
==== Front
Heliyon
Heliyon
Heliyon
2405-8440
Elsevier

S2405-8440(24)12253-0
10.1016/j.heliyon.2024.e36222
e36222
Research Article
Bibliometric and visualized analysis on hip fracture surgery and venous thromboembolism
Wang Yiteng
Wang Xin
Xu Zhendong
Li Zuohong davelee2024@163.com
⁎
Department of Sports Medicine, Dalian Municipal Central Hospital, Dalian, Liaoning, China
⁎ Corresponding author. Department of Sports Medicine, Dalian Municipal Central Hospital, No.826 Southwest Road, Shahekou District, Dalian, Liaoning, 116021, China. davelee2024@163.com
13 8 2024
30 8 2024
13 8 2024
10 16 e3622222 2 2024
9 8 2024
12 8 2024
© 2024 The Authors
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Background

Hip fractures primarily occur in older people and represent a significant public health issue due to their high incidence and mortality rate. The concurrent occurrence of venous thromboembolism (VTE) during the perioperative period exacerbates the threat to patient health.

Methods

We retrieved all articles related to hip fracture surgery and venous VTE from the Web of Science core collection database from 2000 to 2023. For bibliometric analysis, we extracted relevant information, including year of publication, country, institution, journal, impact factor, title, author, category, reference, keywords, number of citations, average number of citations, and H-index.

Results

A total of 1079 articles were retrieved, with 67 countries, 341 institutions, and 256 journals participating in research on hip fracture surgery and venous thromboembolism. The overall research showed an increasing trend. The United States, Harvard University, Injury-International Journal of The Care of The Injured, and Lassen MR are the leading country, institution, journal, and author respectively, in terms of publication. Research directions in this field mainly include the impact of preoperative anticoagulation on fracture surgery, intraoperative blood protection strategies, and postoperative prevention and treatment of VTE. Hotspots and trends in research include the relationship between direct oral anticoagulants and surgical timing, perioperative blood protection, intertrochanteric fractures, and geriatric traumatic fractures.

Conclusions

This study constructed the knowledge structure of hip fracture surgery and VTE and identified research hotspots and trends. Future research should focus on developing a prediction system for VTE in hip fracture surgery to guide individualized prevention and treatment.

Keywords

Hip fracture surgery
Venous thromboembolism
Direct oral anticoagulant
Intertrochanteric fracture
Bibliometric analysis
==== Body
pmc1 Introduction

Hip fractures pose a considerable public health concern due to a high incidence and mortality rate. The 1-year mortality rate is as high as 20 % [1]. The incidence is predicted to reach 6.26 million by 2050 [2]. Hip fractures, which include femoral neck, intertrochanteric, and subtrochanteric fractures, are among the most common fractures associated with osteoporosis in older people. Early surgery is crucial for reducing perioperative complications and the risk of death.

Individuals suffering hip fractures have an increased risk of venous thromboembolism (VTE). VTE includes deep vein thrombosis (DVT) and pulmonary embolism (PE), which are life-threatening public health problems, particularly in older patients. Preoperative DVT affects 8–34.9 % of patients with hip fractures, and the prevalence is as high as 62 % in those with delayed surgery. Advanced age, women, dementia, coronary artery disease, pulmonary disease, smoking, and a history of thrombosis are factors associated with preoperative DVT [3]. Coronary heart disease, venous thrombosis, the duration between fracture occurrence and the surgery, and blood loss are independent risk factors for postoperative DVT [4]. The actual incidence of VTE after hip fractures may be underestimated. Patients with an increased risk of bleeding are advised to take mechanical preventive measures. In individuals at high risk of thrombosis, chemical and mechanical prevention have been proven effective in preventing VTE.

Bibliometric analysis, supported by visual methods, helps researchers understand the developmental context and research hotspots in relevant academic fields. It primarily involves literature quantity, collaboration, impact, and keyword analyses. Recently, studies related to hip fracture surgery and VTE have been growing rapidly, making it essential to elucidate the status, hotspots, and trends in this field. This study aimed to comprehensively analyze published articles, construct the knowledge structure of hip fracture surgery and VTE, and explore the status of research productivity, hotspots, and trends.

2 Methods

2.1 Data collection

The Web of Science Core Collection (WOSCC) database was selected for data collection. The search query was determined as (((((TS=(hip fracture surgery)) OR TS=(intertrochanteric fracture surgery)) OR TS=(subtrochanteric fracture surgery)) OR TS=(femoral neck fracture surgery)) AND (((((((((TS=(thromb*)) OR TS=(antithrombotic)) OR TS=(anticoagulation)) OR TS=(anticoagulant)) OR TS=(anticoagulants)) OR TS=(VTE)) OR TS=(venous thromboembolism)) OR TS=(pulmonary embolism)) OR TS=(deep vein thrombosis)). The data collection period was from January 1, 2000, to December 30, 2023. The document type selected was articles without no language restrictions. To minimize bias, the search ended on December 31, 2023. Nonrelevant articles were eliminated to ensure that only articles exclusively related to hip fracture surgery and VTE were included. A comprehensive bibliometric analysis was performed for 1079 included articles. The records were exported to a plain text file with full records and cited references selected. Information such as publication year, journal, impact factor (IF), title, author, country, institution, category, reference, keywords, number of citations, average number of citations, and H-index was extracted. The impact factor was obtained from the latest Web of Science Journal Citation Reports (JCR) data.

3 Data analysis and visualization

This study used Citespace (version 6.2.4), developed by Professor Chamoe Chen at Drexel University, as a visualization tool for bibliometric analysis. We analyzed the country, institution, author, and category collaboration networks, and co-cited references network, and timeline analysis. We used Citespace to generate the top 25 keywords with the strongest citation bursts to explore the temporal evolution of research hotspots.

The time range was set from 2000 to 2023, with each year representing a one-time slice for the analysis. Nodes were selected for author, institution, country, reference, and category, with the top N = 50 in the selection. Other attribute values used default parameters. The Pathfinder pruning method was chosen to optimize the network structure. Nodes with a purple outer circle represent a higher centrality.

The R 4.1.3 language was used to run Bibliometrix software, which calculated historical changes in journals, created visual graphs, and predicted the trend of journal publications.

VOSviewer software, developed by van Eck and Waltman, was used to analyze keyword clustering visually. Based on coupling and co-citation analysis principles, this software constructs and displays graphs with distance, size, and density differences between nodes to examine research directions and hotspots. The type of analysis was set to co-occurrence, the unit of analysis to author keywords, and the counting method to full counting. Synonyms were replaced, and meaningless keywords were removed.

4 Results

4.1 Analysis of publication outputs

A total of 1079 articles on the topic of hip fracture surgery and VTE were retrieved from 2000 to 2023. Fig. 1-A illustrates the annual publication and citation trends. The publication volume from 2000 to 2010 shows a modest increase. However, the annual and cumulative volumes in the subsequent years demonstrate a steady upward trend. The fitted growth curve indicates that the publication volume growth is exponential. Regarding citation frequency, the total number of citations amounts to 25,364, with 22,784 after excluding self-citations. The citation frequency increased substantially from 2010 to 2023, reaching 3045 citations in 2022.Fig. 1 (A) Trends in annual production of hip fractures associated with VTE from 2000 to 2023. (B) Trends in annual publications in the Top 11 productive countries.

Fig. 1

4.2 Analysis of countries and institutions

The 1079 articles originated mainly from 67 countries. Table 1 reveals that the United States tops the list of publications with 317 articles, accounting for 29.38 % (317/1079), with a total citation count of 10,896, an average citation frequency of 34.26, and an H-index of 48. The United States also ranks first in the distribution of the top 11 countries by annual publication volume (Fig. 1-B). China has grown substantially in publication volume over the last ten years. Germany has consistently maintained its interest in hip fracture surgery and VTE. Fig. 2-A shows the density of the national collaboration network (density = 0.0403). Network density reflects the connectivity between nodes, and this study showed that the collaboration between countries is not very close. South Africa has a centrality of 0.46, France of 0.4, and Sweden of 0.33, indicating that these countries play an important intermediary role and have largely control the network.Table 1 Top 11 countries according to the total number of publications.

Table 1Rank	Country	Number of articles	Total citation	Average citation	H-index	
1	USA	317	10896	34.26	48	
2	China	187	1955	10.29	21	
3	England	109	4355	42.28	31	
4	Germany	84	1200	14.46	19	
5	Canada	58	7823	134.88	27	
6	Australia	49	746	24.06	16	
7	Italy	42	1085	27.13	15	
8	France	39	1382	36.37	15	
9	Japan	34	483	14.64	12	
10	Denmark	33	2022	61.27	16	
11	Spain	33	678	21.19	17	

Fig. 2 Cooperation network among (A) countries, (B) institutions, and(C) authors and(D) categories.

Fig. 2

As many as 341 institutions were engaged in research in hip fracture surgery and VTE. Table 2 displays the top 11 leading institutions with a cumulative publication volume of 158 articles, accounting for 14.64 % of the total publication volume (158/1079). Harvard University leads in publication volume with 22 articles, representing 2.04 % (22/1079). Based on the average citation, the top three institutions are McMaster, Harvard, and Aarhus, indicating their high academic level in this field. The density of the institutional collaboration network is 0.0071 (Fig. 2-B), indicating a relatively loose collaboration among institutions. Harvard Medical School, Sahlgrenska University Hospital, Hebei Medical University, the University of California System, and the University of Toronto have published many articles in a short period, highlighting great attention to hip fracture surgery and VTE in recent years.Table 2 Top 11 institutions according to the total number of publications.

Table 2Rank	Institution	Country	Number of articles	Total citation	Average citation	H-index	
1	Harvard University	USA	22	2005	69.14	14	
2	McMaster University	Canada	21	4249	177.04	17	
3	University of California System	USA	19	370	13.70	11	
4	Assistance Publique Hopitaux Paris (APHP)	France	14	354	27.23	10	
5	Hebei Medical University	China	14	181	10.06	8	
6	Aarhus University	Denmark	12	331	27.58	7	
7	Mayo Clinic	USA	12	296	19.73	8	
8	Xi'an Jiaotong University	China	11	194	13.86	8	
9	Sichuan University	China	11	203	14.5	6	
10	Sackler Faculty of Medicine	Israel	11	290	17.06	9	
11	Tel Aviv University	Israel	11	290	17.06	9	

5 Analysis of authors

Among the top 11 authors (Table 3), Lassen MR from Denmark has the highest publication volume with 16 articles, a total citation count of 3,990, and an average citation frequency of 249.38. Fig. 2-C depicts the author collaboration network (density = 0.0038). The networks show numerous sub-networks, suggesting that authors form small clusters with limited group interactions. Lassen MR, Turpie AGG, Eriksson BI, and Bauer KA have close collaborative relationships. Zhu Yanbin, Chen Wei, Zhang Yingze, Li Chao, and Zhao Kuo also have close collaborative relationships. Research categories for hip fracture surgery and VTE comprise 59 nodes and 62 links. Fig. 2-D reveals the top five categories: ORTHOPEDICS, SURGERY, MEDICINE, GENERAL & INTERNAL, EMERGENCY MEDICINE, and HEMATOLOGY.Table 3 Top 11 most productive authors according to the total number of publications.

Table 3Rank	Author	Country	Number of articles	Total citation	Average citation	H-index	
1	Lassen, MR	Denmark	16	3990	249.38	12	
2	Dahl, OE	Norway	14	2065	147.50	12	
3	Turpie, AGG	Canada	13	1571	120.85	11	
4	Zhu, Yanbin	China	10	69	6.90	5	
5	Egol, Kenneth A	USA	9	220	24.44	5	
6	Zhang, Binfei	China	9	131	14.56	5	
7	Parvizi, Javad	USA	8	439	54.88	6	
8	Chen,Wei	China	8	67	8.38	5	
9	Wang, Pengfei	China	7	130	18.57	5	
10	Koo,kyung-Hoi	South Korea	7	74	10.57	7	
11	Zhang,Kun	China	7	130	18.57	5	

5.1 Analysis of journals

A total of 256 journals have published articles on hip fracture surgery and VTE research. The publication volumes of the top 11 journals are presented in Table 4. The Injury International Journal of The Care of The Injured has the highest publication volume (n = 52, 4.82 %). The Journal of Bone and Joint Surgery-American Volume has the highest IF, JCR quartile, and average citation. Fig. 3 shows the publication trends of the top 11 journals from 2000 to 2023 and represents a smoothed curve created using regression analysis based on the principles of the Loess Smoothing technique. The journal with the most upward trend is the Injury-International Journal of The Care of The Injured, indicating its strong focus on hip fracture surgery and VTE research. The number of publications in the Journal of Orthopaedic Trauma has increased significantly over the last five years.Table 4 Top 11 journals of the most publications related to Venous Thromboembolism after hip fracture surgery.

Table 4Rank	Journal	Count	Percentage(%)	Cumulative percentage(%)	IF	Quartile in Category	Total citation	Average citation	H-index	
1	INJURY-INTERNATIONAL JOURNAL OF THE CARE OF THE INJURED	52	4.82	4.82	2.5	Q2	1301	24.55	22	
2	JOURNAL OF ORTHOPAEDIC TRAUMA	41	3.80	8.62	2.3	Q2	744	18.15	16	
3	BMC MUSCULOSKELETAL DISORDERS	26	2.41	11.03	2.3	Q2	460	16.43	11	
4	JOURNAL OF ARTHROPLASTY	24	2.22	13.25	3.5	Q1	570	23.75	12	
5	CLINICAL ORTHOPAEDICS AND RELATED RESEARCH	24	2.22	15.47	4.3	Q1	893	37.21	14	
6	ORTHOPAEDIC SURGERY	23	2.13	17.60	2.1	Q3	178	7.74	7	
7	ARCHIVES OF ORTHOPAEDIC AND TRAUMA SURGERY	20	1.85	19.45	2.3	Q2	327	16.35	12	
8	INTERNATIONAL ORTHOPAEDICS	19	1.76	21.21	2.7	Q2	266	14	10	
9	GERIATRIC ORTHOPAEDIC SURGERY & REHABILITATION	18	1.67	22.88	1.6	Q3	102	6.38	7	
10	JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME	18	1.67	24.55	5.3	Q1	987	51.95	10	
11	JOURNAL OF ORTHOPAEDIC SURGERY AND RESEARCH	18	1.67	26.22	2.6	Q2	232	12.89	10	

Fig. 3 Top 11 journals growth.

Fig. 3

5.2 Analysis of high-cited references and Co-citation

The top 10 most cited references (Table 5) are from 1987 to 2012. Four were published in the Chest, primarily focusing on the prevention and treatment of VTE and the timing of hip fracture surgery. In the co-cited references network and timeline (Fig. 4-A and Fig. 4-B), each node represents a co-cited reference, with the size of the node indicating the citation frequency. Each line in the timeline represents a cluster, arranged in descending order by the number of references in each cluster. This study integrated the co-cited references network, resulting in 263 nodes and 393 connections. Clustering was performed using the log-likelihood ratio algorithm, with Modularity Q = 0.8788 > 0.7, indicating high reliability, and Silhouette = 0.936 > 0.3, showing significant clustering. The co-cited references are mainly categorized into 15 clusters. The largest category is#0, with research focusing on risk factors; #1, transfusion and #2, aminocaproic acid, mainly related to blood management; and #3, primarily covers direct oral anticoagulants (DOAC).Table 5 Top 10 high-cited references related to venous thromboembolism after hip fracture surgery.

Table 5Rank	Title	First Author	Year	Journal	Citation	
1	Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines	Falck-Ytter Y	2012	Chest	97	
2	Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)	Geerts WH	2008	Chest	86	
3	Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy	Geerts WH	2004	Chest	81	
4	Fondaparinux compared with enoxaparin for the prevention of venous thromboembolism after hip-fracture surgery	Eriksson BI	2001	NEW ENGL J MED	81	
5	Duration of prophylaxis against venous thromboembolism with fondaparinux after hip fracture surgery: a multicenter, randomized, placebo-controlled, double-blind study	Eriksson BI	2003	ARCH INTERN MED	70	
6	Prevention of venous thromboembolism	Geerts WH	2001	Chest	61	
7	Prevention of pulmonary embolism and deep vein thrombosis with low dose aspirin:Pulmonary Embolism Prevention (PEP) trial	O'Brien J	2000	Lancet	61	
8	Early mortality after hip fracture: is delay before surgery important?	Moran CG	2005	J BONE JOINT SURG AM	54	
9	Is operative delay associated with increased mortality of hip fracture patients? Systematic review, meta-analysis, and meta-regression	Shiga T	2008	CAN J ANAESTH	54	
10	A new method of classifying prognostic comorbidity in longitudinal studies: development and validation	CHARLSON ME	1987	J CHRON DIS	52	

Fig. 4 (A) The co-cited references knowledge map. (B) The timeline graph of co-cited references clustering.

Fig. 4

Analysis of Keywords; Keywords with the strongest citation bursts indicate a sudden increase within a specific period, enabling the exploration of the temporal evolution of research hotspots. The keyword burst (Fig. 5) reveals recent research hotspots: time, tranexamic acid (TXA), transfusion, and intertrochanteric fracture. Co-word clustering analysis was conducted on 58 high-frequency keywords with a frequency ≥7 (Fig. 6-A), with different colors representing different themes. Research on hip fracture surgery and VTE is divided into three research directions: The red cluster focuses on the impact of preoperative anticoagulation on fracture surgery and includes 24 keywords (hip fracture, complications, mortality, etc.) The blue cluster explores intraoperative blood protection strategies and contains 11 keywords (tranexamic acid, elderly, blood loss, etc.) The green cluster addresses postoperative VTE prevention and treatment and involves 23 keywords (venous thromboembolism, deep vein thrombosis, total hip arthroplasty, etc.) The keyword co-occurrence timeline (Fig. 6-B) can explore emerging research topics. The color of the node represents the initial time of the research topics. The timeline confirms that DOAC, surgical timing, perioperative blood protection, intertrochanteric fracture, and geriatric traumatic fracture are hotspots and future research directions in this field, consistent with the results of the keywords bursts.Fig. 5 Top 25 keywords with the strongest citation bursts.

Fig. 5

Fig. 6 Keyword co-occurrence analysis and time graph.

Fig. 6

6 Discussion

6.1 General information

The global incidence of hip fractures is expected to rise as life expectancy increases. Hip fractures pose an exceptionally high risk of thrombosis among various types of injuries. People aged ≥65 have a higher risk of thrombosis. The presence of comorbidities exacerbated the risk of thrombosis in individuals with hip fractures. This study visualized the global research status of hip fracture surgery and VTE from 2000 to 2023 through a bibliometric analysis, revealing the knowledge structure, research directions, and hotspots in this field to guide future research. A total of 1079 articles on hip fracture surgery and VTE were published by 256 journals from 67 countries and 341 institutions. The overall publication volume steadily increases, indicating a growing interest in this field. Only a dozen articles were published early, showing that researchers initially recognized the relationship between hip fracture surgery and VTE. However, after 2020, the number of publications exceeded 100, indicating that researchers have shifted from unilateral research on hip fracture surgery or VTE to the association between hip fracture surgery and VTE.

The visualization analysis of the distribution of countries, institutions, and journals shows the state of scientific research productivity. Highly cited authors and articles have made outstanding contributions to this field. The statistical results show that a stable, continuous, and influential group of researchers and institutions is emerging. Examining these publications helps to understand the knowledge structure in this field. Analyzing collaborative networks offers insights into influential research teams and potential collaborators. However, collaboration between countries, institutions, and authors is relatively loose. This can hinder the research development. Therefore, researchers should dismantle academic barriers, foster collaboration and data sharing, and advance research on hip fracture surgery and VTE.

7 Research hotspots and trends

Keywords can help researchers understand current research directions and emerging trends. According to the visualization analysis of keywords, there are currently three main research directions in this field: the impact of preoperative anticoagulation on fracture surgery, intraoperative blood protection strategies, and postoperative prevention and treatment of VTE. Research hotspots include surgery timing, blood protection, traumatic fractures in older people, and intertrochanteric fractures.

7.1 Surgery time and OACs

There are 4.5 million cases of hip fractures worldwide every year. Around a third of patients are treated with anticoagulants, including platelet aggregation inhibitors, vitamin K antagonists (VKA), and DOACs. Among them, the indications for oral anticoagulants (OACs) continue to expand. Up to 40 % of patients with hip fractures receive OACs on admission [5]. Early surgical intervention is the mainstay of treatment for hip fractures; therefore, balancing the risk factors associated with surgical delay and bleeding is necessary. Delaying surgery is associated with an increased overall mortality rate. A retrospective study found that a surgical time exceeding 24 h was associated with an increased 30-day mortality rate [6]. An interval of >24 h also correlated with increased incidence of perioperative complications and prolonged hospital stay [7]. Postoperative complications include infection, pulmonary embolism, renal failure, pulmonary edema, and myocardial ischemia [8,9]. Compared with delayed surgery, early surgery significantly reduces mortality and complications. Therefore, most guidelines recommend patients to undergo surgery within 48 h [10]. However, surgery for anticoagulated patients is often delayed [11].

Currently, there is no consensus on the optimal timing for surgery and its impact on postoperative clinical outcomes in patients with hip fractures taking OACs on admission. Some studies suggest that patients with hip fractures taking OACs before injury had delayed surgery and higher mortality than patients not taking anticoagulants [12].

A meta-analysis found that patients receiving DOAC treatment had a significantly delayed surgical time in six studies. Regarding transfusion rates, three studies found a significantly higher transfusion frequency in patients taking DOAC. Concerning rehospitalization, one study indicated a higher risk of rehospitalization in patients receiving DOAC. None of the studies found a significant difference in VTE and stroke. Eight studies observed no difference in postoperative mortality between the DOAC and control groups. The above results suggest that delaying surgery may be unnecessary for emergency surgery in patients with hip fractures receiving DOACs [13]. Other studies have also confirmed these above observations. Patients receiving DOACs patients showed no increase in mortality rate, blood loss, transfusion, stroke complication, and reoperation or readmission compared with patients not treated with anticoagulants [14].

One study found that although individuals with hip fractures who were prescribed OACs had increased surgical bleeding and a high risk of transfusion, delaying surgery did not reduce these risks. There was no difference in postoperative VTE [15].

Patients with hip fractures treated with VKA before surgery can easily receive effective reversal agents. A study found that patients treated with VKA who underwent hip fracture surgery within 24 h had no differences in transfusion, complications, or mortality after reversal compared with patients without anticoagulants [16]. Similarly, studies revealed that patients using DOAC or VKA undergoing hip fracture surgery showed no differences in surgical delay, early mortality, transfusions, and length of hospital stay [17].

Surgery time, rather than surgical technique, is an essential factor influencing the long-term survival of patients with hip fractures. In patients with hip fractures receiving anticoagulant treatment, surgical time should not be routinely delayed. Medical teams should consider blood conservation strategies to limit bleeding. These include adequate surgical fixation, local application of hemostatic agents, and intraoperative cell salvage. Anesthetic strategies help to minimize the risks with critical interventions, including regional anesthesia, permissive hypotension, avoidance of hypothermia, prudent use of blood products, and systemic hemostatic agents.

7.2 Prophylaxis and treatment of VTE

Patients with hip fractures have a high risk of developing DVT and PE. VTE prophylactic medications include aspirin, unfractionated heparin, low molecular weight heparin (LMWH), VKA, synthetic pentasaccharide (fondaparinux), oral Xa factor inhibitors, and direct thrombin inhibitors. The American College of Chest Physicians (ACCP) recommends using LMWH, low-dose unfractionated heparin, VKA, fondaparinux, aspirin, or intermittent pneumatic compression devices to prevent VTE. LMWH, which ACCP recommends, the National Institute for Health and Clinical Excellence (NICE), the American Society of Hematology (ASH), and the Scottish Intercollegiate Guidelines Network (SIGN), is the optimal drug for preventing VTE in patients undergoing knee or total hip arthroplasty or hip fracture surgery [18].

ACCP recommends using DOAC for selective knee and hip arthroplasty but not for hip fracture surgery. In the United States, dabigatran is an orally administered direct thrombin inhibitor approved by the U.S. Food and Drug Administration for preventing atrial fibrillation and stroke but not for VTE prevention after knee or total hip arthroplasty [19]. However, NICE, ASH, and SIGN guidelines recommend DOACs instead of LMWH as the first choice [20,21]. A meta-analysis suggests that DOACs are as effective and safe as LMWH and have a similar mortality rate in patients with hip fractures [22]. Most guidelines and systematic reviews do not recommend using aspirin. VKA is significantly less effective than LMWH in preventing DVT, and the differences between VKA and LMWH in bleeding and wound hematoma are not significant [23]. Fondaparinux is significantly superior to LMWH in reducing VTE. However, it may be associated with a higher risk of bleeding [24].

The optimal duration of thromboprophylaxis after hip fracture surgery is still controversial. The usual practice is using LMWH or unfractionated heparin until discharge, usually 7–14 days after surgery. International guidelines recommend extending thromboprophylaxis to 35 days. A personalized pharmacological VTE prevention plan should be used based on each patient's surgical plan, baseline conditions, and thrombotic risk. Using a low dose of LMWH before surgery is considered safe. It is recommended to discontinue it 12 h before the surgery to minimize bleeding risk. Postoperative prophylaxis against VTE also usually begins 8–12 h after surgery for the same reason. In the first five weeks after fracture, the risk of VTE is high (4.3 %) if no prevention is carried out [18].

In conclusion, based on risk stratification, a combination of medication and mechanical prevention is recommended for patients with an increased risk of VTE. In patients with an increased risk of bleeding, mechanical prophylaxis alone can be considered.

7.2.1 Blood protection strategies

TXA is often used to manage bleeding. Although TXA has been proven safe in selective knee and hip arthroplasty, the risk of VTE when TXA is used in hip fracture surgery remains uncertain. TXA works by inactivating the fibrinolysis system rather than initiating the cascade reaction of coagulation, leading to a blood loss reduction. For intertrochanteric hip fractures in older people, robust evidence from meta-analyses confirms the efficacy and safety of intravenous TXA. Some meta-analyses provide strong evidence for the efficacy and safety of intravenous TXA in older people with intertrochanteric hip fractures. TXA significantly reduces blood loss and transfusion requirements without increasing the risk of VTE events or death [25,26]. This implies that using TXA in hip fracture surgery is safe.

There is still no consensus on the route, dosage, and timing of TXA administration in orthopedic surgery. Studies have shown that local injection of TXA can significantly reduce the need for blood transfusions in hip fracture surgery [27]. Local administration of TXA offers advantages such as achieving maximum concentration at the surgical site and minimizing systemic absorption. This approach helps to reduce the risk of VTE [28]. However, studies showed that no route of administration significantly reduced perioperative bleeding [29]. Compared to higher doses, a single dose of 15 mg/kg significantly reduced adverse events [30].

7.3 Intertrochanteric fracture

Intertrochanteric fractures, a common type of fracture in older people, are primarily associated with osteoporosis. The incidence of these fractures is rapidly increasing, accounting for 3.13 % of adult fractures and 50 % of all hip fractures [31,32]. Fracture morphology is an independent risk factor, as proximal femoral fractures are usually associated with injury to the circumflex femoral artery. In hip fractures, intracapsular fracture bleeding is generally self-limiting. The minimum average Hb value is significantly lower in patients with extracapsular fractures than those with intracapsular fractures. Intertrochanteric fractures are extracapsular fractures that are usually accompanied by considerable perioperative bleeding, including intraoperative and hidden blood losses [33]. The substantial hidden blood loss in intertrochanteric fractures can be attributed to the larger surface area of blood loss, intraoperative medullary cavity expansion, excessive trauma-induced fibrinolysis, and continuous postoperative bleeding [34].

VTE is a common complication during the perioperative period in intertrochanteric fractures [35]. Recently, the focus of research has shifted from the prevention of postoperative VTE in intertrochanteric fractures to the prediction of preoperative VTE risk factors. Compared with femoral neck fractures, intertrochanteric fractures are a major risk factor for preoperative DVT [36]. The incidence of preoperative DVT in older patients with intertrochanteric fractures patients is 10.2 % [37]. Causes of posttraumatic thrombosis include postfracture hypercoagulability, hemostatic treatment, surgery, and complications. Intertrochanteric fractures usually require more traumatic force than femoral neck fractures. The presence of severe stress reactions will further increase the incidence of DVT. Independent risk factors associated with DVT include smoking, preoperative time, D-dimer levels, hypertension, and diabetes [38].

Recent studies have focused on TXA application in intramedullary fixation of femoral intertrochanteric fractures. A randomized controlled trial included 972 patients with intertrochanteric fractures treated with TXA. The TXA group showed significantly lower total intraoperative and hidden blood losses, transfusion rates, and hospital stays than the control group. There were no significant differences in VTE and mortality between the TXA and control groups [39]. TXA appears to be safe and effective for perioperative bleeding in intertrochanteric fractures with intramedullary fixation.

7.4 Strengths and limitations

Based on visualization, this bibliometric analysis allows scholars to swiftly comprehend the focus and trends in hip fracture surgery and VTE. This study is a pioneering bibliometric analysis of hip fracture surgery and VTE. However, this study also has some limitations. Firstly, only the WOSCC database was retrieved. It may only cover some studies on hip fracture surgery and VTE. Second, the limitations associated with the extraction time may cause the number of relevant articles to change over time, leading to incomplete analysis data. Third, this study only included articles on human research, which may have overlooked other research hotspots.

8 Conclusions

This study established the knowledge structure of hip fracture surgery and VTE, revealing research hotspots and trends. These findings can form the basis for future research in this field. Hip fracture surgery and VTE have significant research value, and attention is growing. However, the lack of collaboration is limiting its progress. Therefore, research institutions and scholars need more collaboration and data sharing.

Funding

This research received no specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Ethics statement

Review and/or approval by an ethics committee was not needed for this study because it doesn't include any human or animal participation.

Data availability statement

The date will be made available on request.

CRediT authorship contribution statement

Yiteng Wang: Conceptualization. Xin Wang: Visualization, Supervision. Zhendong Xu: Writing – original draft. Zuohong Li: Conceptualization.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

None.
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