Morphological characteristics analysis of femoral neck fracture in children

Morphological characteristics analysis of femoral neck fracture in children | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Morphological characteristics analysis of femoral neck fracture in children Niu-Niu Zhao, Xue-Lian Gu, Zhen-Zhen Dai, Chen-Chen Wu, Tian-Yi Zhang, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4445093/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Purpose To investigate the morphological characteristics of pediatric femoral neck fracture (FNF) from clinical cases by fracture mapping technology and to analyze the relationship between fracture classifications and age. Methods The CT data were collected from 46 consecutive pediatric inpatients diagnosis of FNF from March 2009 to December 2022. The fracture imaging were reconstructed in three dimensions and performed simulated anatomical reduction by Mimics and 3-matic. Both Delbet classification and Pauwels angle classification were documented according to the fracture line in each patient. Furthermore, all of the fracture lines in these patients were superimposed to form a fracture map and a heat map. Results This study included 24 boys and 22 girls (average age, 9.61 ± 3.17 years (4 to 16 years)). The fracture lines of anterior and superior femoral neck were found to be mainly located in the middle and lower regions of the femoral neck, while fracture lines of posterior and inferior neck were mainly concentrated in the middle region. Most children younger than 10 years had Delbet Ⅲ type of fracture (69%), whereas those older than 10 years had Delbet Ⅱ type of fracture (73%). Furthermore, most children had Pauwels angle III type of fracture (63%), especially in those over 10 years old (80%) ( p < 0.05). Conclusion FNF in children are predominantly located in the middle and lower regions of the neck. Older children may be prone to be affected with higher fracture location of FNF or unstable type of fracture. Pediatric Femoral neck fracture Fracture mapping Morphology Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Femoral neck fracture (FNF) is a rare but serious fracture in children[ 1 ]. This type of injury typically results from high-impact trauma and can lead to various complications, such as avascular necrosis (AVN) in femoral head, cox varus, nonunion and premature of the femoral head physis, which bring tough treatment challenges to surgeon[ 2 ]. The occurrence of these complications was thought to be associated to both the morphological characteristics of the fracture and the stability of surgical internal fixation. Therefore, the morphological characteristics of fracture is important for surgeon to decide optimal treatment[ 3 ]. Delbet classification is commonly used for FNF in children[ 4 ] to describe the fracture location rather than fracture stability, therefore it cannot help surgeon to choose the appropriate internal fixation. While, for FNF in adults, Pauwels angle classification is widely used to reflect injury mechanism and fracture stability[ 5 ], and can provide guidance on internal fixation selection. However, there were few studies on the stability characteristics of FNF in children. Age is also a factor that influences the choice of internal fixation for pediatric FNF. Research on FNF in children has shown that internal fixation methods should be different between adolescent and younger children[ 6 ]. However, research on fracture types in different age groups remains unclear. X-ray examination is one of the most commonly used imaging methods for assessing FNF[ 7 ], which serves as the basis for determining Delbet or Pauwels type. However, due to the patient's position after injury, it is difficult to clearly determine the fracture line by X-ray. Therefore, CT has been used more and more widely in evaluation of FNF[ 8 ]. Recently, fracture mapping technology utilizes the reconstruction technique of CT[ 9 ] scans to superimpose fracture lines of multiple patients after stimulated fracture reduction and to create a fracture lines distribution map and a heat map[ 10 ], which determine the fracture pattern at specific anatomical locations. It can help clinical doctors to better understand the morphology of the fractures and formulate treatment plans. Cho et al.[ 11 ] used fracture mapping technology to determine the location and frequency of fracture lines on the patellar joint surface. Li et al.[ 12 ] investigated more precise and accurate information about intertrochanteric fractures by fracture mapping technique, enabling better surgical approaches, pre-operative planning, and implant strategies. This study investigated the morphological characteristics of pediatric FNF by fracture mapping technology on basis of CT data from retrospective series patients. Materials and methods Subjects A retrospective review was conducted on the database of our hospital, retrieving continuous pediatric patients’ series diagnosis of FNF from March 2009 to December 2022. The inclusion criteria were as follows: (1) boy was less than 16 years old and girl was less than 14 years old; (2) with open physis showed by X-ray at injury; (3) with complete preoperative CT imaging data within 2 weeks of the injury. The exclusion criteria were as follows: (1) pathological fractures caused by other diseases, such as bone cysts; (2) with previous fracture history in the femoral neck on the same side; (3) open fracture. Reconstruction and mapping of a three-dimensional model The CT images of FNF (Fig. 1 .a) were generated a 3D fracture model by Mimics 21.0 image processing software (Materialise, Belgium) (Fig. 1 .b). The displaced fracture fragments was reduced according to the unaffected side as control by 3-matic 15.0 software (Materialise, Belgium) (Fig. 1 .c) [ 13 ]. The proximal femur model was mirrored on the other side to ensure consistency in the fracture model. The proximal femoral model of a child (10 years old) was served as a reference to proportionally adjust the proximal femoral neck of patients of different ages. The tools such as rotation, normalization and multi-point registration were used to align the fracture model with the standardized template (Fig. 1 .d). The fracture lines of all the patients were reflected on the standard template to obtain a fracture lines distribution map (Fig. 1 .e). Finally, the fracture lines were superimposed into the E-3D software (E-3D Digital Medical and Virtual Reality Research Center, Central South University) and converted into a heat map (Fig. 1 .f). In order to study the concentrated distribution areas of fractures, the femoral neck region was divided into four equal parts according to the method by Ranajit[ 14 ], with each zone occupying 25% of the length of the femoral neck. From proximal to distal, these are designated as Zone 1, Zone 2, Zone 3, and Zone 4, as shown in Fig. 2 .a. Measurement of Pauwels angle based on the fracture line The Pauwels angle is defined as the complementary angle between the fracture line and the axis of the femoral shaft L1[ 15 ]. The axis of the femoral shaft L1was determined through cylindrical fitting of the femoral shaft, the fracture line was identified using regional marker fracture surface analysis. Subsequently, the angle between the fracture line and the axis of the femoral shaft was measured as∠1. The Pauwels angle (∠α) is the supplementary Angle to ∠1. Delbet classification of FNF in children The Delbet classification[ 4 ] divides the fractures into 4 types based on the location of the fracture line, as shown in Fig. 2 .c. This classification is closely related to possibility of AVN of femoral head, and the higher the fracture location, the more AVN is likely to occur. If the fracture spans more than one area (Fig. 3 ), the classification was recorded according to of the highest area through which the fracture line passes. For example ( in Fig. 3 ), the fracture line passed through the upper of femoral neck to base of the neck, and it was recorded as type II because the complication of AVN of Delbet type II was higher than that of Delbet type III[ 16 ]. Data analysis The qualitative data were expressed as the number of cases (percentage), while the quantitative data were presented as the mean (standard deviation). Descriptive analysis was conducted to examine the distribution and frequency of fractures. The reliability of Pauwels angle measurements was assessed using the intra-class correlation coefficient, and the relations between fracture types and age were examined using the chi-square goodness-of-fit test. Statistical significance was determined at a significance level of p < 0.05, and all statistical analyses were performed using SPSS 26 software (IBM, USA). Results Patient characteristics A total of 46 patients with FNF were analyzed (24 boys, and 22 girls). The mean age of the patients was 9.61 ± 3.17 years old (range from 4 to 16 years). Sixteen patients were under 10 years of age and 30 patients were over 10 years of age. According to Delbet classification, there was 26 cases (56.52%) of type II, 18 cases (39.14%) of type III. According to Pauwels angular classification, there were 29 cases (63.04%) of type III. The patient characteristics are summarized in Table 1 . Table 1 Patient demographics (N = 46). Variable Value Age (mean) (range) 9.61 ± 3.17 years (4–16 years) Sex (no. [%]) Male 24(52.17) Female 22(47.83) Delbet Classification (no. [%]) Type Ⅰ 1(2.17) Type Ⅱ 26(56.52) Type Ⅲ 18(39.14) Type Ⅳ 1(2.17) Pauwels Classification (no. [%]) Type Ⅰ 7(15.22) Type Ⅱ 10(21.74) Type Ⅲ 29(63.04) Value were presented as Mean ± SD (range), or frequency (percentage). Fracture mapping The heat map of the pediatric FNF shows the fracture lines mainly concentrated in the middle of the neck (Fig. 4 ). The anterior and superior fracture line is mainly concentrated in zones 3 and 4 of the femoral neck, while posterior and inferior fractures line in zones 2 and 3 of the femoral neck. Femoral neck fracture type Delbet type III was more common (69%) in patients under 10 years old (Fig. 5 .a), while Delbet type II was more common (73%) in patients over 10 years of age (Fig. 5 .c) ( p 0.95 within the group ( p < 0.05). With regard to Pauwels angle classification, among patients under 10 years old, there were 6 cases (37.5%) of type I, 5 cases (31.25%) of type II, and 5 cases (31.25%) of type III; among patients 10 years or older, there were 1 case (3.33%) of type I, 5 cases (16.67%) of type II, and 24 cases (80%) of type III. Pauwels angle type III is more common in children over 10 years old ( p < 0.05), There was no significant difference in the number of Pauwels angle type among patients under 10 years of age ( p = 0.973). (Fig. 5 .e, f.). Discussion The fracture lines were found to be mainly located in the middle and lower areas of the anterior and superior regions of the femoral neck, while in the middle region of the posterior and inferior regions. Patients under 10 years old, fractures mainly occurred at the base of the femoral neck, whereas for patients over the age of 10 fractures predominantly was located in the middle region of the femoral neck. Furthermore, most children had Pauwels angle III type of fracture (63%), especially in those over 10 years old. The results from adults studied by Wu et al.[ 13 ] on fracture mapping of femoral neck displaced fractures in middle-aged and elderly was different from the present study, as they found fracture lines concentrated mainly in the superior region of the femoral neck. It may attributed that with aging bone microstructure in the superior femoral neck of adults decrease, weakening the region's supportive capacity[ 17 ]. However, for children, the incomplete development of bone trabeculae and the limited tensile strength of bone tissue may contribute to the dispersion of fracture lines in superior region of femoral neck[ 18 ]. That may be why the superior fracture area is more concentrated in the elderly adults than in children. In this study, the fracture line in the inferior of femoral neck demonstrated a relatively concentrated pattern. This phenomenon may be contribute to the thicker cortex in inferior of the femoral neck in children[ 18 ], higher cortical porosity of the superior neck[ 19 ], and lower levels of habitual stress[ 20 ]. Therefore, in pediatric FNF, most fracture lines will concentrate in inferior of the femoral neck. Most research on pediatric FNF have shown that Delbet type II of fracture is the predominant subtype, followed by Delbet type III, collectively accounting for approximately 65–85% of all the pediatric FNF[ 21 , 22 ]. It was consistent with our finding. However, we also found that Delbet type was related to age of children, Delbet type III of fracture was more common in patients under 10 years of age, while Delbet type II more in patients over 10 years of age. In this study, the majority (63.04%) of femoral neck fractures were unstable fracture according to Pauwels angle type, especially in patients aged over 10 years (P < 0.05). The majority of FNF in adolescents may be attributed to high-energy trauma[ 23 ]. Consequently, young FNF commonly result from high-energy vertical shear forces and predominantly manifest as Pauwels type III fractures[ 24 ]. It is plausible that with increasing age, these children are more likely to develop high-energy injuries and lead to unstable fractures. Pauwels type III fractures present a significant challenge for achieving stable fixation due to substantial shear forces. To enhance the stability of fracture fixation, internal fixation devices should distribute stress along the fracture line at the fracture site. Additionally, it is not advisable for an internal fixator with a large diameter to cross epiphyseal plate of femoral head in children [ 25 ]. Ranajit et al.[ 15 ] recommended using smooth pins crossing the epiphyseal plate for fixation of fracture. The fracture mapping of FNF in this study revealed a predominant concentration of fracture areas in zone 2, 3 and zone 4 of femoral neck, with fewer occurrences of fracture lines observed in zone 1 adjacent to the epiphyseal plate. To ensure stability during fixation, it is recommended to select thin smooth pins through involved zone 1 of femoral neck. There are also some limitations of this study that should be taken into account. Firstly, due to the rarity of pediatric FNF, the sample size in the present study was small and weaken our findings. Therefore, multi-center studies should be conducted in the future. Secondly, for those compression fractures, the accuracy of reduction and determination of fracture line may be disturbed. To address the deviation, the reduction took the uninjured side as standard. Finally, due to variations in proximal femur morphology associated with age, each patient's proximal femur may not perfectly align with a standard template. Consequently, some deviation is inevitable when delineating the fracture line using current technology. Conclusion FNF in children are predominantly located in the middle and lower regions of the neck. Older children may be prone to be insulted with higher fracture location of or unstable type of fracture. Declarations Conflict of interest There was no conflict of interest. Funding The authors declare that no funds, grants, or other support were received during the preparation of this manuscript. Ethical approval Due to the retrospective nature of the study, the study had no impact on the existed treatment. No biospecimens were collected from patients in this study. The confidentiality of patients’ privacy and identity information was guaranteed, and there was no commercial interest involved, so that this research met the conditions for exemption from informed consent. The study received approval from the Institutional Review Board/Ethics Committee of Xin-Hua Hospital (Reference number: XHEC-D-2024-038). The study was conducted according to the ethical principles stated in the Declaration of Helsinki. Informed consent Written informed consent was obtained from legally authorized representatives of the patients. Acknowledgements Not applicable. Authors’ contribution All authors participated in the design, interpretation of the studies and analysis of the data and review of the manuscript. Li H , Gu XL and Zhao NN did the design of the study and drafted the manuscript, Zhao NN, Dai ZZ ,Wu CC, Zhang TY, and Li H reviewed the patients and analyzed the data, Li H and Zhao NN wrote the manuscript. All authors read and approved the final manuscript. Data availability The authors confirm that the data supporting the findings of this study are available within the article. References Gurnea TP, Nielsen RC, Althausen PL (2020) Use of Proximal Humerus Locking Plates for Fixation of Pediatric Femoral Neck Fractures: Technical Trick. Journal of Orthopaedic Trauma 34:e312–e315. https://doi.org/10.1097/BOT.0000000000001765 Wang WT, Li YQ, Guo YM, et al (2019) Risk factors for the development of avascular necrosis after femoral neck fractures in children: a review of 239 cases. The Bone & Joint Journal 101-B:1160–1167. https://doi.org/10.1302/0301-620X.101B9.BJJ-2019-0275.R1 Yao X, Zhou K, Lv B, et al (2020) 3D mapping and classification of tibial plateau fractures. 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Injury 46:1969–1974. https://doi.org/10.1016/j.injury.2015.06.016 Sarwar S, Khan K, Bhat TA, Nazir I (2022) Pediatric Femoral Neck Fractures: Our Institutional Experience of 5 Years. IJRSMS 9:S23–S30. https://doi.org/10.1055/s-0042-1751064 Milovanovic P, Djonic D, Hahn M, et al (2017) Region-dependent patterns of trabecular bone growth in the human proximal femur: A study of 3D bone microarchitecture from early postnatal to late childhood period: MILOVANOVIC et al . Am J Phys Anthropol 164:281–291. https://doi.org/10.1002/ajpa.23268 Djuric M, Milovanovic P, Djonic D, et al (2012) Morphological characteristics of the developing proximal femur: A biomechanical perspective. Srp Arh Celok Lek 140:738–745. https://doi.org/10.2298/SARH1212738D Rolvien T, vom Scheidt A, Stockhausen KE, et al (2018) Inter-site variability of the osteocyte lacunar network in the cortical bone underpins fracture susceptibility of the superolateral femoral neck. Bone 112:187–193. https://doi.org/10.1016/j.bone.2018.04.018 Von Kroge S, Stürznickel J, Bechler U, et al (2022) Impaired bone quality in the superolateral femoral neck occurs independent of hip geometry and bone mineral density. Acta Biomaterialia 141:233–243. https://doi.org/10.1016/j.actbio.2022.01.002 Wu C, Ning B, Xu P, et al (2020) Efficacy and complications after delayed fixation of femoral neck fractures in children. J Orthop Surg (Hong Kong) 28:2309499019889682. https://doi.org/10.1177/2309499019889682 Xin P, Li Z, Pei S, et al (2023) The incidence and risk factors for femoral head necrosis after femoral neck fracture in pediatric patients: a systematic review and meta-analysis. J Orthop Surg Res 18:22. https://doi.org/10.1186/s13018-023-03502-4 Subramanyam KN, Mundargi AV, Reddy PS, Umerjikar S (2018) Pathological Neck of Femur Fracture with Failed Osteosynthesis in Adolescent: A Report of Two Cases. J Orthop Case Rep 8:88–91. https://doi.org/10.13107/jocr.2250-0685.1274 Shen M, Wang C, Chen H, et al (2016) An update on the Pauwels classification. Journal of Orthopaedic Surgery and Research 11:161. https://doi.org/10.1186/s13018-016-0498-3 Dial BL, Lark RK (2018) Pediatric proximal femur fractures. Journal of Orthopaedics 15:529–535. https://doi.org/10.1016/j.jor.2018.03.039 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4445093","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":319216162,"identity":"11ed0266-19d6-454a-b75e-27a1114db607","order_by":0,"name":"Niu-Niu Zhao","email":"","orcid":"","institution":"University of Shanghai for Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Niu-Niu","middleName":"","lastName":"Zhao","suffix":""},{"id":319216163,"identity":"2cea8089-ab08-4564-9489-3c53de88a18a","order_by":1,"name":"Xue-Lian Gu","email":"","orcid":"","institution":"University of Shanghai for Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Xue-Lian","middleName":"","lastName":"Gu","suffix":""},{"id":319216164,"identity":"f6452399-9754-4986-81bd-b31abac25801","order_by":2,"name":"Zhen-Zhen Dai","email":"","orcid":"","institution":"Xin Hua Hospital, Shanghai Jiao Tong University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Zhen-Zhen","middleName":"","lastName":"Dai","suffix":""},{"id":319216165,"identity":"a3751883-10bc-46bb-b37b-4d5ec97aa001","order_by":3,"name":"Chen-Chen Wu","email":"","orcid":"","institution":"University of Shanghai for Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Chen-Chen","middleName":"","lastName":"Wu","suffix":""},{"id":319216166,"identity":"d05015b7-5cdb-4156-b3cb-9749c6fde343","order_by":4,"name":"Tian-Yi Zhang","email":"","orcid":"","institution":"University of Shanghai for Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Tian-Yi","middleName":"","lastName":"Zhang","suffix":""},{"id":319216167,"identity":"82182814-3d4f-4859-b9c7-4bad1545ba5f","order_by":5,"name":"Hai Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2ElEQVRIiWNgGAWjYBACPmYeBoaECgYeBgkwn5mwFjawljMkaQEqZmBsA7KI18LOe/DDw3mHZcyleww/3aiwZuBv705g+LkDn8P4kiUSt6XxWM45YyydcyadQeLM2Q2MvWfw+sUAqMWGx+BGjoF0btthBgOJ3A3MYKfi1mL8I3GOBEiL8e/cf8RpMZNIbADbYiad20CkFouEY2lALWll1jnH0nlAfjnYi0cLP/8Z45s/ag7bG9xI3nw7p8Zajr+9d+ODn3i0YAAeEHGABA2jYBSMglEwCrAAACVgRm0fypExAAAAAElFTkSuQmCC","orcid":"","institution":"Xin Hua Hospital, Shanghai Jiao Tong University School of Medicine","correspondingAuthor":true,"prefix":"","firstName":"Hai","middleName":"","lastName":"Li","suffix":""}],"badges":[],"createdAt":"2024-05-19 16:29:57","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4445093/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4445093/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":59968044,"identity":"adc299f4-4e4a-43f1-b897-de27d8554a85","added_by":"auto","created_at":"2024-07-10 02:31:23","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":330090,"visible":true,"origin":"","legend":"\u003cp\u003eKey processes and steps of fracture 3D model reconstruction and mapping. \u003cstrong\u003e(a)\u003c/strong\u003e CT image. \u003cstrong\u003e(b)\u003c/strong\u003e Three-dimensional fracture model. \u003cstrong\u003e(c)\u003c/strong\u003e The displaced fracture fragments was reduced according to the unaffected side as control. \u003cstrong\u003e(d)\u003c/strong\u003e Align the fracture model with the standardized template. \u003cstrong\u003e(e)\u003c/strong\u003eFracture lines distribution map. \u003cstrong\u003e(f)\u003c/strong\u003e Heat map.\u003c/p\u003e","description":"","filename":"figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-4445093/v1/ed734bb2dc01cb0ca1bd1f8d.png"},{"id":59968045,"identity":"b579d6b7-b4ed-435a-a028-e2f06251ba10","added_by":"auto","created_at":"2024-07-10 02:31:23","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":396770,"visible":true,"origin":"","legend":"\u003cp\u003eThe key diagram. (\u003cstrong\u003ea)\u003c/strong\u003e Femoral neck subzones. (\u003cstrong\u003eb)\u003c/strong\u003e Measurement of the Pauwels angle in FNF. (\u003cstrong\u003ec)\u003c/strong\u003e The Delbet classification (type I, II, III and IV) for FNF in children.\u003c/p\u003e","description":"","filename":"figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-4445093/v1/9fbfbb3e23eb956ecea6c038.png"},{"id":59969016,"identity":"1339c388-084b-4a1a-b9b8-25c4f57657bb","added_by":"auto","created_at":"2024-07-10 02:39:23","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":106770,"visible":true,"origin":"","legend":"\u003cp\u003eThe fracture line passes through multiple regions.\u003c/p\u003e","description":"","filename":"figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-4445093/v1/3b30b736dc4d5828ffc993cd.png"},{"id":59968046,"identity":"3ef7eb03-2eef-44a2-a633-c6cd688f6f8b","added_by":"auto","created_at":"2024-07-10 02:31:23","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":578672,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution map (top) and heat map (bottom).\u003c/p\u003e","description":"","filename":"figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-4445093/v1/49cbb828f27896df86ff1ca6.png"},{"id":59968048,"identity":"9dc1dbae-3c6d-4fb3-bbc1-77d9a8bf1deb","added_by":"auto","created_at":"2024-07-10 02:31:24","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":500673,"visible":true,"origin":"","legend":"\u003cp\u003eThe fracture maps, different age groups, Delbet type and Pauwels angle type. Distribution of Delbet types in patients aged below 10 years (a, b) or above 10 years (c, d). Distribution of Pauwels types in patients aged below 10 years (e) or (f) above 10 years.\u003c/p\u003e","description":"","filename":"figure5.png","url":"https://assets-eu.researchsquare.com/files/rs-4445093/v1/2b6651aa2db68f325d9bb020.png"},{"id":63450826,"identity":"0dffd5ef-20c9-4020-8d38-ece4078b5427","added_by":"auto","created_at":"2024-08-28 09:20:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3224580,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4445093/v1/c0cd064b-963c-4c7f-a029-90bc8e8a9a1b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Morphological characteristics analysis of femoral neck fracture in children","fulltext":[{"header":"Introduction","content":"\u003cp\u003eFemoral neck fracture (FNF) is a rare but serious fracture in children[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. This type of injury typically results from high-impact trauma and can lead to various complications, such as avascular necrosis (AVN) in femoral head, cox varus, nonunion and premature of the femoral head physis, which bring tough treatment challenges to surgeon[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. The occurrence of these complications was thought to be associated to both the morphological characteristics of the fracture and the stability of surgical internal fixation. Therefore, the morphological characteristics of fracture is important for surgeon to decide optimal treatment[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDelbet classification is commonly used for FNF in children[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] to describe the fracture location rather than fracture stability, therefore it cannot help surgeon to choose the appropriate internal fixation. While, for FNF in adults, Pauwels angle classification is widely used to reflect injury mechanism and fracture stability[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], and can provide guidance on internal fixation selection. However, there were few studies on the stability characteristics of FNF in children.\u003c/p\u003e \u003cp\u003eAge is also a factor that influences the choice of internal fixation for pediatric FNF. Research on FNF in children has shown that internal fixation methods should be different between adolescent and younger children[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. However, research on fracture types in different age groups remains unclear.\u003c/p\u003e \u003cp\u003eX-ray examination is one of the most commonly used imaging methods for assessing FNF[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], which serves as the basis for determining Delbet or Pauwels type. However, due to the patient's position after injury, it is difficult to clearly determine the fracture line by X-ray. Therefore, CT has been used more and more widely in evaluation of FNF[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Recently, fracture mapping technology utilizes the reconstruction technique of CT[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] scans to superimpose fracture lines of multiple patients after stimulated fracture reduction and to create a fracture lines distribution map and a heat map[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], which determine the fracture pattern at specific anatomical locations. It can help clinical doctors to better understand the morphology of the fractures and formulate treatment plans. Cho et al.[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] used fracture mapping technology to determine the location and frequency of fracture lines on the patellar joint surface. Li et al.[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] investigated more precise and accurate information about intertrochanteric fractures by fracture mapping technique, enabling better surgical approaches, pre-operative planning, and implant strategies. This study investigated the morphological characteristics of pediatric FNF by fracture mapping technology on basis of CT data from retrospective series patients.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSubjects\u003c/h2\u003e \u003cp\u003eA retrospective review was conducted on the database of our hospital, retrieving continuous pediatric patients\u0026rsquo; series diagnosis of FNF from March 2009 to December 2022. The inclusion criteria were as follows: (1) boy was less than 16 years old and girl was less than 14 years old; (2) with open physis showed by X-ray at injury; (3) with complete preoperative CT imaging data within 2 weeks of the injury. The exclusion criteria were as follows: (1) pathological fractures caused by other diseases, such as bone cysts; (2) with previous fracture history in the femoral neck on the same side; (3) open fracture.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eReconstruction and mapping of a three-dimensional model\u003c/h2\u003e \u003cp\u003eThe CT images of FNF (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.a) were generated a 3D fracture model by Mimics 21.0 image processing software (Materialise, Belgium) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.b). The displaced fracture fragments was reduced according to the unaffected side as control by 3-matic 15.0 software (Materialise, Belgium) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.c) [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe proximal femur model was mirrored on the other side to ensure consistency in the fracture model. The proximal femoral model of a child (10 years old) was served as a reference to proportionally adjust the proximal femoral neck of patients of different ages. The tools such as rotation, normalization and multi-point registration were used to align the fracture model with the standardized template (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.d). The fracture lines of all the patients were reflected on the standard template to obtain a fracture lines distribution map (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.e). Finally, the fracture lines were superimposed into the E-3D software (E-3D Digital Medical and Virtual Reality Research Center, Central South University) and converted into a heat map (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.f). In order to study the concentrated distribution areas of fractures, the femoral neck region was divided into four equal parts according to the method by Ranajit[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], with each zone occupying 25% of the length of the femoral neck. From proximal to distal, these are designated as Zone 1, Zone 2, Zone 3, and Zone 4, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.a.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eMeasurement of Pauwels angle based on the fracture line\u003c/h2\u003e \u003cp\u003eThe Pauwels angle is defined as the complementary angle between the fracture line and the axis of the femoral shaft L1[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. The axis of the femoral shaft L1was determined through cylindrical fitting of the femoral shaft, the fracture line was identified using regional marker fracture surface analysis. Subsequently, the angle between the fracture line and the axis of the femoral shaft was measured as\u0026ang;1. The Pauwels angle (\u0026ang;α) is the supplementary Angle to \u0026ang;1.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eDelbet classification of FNF in children\u003c/h2\u003e \u003cp\u003eThe Delbet classification[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] divides the fractures into 4 types based on the location of the fracture line, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.c. This classification is closely related to possibility of AVN of femoral head, and the higher the fracture location, the more AVN is likely to occur.\u003c/p\u003e \u003cp\u003eIf the fracture spans more than one area (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e), the classification was recorded according to of the highest area through which the fracture line passes. For example ( in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e), the fracture line passed through the upper of femoral neck to base of the neck, and it was recorded as type II because the complication of AVN of Delbet type II was higher than that of Delbet type III[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eData analysis\u003c/h2\u003e \u003cp\u003eThe qualitative data were expressed as the number of cases (percentage), while the quantitative data were presented as the mean (standard deviation). Descriptive analysis was conducted to examine the distribution and frequency of fractures. The reliability of Pauwels angle measurements was assessed using the intra-class correlation coefficient, and the relations between fracture types and age were examined using the chi-square goodness-of-fit test. Statistical significance was determined at a significance level of \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, and all statistical analyses were performed using SPSS 26 software (IBM, USA).\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003ePatient characteristics\u003c/h2\u003e \u003cp\u003eA total of 46 patients with FNF were analyzed (24 boys, and 22 girls). The mean age of the patients was 9.61\u0026thinsp;\u0026plusmn;\u0026thinsp;3.17 years old (range from 4 to 16 years). Sixteen patients were under 10 years of age and 30 patients were over 10 years of age. According to Delbet classification, there was 26 cases (56.52%) of type II, 18 cases (39.14%) of type III. According to Pauwels angular classification, there were 29 cases (63.04%) of type III. The patient characteristics are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePatient demographics (N\u0026thinsp;=\u0026thinsp;46).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eValue\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (mean) (range)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.61\u0026thinsp;\u0026plusmn;\u0026thinsp;3.17 years (4\u0026ndash;16 years)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex (no. [%])\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24(52.17)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22(47.83)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eDelbet Classification (no. [%])\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType Ⅰ\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1(2.17)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType Ⅱ\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26(56.52)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType Ⅲ\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18(39.14)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType Ⅳ\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1(2.17)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003ePauwels Classification (no. [%])\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType Ⅰ\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7(15.22)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType Ⅱ\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10(21.74)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType Ⅲ\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29(63.04)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003eValue were presented as Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD (range), or frequency (percentage).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eFracture mapping\u003c/h2\u003e \u003cp\u003eThe heat map of the pediatric FNF shows the fracture lines mainly concentrated in the middle of the neck (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The anterior and superior fracture line is mainly concentrated in zones 3 and 4 of the femoral neck, while posterior and inferior fractures line in zones 2 and 3 of the femoral neck.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eFemoral neck fracture type\u003c/h2\u003e \u003cp\u003eDelbet type III was more common (69%) in patients under 10 years old (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e.a), while Delbet type II was more common (73%) in patients over 10 years of age (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e.c) (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The Pauwels angle was measured three times, and the correlation coefficient ICC was \u0026gt;\u0026thinsp;0.95 within the group (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). With regard to Pauwels angle classification, among patients under 10 years old, there were 6 cases (37.5%) of type I, 5 cases (31.25%) of type II, and 5 cases (31.25%) of type III; among patients 10 years or older, there were 1 case (3.33%) of type I, 5 cases (16.67%) of type II, and 24 cases (80%) of type III. Pauwels angle type III is more common in children over 10 years old (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), There was no significant difference in the number of Pauwels angle type among patients under 10 years of age (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.973). (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e.e, f.).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe fracture lines were found to be mainly located in the middle and lower areas of the anterior and superior regions of the femoral neck, while in the middle region of the posterior and inferior regions. Patients under 10 years old, fractures mainly occurred at the base of the femoral neck, whereas for patients over the age of 10 fractures predominantly was located in the middle region of the femoral neck. Furthermore, most children had Pauwels angle III type of fracture (63%), especially in those over 10 years old.\u003c/p\u003e \u003cp\u003eThe results from adults studied by Wu et al.[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] on fracture mapping of femoral neck displaced fractures in middle-aged and elderly was different from the present study, as they found fracture lines concentrated mainly in the superior region of the femoral neck. It may attributed that with aging bone microstructure in the superior femoral neck of adults decrease, weakening the region's supportive capacity[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. However, for children, the incomplete development of bone trabeculae and the limited tensile strength of bone tissue may contribute to the dispersion of fracture lines in superior region of femoral neck[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. That may be why the superior fracture area is more concentrated in the elderly adults than in children. In this study, the fracture line in the inferior of femoral neck demonstrated a relatively concentrated pattern. This phenomenon may be contribute to the thicker cortex in inferior of the femoral neck in children[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], higher cortical porosity of the superior neck[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], and lower levels of habitual stress[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Therefore, in pediatric FNF, most fracture lines will concentrate in inferior of the femoral neck.\u003c/p\u003e \u003cp\u003eMost research on pediatric FNF have shown that Delbet type II of fracture is the predominant subtype, followed by Delbet type III, collectively accounting for approximately 65\u0026ndash;85% of all the pediatric FNF[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. It was consistent with our finding. However, we also found that Delbet type was related to age of children, Delbet type III of fracture was more common in patients under 10 years of age, while Delbet type II more in patients over 10 years of age.\u003c/p\u003e \u003cp\u003eIn this study, the majority (63.04%) of femoral neck fractures were unstable fracture according to Pauwels angle type, especially in patients aged over 10 years (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The majority of FNF in adolescents may be attributed to high-energy trauma[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Consequently, young FNF commonly result from high-energy vertical shear forces and predominantly manifest as Pauwels type III fractures[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. It is plausible that with increasing age, these children are more likely to develop high-energy injuries and lead to unstable fractures.\u003c/p\u003e \u003cp\u003ePauwels type III fractures present a significant challenge for achieving stable fixation due to substantial shear forces. To enhance the stability of fracture fixation, internal fixation devices should distribute stress along the fracture line at the fracture site. Additionally, it is not advisable for an internal fixator with a large diameter to cross epiphyseal plate of femoral head in children [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Ranajit et al.[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] recommended using smooth pins crossing the epiphyseal plate for fixation of fracture. The fracture mapping of FNF in this study revealed a predominant concentration of fracture areas in zone 2, 3 and zone 4 of femoral neck, with fewer occurrences of fracture lines observed in zone 1 adjacent to the epiphyseal plate. To ensure stability during fixation, it is recommended to select thin smooth pins through involved zone 1 of femoral neck.\u003c/p\u003e \u003cp\u003eThere are also some limitations of this study that should be taken into account. Firstly, due to the rarity of pediatric FNF, the sample size in the present study was small and weaken our findings. Therefore, multi-center studies should be conducted in the future. Secondly, for those compression fractures, the accuracy of reduction and determination of fracture line may be disturbed. To address the deviation, the reduction took the uninjured side as standard. Finally, due to variations in proximal femur morphology associated with age, each patient's proximal femur may not perfectly align with a standard template. Consequently, some deviation is inevitable when delineating the fracture line using current technology.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eFNF in children are predominantly located in the middle and lower regions of the neck. Older children may be prone to be insulted with higher fracture location of or unstable type of fracture.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere was no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDue to the retrospective nature of the study, the study had no impact on the existed treatment. No biospecimens were collected from patients in this study. The confidentiality of patients\u0026rsquo; privacy and identity information was guaranteed, and there was no commercial interest involved, so that this research met the conditions for exemption from informed consent. The study received approval from the Institutional Review Board/Ethics Committee of Xin-Hua Hospital (Reference number: XHEC-D-2024-038). The study was conducted according to the ethical principles stated in the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInformed consent\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from legally authorized representatives of the patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors participated in the design, interpretation of the studies and analysis of the data and review of the manuscript. Li H , Gu XL and Zhao NN did the design of the study and drafted the manuscript, Zhao NN, Dai ZZ ,Wu CC, Zhang TY, and Li H reviewed the patients and analyzed the data, Li H and Zhao NN wrote the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors confirm that the data supporting the findings of this study are available within the article.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eGurnea TP, Nielsen RC, Althausen PL (2020) Use of Proximal Humerus Locking Plates for Fixation of Pediatric Femoral Neck Fractures: Technical Trick. Journal of Orthopaedic Trauma 34:e312\u0026ndash;e315. https://doi.org/10.1097/BOT.0000000000001765\u003c/li\u003e\n\u003cli\u003eWang WT, Li YQ, Guo YM, et al (2019) Risk factors for the development of avascular necrosis after femoral neck fractures in children: a review of 239 cases. The Bone \u0026amp; Joint Journal 101-B:1160\u0026ndash;1167. https://doi.org/10.1302/0301-620X.101B9.BJJ-2019-0275.R1\u003c/li\u003e\n\u003cli\u003eYao X, Zhou K, Lv B, et al (2020) 3D mapping and classification of tibial plateau fractures. Bone Joint Res 9:258\u0026ndash;267. https://doi.org/10.1302/2046-3758.96.BJR-2019-0382.R2\u003c/li\u003e\n\u003cli\u003ePavone V, Testa G, Riccioli M, et al (2019) Surgical treatment with cannulated screws for pediatric femoral neck fractures: A case series. Injury 50:S40\u0026ndash;S44. https://doi.org/10.1016/j.injury.2019.01.043\u003c/li\u003e\n\u003cli\u003eNandi S (2021) Revisiting Pauwels\u0026rsquo; classification of femoral neck fractures. World Journal of Orthopedics 12:811\u0026ndash;815. https://doi.org/10.5312/wjo.v12.i11.811\u003c/li\u003e\n\u003cli\u003ePatterson JT, Tangtiphaiboontana J, Pandya NK (2018) Management of Pediatric Femoral Neck Fracture. JAAOS - Journal of the American Academy of Orthopaedic Surgeons 26:411. https://doi.org/10.5435/JAAOS-D-16-00362\u003c/li\u003e\n\u003cli\u003eYimam HM, Dey R, Rachuene PA, et al (2022) Identification of recurring scapular fracture patterns using 3-dimensional computerized fracture mapping. Journal of Shoulder and Elbow Surgery 31:571\u0026ndash;579. https://doi.org/10.1016/j.jse.2021.08.036\u003c/li\u003e\n\u003cli\u003e\u0026Ouml;ğ\u0026uuml;ms\u0026ouml;ğ\u0026uuml;tl\u0026uuml; E, Kılın\u0026ccedil;oğlu V (2023) Fracture mapping of adult femoral neck fractures with three dimensional computed tomography. International Orthopaedics (SICOT) 47:1323\u0026ndash;1330. https://doi.org/10.1007/s00264-023-05742-9\u003c/li\u003e\n\u003cli\u003eMills AT, LaRoque MC, Thomas CN, et al (2023) Mapping of Pelvic Ring Injuries From High-Energy Trauma Using Unfolded CT Image Technology. J Orthop Trauma 37:257\u0026ndash;261. https://doi.org/10.1097/BOT.0000000000002544\u003c/li\u003e\n\u003cli\u003eMellema JJ, Eygendaal D, van Dijk CN, et al (2016) Fracture mapping of displaced partial articular fractures of the radial head. Journal of Shoulder and Elbow Surgery 25:1509\u0026ndash;1516. https://doi.org/10.1016/j.jse.2016.01.030\u003c/li\u003e\n\u003cli\u003eCho J-W, Yang Z, Lim EJ, et al (2021) Multifragmentary patellar fracture has a distinct fracture pattern which makes coronal split, inferior pole, or satellite fragments. Sci Rep 11:22836. https://doi.org/10.1038/s41598-021-02215-0\u003c/li\u003e\n\u003cli\u003eLi M, Li Z-R, Li J-T, et al (2019) Three-dimensional mapping of intertrochanteric fracture lines. Chin Med J (Engl) 132:2524\u0026ndash;2533. https://doi.org/10.1097/CM9.0000000000000446\u003c/li\u003e\n\u003cli\u003eWu S, Zhu X, Wang W, et al (2022) Three-dimensional computed tomography mapping and clinical predictive factors for morphologic characterization of displaced femoral neck fractures. Ann Transl Med 10:1096. https://doi.org/10.21037/atm-22-1213\u003c/li\u003e\n\u003cli\u003ePanigrahi R, Sahu B, Mahapatra AK, et al (2015) Treatment analysis of paediatric femoral neck fractures: a prospective multicenter theraupetic study in Indian scenario. International Orthopaedics (SICOT) 39:1121\u0026ndash;1127. https://doi.org/10.1007/s00264-015-2677-y\u003c/li\u003e\n\u003cli\u003eWang S-H, Yang J-J, Shen H-C, et al (2015) Using a modified Pauwels method to predict the outcome of femoral neck fracture in relatively young patients. Injury 46:1969\u0026ndash;1974. https://doi.org/10.1016/j.injury.2015.06.016\u003c/li\u003e\n\u003cli\u003eSarwar S, Khan K, Bhat TA, Nazir I (2022) Pediatric Femoral Neck Fractures: Our Institutional Experience of 5 Years. IJRSMS 9:S23\u0026ndash;S30. https://doi.org/10.1055/s-0042-1751064\u003c/li\u003e\n\u003cli\u003eMilovanovic P, Djonic D, Hahn M, et al (2017) Region-dependent patterns of trabecular bone growth in the human proximal femur: A study of 3D bone microarchitecture from early postnatal to late childhood period: MILOVANOVIC et al . Am J Phys Anthropol 164:281\u0026ndash;291. https://doi.org/10.1002/ajpa.23268\u003c/li\u003e\n\u003cli\u003eDjuric M, Milovanovic P, Djonic D, et al (2012) Morphological characteristics of the developing proximal femur: A biomechanical perspective. Srp Arh Celok Lek 140:738\u0026ndash;745. https://doi.org/10.2298/SARH1212738D\u003c/li\u003e\n\u003cli\u003eRolvien T, vom Scheidt A, Stockhausen KE, et al (2018) Inter-site variability of the osteocyte lacunar network in the cortical bone underpins fracture susceptibility of the superolateral femoral neck. Bone 112:187\u0026ndash;193. https://doi.org/10.1016/j.bone.2018.04.018\u003c/li\u003e\n\u003cli\u003eVon Kroge S, St\u0026uuml;rznickel J, Bechler U, et al (2022) Impaired bone quality in the superolateral femoral neck occurs independent of hip geometry and bone mineral density. Acta Biomaterialia 141:233\u0026ndash;243. https://doi.org/10.1016/j.actbio.2022.01.002\u003c/li\u003e\n\u003cli\u003eWu C, Ning B, Xu P, et al (2020) Efficacy and complications after delayed fixation of femoral neck fractures in children. J Orthop Surg (Hong Kong) 28:2309499019889682. https://doi.org/10.1177/2309499019889682\u003c/li\u003e\n\u003cli\u003eXin P, Li Z, Pei S, et al (2023) The incidence and risk factors for femoral head necrosis after femoral neck fracture in pediatric patients: a systematic review and meta-analysis. J Orthop Surg Res 18:22. https://doi.org/10.1186/s13018-023-03502-4\u003c/li\u003e\n\u003cli\u003eSubramanyam KN, Mundargi AV, Reddy PS, Umerjikar S (2018) Pathological Neck of Femur Fracture with Failed Osteosynthesis in Adolescent: A Report of Two Cases. J Orthop Case Rep 8:88\u0026ndash;91. https://doi.org/10.13107/jocr.2250-0685.1274\u003c/li\u003e\n\u003cli\u003eShen M, Wang C, Chen H, et al (2016) An update on the Pauwels classification. Journal of Orthopaedic Surgery and Research 11:161. https://doi.org/10.1186/s13018-016-0498-3\u003c/li\u003e\n\u003cli\u003eDial BL, Lark RK (2018) Pediatric proximal femur fractures. Journal of Orthopaedics 15:529\u0026ndash;535. https://doi.org/10.1016/j.jor.2018.03.039\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Pediatric, Femoral neck fracture, Fracture mapping, Morphology","lastPublishedDoi":"10.21203/rs.3.rs-4445093/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4445093/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eTo investigate the morphological characteristics of pediatric femoral neck fracture (FNF) from clinical cases by fracture mapping technology and to analyze the relationship between fracture classifications and age.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThe CT data were collected from 46 consecutive pediatric inpatients diagnosis of FNF from March 2009 to December 2022. The fracture imaging were reconstructed in three dimensions and performed simulated anatomical reduction by Mimics and 3-matic. Both Delbet classification and Pauwels angle classification were documented according to the fracture line in each patient. Furthermore, all of the fracture lines in these patients were superimposed to form a fracture map and a heat map.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThis study included 24 boys and 22 girls (average age, 9.61\u0026thinsp;\u0026plusmn;\u0026thinsp;3.17 years (4 to 16 years)). The fracture lines of anterior and superior femoral neck were found to be mainly located in the middle and lower regions of the femoral neck, while fracture lines of posterior and inferior neck were mainly concentrated in the middle region. Most children younger than 10 years had Delbet Ⅲ type of fracture (69%), whereas those older than 10 years had Delbet Ⅱ type of fracture (73%). Furthermore, most children had Pauwels angle III type of fracture (63%), especially in those over 10 years old (80%) (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eFNF in children are predominantly located in the middle and lower regions of the neck. Older children may be prone to be affected with higher fracture location of FNF or unstable type of fracture.\u003c/p\u003e","manuscriptTitle":"Morphological characteristics analysis of femoral neck fracture in children","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-10 02:31:18","doi":"10.21203/rs.3.rs-4445093/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a20f0dca-8903-4a81-93bf-0ed98ba5706b","owner":[],"postedDate":"July 10th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-08-28T09:12:09+00:00","versionOfRecord":[],"versionCreatedAt":"2024-07-10 02:31:18","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4445093","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4445093","identity":"rs-4445093","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}