Hip Abduction Angle and the Risk of Avascular Necrosis (AVN) After Closed Reduction (CR) in Developmental Dysplasia of the Hip (DDH)

Hip Abduction Angle and the Risk of Avascular Necrosis (AVN) After Closed Reduction (CR) in Developmental Dysplasia of the Hip (DDH) | 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 Hip Abduction Angle and the Risk of Avascular Necrosis (AVN) After Closed Reduction (CR) in Developmental Dysplasia of the Hip (DDH) Mohamad Samih Yasin, Bashar Abukhalaf, Dana Q. Khateeb, Reham Badayneh, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5335761/v2 This work is licensed under a CC BY 4.0 License Status: Posted Version 2 posted You are reading this latest preprint version Show more versions Abstract Objectives Developmental dysplasia of the hip (DDH) is a prevalent pediatric orthopedic condition with a prevalence of 5–13 per 1000 live births worldwide. Early detection and management are paramount to mitigate long-term complications such as osteoarthritis and avascular necrosis of the hip (AVN). While various interventions exist, closed reduction (CR) and spica casting play pivotal roles in restoring normal hip anatomy. Given that AVN is a significant concern after CR, we aimed to investigate the correlation between the hip abduction angle in the spica and the risk of AVN. Methods This retrospective cohort study was conducted at Jordan University Hospital from 2016–2022. A total of 74 patients, aged up to 20 months, underwent CR, which was followed by CT scans with a minimum 12-month follow-up. CT scans were used for calculating the hip abduction angle, and X-rays were used for determining the Salter classification of AVN. Results The mean age at the time of CR was 7.29 ± 2.71 months. Fifty-one percent of the patients had bilateral DDH, and 7.6% had a positive personal or family history of DDH. The mean right and left abduction angles were 60.37° ± 8.03° and 59.53° ± 7.12°, respectively. The mean right and left International Hip Dysplasia Institute (IHDI) scores were 3.13 ± 0.7 and 3.38 ± 0.67, respectively. The mean right and left Salter AVN indices were 0.48 ± 1.13 and 0.55 ± 1.29, respectively. There were statistically significant relationships between right and left Salter (r = 0.793, p < 0.001), between right and left abduction angles (r = 0.335, p = 0.043), between right and left IHDI grades (r = 0.336, p = 0.039), between left IHDI grades and left Salter (r = 0.261, p = 0.047), and between left Salter and age (r = 0.264, p = 0.047). Neither the right nor the left abduction angle was associated with increased right or left Salter AVN grade, as indicated by the p values. Conclusions If a patient develops AVN on one side, the other side is also likely to be affected; however, the degree of abduction in CR does not correlate with the AVN rate. There was a correlation between the degree of abduction and the degree of subluxation/dislocation. Additionally, age at reduction is correlated with the risk of AVN. Avascular Necrosis AVN Closed Reduction DDH Hip Abduction Angle Salter Introduction Developmental dysplasia of the hip (DDH) represents a spectrum of abnormalities in the development of the hip joint, encompassing subluxation and dislocation [1,2]. It is the most common pediatric orthopedic condition [3], affecting approximately 5–13 per 1000 live births worldwide [1-2], with a relatively high prevalence in females and breech presentations [1-5]. A systematic review led by M. de Hundt et al. explored other possible factors, such as familial aggregation and clicking hips [5]. Early detection and management are crucial for preventing long-term complications such as osteoarthritis and avascular necrosis of the hip (AVN). [1,3-5] Management of DDH varies on the basis of age and the response to interventions, but generally, the main goal of managing DDH is to achieve concentric reduction of the hip within the acetabulum while mitigating the potential risks of avascular necrosis or osteoarthrosis that may arise. [1,5-9] Typically, the Pavlik harness (dynamic hip abduction orthosis) is the treatment of choice for children up to 6 months of age. Closed reduction and spica casting for at least 3 months is usually the next step for children up to 18 months of age, whereas open reduction and surgical osteotomies are preserved for older children or those who fail less invasive treatments. [1,6-8] Closed reduction (CR), a cornerstone in the treatment of DDH, aims to restore the normal anatomy of the hip joint by manipulating the femoral head back into the acetabulum without surgical exposure [9-10,12]. However, despite its widespread adoption, closed reduction is not without risk. One of the most feared complications associated with closed reduction of DDH, with an incidence that varies widely between 2% and 36% [9-10,12-13], is avascular necrosis, which is characterized by the interruption of the blood supply to the femoral head, leading to ischemic necrosis and potential long-term sequelae [1,10-12]. While closed reduction is a promising approach for managing DDH, clinicians must be vigilant with respect to the risk of AVN. Understanding the factors predisposing patients to AVN postreduction is paramount for optimizing treatment strategies and minimizing complications. Many recent studies have discussed the risk factors predisposing patients to AVN after closed reduction; however, debates persist, highlighting the need for a more thorough identification of risk factors for AVN for both prognostic and preventive aims. Our hypothesis was that an increased hip abduction angle in the spica cast following CR leads to avascular necrosis of the hip. Therefore, in this study, we aimed primarily to explore the relationship between an increased angle of hip abduction and the risk of developing avascular necrosis (AVN) in patients with DDH treated by closed reduction and spica cast immobilization and to investigate other factors that may contribute to AVN. Methodology The present study adopted a retrospective cohort design to investigate the relationship between the hip abduction angle and avascular necrosis (AVN) rate in patients with developmental dysplasia of the hip (DDH) treated with closed reduction and spica cast immobilization. The study included 74 patients with a diagnosis of a subluxated or dislocated hip, all within the age range of up to 20 months, requiring closed reduction under general anesthesia in the operating room plus spica cast application, computed tomography (CT) scanning following reduction, and a minimum of 12 months of clinical and radiographic follow-up. Patients with neuromuscular disease or teratologic dislocations, a history of open reduction, incomplete or missed radiographic data, a history of prior unsuccessful treatment, and the onset of avascular necrosis (AVN) after subsequent surgery were excluded from the study. The data and radiograph results were retrieved from medical records and the electronic medical records system at Jordan University Hospital (JUH) from 2016--2022. Jordan University Hospital (JUH) is a tertiary medical center that lies northwest of the capital Amman and provides health care for approximately half a million patients a year, from all over the country, as outpatients, inpatients, emergents and other services. This study captured the sociodemographic characteristics of the samples, including but not limited to age, sex, and the presence of comorbidities. Preoperative plain radiographs were reviewed to determine the presence of subluxation or dislocation. If dislocation was present, it was classified according to the IHDI system. This classification uses the position of the proximal femoral metaphysis, rather than the ossific nucleus, as the key reference point for determining the hip location [27]. Additionally, the characteristics of DDH, including unilaterality or bilaterality, and the presence of a femoral ossific nucleus were also assessed. Postoperative computed tomography (CT) findings were reviewed to measure the hip abduction angle. Plain radiographs at follow-ups were reviewed to look for the development of AVN. The Salter criteria were used to assess the presence of AVN. These criteria include (1) failure of the ossific nucleus of the femoral head to appear for one year or longer after reduction and (2) lack of growth in an existing ossific nucleus for one year or longer after reduction, (3) broadening of the femoral neck within one year after reduction, (4) increased radiographic density of the femoral head followed by the appearance of fragmentation on radiographs, and (5) residual deformities of the femoral head and neck after reossification is complete. These deformities include coxa magna, coxa plana, coxa vara, and a short, broad femoral neck. [28]. The senior authors reviewed all the radiographs. The findings from the arthrogram-guided CR were documented when performed intraoperatively, along with any additional adductor tenotomy procedures that were conducted. This study ensured patient confidentiality and received approval from Jordan University Hospital (JUH) and the Institutional Review Board ethics committee (IRB) at the University of Jordan. Statistical analysis SPSS version 28.0 (Chicago, USA) was used for statistical analysis. Variability analysis in the form of the mean (standard deviation) and the range were used to describe the data. Sociodemographic factors were provided as frequencies (percentages) via standard descriptive statistical parameters. The normality of the distribution of variables was examined via the Shapiro–Wilk test. Pearson’s chi-square test or Fisher's exact test was used to investigate the associations between the Hill‐bone CHBPTS adherence groups and other categorical variables at a 95% confidence interval. A p value < 0.05 was considered statistically significant. Results Demographic and medical characteristics Seventy-four children were enrolled, with a mean age of 7.29 ± 2.71 months (mean ± SD) and a range of 15 weeks (4–19). Bilateral developmental dysplasia of the hip (DDH) was reported in 38 patients (51.4%), whereas a positive medical history for the children themselves or a family history of DDH was reported in 5 patients (7.6%). The mean right and left abduction angles were 60.37° ± 8.03° and 59.53° ± 7.12°, respectively. The mean right and left IHDI scores were 3.13 ± 0.7 and 3.38 ± 0.67, respectively. Finally, the mean right and left Salter indices were 0.48 ± 1.13 and 0.55 ± 1.29, respectively. Table 1 shows the frequency of the cohort characteristics. Table 1 Demographic and medical characteristics. (n = 74) Variable Frequency (%) Mean ± SD Range (min – max) Gender Male 6 (8.1) . . Female 68 (91.9) . . Age (months) . 7.29 ± 2.71 15 (4–19) Site Left 20 (27.0) . . Right 16 (21.6) . . Bilateral 38 (51.4) . . Past medical history Negative 61 (92.4) . . Positive 5 (7.6) . . Family history of DDH Negative 61 (92.4) . . Positive 5 (7.6) . . Right abduction (degree) . 60.37 ± 8.03 35 (43–78) Left abduction (degree) . 59.53 ± 7.12 31 (43–74) Right IHDI . 3.13 ± 0.7 2 (2–4) Left IHDI . 3.38 ± 0.67 2 (2–4) Right Salter . 0.48 ± 1.13 4 (0–4) Left Salter . 0.55 ± 1.29 4 (0–4) DDH: developmental dysplasia of the hip; IHDI: International Hip Dysplasia Institute; SD: standard deviation. Pearson correlation was conducted to investigate the potential associations between right and left abduction, the IHDI, and Salter. There was a significant positive strong correlation between right and left Salter (r = 0.793, p < 0.001). Furthermore, there were significant positive moderate associations between right and left abduction (r = 0.335, p = 0.043) and between right and left IHDI (r = 0.336, p = 0.039). Finally, there were significant positive weak associations between left IHDI and left Salter (r = 0.261, p = 0.047) and between left Salter and age (r = 0.264, p = 0.047). Table 2 shows the Pearson correlation. Table 2 Correlations between the IHDI score, the Salter index, abduction, and age in pediatric patients. Variable Right abduction Left abduction Right IHDI Left IHDI Right Salter Left salter Right abduction Pearson Correlation coefficient (r) 0.335* 0.070 0.071 − 0.228 − 0.115 P value 0.043 0.617 0.674 0.1 0.493 Left abduction Pearson Correlation coefficient (r) 0.335* 0.082 − 0.036 0.099 0.136 P value 0.043 0.625 0.793 0.553 0.314 Right IHDI Pearson Correlation coefficient (r) 0.070 0.082 0.336* 0.182 0.149 P value 0.617 0.625 0.039 0.188 0.372 Left IHDI Pearson Correlation coefficient (r) 0.071 − 0.036 0.336* − 0.048 0.261* P value 0.674 0.793 0.039 0.773 0.047 Right Salter Pearson Correlation coefficient (r) − 0.228 0.099 0.182 − 0.048 0.793* P value 0.100 0.553 0.188 0.773 < 0.001 Left salter Pearson Correlation coefficient (r) − 0.115 0.136 0.149 0.261* 0.793* P value 0.493 0.314 0.372 0.047 < 0.001 Age Pearson Correlation coefficient (r) 0.109 0.052 0.219 0.129 0.257 0.264* P value 0.432 0.704 0.111 0.337 0.061 0.047 *Correlation is significant at the 0.05 level (two-tailed). Discussion Avascular necrosis (AVN) is a complication that occurs after closed reduction (CR) of developmental dysplasia of the hip (DDH). While several studies have reported several risk factors for developing AVN after CR [1–12], the abduction angle to which the femoral head has been reduced plays a significant role [10]. The aim of treatment is to obtain stable reduction of the hip while limiting the risk of AVN. Therefore, this study was conducted to explore the potential relationship between the hip abduction angle and the development of AVN. Similar to earlier studies on various possible factors related to AVN, including age at the onset of treatment [14], sex [13], severity of hip dislocation at treatment [15], and laterality (unilateral/bilateral DDH) [16], our current study considered the age of the patient, sex, laterality of their DDH, and past medical history and family history of DDH. Most patients were female, were medically free, had bilateral DDH, and had a negative family history of DDH. Our results revealed a statistically significant relationship between the right and left sides, which means that if a patient develops AVN on one side, the other side is likely to also be affected as a positive relationship exists between the two sides, indicating that there might be patient-related factors, such as the vascularity of the area, warranting further research. Additionally, there was a statistically significant relationship between the right and left abduction angles, meaning that the surgeon is likely to apply the same abduction angle on both sides during the intervention, making this study a useful resource for surgeons to consider adopting extreme care for both sides. A statistically significant relationship between the right and left IHDI scores was found, indicating that the degree of subluxation or dislocation on one side matches that on the other side. Additionally, a statistically significant relationship was found between the left IHDI and left Salter; that is, having a certain subluxation/dislocation grade on the left side influences the development of AVN on the same side, and finally, there was a statistically significant relationship between the left Salter and age—that is, the age at the time of reduction affects the development of AVN on the left side. A moderately positive statistically significant relationship was found between abduction angle and IHDI grade. No statistically significant relationship was found between abduction angle and the Salter criteria for AVN on the basis of p values, which answers our research problem. These results are somewhat concordant with the previously reviewed literature [10–12], although previous studies that considered excessive hip abduction as a potential risk factor for AVN lacked consistent conclusions [1][10][11]. The effects of AVN-related variables were not parallel, which could be due to differences in the definitions of AVN and the timing of follow-up. Additionally, previous studies reported discrepant rates of AVN, ranging from 0–67% [17]. These wide variations are likely due to common cause variation, which is difficult to eliminate, or they could be because of special cause variations, such as differences in technique, surgeon factors or systematic differences in the way that a study is run [18]. However, our study is similar to the relevant literature, as Liu YH et al. [19] reported that an abduction angle of up to 70.2° following CR did not increase the AVN rate in children aged six to 28 months with late-detected DDH treated by CR. Additionally, Schur MD et al. [13] reported no significant association between hip abduction and AVN in DDH patients older than six months of age at the time of CR, although they reported that in patients under six months of age at the time of CR, a hip abduction angle > 50° may significantly increase the risk of AVN, which is consistent with the results of our study in terms of age and the Salter AVN association. Similarly, the age at the time of the first visit tended to be younger in those who developed AVN at the follow-up [20]. The more severe forms of avascular necrosis were found to be most prevalent in those patients in whom treatment began between birth and the age of six months [21]. This finding is consistent with our findings that a relationship between age and the development of AVN exists, even if weakly so. A systematic review of 538 hips that achieved CR revealed that the overall rate of AVN at the 7.6-year follow-up was only 10% [22]. Another similar result to our study revealed a nonsignificant reduction in the incidence of AVN when the hip abduction angle was reduced [23]. In terms of the relationship between the IHDI grade and the development of AVN, which was positive on the left side in our study, the incidence of AVN increased with the grade of dislocation [11]. A higher preoperative IHDI grade (IHDI 3–4) was a significant risk factor for AVN (P = 0.032) in patients older than 10 months [24], and the degree of initial dislocation was a significant risk factor for AVN [25]. In contrast to our findings, some existing studies reported otherwise different correlations between the age of the patient and the risk of AVN. Bian Z et al. [11] reported that age at reduction was not a significant factor for the occurrence of AVN, that age at reduction (> 12 months versus ≤ 12 months) was not associated with osteonecrosis after closed reduction [25], and that the risk of osteonecrosis was unaffected by age at CR (P = 0.745) [12]. Regarding the relationship between the abduction angle and Salter AVN, Smith et al. reported that the subsequent development of avascular necrosis was statistically associated with hip abduction angles > 55°, as measured via postreduction CT scans [26]. This discrepancy in the literature, per se, implicates further research on the topic, as DDH has long-term sequelae, such as chronic hip pain, abnormal gait with leg-length discrepancy and early degenerative hip disease. Additional research on this topic would warrant improving future interventions and the timing of these interventions, i.e., the age at which surgeons choose to operate and the length of follow-up (long-term vs. short-term). The use of prospective study designs on a larger population scale is still needed to eliminate the controversy and variability in study outcomes. Some implications can be used in a real-world context, as surgeons can still try to manipulate the femoral head with the angle being as limited as possible to lower the chances of AVN, given that a relationship exists, provided that the angle is also sufficient for achieving concentric reduction of the femoral head into the acetabulum and prevention of the aforementioned long-term sequelae. This type of study shows usefulness in achieving both the main goal of determining the relationship between the risk of AVN and the abduction angle and the second goal of exploring the relationship between the abduction angle and other factors, such as laterality and age. Building this knowledge using already existing data—the data were secondarily collected from hospital archives—makes this study efficient and cost-effective. However, it has several limitations, such as convenience sampling, which is not representative of the general population. Furthermore, data extracted from radiographs are prone to image inaccuracy and rater reliability. Misclassification bias could be an issue. The length of follow-up is too short to detect all actual AVN cases. Although the sample size was not large enough, this can be explained by the small number of DDH cases, the choice of treatment modalities other than closed reduction and the failure of attempts at closed reduction. Conclusion In conclusion, closed reduction remains an effective treatment option for many patients with DDH, although the risk of AVN remains a concern for both the patient and the surgeon. This study demonstrated that left and right Salter are not influenced by the degree of abduction in closed reduction. Patients with bilateral DDH were found to have significant concordance between the left and right sides. Moreover, the degree of abduction was influenced by the grade according to the IHDI classification. The patients in this study were followed for one year after closed reduction, which means that the results of this study are early-term results, which warrants further research to accurately identify the risks that lead to AVN and other complications following closed reduction and to refine interventional practices, patient care and clinical outcomes. Declarations Ethics approval and consent to participate: This study ensured patient confidentiality and received approval from Jordan University Hospital (JUH) and the Institutional Review Board ethics committee (IRB) at the University of Jordan, Patients were also consented to participate. Consent for publication was obtained. Data and Materials are available upon request There were no Competing interests No funding was needed Authors' contributions: M.Y.: Conception of the work and supervision and review of data collection M.Y., O.S., F.A.: Revised the manuscript B.A., D.K., R.B., N.M, B.T., J.A., O.A.: Data Collection, Interpretation of data, Literature review, Draft writing J.A.: Data Analysis and results All authors reviewed the manuscript Acknowledgements: All contributing authors were added to the list of authors References Vaquero-Picado A, González-Morán G, Garay EG, Moraleda L. Developmental dysplasia of the hip: update of management. EFORT Open Rev. 2019 Sep 17;4(9):548-556. doi: 10.1302/2058-5241.4.180019. PMID: 31598333; PMCID: PMC6771078. Bakarman K, Alsiddiky AM, Zamzam M, Alzain KO, Alhuzaimi FS, Rafiq Z. Developmental Dysplasia of the Hip (DDH): Etiology, Diagnosis, and Management. Cureus. 2023 Aug 9;15(8):e43207. doi: 10.7759/cureus.43207. PMID: 37692580; PMCID: PMC10488138. 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Clin Orthop Relat Res 474 , 1166–1177 (2016). Smith, Brian; Millis, Michael; Hey, Lloyd; Jaramillo, Diego*; Kasser, James. Postreduction Computed Tomography in Developmental Dislocation of the Hip: Part II: Predictive Value for Outcome. Journal of Pediatric Orthopedics 17(5):p 631-636, September 1997. Narayanan, U., Mulpuri, K., Sankar, W. N., Clarke, N. M., Hosalkar, H., Price, C. T., & International Hip Dysplasia Institute (2015). Reliability of a New Radiographic Classification for Developmental Dysplasia of the Hip. Journal of pediatric orthopedics, 35(5), 478–484. Salter, R. B., Kostuik, J., & Dallas, S. (1969). Avascular necrosis of the femoral head as a complication of treatment for congenital dislocation of the hip in young children: a clinical and experimental investigation. Canadian journal of surgery. Journal canadien de chirurgie, 12(1), 44–61. Additional Declarations The authors declare no competing interests. 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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-5335761","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":375601767,"identity":"b6bbb07e-c5a1-4a4d-afb6-23b61df982f9","order_by":0,"name":"Mohamad Samih Yasin","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAv0lEQVRIiWNgGAWjYLCCBAYbZhAtwcDARrSWNFK1MDAcZoBqIQLozkh+/OHhjvPsBgeYD97mYeCTI6jF7EaamUTimdvMBgfYkq15GNiMidCSYMaQ2AbSwmMmDdSS2EBYS/rnD4lt54Ba+L8RqyXHQCKx7QDIFjYitZx5UwbUkswseZjN2HKOATF+OZ6++ePPNrtkvuPND2+8qThGOMQYBBLAVDIDODINjhHWwcB/AEzZQbk1RGgZBaNgFIyCkQYAykM3gbzS5lQAAAAASUVORK5CYII=","orcid":"","institution":"The University of Jordan","correspondingAuthor":true,"prefix":"","firstName":"Mohamad","middleName":"Samih","lastName":"Yasin","suffix":""},{"id":375601768,"identity":"67c9e148-aae4-4689-9d0e-80bdf7942505","order_by":1,"name":"Bashar Abukhalaf","email":"","orcid":"","institution":"The University of Jordan","correspondingAuthor":false,"prefix":"","firstName":"Bashar","middleName":"","lastName":"Abukhalaf","suffix":""},{"id":375601769,"identity":"2ee71ab5-7ff3-4510-9bc9-7f1062391387","order_by":2,"name":"Dana Q. Khateeb","email":"","orcid":"","institution":"The University of Jordan","correspondingAuthor":false,"prefix":"","firstName":"Dana","middleName":"Q.","lastName":"Khateeb","suffix":""},{"id":375601770,"identity":"82a975b3-a66f-4c7d-821f-22e202d3d5d9","order_by":3,"name":"Reham Badayneh","email":"","orcid":"","institution":"The University of Jordan","correspondingAuthor":false,"prefix":"","firstName":"Reham","middleName":"","lastName":"Badayneh","suffix":""},{"id":375601771,"identity":"9868c6a3-5ef3-40d2-96bc-de4c1d643b3e","order_by":4,"name":"Nadine Mufleh","email":"","orcid":"","institution":"The University of Jordan","correspondingAuthor":false,"prefix":"","firstName":"Nadine","middleName":"","lastName":"Mufleh","suffix":""},{"id":375601772,"identity":"49bad3a7-9f27-4878-9a13-17ee36d83a38","order_by":5,"name":"Basil Twal","email":"","orcid":"","institution":"The University of Jordan","correspondingAuthor":false,"prefix":"","firstName":"Basil","middleName":"","lastName":"Twal","suffix":""},{"id":375601773,"identity":"5e9a30ab-af1c-4e97-ae1c-db279b37e1cf","order_by":6,"name":"Jehad Feras AlSamhori","email":"","orcid":"","institution":"The University of Jordan","correspondingAuthor":false,"prefix":"","firstName":"Jehad","middleName":"Feras","lastName":"AlSamhori","suffix":""},{"id":375601774,"identity":"01d4dfd5-3c40-4474-bad7-fb9d49053612","order_by":7,"name":"Osama Aldowekat","email":"","orcid":"","institution":"The University of Jordan","correspondingAuthor":false,"prefix":"","firstName":"Osama","middleName":"","lastName":"Aldowekat","suffix":""},{"id":375601775,"identity":"cd893e08-844e-4c74-9948-8e18c3b68cb3","order_by":8,"name":"Omar Q. Samarah","email":"","orcid":"","institution":"The University of Jordan","correspondingAuthor":false,"prefix":"","firstName":"Omar","middleName":"Q.","lastName":"Samarah","suffix":""},{"id":375601776,"identity":"6c37288e-89f4-47b8-a33b-54bc4709a0f9","order_by":9,"name":"Freih O. AbuHassan","email":"","orcid":"","institution":"The University of Jordan","correspondingAuthor":false,"prefix":"","firstName":"Freih","middleName":"O.","lastName":"AbuHassan","suffix":""},{"id":424146435,"identity":"a56b61df-5f11-479c-8e7f-064d66fa3bbe","order_by":10,"name":"Bassem I. Haddad","email":"","orcid":"","institution":"The University of Jordan","correspondingAuthor":false,"prefix":"","firstName":"Bassem","middleName":"I.","lastName":"Haddad","suffix":""}],"badges":[],"createdAt":"2024-10-26 06:08:10","currentVersionCode":2,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-5335761/v2","doiUrl":"https://doi.org/10.21203/rs.3.rs-5335761/v2","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":78849818,"identity":"c9f6b196-39d6-49a8-82f2-0be9a403b4b2","added_by":"auto","created_at":"2025-03-19 18:40:28","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":804137,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5335761/v2/a48f1f70-c9e3-4928-99c1-60473fdc270e.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"Hip Abduction Angle and the Risk of Avascular Necrosis (AVN) After Closed Reduction (CR) in Developmental Dysplasia of the Hip (DDH)","fulltext":[{"header":"Introduction","content":"\u003cp\u003eDevelopmental\u0026nbsp;dysplasia\u0026nbsp;of the\u0026nbsp;hip\u0026nbsp;(DDH) represents a spectrum of abnormalities in the development of the hip joint, encompassing subluxation and dislocation [1,2]. It is the most common pediatric orthopedic condition [3], affecting approximately\u0026nbsp;5\u0026ndash;13\u0026nbsp;per 1000 live births worldwide [1-2], with a\u0026nbsp;relatively high\u0026nbsp;prevalence in females and breech presentations [1-5]. A systematic review led by M. de Hundt et al. explored\u0026nbsp;other possible factors,\u0026nbsp;such as familial aggregation and clicking hips [5]. Early detection and management are crucial\u0026nbsp;for preventing\u0026nbsp;long-term complications such as osteoarthritis and avascular necrosis of the hip (AVN). [1,3-5]\u003c/p\u003e\n\u003cp\u003eManagement of DDH varies on\u0026nbsp;the basis of\u0026nbsp;age and the response to interventions, but generally,\u0026nbsp;the main goal of managing DDH is to achieve concentric reduction of the hip within the acetabulum while mitigating the potential risks of avascular necrosis or osteoarthrosis that may arise.\u0026nbsp;[1,5-9] Typically,\u0026nbsp;the\u0026nbsp;Pavlik harness (dynamic hip abduction orthosis) is the treatment of choice for children up to 6 months of age. Closed\u0026nbsp;reduction and spica\u0026nbsp;casting\u0026nbsp;for at least 3 months is usually the next step for children up to 18 months of age,\u0026nbsp;whereas\u0026nbsp;open reduction and surgical osteotomies are preserved for older children or those who\u0026nbsp;fail\u0026nbsp;less invasive treatments.\u0026nbsp;[1,6-8]\u003c/p\u003e\n\u003cp\u003eClosed reduction (CR), a cornerstone in the treatment of DDH, aims to restore the normal anatomy\u0026nbsp;of the hip joint\u0026nbsp;by manipulating the femoral head back into the acetabulum without surgical exposure [9-10,12]. However, despite its widespread adoption, closed reduction is not without\u0026nbsp;risk. One of the most feared complications associated with closed reduction of DDH,\u0026nbsp;with an incidence that varies widely between 2% and 36% [9-10,12-13],\u0026nbsp;is avascular necrosis,\u0026nbsp;which is\u0026nbsp;characterized by the interruption of\u0026nbsp;the\u0026nbsp;blood supply to the femoral head, leading to ischemic necrosis and potential long-term sequelae [1,10-12].\u003c/p\u003e\n\u003cp\u003eWhile closed reduction is a promising approach for managing DDH, clinicians must be vigilant with respect to the risk of AVN. Understanding the factors predisposing patients to AVN postreduction is paramount for optimizing treatment strategies and minimizing complications. Many recent studies have discussed the risk factors predisposing patients to AVN after closed reduction; however, debates persist, highlighting the need for a more thorough identification of risk factors for AVN for both prognostic and preventive aims. Our hypothesis was that an increased hip abduction angle in the spica cast following CR leads to avascular necrosis of the hip. Therefore, in this study, we aimed primarily to explore the relationship between an increased angle of hip abduction and the risk of developing avascular necrosis (AVN) in patients with DDH treated by closed reduction and spica cast immobilization and to investigate other factors that may contribute to AVN.\u003c/p\u003e"},{"header":"Methodology","content":"\u003cp\u003eThe present study\u0026nbsp;adopted\u0026nbsp;a retrospective cohort design to investigate the relationship between\u0026nbsp;the\u0026nbsp;hip abduction angle and avascular necrosis (AVN)\u0026nbsp;rate\u0026nbsp;in patients with developmental dysplasia of the hip (DDH) treated\u0026nbsp;with\u0026nbsp;closed reduction and spica cast immobilization.\u0026nbsp;The study included 74 patients with a diagnosis of a subluxated or dislocated hip, all within the age range of up to 20 months, requiring closed reduction under general anesthesia in the operating room plus spica cast application, computed tomography (CT)\u0026nbsp;scanning\u0026nbsp;following reduction, and a minimum of 12 months of clinical and radiographic follow-up. Patients with neuromuscular disease or teratologic dislocations,\u0026nbsp;a\u0026nbsp;history of open reduction, incomplete or missed radiographic data,\u0026nbsp;a\u0026nbsp;history of prior unsuccessful treatment, and\u0026nbsp;the\u0026nbsp;onset of avascular necrosis (AVN) after subsequent surgery were excluded from the study.\u003c/p\u003e\n\u003cp\u003eThe data and radiograph results were retrieved from medical records and the electronic medical\u0026nbsp;records\u0026nbsp;system at Jordan University Hospital (JUH)\u0026nbsp;from 2016--2022. Jordan University\u0026nbsp;Hospital (JUH) is\u0026nbsp;a\u0026nbsp;tertiary medical center that lies\u0026nbsp;northwest\u0026nbsp;of the capital Amman and provides\u0026nbsp;health care for\u0026nbsp;approximately\u0026nbsp;half\u0026nbsp;a\u0026nbsp;million patients\u0026nbsp;a year, from\u0026nbsp;all over the country,\u0026nbsp;as\u0026nbsp;outpatients, inpatients,\u0026nbsp;emergents\u0026nbsp;and other services.\u003c/p\u003e\n\u003cp\u003eThis study captured the sociodemographic characteristics of the samples, including but not limited to age,\u0026nbsp;sex, and the presence of comorbidities.\u0026nbsp;Preoperative\u0026nbsp;plain radiographs were reviewed to determine the presence of subluxation or dislocation. If dislocation was present, it was classified according to the IHDI system. This classification uses the position of the proximal femoral metaphysis, rather than the ossific nucleus, as the key reference point for determining\u0026nbsp;the\u0026nbsp;hip location [27]. Additionally, the characteristics of DDH, including unilaterality or bilaterality, and the presence of a femoral ossific nucleus were also assessed.\u003c/p\u003e\n\u003cp\u003ePostoperative\u0026nbsp;computed tomography (CT) findings were reviewed to measure the hip abduction angle.\u0026nbsp;Plain radiographs at follow-ups were reviewed to look for the development of AVN. The Salter\u0026nbsp;criteria\u0026nbsp;were used to assess the presence of AVN. These criteria include (1) failure of the ossific nucleus of the femoral head to appear for one year or longer after reduction\u0026nbsp;and\u0026nbsp;(2) lack of growth in an existing ossific nucleus for one year or longer after\u003c/p\u003e\n\u003cp\u003ereduction, (3) broadening of the femoral neck within one year after reduction, (4) increased radiographic density of the femoral head followed by the appearance of fragmentation on radiographs, and (5) residual deformities of the femoral head and neck after reossification is complete. These deformities include coxa magna, coxa plana, coxa vara, and a short, broad femoral neck. [28]. The senior authors reviewed all\u0026nbsp;the\u0026nbsp;radiographs.\u003c/p\u003e\n\u003cp\u003eThe findings from the arthrogram-guided CR were documented when performed intraoperatively, along with any additional adductor tenotomy procedures that were conducted.\u003c/p\u003e\n\u003cp\u003eThis study ensured\u0026nbsp;patient\u0026nbsp;confidentiality and received approval from Jordan University Hospital (JUH) and\u0026nbsp;the\u0026nbsp;Institutional Review Board ethics committee (IRB) at the University of Jordan.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eanalysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSPSS version 28.0 (Chicago, USA) was used for statistical analysis. Variability analysis in the form of the mean (standard deviation) and the range were used to describe the data. Sociodemographic factors were provided as frequencies (percentages) via standard descriptive statistical parameters. The normality of the distribution of variables was examined via the Shapiro\u0026ndash;Wilk test. Pearson\u0026rsquo;s chi-square test or Fisher\u0026apos;s exact test was used to investigate the associations between the Hill‐bone CHBPTS adherence groups and other categorical variables at a 95% confidence interval. A p value \u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec2\" class=\"Section2\"\u003e \u003ch2\u003eDemographic and medical characteristics\u003c/h2\u003e \u003cp\u003eSeventy-four children were enrolled, with a mean age of 7.29 ± 2.71 months (mean ± SD) and a range of 15 weeks (4–19). Bilateral developmental dysplasia of the hip (DDH) was reported in 38 patients (51.4%), whereas a positive medical history for the children themselves or a family history of DDH was reported in 5 patients (7.6%). The mean right and left abduction angles were 60.37° ± 8.03° and 59.53° ± 7.12°, respectively. The mean right and left IHDI scores were 3.13 ± 0.7 and 3.38 ± 0.67, respectively. Finally, the mean right and left Salter indices were 0.48 ± 1.13 and 0.55 ± 1.29, respectively. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows the frequency of the cohort characteristics.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\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\u003e\u003cem\u003eDemographic and medical characteristics. (n = 74)\u003c/em\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003c/colgroup\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\u003eFrequency (%)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMean ± SD\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eRange (min – max)\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6 (8.1)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.\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=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e68 (91.9)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge (months)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.29 ± 2.71\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15 (4–19)\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSite\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20 (27.0)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16 (21.6)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBilateral\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e38 (51.4)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePast medical history\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNegative\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e61 (92.4)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePositive\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5 (7.6)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFamily history of DDH\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNegative\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e61 (92.4)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePositive\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5 (7.6)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRight abduction (degree)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e60.37 ± 8.03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e35 (43–78)\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLeft abduction (degree)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e59.53 ± 7.12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e31 (43–74)\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRight IHDI\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.13 ± 0.7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (2–4)\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLeft IHDI\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.38 ± 0.67\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (2–4)\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRight Salter\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.48 ± 1.13\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 (0–4)\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLeft Salter\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.55 ± 1.29\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 (0–4)\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eDDH: developmental dysplasia of the hip; IHDI: International Hip Dysplasia Institute; SD: standard deviation.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003ePearson correlation was conducted to investigate the potential associations between right and left abduction, the IHDI, and Salter. There was a significant positive strong correlation between right and left Salter (r = 0.793, p \u0026lt; 0.001). Furthermore, there were significant positive moderate associations between right and left abduction (r = 0.335, p = 0.043) and between right and left IHDI (r = 0.336, p = 0.039). Finally, there were significant positive weak associations between left IHDI and left Salter (r = 0.261, p = 0.047) and between left Salter and age (r = 0.264, p = 0.047). Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the Pearson correlation.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\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\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003cem\u003eCorrelations between the IHDI score, the Salter index, abduction, and age in pediatric patients.\u003c/em\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"8\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRight abduction\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLeft abduction\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRight IHDI\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLeft IHDI\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eRight Salter\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eLeft salter\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRight abduction\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ePearson Correlation coefficient (r)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.335*\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.070\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.071\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e− 0.228\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e− 0.115\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eP value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.043\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.617\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.674\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.493\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLeft abduction\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ePearson Correlation coefficient (r)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.335*\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.082\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e− 0.036\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.099\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.136\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eP value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e0.043\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.625\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.793\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.553\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.314\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRight IHDI\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ePearson Correlation coefficient (r)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.070\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.082\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.336*\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.182\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.149\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eP value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.617\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.625\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.039\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.188\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.372\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLeft IHDI\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ePearson Correlation coefficient (r)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.071\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e− 0.036\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.336*\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e− 0.048\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.261*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eP value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.674\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.793\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.039\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.773\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e0.047\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRight Salter\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ePearson Correlation coefficient (r)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e− 0.228\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.099\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.182\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e− 0.048\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.793*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eP value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.100\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.553\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.188\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.773\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt; 0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLeft salter\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ePearson Correlation coefficient (r)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e− 0.115\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.136\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.149\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.261*\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.793*\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eP value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.493\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.314\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.372\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.047\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt; 0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ePearson Correlation coefficient (r)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.109\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.052\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.219\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.129\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.257\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.264*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eP value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.432\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.704\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.111\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.337\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.061\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e0.047\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"8\"\u003e*Correlation is significant at the 0.05 level (two-tailed).\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eAvascular necrosis (AVN) is a complication that occurs after closed reduction (CR) of developmental dysplasia of the hip (DDH). While several studies have reported several risk factors for developing AVN after CR [1–12], the abduction angle to which the femoral head has been reduced plays a significant role [10]. The aim of treatment is to obtain stable reduction of the hip while limiting the risk of AVN. Therefore, this study was conducted to explore the potential relationship between the hip abduction angle and the development of AVN.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eSimilar to earlier studies on various possible factors related to AVN, including age at the onset of treatment [14], sex [13], severity of hip dislocation at treatment [15], and laterality (unilateral/bilateral DDH) [16], our current study considered the age of the patient, sex, laterality of their DDH, and past medical history and family history of DDH. Most patients were female, were medically free, had bilateral DDH, and had a negative family history of DDH.\u003c/p\u003e\u003cp\u003eOur results revealed a statistically significant relationship between the right and left sides, which means that if a patient develops AVN on one side, the other side is likely to also be affected as a positive relationship exists between the two sides, indicating that there might be patient-related factors, such as the vascularity of the area, warranting further research. Additionally, there was a statistically significant relationship between the right and left abduction angles, meaning that the surgeon is likely to apply the same abduction angle on both sides during the intervention, making this study a useful resource for surgeons to consider adopting extreme care for both sides. A statistically significant relationship between the right and left IHDI scores was found, indicating that the degree of subluxation or dislocation on one side matches that on the other side. Additionally, a statistically significant relationship was found between the left IHDI and left Salter; that is, having a certain subluxation/dislocation grade on the left side influences the development of AVN on the same side, and finally, there was a statistically significant relationship between the left Salter and age—that is, the age at the time of reduction affects the development of AVN on the left side.\u003c/p\u003e\u003cp\u003eA moderately positive statistically significant relationship was found between abduction angle and IHDI grade. No statistically significant relationship was found between abduction angle and the Salter criteria for AVN on the basis of p values, which answers our research problem.\u003c/p\u003e\u003cp\u003eThese results are somewhat concordant with the previously reviewed literature [10–12], although previous studies that considered excessive hip abduction as a potential risk factor for AVN lacked consistent conclusions [1][10][11]. The effects of AVN-related variables were not parallel, which could be due to differences in the definitions of AVN and the timing of follow-up. Additionally, previous studies reported discrepant rates of AVN, ranging from 0–67% [17]. These wide variations are likely due to common cause variation, which is difficult to eliminate, or they could be because of special cause variations, such as differences in technique, surgeon factors or systematic differences in the way that a study is run [18].\u003c/p\u003e\u003cp\u003eHowever, our study is similar to the relevant literature, as Liu YH et al. [19] reported that an abduction angle of up to 70.2° following CR did not increase the AVN rate in children aged six to 28 months with late-detected DDH treated by CR. Additionally, Schur MD et al. [13] reported no significant association between hip abduction and AVN in DDH patients older than six months of age at the time of CR, although they reported that in patients under six months of age at the time of CR, a hip abduction angle \u0026gt; 50° may significantly increase the risk of AVN, which is consistent with the results of our study in terms of age and the Salter AVN association. Similarly, the age at the time of the first visit tended to be younger in those who developed AVN at the follow-up [20]. The more severe forms of avascular necrosis were found to be most prevalent in those patients in whom treatment began between birth and the age of six months [21]. This finding is consistent with our findings that a relationship between age and the development of AVN exists, even if weakly so. A systematic review of 538 hips that achieved CR revealed that the overall rate of AVN at the 7.6-year follow-up was only 10% [22]. Another similar result to our study revealed a nonsignificant reduction in the incidence of AVN when the hip abduction angle was reduced [23]. In terms of the relationship between the IHDI grade and the development of AVN, which was positive on the left side in our study, the incidence of AVN increased with the grade of dislocation [11]. A higher preoperative IHDI grade (IHDI 3–4) was a significant risk factor for AVN (P = 0.032) in patients older than 10 months [24], and the degree of initial dislocation was a significant risk factor for AVN [25].\u003c/p\u003e\u003cp\u003eIn contrast to our findings, some existing studies reported otherwise different correlations between the age of the patient and the risk of AVN. Bian Z et al. [11] reported that age at reduction was not a significant factor for the occurrence of AVN, that age at reduction (\u0026gt; 12 months versus ≤ 12 months) was not associated with osteonecrosis after closed reduction [25], and that the risk of osteonecrosis was unaffected by age at CR (P = 0.745) [12]. Regarding the relationship between the abduction angle and Salter AVN, Smith et al. reported that the subsequent development of avascular necrosis was statistically associated with hip abduction angles \u0026gt; 55°, as measured via postreduction CT scans [26].\u003c/p\u003e\u003cp\u003eThis discrepancy in the literature, per se, implicates further research on the topic, as DDH has long-term sequelae, such as chronic hip pain, abnormal gait with leg-length discrepancy and early degenerative hip disease. Additional research on this topic would warrant improving future interventions and the timing of these interventions, i.e., the age at which surgeons choose to operate and the length of follow-up (long-term vs. short-term). The use of prospective study designs on a larger population scale is still needed to eliminate the controversy and variability in study outcomes.\u003c/p\u003e\u003cp\u003eSome implications can be used in a real-world context, as surgeons can still try to manipulate the femoral head with the angle being as limited as possible to lower the chances of AVN, given that a relationship exists, provided that the angle is also sufficient for achieving concentric reduction of the femoral head into the acetabulum and prevention of the aforementioned long-term sequelae.\u003c/p\u003e\u003cp\u003eThis type of study shows usefulness in achieving both the main goal of determining the relationship between the risk of AVN and the abduction angle and the second goal of exploring the relationship between the abduction angle and other factors, such as laterality and age. Building this knowledge using already existing data—the data were secondarily collected from hospital archives—makes this study efficient and cost-effective. However, it has several limitations, such as convenience sampling, which is not representative of the general population. Furthermore, data extracted from radiographs are prone to image inaccuracy and rater reliability. Misclassification bias could be an issue. The length of follow-up is too short to detect all actual AVN cases. Although the sample size was not large enough, this can be explained by the small number of DDH cases, the choice of treatment modalities other than closed reduction and the failure of attempts at closed reduction.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, closed reduction remains an effective treatment option for many patients with DDH, although the risk of AVN remains a concern for both the patient and the surgeon. This study demonstrated that left and right Salter are not influenced by the degree of abduction in closed reduction. Patients with bilateral DDH were found to have significant concordance between the left and right sides. Moreover, the degree of abduction was influenced by the grade according to the IHDI classification.\u003c/p\u003e \u003cp\u003eThe patients in this study were followed for one year after closed reduction, which means that the results of this study are early-term results, which warrants further research to accurately identify the risks that lead to AVN and other complications following closed reduction and to refine interventional practices, patient care and clinical outcomes.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate:\u0026nbsp;This study ensured patient confidentiality and received approval from Jordan University Hospital (JUH) and the Institutional Review Board ethics committee (IRB) at the University of Jordan, Patients were also consented to participate.\u003c/p\u003e\n\u003cp\u003eConsent for publication was obtained.\u003c/p\u003e\n\u003cp\u003eData and Materials are available upon request\u003c/p\u003e\n\u003cp\u003eThere were no Competing interests\u003c/p\u003e\n\u003cp\u003eNo funding was needed\u003c/p\u003e\n\u003cp\u003eAuthors\u0026apos; contributions:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eM.Y.: Conception of the work and supervision and review of data collection\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eM.Y., O.S., F.A.: Revised the manuscript\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eB.A., D.K., R.B., N.M, B.T., J.A., O.A.: Data Collection, Interpretation of data, Literature review, Draft writing\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eJ.A.: Data Analysis and results\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll authors reviewed the manuscript\u003c/p\u003e\n\u003cp\u003eAcknowledgements: All contributing authors were added to the list of authors\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eVaquero-Picado A, Gonz\u0026aacute;lez-Mor\u0026aacute;n G, Garay EG, Moraleda L. Developmental dysplasia of the hip: update of management. EFORT Open Rev. 2019 Sep 17;4(9):548-556. doi: 10.1302/2058-5241.4.180019. PMID: 31598333; PMCID: PMC6771078.\u003c/li\u003e\n \u003cli\u003eBakarman K, Alsiddiky AM, Zamzam M, Alzain KO, Alhuzaimi FS, Rafiq Z. Developmental Dysplasia of the Hip (DDH): Etiology, Diagnosis, and Management. Cureus. 2023 Aug 9;15(8):e43207. doi: 10.7759/cureus.43207. PMID: 37692580; PMCID: PMC10488138.\u003c/li\u003e\n \u003cli\u003eSwarup I, Penny CL, Dodwell ER. Developmental dysplasia of the hip: an update on diagnosis and management from birth to 6 months. Curr Opin Pediatr. 2018 Feb;30(1):84-92. doi: 10.1097/MOP.0000000000000574. PMID: 29194074.\u003c/li\u003e\n \u003cli\u003eHarsanyi S, Zamborsky R, Krajciova L, Kokavec M, Danisovic L. Developmental Dysplasia of the Hip: A Review of Etiopathogenesis, Risk Factors, and Genetic Aspects. Medicina (Kaunas). 2020 Mar 31;56(4):153. doi: 10.3390/medicina56040153. PMID: 32244273; PMCID: PMC7230892.\u003c/li\u003e\n \u003cli\u003ede Hundt M, Vlemmix F, Bais JM, Hutton EK, de Groot CJ, Mol BW, Kok M. Risk factors for developmental dysplasia of the hip: a meta-analysis. Eur J Obstet Gynecol Reprod Biol. 2012 Nov;165(1):8-17. doi: 10.1016/j.ejogrb.2012.06.030. Epub 2012 Jul 21. PMID: 22824571.\u003c/li\u003e\n \u003cli\u003eYang S, Zusman N, Lieberman E, Goldstein RY. Developmental Dysplasia of the Hip. Pediatrics. 2019 Jan;143(1):e20181147. doi: 10.1542/peds.2018-1147. PMID: 30587534.\u003c/li\u003e\n \u003cli\u003eYoung JR, Anderson MJ, O\u0026apos;Connor CM, Kazley JM, Mantica AL, Dutt V. Team Approach: Developmental Dysplasia of the Hip. JBJS Rev. 2020 Sep;8(9):e20.00030. doi: 10.2106/JBJS.RVW.20.00030. PMID: 32890048.\u003c/li\u003e\n \u003cli\u003eAl-Essa RS, Aljahdali FH, Alkhilaiwi RM, Philip W, Jawadi AH, Khoshhal KI. Diagnosis and treatment of developmental dysplasia of the hip: A current practice of pediatric orthopedic surgeons. J Orthop Surg (Hong Kong). 2017 May-Aug;25(2):2309499017717197. doi: 10.1177/2309499017717197. PMID: 28659058.\u003c/li\u003e\n \u003cli\u003eZhang G, Li M, Qu X, Cao Y, Liu X, Luo C, Zhang Y. Efficacy of closed reduction for developmental dysplasia of the hip: midterm outcomes and risk factors associated with treatment failure and avascular necrosis. J Orthop Surg Res. 2020 Dec 2;15(1):579. doi: 10.1186/s13018-020-02098-3. PMID: 33267908; PMCID: PMC7709328.\u003c/li\u003e\n \u003cli\u003eKheiri S, Tahririan MA, Shahnaser S, Ardakani MP. Avascular necrosis predictive factors after closed reduction in patients with developmental dysplasia of the hip. J Res Med Sci. 2023 Nov 30;28:81. doi: 10.4103/jrms.jrms_288_23. PMID: 38292338; PMCID: PMC10826850.\u003c/li\u003e\n \u003cli\u003eBian Z, Guo Y, Lyu X, Zhu Z, Yang Z, Wang Y. Risk Factors for Avascular Necrosis After Closed Reduction for Developmental Dysplasia of the Hip. J Pediatr Orthop. 2022 Oct 1;42(9):467-473. doi: 10.1097/BPO.0000000000002228. Epub 2022 Aug 11. PMID: 35948526; PMCID: PMC9470038.\u003c/li\u003e\n \u003cli\u003eSankar WN, Gornitzky AL, Clarke NMP, Herrera-Soto JA, Kelley SP, Matheney T, Mulpuri K, Schaeffer EK, Upasani VV, Williams N, Price CT; International Hip Dysplasia Institute. Closed Reduction for Developmental Dysplasia of the Hip: Early-term Results From a Prospective, Multicenter Cohort. J Pediatr Orthop. 2019 Mar;39(3):111-118. doi: 10.1097/BPO.0000000000000895. PMID: 30730414; PMCID: PMC6416015.\u003c/li\u003e\n \u003cli\u003eSchur MD, Lee C, Arkader A, Catalano A, Choi PD. Risk factors for avascular necrosis after closed reduction for developmental dysplasia of the hip. J Child Orthop. 2016 Jun;10(3):185-92. doi: 10.1007/s11832-016-0743-7. Epub 2016 May 13. PMID: 27177477; PMCID: PMC4909658.\u003c/li\u003e\n \u003cli\u003eKruczynski J. Avascular necrosis of the proximal femur in developmental dislocation of the hip. Incidence, risk factors, sequelae and MR imaging for diagnosis and prognosis. Acta Orthop Scand Suppl. 1996 Apr;268:1-48. PMID: 8629451.\u003c/li\u003e\n \u003cli\u003eSibiński M, Synder M, Domzalski M, Grzegorzewski A. Risk factors for avascular necrosis after closed hip reduction in developmental dysplasia of the hip. Ortop Traumatol Rehabil. 2004 Feb 28;6(1):60-6. PMID: 17676009.\u003c/li\u003e\n \u003cli\u003eMorbi AH, Carsi B, Gorianinov V, Clarke NM. Adverse Outcomes in Infantile Bilateral Developmental Dysplasia of the Hip. J Pediatr Orthop. 2015 Jul-Aug;35(5):490-5. doi: 10.1097/BPO.0000000000000310. PMID: 25171675.\u003c/li\u003e\n \u003cli\u003eChen C, Doyle S, Green D, Blanco J, Scher D, Sink E, Dodwell ER. Presence of the Ossific Nucleus and Risk of Osteonecrosis in the Treatment of Developmental Dysplasia of the Hip: A Meta-Analysis of Cohort and Case\u003cins cite=\"mailto:Editor\" datetime=\"2024-10-26T04:01\"\u003e‒\u003c/ins\u003eControl Studies. J Bone Joint Surg Am. 2017 May 3;99(9):760-767. doi: 10.2106/JBJS.16.00798. PMID: 28463920.\u003c/li\u003e\n \u003cli\u003ePerry DC, Parsons N, Costa ML. Surgeon level data. Bone Joint J. 2013;95-B(9):1156-1157. doi:10.1302/0301-620X.95B9.32782\u003c/li\u003e\n \u003cli\u003eLiu YH, Xu HW, Li YQ, et al. Effect of abduction on avascular necrosis of the femoral epiphysis in patients with late-detected developmental dysplasia of the hip treated by closed reduction: A MRI study of 59 hips. Journal of Children\u0026rsquo;s Orthopedics. 2019;13(5):438-444. doi:10.1302/1863-2548.13.1900451.\u003c/li\u003e\n \u003cli\u003eAl Faleh AF, Jawadi AH, Sayegh SA, Al Rashedan BS, Al Shehri M, Al Shahrani A. Avascular necrosis of the femoral head: Assessment following developmental dysplasia of the hip management. Int J Health Sci (Qassim). 2020 Jan-Feb;14(1):20-23. PMID: 31983917; PMCID: PMC6968880.\u003c/li\u003e\n \u003cli\u003eKalamchi, A; MacEwen, G D. Avascular necrosis following treatment of congenital dislocation of the hip.. The Journal of Bone \u0026amp; Joint Surgery 62(6):p 876-888, Sep 1980.\u003c/li\u003e\n \u003cli\u003eBradley CS, Perry DC, Wedge JH, Murnaghan ML, Kelley SP. Avascular necrosis following closed reduction for treatment of developmental dysplasia of the hip: A systematic review. Journal of Children\u0026rsquo;s Orthopedics. 2016;10(6):627-632. doi:10.1007/s11832-016-0776-y\u003c/li\u003e\n \u003cli\u003eMadhu TS, Akula M, Scott BW, Templeton PA. Treatment of developmental dislocation of hip: does changing the hip abduction angle in the hip spica affect the rate of avascular necrosis of the femoral head? J Pediatr Orthop B. 2013 May;22(3):184-8. doi: 10.1097/BPB.0b013e32835ec690. PMID: 23407430.\u003c/li\u003e\n \u003cli\u003eBozkurt C, Sarikaya B, Sipahioğlu S, \u0026Ccedil;etin BV, Bekin Sarikaya PZ, Kaptan AY, Altay MA. Evaluation of avascular necrosis risk factors after closed reduction for developmental dysplasia of the hip before walking age. J Pediatr Orthop B. 2022 May 1;31(3):237-241. doi: 10.1097/BPB.0000000000000846. PMID: 34116555.\u003c/li\u003e\n \u003cli\u003eNovais, E.N., Hill, M.K., Carry, P.M.\u0026nbsp;et al\u003cem\u003e.\u003c/em\u003e Is Age or Surgical Approach Associated With Osteonecrosis in Patients With Developmental Dysplasia of the Hip? A Meta-analysis. \u003cem\u003eClin Orthop Relat Res\u003c/em\u003e \u003cstrong\u003e474\u003c/strong\u003e, 1166\u0026ndash;1177 (2016).\u003c/li\u003e\n \u003cli\u003eSmith, Brian; Millis, Michael; Hey, Lloyd; Jaramillo, Diego*; Kasser, James. Postreduction Computed Tomography in Developmental Dislocation of the Hip: Part II: Predictive Value for Outcome. Journal of Pediatric Orthopedics 17(5):p 631-636, September 1997.\u003c/li\u003e\n \u003cli\u003eNarayanan, U., Mulpuri, K., Sankar, W. N., Clarke, N. M., Hosalkar, H., Price, C. T., \u0026amp; International Hip Dysplasia Institute (2015). Reliability of a New Radiographic Classification for Developmental Dysplasia of the Hip.\u0026nbsp;Journal of pediatric orthopedics,\u0026nbsp;35(5), 478\u0026ndash;484.\u003c/li\u003e\n \u003cli\u003eSalter, R. B., Kostuik, J., \u0026amp; Dallas, S. (1969). Avascular necrosis of the femoral head as a complication of treatment for congenital dislocation of the hip in young children: a clinical and experimental investigation. Canadian journal of surgery. Journal canadien de chirurgie, 12(1), 44\u0026ndash;61.\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":"Avascular Necrosis, AVN, Closed Reduction, DDH, Hip Abduction Angle, Salter","lastPublishedDoi":"10.21203/rs.3.rs-5335761/v2","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5335761/v2","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjectives\u003c/h2\u003e \u003cp\u003eDevelopmental dysplasia of the hip (DDH) is a prevalent pediatric orthopedic condition with a prevalence of 5\u0026ndash;13 per 1000 live births worldwide. Early detection and management are paramount to mitigate long-term complications such as osteoarthritis and avascular necrosis of the hip (AVN). While various interventions exist, closed reduction (CR) and spica casting play pivotal roles in restoring normal hip anatomy. Given that AVN is a significant concern after CR, we aimed to investigate the correlation between the hip abduction angle in the spica and the risk of AVN.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis retrospective cohort study was conducted at Jordan University Hospital from 2016\u0026ndash;2022. A total of 74 patients, aged up to 20 months, underwent CR, which was followed by CT scans with a minimum 12-month follow-up. CT scans were used for calculating the hip abduction angle, and X-rays were used for determining the Salter classification of AVN.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe mean age at the time of CR was 7.29\u0026thinsp;\u0026plusmn;\u0026thinsp;2.71 months. Fifty-one percent of the patients had bilateral DDH, and 7.6% had a positive personal or family history of DDH. The mean right and left abduction angles were 60.37\u0026deg; \u0026plusmn; 8.03\u0026deg; and 59.53\u0026deg; \u0026plusmn; 7.12\u0026deg;, respectively. The mean right and left International Hip Dysplasia Institute (IHDI) scores were 3.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7 and 3.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67, respectively. The mean right and left Salter AVN indices were 0.48\u0026thinsp;\u0026plusmn;\u0026thinsp;1.13 and 0.55\u0026thinsp;\u0026plusmn;\u0026thinsp;1.29, respectively. There were statistically significant relationships between right and left Salter (r\u0026thinsp;=\u0026thinsp;0.793, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), between right and left abduction angles (r\u0026thinsp;=\u0026thinsp;0.335, p\u0026thinsp;=\u0026thinsp;0.043), between right and left IHDI grades (r\u0026thinsp;=\u0026thinsp;0.336, p\u0026thinsp;=\u0026thinsp;0.039), between left IHDI grades and left Salter (r\u0026thinsp;=\u0026thinsp;0.261, p\u0026thinsp;=\u0026thinsp;0.047), and between left Salter and age (r\u0026thinsp;=\u0026thinsp;0.264, p\u0026thinsp;=\u0026thinsp;0.047). Neither the right nor the left abduction angle was associated with increased right or left Salter AVN grade, as indicated by the p values.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eIf a patient develops AVN on one side, the other side is also likely to be affected; however, the degree of abduction in CR does not correlate with the AVN rate. There was a correlation between the degree of abduction and the degree of subluxation/dislocation. Additionally, age at reduction is correlated with the risk of AVN.\u003c/p\u003e","manuscriptTitle":"Hip Abduction Angle and the Risk of Avascular Necrosis (AVN) After Closed Reduction (CR) in Developmental Dysplasia of the Hip (DDH)","msid":"","msnumber":"","nonDraftVersions":[{"code":2,"date":"2025-03-19 18:32:21","doi":"10.21203/rs.3.rs-5335761/v2","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}},{"code":1,"date":"2024-11-08 06:41:03","doi":"10.21203/rs.3.rs-5335761/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":"9fa66724-a1f1-488f-ab1b-41a059c30254","owner":[],"postedDate":"March 19th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-11-12T11:08:52+00:00","versionOfRecord":[],"versionCreatedAt":"2025-03-19 18:32:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v2","identity":"rs-5335761","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5335761","identity":"rs-5335761","version":["v2"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}