods: In this comparative large-sample cohort study, we analyzed data from the 2011 to 2018 Korean National Health Insurance Review and Assessment Service database. The included patients were defined as elderly individuals aged 60 years or older who underwent HA or THA for a femoral neck fracture. A 1:1 risk-set matching was performed on the propensity score, using a nearest-neighbor matching algorithm with a maximum caliper of 0.01 of the hazard components. In comparative interrupted time series analysis, time series were constructed using the time unit of one-quarter before and after 3 years from time zero. For the segmented regression analysis, we utilized a generalized linear model with a gamma distribution and logarithmic link function. Results: A total of 4,246 patients who received THA were matched and included with 4,246 control patients who underwent HA. Although there was no statistically significant difference in direct medical expense and hospital LOS for the first 6 months after surgery, direct medical expenses and hospital LOS in THA were relatively reduced compared to the HA up to 24 months after surgery (p < 0.05). In the subgroup analysis, the THA group’s hospital LOS decreased significantly compared to that of the HA group during the 7 to 36 months postoperative period in the 65 ≤ age < 80 age group (p < 0.05). Direct medical expenses of the THA group significantly decreased compared to those of the HA group during the period from 7 to 24 months after surgery in the men group (p < 0.05). Conclusions When performing THA in elderly patients with femoral neck fractures, the possibility of survival for at least 2 years should be considered from the perspective of medical expense and medical utilization. Additionally, in healthy and active male femoral neck fracture patients under the age of 80 years, THA may be more recommended than HA.