Genetics of hip dysplasia - a systematic literature review.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a congenital condition affecting 2-3% of all newborns. DDH increases the risk of osteoarthritis and is the cause of 30% of all total hip arthroplasties in adults < 40 years of age. We aim to explore the genetic background of DDH in order to improve diagnosis and personalize treatment. METHODS: We conducted a structured literature review using PRISMA guidelines searching the Medline, Embase and Cochrane databases. We included 31 case control studies examining single nucleotide polymorphisms (SNPs) in non-syndromic DDH. RESULTS: A total of 73 papers were included for full text review, of which 31 were single nucleotide polymorphism (SNP) case/control association studies. The literature review revealed that the majority of published papers on the genetics of DDH were mostly underpowered for detection of any significant association. One large genome wide association study has been published (N = 9,915), establishing GDF5 as a plausible risk factor. CONCLUSIONS: DDH is known to be congenital and heritable, with family occurrence of DDH already included as a risk factor in most screening programs. Despite this, high quality genetic research is scarce and no genetic risk factors have been soundly established, prompting the need for more research.

Using 2D U-Net convolutional neural networks for automatic acetabular and proximal femur segmentation of hip MRI images and morphological quantification: a preliminary study in DDH.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a common pediatric orthopedic condition characterized by varying degrees of acetabular dysplasia and hip dislocation. Current 2D imaging methods often fail to provide sufficient anatomical detail for effective treatment planning, leading to higher rates of misdiagnosis and missed diagnoses. MRI, with its advantages of being radiation-free, multi-planar, and containing more anatomical information, can provide the crucial morphological and volumetric data needed to evaluate DDH. However, manual techniques for measuring parameters like the center-edge angle (CEA) and acetabular index (AI) are time-consuming. Automating these processes is essential for accurate clinical assessments and personalized treatment strategies. METHODS: This study employed a U-Net-based CNN model to automate the segmentation of hip MRI images in children. The segmentation process was validated using a leave-one-out method during training. Subsequently, the segmented hip joint images were utilized in clinical settings to perform automated measurements of key angles: AI, femoral neck angle (FNA), and CEA. This automated approach aimed to replace manual measurements and provide an objective reference for clinical assessments. RESULTS: The U-Net-based network demonstrates high effectiveness in hip segmentation compared to manual radiologist segmentations. In test data, it achieves average DSC values of 0.9109 (acetabulum) and 0.9244 (proximal femur), with a 91.76% segmentation success rate. The average ASD values are 0.3160 mm (acetabulum) and 0.6395 mm (proximal femur) in test data, with Ground Truth (GT) edge points and predicted segmentation maps having a mean distance of less than 1 mm. Using automated segmentation models for clinical hip angle measurements (CEA, AI, FNA) shows no statistical difference compared to manual measurements (p > 0.05). CONCLUSION: Utilizing U-Net-based image segmentation and automated measurement of morphological parameters significantly enhances the accuracy and efficiency of DDH assessment. These methods improve precision in automatic measurements and provide an objective basis for clinical diagnosis and treatment of DDH.

Association between ossific nucleus volume changes and postoperative avascular necrosis risk in children with developmental dysplasia of the hip.

This study aimed to investigate the correlation between ossific nucleus volume and avascular necrosis (AVN) in pediatric patients diagnosed with developmental dysplasia of the hip (DDH). Analyzing 211 cases, including 119 open reduction (OR) and 92 closed reduction (CR) procedures, we quantified ossific nucleus volume using magnetic resonance imaging (MRI). Categorizing the OR group based on ossific nucleus volume revealed no statistically significant difference in AVN incidence. Similarly, in the CR cohort, there was no significant discrepancy in AVN occurrence between subgroups with or without the ossific nucleus. Logistic regression in CR identified the international hip dysplasia institute (IHDI) grade as a significant AVN risk factor (p = 0.007). IHDI grades 3 and 4 exhibited a 6.94 times higher likelihood of AVN compared to grades 1 and 2. Across CR and OR, neither initial age nor ossific nucleus volume emerged as AVN risk factors. In conclusion, ossific nucleus volume does not pose a risk for AVN in DDH children undergoing CR or OR, emphasizing the clinical significance of IHDI grading in predicting AVN risk during CR and the importance of early intervention to prevent treatment delays.

Integration of 3D printing and case-based learning in clinical practice for the treatment of developmental dysplasia of the hip.

BACKGROUND: Case-based learning (CBL) utilizing three-dimensional (3D) printed hip joint models is a problem-solving teaching method that combines the tactile and visual advantages of 3D-printed models with CBL. This study aims to investigate the impact of integrating 3D printing with CBL on learning developmental dysplasia of the hip (DDH). METHODS: We conducted a prospective study from 2022 to 2023, including 120 fourth-year clinical medical students at Xuzhou Medical University. Students were randomly allocated into two groups of 60 participants each. The CBL group received conventional CBL teaching methods, while the 3D + CBL group utilized 3D-printed models in conjunction with CBL. Post-teaching, we analyzed and compared the theoretical and practical achievements of both groups. A questionnaire was designed to assess the impact of the educational approach on orthopedic surgery learning. RESULTS: The theory scores of the CBL group (62.88 ± 7.98) and 3D + CBL group (66.35 ± 8.85) were significantly different (t = 2.254, P = 0.026); the practical skills scores of the CBL group (57.40 ± 8.80) and 3D + CBL group (63.42 ± 11.14) were significantly different (t = 3.283, P = 0.001). The questionnaire results showed that the 3D + CBL group was greater than the CBL group in terms of hip fundamentals, ability to diagnose cases and plan treatments, interesting teaching content, willingness to communicate with the instructor and satisfaction. CONCLUSIONS: The integration of 3D printing with case-based learning has yielded positive outcomes in teaching DDH, providing valuable insights into the use of 3D-printed orthopedic models in clinical education.

[Total hip arthroplasty with supracondylar shortening osteotomy in Crowe 4 inveterate hip dislocation: case report and surgical technique]. / Artroplastía total de cadera con osteotomía de acortamiento supracondílea en luxación inveterada de cadera Crowe 4: caso clínico y técnica quirúrgica.

Structural deformities of the acetabulum secondary to developmental dysplasia of the hip (DDH) are one of the most common causes requiring total hip arthroplasty (THA), whether in conjunction with femoral osteotomy in cases of Crowe dislocation 4. Several techniques have been described, studied, and compared, but there is no superiority of one technique over another. Currently, most hip surgeons perform a subtrochanteric osteotomy. With a follow-up of 10 years, good results have been obtained, so there is a need to present a therapeutic alternative with potential benefits, mainly in restoring the center of rotation of the hip, preserving the proximal bone component, and reducing complications. Therefore, this study aims to describe the surgical technique of CTA in conjunction with supracondylar shortening osteotomy in a 29-year-old female patient, using an uncemented acetabular cup, a short uncemented stem with ceramic-polyethylene bearing, and distal fixation with a 4-hole plate LC-LCP, with the goal of restoring the natural biomechanics of the hip.

Las deformidades estructurales del acetábulo como secuelas de displasia en el desarrollo de la cadera es una de las patologías más frecuentes que ameritan como tratamiento la cirugía de artroplastía total de cadera (ATC) asociada o no a osteotomía femoral en casos de luxación inveterada clasificada como Crowe 4. Múltiples técnicas han sido descritas, estudiadas y comparadas; sin embargo, no existe superioridad de una sobre otra. Actualmente, la osteotomía realizada por la mayoría de los cirujanos de cadera es subtrocantérica, se han reportado buenos resultados a 10 años de seguimiento. La necesidad de presentar una alternativa terapéutica con posibles beneficios, principalmente en la restitución del centro de rotación de la cadera, preservación de componente óseo proximal y disminución de las complicaciones, es meritoria en el campo quirúrgico. Por lo tanto, este estudio se propone describir la técnica quirúrgica de ATC asociada a osteotomía de acortamiento supracondílea en un paciente femenino de 29 años, con uso de copa acetabular no cementada, vástago corto no cementado con par de fricción cerámica-polietileno y fijación distal con placa LC-LCP de cuatro orificios, con el objetivo de restaurar la biomecánica natural de la cadera.

Mid-term outcomes of total hip arthroplasty in patients younger than 30 years.

INTRODUCTION: Total hip arthroplasty (THA) has predominantly been utilized to treat older patients with primary osteoarthritis. However, recent improvements in surgical technique and implant materials have increased implant longevity, making THA a viable option for younger patients (< 30 years old). While trend analyses indicate an expanding utilization of THA in younger patients with non-OA diagnoses, current data on mid- and long-term THA outcomes in this population are limited. This study aims to describe the demographics, perioperative data, and implant survivorship of patients younger than 30 years undergoing THA. METHODS: A retrospective study across two large urban academic medical institutions identified 135 patients aged < 30 years who underwent 155 primary THAs between 2012 and 2017, with up to 10-year clinical follow-up. Baseline demographics, surgical indications, intraoperative details, and postoperative outcomes were analyzed. RESULTS: The mean age at surgery was 24.9 years (range 18-29). Osteonecrosis of the femoral head (55.5%), developmental hip dysplasia (28.3%), and arthritis (15.5%) were the primary indications. Most surgeries utilized the posterior approach (64.5%), manual technique (65.8%), and Ceramic-on-Polyethylene articulation (71.6%). Seven patients (4.5%) were readmitted within 90-days of surgery, including three non-orthopedic-related readmissions (1.9%) and four orthopedic-related readmissions (2.6%). Dislocations were reported in two patients (1.3%). There were six all-cause revisions (3.9%), four aseptic (2.6%) and two septic (1.3%). Kaplan-Meier analysis showed 10-year survival from implant retaining reoperation was 98.7%, 10-year survival from all-cause revision was 96.1%, and 10-year survival from aseptic revision was 97.4%. CONCLUSION: With a 10-year aseptic implant survivorship rate of 97.4%, THA is a reliable surgical intervention for patients younger than 30 years of age who have severe hip pathology. Further studies are warranted for a more comprehensive understanding of mid- and long-term survivorship risk factors in this demanding population, facilitating improved risk assessment and informed surgical decisions.

Protective effect of modified lange "second position" for developing avascular necrosis following closed reduction for developmental dysplasia of the hip.

BACKGROUND: Developmental Dysplasia of the Hip (DDH) is a condition affecting hip joint development in children, presenting multiple manifestations. Immobilization methods to ensure hip concentricity, such as the human position and modified Lange position, vary in effectiveness and risks, especially avascular necrosis. The purpose of this study was to identify whether closed reduction (CR), with two different immobilization techniques, is effective in avoiding complications such as residual hip dysplasia (RHD), re-dislocation, and Avascular Necrosis (AVN). METHODS: A total of 66 patients with DDH (84 hips) were treated with two different techniques of immobilization (groups A and B); the mean age at the time of reduction was 8 (6-13) months. The rates of RHD, Re-dislocation, and AVN were determined with a minimum follow-up of 48 months in both techniques. RESULTS: The Chi-square analysis conducted across the study groups unveiled that patients in Group B demonstrated a protective effect against AVN compared to those in Group A (OR: 0.248, 95% CI: 0.072-0.847, p = 0.026). However, no statistically significant differences were found between the groups concerning RHD (p = 0.563) and re-dislocation (p = 0.909). CONCLUSIONS: After the initial Human Position immobilization, the second cast with the modified Lange "second position" demonstrated a protective effect compared with maintaining the Human Position immobilization throughout the immobilization period, reducing the likelihood of AVN development in patients undergoing closed reduction for developmental dysplasia of the hip.

The diagnostic value of artificial intelligence-assisted imaging for developmental dysplasia of the hip: a systematic review and meta-analysis.

OBJECTIVE: To clarify the efficacy of artificial intelligence (AI)-assisted imaging in the diagnosis of developmental dysplasia of the hip (DDH) through a meta-analysis. METHODS: Relevant literature on AI for early DDH diagnosis was searched in PubMed, Web of Science, Embase, and The Cochrane Library databases until April 4, 2024. The Quality Assessment of Diagnostic Accuracy Studies tool was used to assess the quality of included studies. Revman5.4 and StataSE-64 software were used to calculate the combined sensitivity, specificity, AUC value, and DOC value of AI-assisted imaging for DDH diagnosis. RESULTS: The meta-analysis included 13 studies (6 prospective and 7 retrospective) with 28 AI models and a total of 10,673 samples. The summary sensitivity, specificity, AUC value, and DOC value were 99.0% (95% CI: 97.0-100.0%), 94.0% (95% CI: 89.0-96.0%), 99.0% (95% CI: 98.0-100.0%), and 1342 (95% CI: 469-3842), respectively. CONCLUSION: AI-assisted imaging demonstrates high diagnostic efficacy for DDH detection, improving the accuracy of early DDH imaging examination. More prospective studies are needed to further confirm the value of AI-assisted imaging for early DDH diagnosis.

Residual gait deviations in children treated by medial open reduction for developmental dysplasia of the hip at long-term follow-up: a comparison with healthy controls.

PURPOSE: This study aimed to analyze and compare gait patterns and deviations at long-term follow-up in children who received medial open reduction (MOR) before 18 months for unilateral or bilateral hip developmental dysplasia (DDH). METHODS: A retrospective chart review was conducted on children who underwent MOR. The study population was divided into two groups: the unilateral group, including unilateral (five children with unilateral) and bilateral (five children with bilateral DDH). Ten healthy children were recruited for the control group. Spatiotemporal, kinematic, stiff-knee gait (SKG), and kinetic gait characteristics were analyzed. RESULTS: Stance time was significantly shorter in both the unilateral (median [IQR]; 590 ms, [560.0-612.5] and bilateral (575 ms, [550-637.5]) groups than in the control group (650, [602.5-677.5]) (p < 0.001), whereas swing time did not differ substantially (p = 0.065) There was no considerable difference in the mean knee flexion at swing between the unilateral (31.6°, [30-36]) and control (30.11°, [27.8-33.6] groups (p > 0.05), but the bilateral group (28.5°, [24.9-32.1]) showed the lower values than the other groups (p < 0.001 for bilateral vs unilateral group; p = 0.008 bilateral vs unilateral group). All the SKG parameters significantly differed among the groups in multi-group comparisons (p < 0.001 for each parameter). Three children had borderline SKG, and two had not-stiff limbs in the unilateral group. In the bilateral group, four children had stiff limbs, and one had borderline SKG. Most kinetic gait parameters were not statistically different between groups (p > 0.05). CONCLUSION: This study has revealed notable deviations in gait patterns of children with DDH treated by MOR at long-term follow-up compared to healthy children's gait. MOR could negatively affect pelvic motion during gait due to impaired functions of the iliopsoas and adductor muscles, and SKG can be encountered secondary to iliopsoas weakness.

Two genetic variants in the HIBCH and FTCDNL1 genes are associated with susceptibility to developmental dysplasia of the hips among the Han Chinese population of Southwest China.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a common cause of childhood disability, and the incidence of DDH shows significant familial aggregation. As the genetic factors of DDH remain unknown, the correlation between five candidate single nucleotide polymorphisms (SNPs) and DDH was evaluated in the Han Chinese population of Southwest China. METHODS: A case‒control association study was conducted in 276 patients with DDH and 318 healthy controls. SNP genotyping in the case and control groups was performed by SNPshot and multiple PCR. SNPs were genotyped in the case and control groups by multiplex PCR. The relationship between DDH and candidate SNPs was evaluated using the χ2 test. RESULTS: The genotype distributions of rs291412 in HIBCH and rs769956 in FTCDNL1 were different between the case and control groups (P < 0.05). After genetic model analysis, logistic regression analysis revealed that the C allele of rs291412 had a protective effect on DDH (OR = 0.605, P = 0.010) and that the G allele of rs769956 was a risk factor (OR = 2.939, P = 0.010).s. CONCLUSION: These SNPs could be associated with susceptibility to DDH but larger population-based studies should confirm the current results.

Pediatric hip disorders are not associated with an increased 10-year revision risk after total hip arthroplasty under the age of 55: results from the Dutch Arthroplasty Register.

BACKGROUND AND PURPOSE:  Developmental dysplasia (DDH) and Legg-Calvé-Perthes disease (LCPD) are common indications for total hip arthroplasty (THA) at a young age, and may be associated with increased revision risk. We aimed to investigate the 10-year cumulative aseptic cup revision and overall revision risk of THA, and investigated whether these are increased compared with THA for primary osteoarthritis (OA) in patients below 55 years. METHODS:  All THAs (2007-2019) in patients under the age of 55 for the indications OA, DDH, and LCPD were extracted from the Dutch Arthroplasty register. The 10-year cumulative incidences of aseptic cup failure and overall revision were assessed for the 3 groups, with death as a competing risk. Cox regression analysis was used. RESULTS:  24,263 THAs were identified: 20,645 (85%) for OA, 3,032 (13%) for DDH, and 586 (2%) for LCPD. The 10-year cumulative revision risk for aseptic cup failure was 3.4% (95% confidence interval [CI] 3.0-3.8) for OA, 3.4% (CI 2.4-3.4) for DDH, and 1.7% (CI 0.2-3.1) for LCPD. The 10-year cumulative overall revision risk was 6.0% (CI 5.6-6.5) for OA, 6.0% (CI 4.9-7.2) for DDH, and 5.1% (2.7-7.5) for LCPD. The multivariable Cox regression analysis for aseptic cup failure yielded hazard ratios of 0.7 (0.5-1.2) for DDH, and 0.8 (0.3-2.1) for LCPD compared with OA. No statistically significant differences for overall revision were found. CONCLUSION:  THA performed for DDH or LCDP in patients under the age of 55 was not associated with a statistically significant increased risk of aseptic cup revision or overall revision, compared with THA performed for primary OA in the same age group.

Bimodal machine learning model for unstable hips in infants: integration of radiographic images with automatically-generated clinical measurements.

Bimodal convolutional neural networks (CNNs) are frequently combined with patient information or several medical images to enhance the diagnostic performance. However, the technologies that integrate automatically generated clinical measurements within the images are scarce. Hence, we developed a bimodal model that produced automatic algorithm for clinical measurement (aaCM) from radiographic images and integrated the model with CNNs. In this multicenter research project, the diagnostic performance of the model was investigated with 813 radiographic hip images of infants at risk of developmental dysplasia of the hips (232 and 581 images of unstable and stable hips, respectively), with the ground truth defined by provocative examinations. The results indicated that the accuracy of aaCM was equal or higher than that of specialists, and the bimodal model showed better diagnostic performance than LightGBM, XGBoost, SVM, and single CNN models. aaCM can provide expert's knowledge in a high level, and our proposed bimodal model has better performance than the state-of-art models.

Comparison of brace to observation in stable, radiological developmental dysplasia of the hip: a protocol for a global multicentre non-inferiority randomised trial.

INTRODUCTION: Brace treatment is common to address radiological dysplasia in infants with developmental dysplasia of the hip (DDH); however, it is unclear whether bracing provides significant benefit above careful observation by ultrasound. If observation alone is non-inferior to bracing for radiological dysplasia, unnecessary treatment may be avoided. Therefore, the purpose of this study is to determine whether observation is non-inferior to bracing for infants with radiological dysplasia. METHODS AND ANALYSIS: This will be a multicentre, global, randomised, non-inferiority trial performed under the auspices of a global prospective registry for infants and children diagnosed with DDH. Patients will be included if they present with radiological dysplasia (centred hip, alpha angle 43-60°, percent femoral head coverage greater than 35% measured on ultrasound) of a clinically stable hip under 3 months old. Patients will be excluded if they present with clinical hip instability, have received prior treatment or have known/suspected neuromuscular, collagen, chromosomal or lower-extremity congenital abnormalities or syndromic-associated hip abnormalities. Patients will be enrolled and randomised to undergo observation alone or brace treatment with a Pavlik harness for a minimum of 6 weeks. Follow-up visits will occur at 6 weeks, 1 year and 2 years post-enrolment. The primary outcome will be the norm-referenced acetabular index measured on the 2-year radiograph with a 3° non-inferiority margin. A total of 514 patients will be included.The study is anticipated to start in April 2024 and end in September 2028.The primary outcome will be compared between arms with a mixed-effects model with a random intercept for study centre, and a single covariate for the treatment group. If the lower bound of the 95% CI lies within 3° of the mean, we will treat this as evidence for non-inferiority. ETHICS AND DISSEMINATION: Ethics approval has been obtained from the lead site's ethics board (University of British Columbia, Children's and Women's Research Ethics Board). Ethics approval will be obtained from the local ethics committees or institutional review boards at each institution prior to patient enrolment. It is intended that the results of this study shall be published in peer-reviewed journals and presented at suitable conferences. TRIAL REGISTRATION NUMBER: NCT05869851.

Developmental dysplasia of the hip caused by homozygous TRIM33 pathogenic variant affecting downstream BMP pathway.

BACKGROUND: Developmental dysplasia of the hip (DDH), formerly termed congenital dislocation of the hip, is the most common congenital disease of the musculoskeletal system in newborns. While familial predilection to DDH has been well documented, the molecular genetics/pathways of this common disorder are poorly understood. METHODS: Linkage analysis and whole exome sequencing; real-time PCR studies of skin fibroblasts. RESULTS: Consanguineous Bedouin kindred presented with DDH with apparent autosomal recessive heredity. Linkage analysis and whole exome sequencing delineated a single 3.2 Mbp disease-associated chromosome 1 locus (maximal multipoint Logarithm of the Odds score 2.3), containing a single homozygous variant with a relevant expression pattern: addition of threonine in TRIM33 (NM_015906.4); c.1648_1650dup. TRIM33 encodes a protein that acts both in the TGF-ß and the BMP pathways; however, it has been mostly studied regarding its function in the TGF-ß pathway. Since BMPs are known to act in bone formation, we focused on the BMP pathway, in which TRIM33 functions as a transcription factor, both an activator and repressor. Skin fibroblasts of two affected girls and a heterozygous TRIM33 variant carrier were assayed through reverse-transcription PCR for expression of genes known to be downstream of TRIM33 in the BMP pathway: fibroblasts of affected individuals showed significantly reduced expression of DLX5, significantly increased expression of BGLAP, increased expression of ALPL and no change in expression of RUNX2 or of TRIM33 itself. CONCLUSIONS: DDH can be caused by a biallelic variant in TRIM33, affecting the BMP pathway.

Integrated Acetabular Prosthesis Versus Bone Grafting in Total Hip Arthroplasty for Crowe Type II and III Hip Dysplasia: A Retrospective Case-Control Study.

OBJECTIVE: Many methods of acetabular reconstruction with total hip arthroplasty (THA) for Crowe type II and III adult developmental dysplasia of the hip (DDH) acetabular bone defect have been implemented clinically. However, there was no study comparing the results of integrated acetabular prosthesis (IAP) with bone grafting (BG). This study aims to investigate the efficacy of IAP and BG for acetabular reconstruction in Crowe type II and III DDH. METHODS: The clinical data of 45 patients with unilateral Crowe type II and III DDH who underwent THA from January 2020 to January 2023 were retrospectively analyzed. The patients were divided into two groups: 25 patients using 3D-printed IAP (IAP group) and 20 patients using BG (BG group). The operation time and intraoperative blood loss were recorded. The clinical outcomes were assessed by Harris Hip Score (HHS) and full weight-bearing time. The radiological outcomes were evaluated by the radiological examination. Accordingly, intraoperative and postoperative complications were observed as well. The data between the two groups were compared by independent sample t-tests and the Mann-Whitney U rank sum test. RESULTS: There were no significant differences between the two groups in Harris Hip Score (HHS) (preoperative, 6 months postoperative, and the last follow-up), leg length discrepancy (LLD), cup inclination, cup anteversion, vertical center of rotation (V-COR), horizontal center of rotation (H-COR) (p > 0.05). The mean HHS in the IAP group was higher than in the BG group at 1 and 3 months postoperative (p < 0.001). The mean surgical time and blood loss in the IAP group were less than in the BG group (p < 0.001). The mean full weight-bearing time in the IAP group was shorter than in the BG group (p < 0.01). No complications were observed in either group during the follow-up period. CONCLUSION: IAP and BG have similar radiographic outcomes and long-term clinical efficacy in THA for Crowe type II and III DDH, but the IAP technique has higher surgical safety and facilitates the recovery of hip joint function, which is worthy of clinical promotion.

Using an Innovative Model to Improve Performance of the Infant Hip Examination.

OBJECTIVES: Determine if a new teaching bundle targeting developmental dysplasia of the hip screening improved interns' examination skills across multiple pediatric residency programs. METHODS: This multicenter prospective cohort study included interns across 6 pediatric residency sites within the Academic Pediatric Association's Better Outcomes through Research for Newborns Network in 2022. Participants underwent a baseline hip examination assessment on models using a checklist derived from textbook descriptions of Galeazzi, Ortolani, and Barlow maneuvers before receiving a teaching bundle. Repeat testing occurred after instruction. Data were analyzed using t-test for continuous and χ2 test for categorical variables. Semistructured focus groups provided qualitative feedback regarding the teaching bundle. RESULTS: We enrolled 117 of 155 interns across 6 sites (76%) for participation in the teaching bundle. Only 2% of participants (n = 2) identified a positive Galeazzi sign at baseline, whereas 88% (n = 103, P < .001) did so on the postinstructional assessment. Although 27% of participants (n = 32) correctly identified a positive Barlow sign at baseline, 69% (n = 81, P < .001) did so on the postinstructional assessment. The ability to correctly detect a positive Ortolani sign increased from 22% (n = 26) to 92% (n = 108, P < .001). Fifteen interns participated in the semistructured focus groups, with resultant themes reinforcing the limited experience of the infant hip examination before this intervention and the positive impact of the teaching bundle. CONCLUSIONS: Most participants in this study did not have strong infant hip examination skills at entry into residency. A standardized teaching bundle significantly improved skills in examination technique and identifying abnormalities.

Biomechanical analysis of load distribution in porcine hip joints at different acetabular coverages.

BACKGROUND: Developmental dysplasia of the hip causes secondary osteoarthritis. Finite element analysis suggests high hip joint contact pressure in patients with hip dysplasia and a reduction in contact pressure after periacetabular osteotomy. However, few biomechanical studies have examined the load distribution in the hip joint. This study aimed to investigate the biomechanical properties of load distribution in porcine hip joints at different acetabular coverages. METHODS: Six porcine hip joints were analyzed using three models: 1) neutral coverage, 2) 15° under-coverage (defined as dysplasia model), and 3) 15° over-coverage created by varying the acetabular coverage. The load distribution was assessed using a pressure-mapping sensor system after applying a loading force of 100 N to the hip joint. RESULTS: In the dysplasia model, the load was concentrated at the acetabular rim; in the neutral and over-coverage models, it was dispersed. The average contact pressure was significantly higher in the dysplasia model than in the neutral coverage model ([0.42 vs. 0.3 MPa]; p = 0.004). The contact area was significantly smaller in the dysplasia model than in the neutral coverage model ([250.7 vs. 345.0 mm2]; p = 0.004). No significant differences were observed in contact pressure or area between the neutral and over-coverage models. CONCLUSIONS: Insufficient acetabular coverage in the dysplasia model demonstrated higher contact pressure and smaller contact area than the neutral model. Conversely, the contact pressure and area in the over-coverage model did not differ significantly from those in the normal model. Therefore, surgeons should note that acetabular coverage overcorrection has limited effect; normalization is crucial during periacetabular osteotomy.

Chiropractic rehabilitation in accelerated rehabilitation after total hip arthroplasty for Crowe type IV hip dysplasia.

To investigate the efficacy of chiropractic rehabilitation therapy in Crowe IV developmental dysplasia of the hip (DDH) patients after total hip arthroplasty. Seventy-two patients with Crowe IV type DDH hospitalized in the Department of Orthopedics I of Ya'an Hospital of Traditional Chinese Medicine from January 2021 to June 2023 were selected for the study, and they were divided into 36 cases in the chiropractic rehabilitation therapy group (the treatment group) and 36 cases in the traditional rehabilitation therapy group (the control group) according to the method of randomized grouping. All patients were evaluated at preoperative, 1, 3, and 6 months postoperatively for follow-up, and the muscle strength of the affected limb, the patient's walking gait, the shortened length of the affected limb, the visual analog scale score (VAS score), the Oswestry Dysfunction Index Score (ODI score), the Harris Hip Score, and the degree of pelvic tilt were recorded to evaluate the results of the study. A total of 4 subjects withdrew from the study, 2 in the treatment group, and 2 in the control group. The muscle strength of the affected limb, walking gait, shortened length of the affected limb, VAS score, ODI score, Harris score, and pelvic tilt in the treatment and control groups improved significantly compared with the preoperative period. Comparisons between the 2 groups revealed that at the final follow-up visit, the limp gait of the patients in the treatment group was significantly reduced, the shortened length of the affected limb was significantly reduced, the VAS score was significantly reduced, and the ODI score was significantly reduced, in the treatment group relative to that of the control group, Harris Hip Score was significantly improved, and the degree of pelvic tilt was significantly reduced, but the improvement in muscle strength of the affected limb was not statistically significant. In future clinical practice, we recommend that chiropractic rehabilitation be used as a routine adjunctive treatment after TKA in patients with Crowe IV DDH to optimize outcomes and improve patients' quality of life.

Total hip arthroplasty with porous tantalum trabecular metal pads in patients with Crowe IV developmental dysplasia of the hip: a midterm followup study.

PURPOSE: Crowe IV developmental dysplasia of the hip (DDH) is a catastrophic hip disease. Moreover, obtaining ideal clinical efficacy in conventional total hip arthroplasty (THA) is often difficult. In this study, we aimed to assess the mid-term clinical results of THA with porous tantalum trabecular metal (TM) pads for acetabular reconstruction in the treatment of Crowe IV DDH. METHODS: A cohort of 28 patients (32 hips) diagnosed with Crowe type IV DDH who underwent acetabular reconstruction during THA using TM pads with scheduled follow-up between 2011 and 2018, were included in this study. Eight cases were men and 24 were women, with a mean age of 48.4 years (range, 36-72 years) and a mean follow-up was 74.3 months (range, 42-132 months). All patients underwent acetabular reconstruction using TM pads and total hip replacement with subtrochanteric osteotomy. RESULTS: At the final follow-up, 28 hips (87.5%) demonstrated mild or no postoperative limping. The Harris Hip Score improved from 58.4 ± 10.6 preoperatively to 85.6 ± 8.9. The mean pain, stiffness, and function scores on the Western Ontario and McMaster University Osteoarthritis index were 86.5 ± 10.2, 87.3 ± 12.4 and 85.4 ± 11.6 respectively. The mean score of patient satisfaction was 90.4 ± 7.6. Additionally, the SF-12 physical summary score was 41.8 ± 5.6 and the SF-12 mental summary score was 51.6 ± 5.4. TM construct survivorship due to all-cause failure was 90.6% at 5 years with 3 hips at risk, 87.5% at 10 years with 4 hips at risk. The survivorship due to failure from aseptic loosening was 96.9% at 5 years with 1hips at risk and 93.75% at 10 years with 2 hips at risk. CONCLUSION: This study demonstrated satisfactory mid-term clinical and radiological results with the application of TM pads for acetabular reconstruction combined with THA in patients with Crowe IV DDH. TRIAL REGISTRATION NUMBER: ChiCTR1800014526, Date: 18/01/2018.

Hidden blood loss and its risk factors after hip reconstruction in children.

OBJECTIVE: There were few reports in the literature regarding hidden blood loss following surgery for developmental dysplasia of the hip in children. This study aimed to evaluate the volume of hidden blood loss and its risk factors among children undergoing hip reconstruction for developmental dysplasia of the hip. METHODS: A retrospective analysis of clinical data from 42 patients (58 hips), who underwent Pemberton and femoral osteotomies between March 2020 and March 2023, was conducted. Serial complete blood count assays were conducted on the day of admission and four days post-surgery. Preoperative and postoperative hematocrit levels were documented to calculate hidden blood loss utilizing the Gross formula. Pearson and Spearman correlation analyses, along with multivariable linear regression, were employed to ascertain associations between patient characteristics and hidden blood loss. RESULTS: The mean hidden blood loss was recorded as 283.06 ± 271.05 mL, constituting 70.22% of the total blood loss. Multiple linear regression analysis identified weight and surgical duration as independent risk factors contributing to hidden blood loss. CONCLUSIONS: A relevant amount of postoperative hidden blood loss occurs after Pemberton osteotomy and femoral osteotomy for developmental dysplasia of the hip. Surgeons should be aware that patients who require blood transfusions and have longer surgical durations are at a higher risk of developing more hidden blood loss. Therefore, attention should be given to hidden blood loss to ensure patient safety during the perioperative period for those undergoing Pemberton and femoral osteotomies. LEVEL OF EVIDENCE: IV.