Histiocytic neoplasms are rare diseases involving macrophages, dendritic cells, and monocytes. They include Langer‑ hans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), Rosai-Dorfman disease (RDD), juvenile xanthogranuloma (JXG), and histiocytic sarcoma. Histiocytic neoplasms are characterized by varied clinical courses and prognoses, necessitating a nuanced understanding of their classification, epidemiology, and clinical manifestations. Genetic studies have revealed somatic mutations, predominantly in the MAPK pathway, suggesting a clonal neoplastic nature.This review covers the current understanding of histiocytic neoplasms, molecular pathophysiology, with a particular focus on mutations in genes such as BRAF, MAP2K1, and the PI3K-AKT signaling pathways, and evolving treatment strategies, especially focusing on LCH, ECD, RDD, and JXG. The treatment landscape has evolved with advancements in targeted therapies. BRAF inhibitors, such as vemurafenib and dabrafenib, have shown efficacy, especially in highrisk LCH cases; however, challenges remain, including relapse post-treatment discontinuation, and adverse effects.MEK inhibitors have also demonstrated effectiveness, and cobimetinib has recently been approved for use in adults.Further research is required to determine the optimal treatment duration and strategies for managing therapy inter‑ ruptions. Advancements in molecular genetics and targeted therapies have revolutionized the management of histio‑ cytic neoplasms. However, ongoing research is crucial for optimizing patient outcomes.

Histiocytic neoplasms are rare diseases involving macrophages, dendritic cells, and monocytes. They include Langer‑ hans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), Rosai-Dorfman disease (RDD), juvenile xanthogranuloma (JXG), and histiocytic sarcoma. Histiocytic neoplasms are characterized by varied clinical courses and prognoses, necessitating a nuanced understanding of their classification, epidemiology, and clinical manifestations. Genetic studies have revealed somatic mutations, predominantly in the MAPK pathway, suggesting a clonal neoplastic nature.This review covers the current understanding of histiocytic neoplasms, molecular pathophysiology, with a particular focus on mutations in genes such as BRAF, MAP2K1, and the PI3K-AKT signaling pathways, and evolving treatment strategies, especially focusing on LCH, ECD, RDD, and JXG. The treatment landscape has evolved with advancements in targeted therapies. BRAF inhibitors, such as vemurafenib and dabrafenib, have shown efficacy, especially in highrisk LCH cases; however, challenges remain, including relapse post-treatment discontinuation, and adverse effects.MEK inhibitors have also demonstrated effectiveness, and cobimetinib has recently been approved for use in adults.Further research is required to determine the optimal treatment duration and strategies for managing therapy inter‑ ruptions. Advancements in molecular genetics and targeted therapies have revolutionized the management of histio‑ cytic neoplasms. However, ongoing research is crucial for optimizing patient outcomes.

Histiocytic neoplasms are rare diseases involving macrophages, dendritic cells, and monocytes. They include Langer‑ hans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), Rosai-Dorfman disease (RDD), juvenile xanthogranuloma (JXG), and histiocytic sarcoma. Histiocytic neoplasms are characterized by varied clinical courses and prognoses, necessitating a nuanced understanding of their classification, epidemiology, and clinical manifestations. Genetic studies have revealed somatic mutations, predominantly in the MAPK pathway, suggesting a clonal neoplastic nature.This review covers the current understanding of histiocytic neoplasms, molecular pathophysiology, with a particular focus on mutations in genes such as BRAF, MAP2K1, and the PI3K-AKT signaling pathways, and evolving treatment strategies, especially focusing on LCH, ECD, RDD, and JXG. The treatment landscape has evolved with advancements in targeted therapies. BRAF inhibitors, such as vemurafenib and dabrafenib, have shown efficacy, especially in highrisk LCH cases; however, challenges remain, including relapse post-treatment discontinuation, and adverse effects.MEK inhibitors have also demonstrated effectiveness, and cobimetinib has recently been approved for use in adults.Further research is required to determine the optimal treatment duration and strategies for managing therapy inter‑ ruptions. Advancements in molecular genetics and targeted therapies have revolutionized the management of histio‑ cytic neoplasms. However, ongoing research is crucial for optimizing patient outcomes.

Background: The application of artificial intelligence and large language models in the medical field requires an evaluation of their accuracy in providing medical information. This study aimed to assess the performance of Chat Generative Pre-trained Transformer (ChatGPT) models 3.5 and 4 in solving orthopedic board-style questions. Methods: A total of 160 text-only questions from the Orthopedic Surgery Department at Seoul National University Hospital, conforming to the format of the Korean Orthopedic Association board certification examinations, were input into the ChatGPT 3.5 and ChatGPT 4 programs. The questions were divided into 11 subcategories. The accuracy rates of the initial answers provided by Chat GPT 3.5 and ChatGPT 4 were analyzed. In addition, inconsistency rates of answers were evaluated by regenerating the responses. Results: ChatGPT 3.5 answered 37.5% of the questions correctly, while ChatGPT 4 showed an accuracy rate of 60.0% (p < 0.001). ChatGPT 4 demonstrated superior performance across most subcategories, except for the tumor-related questions. The rates of inconsistency in answers were 47.5% for ChatGPT 3.5 and 9.4% for ChatGPT 4. Conclusions ChatGPT 4 showed the ability to pass orthopedic board-style examinations, outperforming ChatGPT 3.5 in accuracy rate. However, inconsistencies in response generation and instances of incorrect answers with misleading explanations require caution when applying ChatGPT in clinical settings or for educational purposes.

Background: Patient-reported satisfaction following total knee arthroplasty (TKA) can be affected by various factors. This study aimed to assess patient satisfaction rates and identify factors related to patients, surgery, and postoperative knee motion associated with satisfaction in posterior-stabilized TKA among Asian patients. Methods: A retrospective cross-sectional study was conducted in patients with primary osteoarthritis who underwent TKA and had a follow-up period of over 2 years. Patient satisfaction was measured using a 5-point Likert scale, and the patients were divided into satisfied and dissatisfied groups. The factors potentially affecting satisfaction were collected, including demographics, comorbidities, surgical options, and knee motion. Univariate and multivariate regression analyses were performed. Results: Of the 858 patients included, 784 (91.4%) were satisfied and 74 (8.6%) were dissatisfied. Fixed-bearing implants and higher postoperative knee flexion angles were associated with satisfaction (odds ratio [OR], 2.366; p = 0.001 and OR, 1.045; p < 0.001, respectively), whereas cerebrovascular disease was related to dissatisfaction (OR, 0.403; p = 0.005). The regression model demonstrated moderate predictability (R2 = 0.112). Conclusions Fixed-bearing implants and higher postoperative knee flexion angles were associated with patient satisfaction following TKA, whereas cerebrovascular disease was associated with dissatisfaction. The identification of these factors could help improve surgical outcomes and patient satisfaction following TKA.