The video head impulse test (vHIT) is an advanced diagnostic tool that provides objective, quantitative assessment of vestibulo-ocular reflex function across all six semicircular canals (SCCs). Its relevance in the aerospace domain is particularly notable, as the test operates within the 1–5 Hz frequency range—closely matching natural human head movements—and enables independent evaluation of vertical SCCs, which are sensitive to gravitational forces. This review introduces the principles of vHIT and explores its utility in quantifying vestibular function among fighter pilots.The integration of vHIT into aerospace medicine offers a practical and evidencebased approach to evaluating vestibular function and has its potential in monitoring physiological adaptation to high-speed, high-G flight conditions.

Purpose: Cardiac conduction abnormalities detected on electrocardiography are often asymptomatic and considered benign. However, in aviation medicine, they required careful evaluation because of the potential risk of sudden in-flight incapacitation. Data on their clinical significance among military aircrew are limited. Methods: We conducted a retrospective study of 2,827 Korean Air Force aircrew who underwent checkup between 2021 and 2022. Conduction abnormalities—including complete right bundle branch block, left anterior fascicular block, left posterior fascicular block, and bifascicular block—were identified on 12-lead electrocardiography.Clinical, metabolic, echocardiographic, and exercise test data were analyzed. Logistic regression assessed factors associated with conduction abnormalities. Results: Conduction abnormality was identified in 27 participants (1.0%), with left anterior fascicular block being the most common (0.5%). Participants with conduction abnormalities demonstrated normal findings on echocardiography and treadmill test. Complete separation was observed between conduction abnormalities and echocardiographic abnormalities. In univariate analysis, metabolic syndrome was associated with the presence of conduction abnormalities (odds ratio [OR] 2.53, 95% confidence interval [CI] 1.01–6.32), while age, smoking, and other metabolic parameters were not. In multivariable analysis adjusting for age, the association with metabolic syndrome remained of borderline statistical significance (adjusted OR 2.50, 95% CI 0.98–6.35). Conclusion Among military aircrew undergoing checkup, cardiac conduction abnormalities were uncommon and were not accompanied by structural or exerciseinduced cardiac abnormalities. These findings indicate that isolated, asymptomatic conduction abnormalities may occur without detectable structural heart disease in this highly selected population. Further longitudinal studies are required to clarify their long-term clinical and aeromedical significance.

Purpose: Hepatobiliary diseases such as fatty liver, gallbladder polyps, gallstones, hepatic hemangiomas, and gallbladder adenomyomatosis are frequently identified through abdominal ultrasound during health checkups. Although often asymptomatic, these findings may reflect underlying metabolic or structural abnormalities and require long-term monitoring. Fatty liver, in particular, is closely linked to metabolic syndrome and cardiovascular disease. Methods: This retrospective study analyzed abdominal ultrasound findings of 967Republic of Korea Air Force pilots aged ≥40 years who underwent routine medical checkups between January 2017 and December 2023. Data were obtained fromelectronic medical records and structured questionnaires. Fatty liver was graded using the Hamaguchi criteria, and metabolic dysfunction-associated fatty liver disease(MAFLD) was defined according to international consensus. Statistical analysesincluded t-tests, chi-square tests, and multivariate logistic regression. Results: Fatty liver was found in 29.1% of participants, with 22.0% of those cases being moderate or severe. Gallbladder polyps (16.1%), gallstones (3.5%), hepatic hemangiomas (5.8%), and gallbladder adenomyomatosis (1.3%) were also observed.MAFLD was diagnosed in 28.5% of pilots. Independent risk factors for MAFLD includedage, body mass index, waist circumference, white blood cell count, uric acid, fastingglucose, HDL cholesterol, AST/ALT ratio, and albumin. Conclusion Compared to the general population, the prevalence of MAFLD amongmilitary pilots was relatively low, likely due to strict health standards. However, the presence of moderate to severe fatty liver emphasizes the need for continued metabolic screening and preventive strategies, even in well-monitored occupational groups.

Purpose: The objective of this study was to assess the frequency and management protocols for malignant tumors among cases referred for aeromedical consultation. Methods: The research analyzed data collected from aeromedical consultations conducted between January 2014 and December 2022. Parameters examined included demographic information such as sex, age, flight crew classification, and diagnosis. Results: Out of the cases reviewed, 31 patients were diagnosed with malignant tumors, with an average age at diagnosis of 38.5 years, and a male predominance of 26 cases.The most commonly diagnosed malignancies were thyroid cancer, lung cancer, kidney cancer, stomach cancer, and colon cancer. During the initial aeromedical consultation, 22 cases were temporarily grounded while 8 received waivers. Conclusion Given the potential rise in malignant tumor incidence among flight crews due to advancements in medical technology facilitating early detection, it is imperative to emphasize regular check-ups and carefully evaluate aeromedical suitability for flying.

Background/Aims: Synchronous multiple gastric cancer (SMGC) accounts for approximately 6% to 14% of gastric cancer (GC) cases. This study aimed to identify risk factors for SMGC. Methods: A total of 14,603 patients diagnosed with GC were prospectively enrolled. Data including age, sex, body mass index, smoking, alcohol consumption, family history, p53 expression, microsatellite instability, cancer classification, lymph node metastasis, and treatment were collected. Risk factors were analyzed using logistic regression analysis between a single GC and SMGC. Results: The incidence of SMGC was 4.04%, and that of early GC (EGC) and advanced GC (AGC) was 5.43% and 3.11%, respectively. Patients with SMGC were older (65.33 years vs 61.75 years, p<0.001) and more likely to be male. Lymph node metastasis was found in 27% of patients with SMGC and 32% of patients with single GC. Multivariate analysis showed that SMGC was associated with sex (male odds ratio [OR], 1.669; 95% confidence interval [CI], 1.223 to 2.278; p=0.001), age (≥65 years OR, 1.532; 95% CI, 1.169 to 2.008; p=0.002), and EGC (OR, 1.929; 95% CI, 1.432 to 2.600; p<0.001). Survival rates were affected by Lauren classification, sex, tumor size, cancer type, distant metastasis, and venous invasion but were not related to the number of GCs. However, the survival rate of AGC with SMGC was very high. Conclusions SMGC had unique characteristics such as male sex, older age, and EGC, and the survival rate of AGC, in which the intestinal type was much more frequent, was very good (Trial registration number: NCT04973631).

Background/Aims: There are few reports regarding mixed carcinoma, defined as a mixture of glandular and poorly cohesive components, in patients with gastric cancer (GC). The aim of this study was to evaluate the proportion and characteristics of mixed carcinoma in GC patients. Methods: A total of 7,215 patients diagnosed with GC at Seoul National University Bundang Hospital were enrolled from March 2011 to February 2020. GC was divided into four groups (wellmoderately differentiated GC, poorly differentiated GC, poorly cohesive carcinoma, and mixed carcinoma). The proportion of each GC type and the clinicopathological features were analyzed and divided into early GC and advanced GC. Results: The proportion of mixed carcinoma was 10.9% (n=787). In early GC, submucosal invasion was the most common in poorly differentiated (53.7%), and mixed carcinoma ranked second (41.1%). Mixed carcinoma showed the highest proportion of lymph node metastasis in early GC (23.0%) and advanced GC (78.3%). In advanced GC, the rate of distant metastasis was 3.6% and 3.9% in well-moderately differentiated GC and mixed carcinoma, respectively, lower than that in poorly differentiated GC (6.4%) and poorly cohesive carcinoma (5.7%), without statistical significance. Conclusions Mixed carcinoma was associated with lymph node metastasis compared to other histological GC subtypes. And it showed relatively common submucosal invasion in early GC, but the rates of venous invasion and distant metastasis were lower in advanced GC. Further research is needed to uncover the mechanism underlying these characteristics of mixed carcinoma (Trial registration number: NCT04973631).

Objective: The incidence of hip fractures is increasing worldwide with the aging population, causing a challenge to healthcare systems due to the associated morbidities and high risk of mortality. After hip fractures in frail geriatric patients, existing comorbidities worsen and new complications are prone to occur. Comprehensive rehabilitation is essential for promoting physical function recovery and minimizing complications, which can be achieved through a multidisciplinary approach. Recommendations are required to assist healthcare providers in making decisions on rehabilitation post-surgery. Clinical practice guidelines regarding rehabilitation (physical and occupational therapies) and management of comorbidities/complications in the postoperative phase of hip fractures have not been developed. This guideline aimed to provide evidence-based recommendations for various treatment items required for proper recovery after hip fracture surgeries. Methods Reflecting the complex perspectives associated with rehabilitation post-hip surgeries, 15 key questions (KQs) reflecting the complex perspectives associated with post-hip surgery rehabilitation were categorized into four areas: multidisciplinary, rehabilitation, community-care, and comorbidities/complications. Relevant literature from four databases (PubMed, EMBASE, Cochrane Library, and KoreaMed) was searched for articles published up to February 2020. The evidence level and recommended grade were determined according to the grade of recommendation assessment, development, and evaluation method. Results A multidisciplinary approach, progressive resistance exercises, and balance training are strongly recommended. Early ambulation, weigh-bearing exercises, activities of daily living training, community-level rehabilitation, management of comorbidities/complication prevention, and nutritional support were also suggested. This multidisciplinary approach reduced the total healthcare cost. Conclusion This guideline presents comprehensive recommendations for the rehabilitation of adult patients after hip fracture surgery.

Objective: The incidence of hip fractures is increasing worldwide with the aging population, causing a challenge to healthcare systems due to the associated morbidities and high risk of mortality. After hip fractures in frail geriatric patients, existing comorbidities worsen and new complications are prone to occur. Comprehensive rehabilitation is essential for promoting physical function recovery and minimizing complications, which can be achieved through a multidisciplinary approach. Recommendations are required to assist healthcare providers in making decisions on rehabilitation post-surgery. Clinical practice guidelines regarding rehabilitation (physical and occupational therapies) and management of comorbidities/complications in the postoperative phase of hip fractures have not been developed. This guideline aimed to provide evidence-based recommendations for various treatment items required for proper recovery after hip fracture surgeries. Methods Reflecting the complex perspectives associated with rehabilitation post-hip surgeries, 15 key questions (KQs) reflecting the complex perspectives associated with post-hip surgery rehabilitation were categorized into four areas: multidisciplinary, rehabilitation, community-care, and comorbidities/complications. Relevant literature from four databases (PubMed, EMBASE, Cochrane Library, and KoreaMed) was searched for articles published up to February 2020. The evidence level and recommended grade were determined according to the grade of recommendation assessment, development, and evaluation method. Results A multidisciplinary approach, progressive resistance exercises, and balance training are strongly recommended. Early ambulation, weigh-bearing exercises, activities of daily living training, community-level rehabilitation, management of comorbidities/complication prevention, and nutritional support were also suggested. This multidisciplinary approach reduced the total healthcare cost. Conclusion This guideline presents comprehensive recommendations for the rehabilitation of adult patients after hip fracture surgery.

Background: The purpose of this study was to compare early clinical outcomes of manipulation under anesthesia (MUA) and arthroscopic capsular release (ACR) in patients with refractory adhesive capsulitis (AC). Methods: Thirty AC patients who underwent MUA (MUA group) were included. As a control group, thirty AC patients who underwent ACR (ACR group) were matched for age and sex with the MUA group. Visual analog scale (VAS) pain score, American shoulder and Elbow Surgeons (ASES) score, and range of motion (ROM) were evaluated preoperatively and at 3, 6, and 12 months after procedure. Results: Both groups had significant improvements in the VAS pain score, ASES score, and ROM at 12 months after procedure. VAS pain score and ASES score were significantly better in the MUA group than in the ACR group at 3 months after procedure. Mean forward flexion was significantly greater in the MUA group than in the ACR group at 3 months after procedure. Mean external rotation and internal rotation were significantly greater in the MUA group than in the ACR group at 3, 6, and 12 months after procedure. Two patients required additional steroid injections at 3 and 6 months after MUA because of recurrent stiffness with pain. Conclusions Compared with ACR, MUA provided equivalent clinical outcomes in the early period after procedure. Our study suggests that MUA is a useful option to be considered as treatment for refractory AC before choosing ACR.

BACKGROUND: There are limited data available regarding the results of reverse shoulder arthroplasty (RSA) in patients with rheumatoid arthritis (RA). We performed a systematic review of the literature to investigate the radiological and clinical outcomes after RSA in patients with RA. METHODS: A literature search for publications between 1987 and 2014 was conducted by 2 independent reviewers using PubMed, Scopus, Embase, and Cochrane Central Register of Controlled Trials. Articles were retrieved by an electronic search using keywords and their combinations. Studies that met inclusion criteria were assessed for pertinent data. RESULTS: Seven studies including 123 shoulders met the inclusion criteria. The mean age of the patients was 67.9 years and the mean follow-up period was 46.6 months. The mean Constant score and American Shoulder and Elbow Surgeons (ASES) score increased from 18.6 and 27.5 preoperatively to 58.6 and 73.7, respectively, at the final follow-up evaluation. The mean active forward flexion, abduction, and external rotation increased from 57.2°, 50.4°, and 11.4° to 127.1°, 116.7°, and 26.4°, respectively. The incidence of scapular notching was 33.7%. Twenty-seven (22.0%) of 123 shoulders had one or more complications, 12 of which (44.4%) had intraoperative or postoperative fractures. Nine shoulders (7.3%) had one or more revision surgeries. CONCLUSIONS: RSA in RA showed similar short- to mid-term results without higher complication rates as compared to RSA in cuff tear arthropathy. Although RSA can be considered a reliable treatment option in patients with RA, further large-scale studies are required to determine the long-term survival of the implant.
Arthritis, Rheumatoid* ; Arthroplasty* ; Elbow ; Follow-Up Studies ; Humans ; Incidence ; Shoulder* ; Surgeons ; Tears