Feasibility Study of Federated Learning on the Distributed Research Network of OMOP Common Data Model / 대한의료정보학회지

Objectives@#Since protecting patients’ privacy is a major concern in clinical research, there has been a growing need for privacy-preserving data analysis platforms. For this purpose, a federated learning (FL) method based on the Observational Medical Outcomes Partnership (OMOP) common data model (CDM) was implemented, and its feasibility was demonstrated. @*Methods@#We implemented an FL platform on FeederNet, which is a distributed clinical data analysis platform based on the OMOP CDM in Korea. We trained it through an artificial neural network (ANN) using data from patients who received steroid prescriptions or injections, with the aim of predicting the occurrence of side effects depending on the prescribed dose. The ANN was trained using the FL platform with the OMOP CDMs of Kyung Hee University Medical Center (KHMC) and Ajou University Hospital (AUH). @*Results@#The area under the receiver operating characteristic curves (AUROCs) for predicting bone fracture, osteonecrosis, and osteoporosis using only data from each hospital were 0.8426, 0.6920, and 0.7727 for KHMC and 0.7891, 0.7049, and 0.7544 for AUH, respectively. In contrast, when using FL, the corresponding AUROCs were 0.8260, 0.7001, and 0.7928 for KHMC and 0.7912, 0.8076, and 0.7441 for AUH, respectively. In particular, FL led to a 14% improvement in performance for osteonecrosis at AUH. @*Conclusions@#FL can be performed with the OMOP CDM, and FL often shows better performance than using only a single institution's data. Therefore, research using OMOP CDM has been expanded from statistical analysis to machine learning so that researchers can conduct more diverse research.

Digital Tomosynthesis versus Conventional Radiography for Evaluating Osteonecrosis of the Femoral Head

Objective@#The aim of this study was to compare the diagnostic performances of digital tomosynthesis (DTS) and conventional radiography in detecting osteonecrosis of the femoral head (ONFH) using computed tomography (CT), as the reference standard and evaluate the diagnostic reproducibility of DTS. @*Materials and Methods@#Forty-five patients (24 male and 21 female; age range, 25–77 years) with clinically suspected ONFH underwent anteroposterior radiography, DTS, and CT. Two musculoskeletal radiologists independently evaluated the presence and type of ONFH. The diagnostic performance of radiography and DTS in detecting the presence of ONFH and determining the types of ONFH were evaluated. The interobserver and intraobserver reliabilities of each imaging modality were analyzed using Cohen’s kappa. @*Results@#DTS had higher sensitivity (89.4%–100% vs. 74.5%–76.6%) and specificity (97.3%–100% vs. 78.4%–83.8%) for ONFH detection than radiography. DTS showed higher performance than radiography in identifying the subtypes of ONFH with statistical significance in one reader (type 1, 100% vs. 30.8%, p = 0.004; type II, 97.1% vs. 73.5%, p = 0.008). The interobserver agreement was excellent for DTS and moderate for radiography (kappa of 0.86 vs. 0.57, respectively). The intraobserver agreement for DTS was higher than that of radiography (kappa of 0.96 vs. 0.69, respectively). @*Conclusion@#DTS showed higher diagnostic performance and reproducibility than radiography in detecting ONFH. DTS may be used as a first-line diagnostic modality instead of radiography for patients suspected of having ONFH.

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

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.

Diagnosis and Treatment of Inflammatory Joint Disease / 대한고관절학회지

Arthritis damages the cartilage within joints, resulting in degenerative changes, including loss of function and joint instability. Ankylosing spondylitis (AS) is a chronic inflammatory condition affecting the spine and bone-to-tendon attachment area within the sacroiliac joint leading to back pain and progressive spinal stiffness. In the final stages, AS causes hyperkyphosis-a condition closely tied to the human leukocyte antigen-B27 gene. Rheumatoid arthritis is a chronic, systemic autoimmune disease characterized by the simultaneous inflammation of the synovium of multiple joints, leading to joint damage (e.g., destruction, deformation and disability). In the past, nonsteroidal anti-inflammatory drugs or conventional disease-modifying antirheumatic drug (DMARDs) have been used for the treatment of these autoimmune diseases, but biologic DMARDs have recently been introduced with excellent results. Gout is a chronic inflammatory disease that causes an alteration of joints resulting in severe pain. Specifically, gout is associated with an accumulation of uric acid within the body resulting from dysregulated purine metabolism, causing recurrent paroxysmal inflammation in the joints. Allopurinol and febuxostat are the primary treatment options for individuals with gout. It is necessary to have an accurate understanding of the pathogenesis, pathological ecology and treatment of AS, rheumatoid arthritis, and gouty arthritis, which are the representative diseases that may cause inflammatory arthritis.

Risk Factors Associated with Dislocation after Bipolar Hemiarthroplasty in Elderly Patients with Femoral Neck Fracture / 대한고관절학회지

PURPOSE: We investigated the incidence and time of dislocation and other factors associated with dislocation of bipolar hemiarthroplasty related to the treatment of femoral neck fracture in old age patients. MATERIALS AND METHODS: Between January 2002 and April 2014, 498 femoral neck fractures (467 patients) were treated with bipolar hemiarthroplasty and included in this study. All surgeries were performed using the postero-lateral approach. The incidence of dislocation was investigated. A comparative analysis between a control group and dislocation group was performed with respect to patient factors including age, gender, body mass index, comorbidities, the ASA (American Society of Anesthesiologists) score, mental status and center-edge angle, and surgical factors including type of femoral stem, leg length discrepancy, femoral offset and method of short external rotator (SER) reconstruction. RESULTS: The incidence of dislocation was 3.8%, and the dislocation occurred on average 2.2 months (range, 0.6-6.5 months) after operation. No difference in patient-related factors was observed between the two groups. However, a smaller center edge (CE) angle was observed in the dislocation group (42.1°±3.2° vs. 46.9°±5.4°, P<0.001), and significantly lower incidence of dislocation was observed in tendon to bone repair group (0.7% vs 7.8%, P<0.001). CONCLUSION: SERs should be repaired using the tendon-to-bone repair method to reduce dislocation rate in elderly patients who undergo bipolar hemiarthroplasty using the postero-lateral approach due to femoral neck fracture. In addition, patients with smaller CE angle should be carefully monitored due to high incidence of dislocation.

Strategies for prevention of elderly hip fracture

One of the severe complications of osteoporosis is hip fracture, which can occur even with minimal trauma. This burdensome complication is closely associated with an increased risk of mortality, impairment, and decreased quality of life, resulting in enormous health care costs. Hip fracture is significantly related to a previous history of fracture, and its risk can be determined by bone strength and type of trauma-with falls posing an especially high risk. The first step to prevent osteoporotic fracture is the detection of osteoporosis, relying on the quantification of bone density via imaging techniques such as dual-energy X-ray absorptiometry and quantitative computed tomography. In addition, various preventive strategies have been introduced. Above all, proper supplementation of vitamin D, protein, milk, calcium, folic acid, vitamin B12, and vitamin K is beneficial for prevention of osteoporotic fracture for elderly patients who are susceptible to nutrition imbalance. For elderly patients, rehabilitation is considered to be crucial for increasing function and improving patients' activities of daily living as well. A fall-preventive intervention program has been known to be the effective and useful way for elderly patients to reduce fall risk, which can be assessed with the 'timed up and go' test. A home hazard modification program such as wearing anti-slip shoe devices has been proven to decrease fall risk in community-living elderly. Therefore, diagnosis of osteoporosis, proper supplementation of nutrients, rehabilitation, and a fall-preventive intervention program are essential components in the prevention of hip fracture.

Perioperative Pain Management in Total Hip Arthroplasty: Korean Hip Society Guidelines / 대한고관절학회지

Effective perioperative pain management techniques and accelerated rehabilitation programs can improve health-related quality of life and functional status of patients after total hip arthroplasty. Traditionally, postoperative analgesia following arthroplasty was provided by intravenous patient-controlled analgesia or epidural analgesia. Recently, peripheral nerve blockade has emerged alternative analgesic approach. Multimodal analgesia strategy combines analgesics with different mechanisms of action to improve pain management. Intraoperative periarticular injection of multimodal drugs is one of the most important procedures in perioperative pain control for total hip arthroplasty. The goal of this review article is to provide a concise overview of the principles of multimodal pain management regimens as a practical guide for the perioperative pain management for total hip arthroplasty.