Developmental dysplasia of the hip: What has changed in the last 20 years?

Proximal versus distal tenotomy of the iliopsoas tendon in the surgical treatment of developmental dysplasia of the hip: a randomized clinical trial

PURPOSE

This study aimed to compare the release of the iliopsoas tendon at two levels: proximally at the pelvic brim and distally near the lesser trochanter.

METHODS

The study was a randomized clinical trial. It was done to check the equivalence between two parallel groups of patients with DDH of grade 2 or more who underwent open reduction operations for their hips: Group 1, division of the iliopsoas tendon at the pelvic brim, and Group 2, division of the tendon at the lesser trochanter level. All the operations were done through the anterior approach.

RESULTS

Thirty-eight patients (24 females and 14 males) with 54 hips (cases) operated, 27 cases in each group. The mean follow-up period of the cases was 2.4 years (SD 0.6). In the third month postoperatively, children of both groups had grade 2 hip flexion strength. Later, a statistically significant difference (p-value 0.007) occurred between them in the 24th month (Group 1 reached grade 5 and Group 1 to grade 4). More complications, 13 out of 27 (48.2%%), were recorded in Group 2. The complications were active bleeding due to injury to medial circumflex femoral vessels (5 cases) and avascular necrosis of the femoral epiphysis (8 cases). Group 1 had only four cases of avascular necrosis of the femoral epiphysis.

CONCLUSION

Patients who underwent a DDH operation with a division of the iliopsoas tendon proximally at the pelvic brim regained hip flexion strength earlier and achieved a better grade with fewer complications.

Evaluating the Short-Term Impact of Closed Versus Open Reduction Techniques on Acetabular Remodeling in Developmental Hip Dysplasia

INTRODUCTION

Developmental dysplasia of the hip (DDH) encompasses abnormalities in the acetabulum or the femoral head, ranging from mild dysplasia to complete dislocation. The primary goal of DDH treatment is to achieve and maintain a concentric reduction of the hip joint, allowing for normal acetabular and femoral head remodeling.

METHOD

This retrospective study reviewed records of patients treated for idiopathic DDH between 2016 and 2021 at a single institution. Patients included had undergone either closed or open reduction and completed at least two years of follow-up. Demographic data and radiographic assessments at multiple intervals postreduction were collected and analyzed using IBM SPSS Statistics for Windows, Version 29 (Released 2023; IBM Corp., Armonk, New York, United States).

RESULTS

A total of 41 patients (64 hips) were included, with a mean age at reduction of 6.92 months and a follow-up duration of 51.5 months. Closed reduction was performed on 38 hips, while 26 hips underwent open reduction. The mean age at reduction was significantly lower in the closed reduction group (4.58 months) compared to the open reduction group (10.34 months). The mean preoperative acetabular index (AI) decreased from 37.39 to 19.54 in the closed reduction group and from 36.74 to 19.4 in the open reduction group.

CONCLUSION

The study found no significant difference between closed and open reduction techniques in acetabular remodeling. While residual dysplasia and avascular necrosis (AVN) were more common in the closed group, the differences were not statistically significant. Further research with larger sample sizes and longer follow-up periods is recommended to confirm these findings.

Arthroscopic-assisted reduction for Developmental Hip Dysplasia (DDH) through the sub-adductor and anterolateral portals; A 24-month follow-up prospective descriptive study

BACKGROUND

Developmental dysplasia of the hip (DDH) encompasses a spectrum of pathological conditions, including dislocation, subluxation, and deformities of the femoral head and acetabulum. The optimal surgical approach for DDH remains a subject of debate. Successful treatment aims to achieve a stable concentric reduction and prevent future subluxation or dislocation. This study aims to assess the clinical and radiographic outcomes of arthroscopic-assisted surgical reduction of DDH in children aged from 6 months to 5 years old.

METHODS

This prospective study included 57 patients with DDH (68 involved hips) between January 2019 and May 2021. They were treated with arthroscopic-assisted surgical reduction. Dega osteotomy was needed in 22 cases, femoral osteotomy and or shortening was necessary in 11 cases, and combined pelvic and femoral osteotomies were required in nine cases. We evaluated and followed all the patients clinically and radiologically, using Severin, modified Severin scores, Shenton line, and acetabular index measurement up to 24 months postoperatively.

RESULTS

The mean age of the included patients was 26.9 months. The mean operative time was 54.7 (36-90) minutes. Clinical assessment using the modified Severin classification revealed that 53 hips (77.9%) were grade I and 11 hips (16.2%) were grade II at the end of the follow-up. Radiological evaluation using Severin classification revealed that 55 hips (80.9%) were in grade I, and 10 hips (14.7%) were in grade II. There was a statistically significant correlation between clinical and radiological grading (p < 0.001). Hip re-dislocation and avascular necrosis (AVN) were experienced in one and two cases, respectively.

CONCLUSION

These findings suggest that arthroscopic-assisted reduction for DDH, with or without osteotomies, is a promising technique with satisfactory clinical and radiographic outcomes and a low complication rate. However, given the single-center nature of this study and its relatively small sample size, these results should be interpreted with caution.

CLINICAL TRIAL REGISTRATION (RETROSPECTIVELY REGISTERED)

Registration number: NCT06520436. 25-7-2024.

Was the ultrasound examination for developmental dysplasia of the hip performed correctly? Introduction of a rapid training tool for nonexpert practitioners

Pediatricians and general practitioners are involved in the newborn screening for developmental dysplasia of the hip. They often rely on the quality of the ultrasound (US) examination to make diagnostic and therapeutic decisions. Therefore, the professional must be able to assess its quality. The aim of our work is to present a new system to evaluate the quality of a neonatal hip US and to assess the effectiveness and reproducibility of this tool among professionals involved in the evaluation of the neonatal hip but not experts in the radiological examination of hip US. In a 15-min training session, 135 professionals involved in neonatal hip US screening with limited or no experience in evaluating the quality of hip US were taught to recognize the basic landmarks of hip US using evocative descriptions (Christmas ball) despite the technical terms. Before and after training, participants were given a test of 10 hip US images presented in random order and asked to identify incorrect images. One hundred thirty-five physicians participated in the study. In the first and second evaluation, participants answered 1.46 ± 2.49 and 8.64 ± 1.51 questions correctly on average (P < 0.05); analysis of the individual questions showed a significant improvement (P < 0.05) for all questions. A simple and relatively quick training tool can help professionals with little or no experience in interpreting neonatal hip US to understand when a hip US exam has been performed incorrectly and improve their diagnostic and therapeutic decisions. Level of evidence: III.

Functional and radiological outcomes and complications of Bernese periacetabular osteotomy through modified Stoppa approach

BACKGROUND

The Smith-Peterson approach and its modifications provide an extensive exposure and allow osteotomies through a single incision. However, the risk of complications increases when the quadrilateral surface, ischial and pubic osteotomy sites cannot be seen. This study aimed to evaluate the surgical characteristics, complications, and functional and radiological outcomes of patients with acetabular dysplasia who underwent Bernese periacetabular osteotomy (PAO) through modified Stoppa approach and plate-screw fixation.

METHODS

The study included 31 patients (41 hips) who had undergone PAO using a modified Stoppa approach. The characteristics of patients and the surgical procedure were described. The lateral centre-edge angle (LCEA) and Tönnis roof angle were evaluated in the radiological outcome evaluation. The modified Harris Hip Score (mHHS) was used to evaluate functional outcome. Furthermore, complications were described.

RESULTS

The mean age of the patients was 20.4 ± 9.0 years. Of the 31 patients, 21 underwent unilateral Bernese PAO and 10 underwent bilateral Bernese PAO. The mean follow-up period was 25.1 ± 8.8 months. Postoperatively, the mean mHHS improved significantly (68.8 ± 9.4 vs. 88.8 ± 10.0, p < 0.001). Postoperatively, the mean LCEA and Tönnis roof angle improved significantly (17.7 ± 6.0 vs. 42.2 ± 4.8, p < 0.001 for LCEA and 18.3 ± 5.5 vs. 8.0 ± 2.2, p < 0.001 for Tönnis roof angle). There was no significant correlation between preoperative to postoperative improvement in LCEA or Tönnis roof angle and improvement and mHHS (p > 0.005). 5 complications were identified: 1 transient sciatic nerve palsy, 1 external iliac vein injury, 1 infection, and 2 screw irritations of acetabulum.

CONCLUSIONS

Performing Bernese PAO through a modified Stoppa approach with plate-screw fixation results in acceptable complication rates, immediate early weight-bearing opportunity, and improved functional and radiological outcomes in patients with acetabular dysplasia.

Do children <3years at index surgery for DDH have a better outcome at mid-term follow-up in comparison to children >3years at index surgery? A prospective comparative study

BACKGROUND

Diagnosis and management of developmental dysplasia of hip (DDH) in underdeveloped regions is frequently delayed, potentially impacting final outcomes. This prospective study was conducted with the aim of answering the question, "Do children <3 years at index surgery for DDH have better outcome at 5-year follow-up in comparison to children >3 years at index surgery?"

METHODS

Between 2016 and 2021, all walking-age children with DDH were prospectively enrolled in the study. The study cohort was divided into 2groups: Group 1 ⩽3 years of age, and Group 2 included children >3 years old. Intraoperative decisions determined the need for addition of femoral or pelvic osteotomy to the open reduction (OR). Follow-up assessment and group comparison included acetabular-index (AI), proximal femoral growth disturbances (PFGD), and outcomes based on Severin's criteria. Subgroup analysis also compared re-dislocated hips with stable hips post-surgery. Children with follow-ups <3 years were excluded.

RESULTS

45 hips in 38 children analysed (31 in Group 1 and 14 in Group 2). Group 1 had higher pre-op AI (p = 0.0489). More hips in Group 2 underwent OR with femoral osteotomy (p = 0.0016). Re-dislocation occurred in 6 (19%) in Group 1 and 2 (14%) in Group 2. Subgroup analysis revealed higher index postoperative AI in re-dislocated hips (p = 0.0001). At the final follow-up, AI was similar between Groups 1 and 2 (p = 0.27). Overall, satisfactory outcomes were comparable between Groups 1 and 2 (p = 0.21). PFGD changes were significantly higher in Group 2 (p = 0.028) and in re-dislocated hips (p = 0.004). Satisfactory outcomes were found in 89% of non-re-dislocated hips and 75% of re-dislocated hips.

CONCLUSIONS

At an average follow-up of 5 years, children above and below 3 years at index procedure for DDH show similar outcomes but older ones need femoral osteotomy more frequently. Osteonecrosis risk rises with increasing age at index surgery and after re-operations, but its impact is not clear in mid-term.

Assessing Avascular Necrosis Risk and Outcomes After Open Reduction for Developmental Dysplasia of the Hip in Children

Background Avascular necrosis (AVN) of the femoral head is a serious complication after surgical treatment of developmental dysplasia of the hip (DDH). The main objective of this study is to identify the incidence of AVN and to define AVN risk factors. The study also aims to identify the effects of AVN and other factors on final clinical and radiological outcomes. Methods All patients in the study were managed according to King Saud University protocol for surgical treatment of DDH. Occurrence of AVN was reported. All affected hips were evaluated clinically and radiologically after six and 12 months and at final follow-up. Significant variables from the univariate analysis were entered into multivariate regression models. Results A total of 131 patients were included in the study involving 189 hips with DDH. AVN was diagnosed postoperatively in 23 (12%) hips. In the multivariate regression analysis, the presence of AVN (p=0.002), prolonged casting (p=0.016) and the need for a second surgery (p=0.029) were strong determinants of unsatisfactory clinical outcomes. Worse radiological outcomes were significantly associated with the presence of AVN (p=0.002), previous trials of closed reduction (p=0.032) and the need for a second surgery (p=0.013). In the last multivariate regression model, a previous trial of closed reduction (p=0.001), absence of an ossified femoral head (OFH) (p=< 0.001), prolonged casting (p=0.038), and the need for second surgery (p=0) were strong risk factors for AVN. Conclusions The current study highlighted the factors responsible for AVN occurrence after open DDH reduction. The factors which are strong determinants of unsatisfactory clinical and radiological outcomes were identified. Overcoming these factors is mandatory to improve the results.

Outcomes of open reduction for hip dislocations in children with connective tissue disorders

Purpose

While children with hypermobility and/or ligamentous laxity due to coexisting connective tissue disorders might be expected to have worse outcomes after open reduction for hip dislocations, there is minimal prior research on this topic.

Methods

All open reduction surgeries for hip dislocations performed at a single urban, tertiary-care children's hospital from 2009 to 2023 were reviewed retrospectively. Those with connective tissue disorders secondary to a diagnosed syndrome or genetic disorder were included. Patients with <1 year of follow-up or hip instability in the setting of Trisomy 21 were excluded. Clinical and radiographic data was collected. Instances of re-dislocation, proximal femoral growth disturbance, residual acetabular dysplasia, and arthrofibrosis were recorded.

Results

Twenty-three hips (15 patients) were included. Mean age at the time of surgery was 19.6 months (Range: 8.2-36.0 months), and mean follow-up was 4.3 years. The most common connective tissue disorder condition included was Ehlers-Danlos syndrome (13%). A majority of open reductions were performed via an anterior approach (96%). Seven hips (30%) underwent a concomitant pelvic osteotomy without femoral osteotomy and seven hips (30%) underwent both pelvic and femoral osteotomies. Twenty-two hips (96%) were International Hip Dysplasia Institute grade 1 at the final follow-up. Re-dislocation occurred in four hips (17%); eight hips (35%) demonstrated residual acetabular dysplasia, five hips (22%) demonstrated proximal femoral growth disturbance, and nine hips (39%) developed stiffness postoperatively.

Conclusions

Patients with connective tissue disorders and ligamentous laxity have comparable rates of residual acetabular dysplasia, proximal femoral growth disturbance, and (surprisingly) stiffness as typical developmental dysplasia of the hip following open hip reduction surgery. Although the re-dislocation rate in the connective tissue disorders group was approximately 2-3 times higher, the difference did not reach statistical significance. Given that the study was limited by a low sample size, however, it is possible that the findings of no difference in residual acetabular dysplasia and proximal femoral growth disturbance were potentially due to a lack of power.

Level of evidence

IV.

Influence of hip prosthesis position on postoperative gait in symptomatic hip osteoarthritis secondary to hip dysplasia patients after primary total hip arthroplasty: a short-term follow-up study

BACKGROUND

The aim of this study was to analyze the influence of the positioning of the components of total hip arthroplasty (THA) evaluated by the acetabular anteversion (AA) and femoral anteversion (FA) angle on postoperative gait in patients with symptomatic hip osteoarthritis secondary to hip dysplasia undergoing THA.

METHODS

Between May 2023 and May 2024, patients with symptomatic hip osteoarthritis secondary to hip dysplasia (Crowe Type I and IV) who underwent THA were enrolled in the study. The AA angle and FA angle were measured by computer tomography (CT). Gait data were determined by using the Dynamic Right Gait & Posture analysis system. The relationship between FA, AA and gait data was analyzed by Pearson correlation test, subgroup Pearson correlation test, multiple linear regression.

RESULTS

A total of 40 patients (45hips) were included in the study. Compared with preoperative, the patient's postoperative foot progression angle, foot contact angle, plantarflexion velocity, swing foot speed, gait velocity, cadence, stride length were significantly improved. Preoperative FA is significantly different from postoperative FA (P < 0.05), while the difference between preoperative and postoperative AA is not significant. BMI, Crowe Type, AA were related to change of cadence. The less the postoperative AA of patients, and the more the cadence in the postoperative gait of patients.

CONCLUSION

Our study showed that THA could improve the gait function of patients with symptomatic hip osteoarthritis secondary to hip dysplasia. Adjusting AA lower could obtain a much more postoperative cadence.

Incidence, Prevalence, Risk Factors, and Clinical Treatment for Children with Developmental Dysplasia of the Hip in Saudi Arabia. A Systematic Review

BACKGROUND

Developmental dysplasia of the hip (DDH) leads to pain, joint instability, and early degenerative joint disease. Incidence, prevalence, and management strategies of DDH have been well-documented in several countries, but not in Saudi Arabia.

OBJECTIVE

We synthesized the current evidence regarding incidence, prevalence, risk factors, and clinical treatment for children with DDH in Saudi Arabia.

METHODS

We searched 3 databases to locate studies. Studies that included children with DDH in Saudi Arabia; reported either incidence rate, prevalence, risk factors, and/or clinical practice; and were available in English or Arabic were included. We excluded reviews, case studies, or animal studies. Two independent authors reviewed potential studies and assessed study's quality.

RESULTS

Our search yielded 67 potential studies, of which 16 studies were included (total DDH sample = 3,127; age range = 2.5 to 86.4 months). Three studies reported incidence rates ranging from 3.1 to 4.9 per 1000 births, and 3 studies reported prevalence ranging from 6 to 78%. Nine studies reported that female sex, breech position, family history, and age less than 3 years were risk factors associated with DDH. Four studies reported that brace applications and closed reduction were conservative treatments, and 9 studies reported that open hip reduction, adductor tenotomy, and/or pelvic osteotomy were surgical approaches to treat DDH.

CONCLUSIONS

In Saudi Arabia, the Incidence and prevalence rates of DDH are 3.1 to 4.9 per 1,000 births, and 6-78%, respectively (differ from what has been reported in other countries), but the risk factors of DDH in Saudi Arabia appear to be similar in comparison to other countries (female, breech presentation, family history of DDH).

Porcine computational modeling to investigate developmental dysplasia of the hip

While it is well-established that early detection and initiation of treatment of developmental dysplasia of the hip (DDH) is crucial to successful clinical outcomes, research on the mechanics of the hip joint during healthy and pathological hip development in infants is limited. Quantification of mechanical behavior in both the healthy and dysplastic developing joints may provide insight into the causes of DDH and facilitate innovation in treatment options. In this study, subject-specific three-dimensional finite element models of two pigs were developed: one healthy pig and one pig with induced dysplasia in the right hindlimb. The objectives of this study were: (1) to characterize mechanical behavior in the acetabular articular cartilage during a normal walking cycle by analyzing six metrics: contact pressure, contact area, strain energy density, von Mises stress, principal stress, and principal strain; and (2) to quantify the effect on joint mechanics of three anatomic abnormalities previously identified as related to DDH: variation in acetabular coverage, morphological changes in the femoral head, and changes in the articular cartilage. All metrics, except the contact area, were elevated in the dysplastic joint. Morphological changes in the femoral head were determined to be the most significant factors in elevating contact pressure in the articular cartilage, while the effects of acetabular coverage and changes in the articular cartilage were less significant. The quantification of the pathomechanics of DDH in this study can help identify key mechanical factors that restore normal hip development and can lead to mechanics-driven treatment options.

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.

Impact of Pavlik Harness treatment on motor skills acquisition: A case-control study

Purpose

Our purpose was to analyze the impact of Pavlik Harness treatment on children motor skills development, comparing to a control group.

Methods

A total of 121 children were included: 55 cases (children with Developmental Dysplasia of the Hip) and 66 healthy controls. Cases were recruited from 2017 to 2021 and followed up to 2022. Controls (healthy children without orthopedic pathology) were recruited from 2020 to 2022. The primary endpoint was the time of achievement of three gross motor milestones (sitting without support, hands-and-knees crawling, and walking independently).

Results

The groups had no differences regarding sex distribution, gestational age, birth weight, and rate of twin pregnancy. The prevalence of positive family history of Development Dysplasia of the Hip (20.0% vs 3.0%, p < 0.003), breech presentation (38.2% vs 1.5%, p < 0.001), and C-section delivery (60.0% vs 19.7%, p < 0.001) was significantly higher in Development Dysplasia of the Hip group. Children with Development Dysplasia of the Hip achieved the three gross milestones evaluated 1 month later than healthy controls, although this was not statistically significant (p = 0.133 for sitting, p = 0.670 for crawling, and p = 0.499 for walking).

Conclusion

Children with Development Dysplasia of the Hip, treated by Pavlik harness, do not have significant delays in motor skills acquisition.

Imaging of Disease and Normal Variant Patterns in Pediatric Hips

The pediatric hip undergoes significant changes from infancy through adolescence. Proper maturation is crucial for the development of a stable and functional hip joint. Imaging interpretation of the pediatric hip requires distinguishing normal variants and maturation patterns from pathology. We review femoral ossification centers, variants, and conditions that affect the proximal femur, such as Legg-Calvé-Perthes disease; the acetabulum, such as developmental hip dysplasia; the acetabular labrum, such as femoroacetabular impingement; and synovial pathology in children through adolescence. Understanding the spectrum of hip conditions and using advanced imaging techniques are essential for the accurate diagnosis and effective management of pediatric hip disorders.

Rehabilitation following periacetabular osteotomy for acetabular dysplasia: A qualitative interview study exploring challenges, hopes and expectations among patients in Denmark and Australia

INTRODUCTION

Guidelines have been proposed for post-operative rehabilitation following periacetabular osteotomy (PAO). However, the perspectives of individuals undergoing PAO have not been considered.

AIM

The present study aimed to explore the perceived challenges of everyday life and hopes for and expectations of post-PAO rehabilitation from the perspective of individuals with acetabular dysplasia living in Denmark and Australia.

METHODS

In this qualitative study, we used a hermeneutic phenomenological approach with semi-structured interviews to explore the perspectives of 25 participants (four males), aged 16-43 years, who underwent a PAO. Purposeful sampling was used to provide variations in age and sex. Inclusion criteria were age above 15 years, radiographic evidence of acetabular dysplasia, PAO within the last seven weeks and undergoing post-operative rehabilitation. Inductive content analysis was adopted to code and analyse interviews.

RESULTS

The analysis of the interview transcripts revealed four major themes: different expectations, self-confidence, tailored rehabilitation and aligning expectations. Several subthemes emerged within each theme, and similar patterns with minor variations were identified across countries. However, the financial burden of self-funded surgery and rehabilitation challenged some Australian participants, whereas none of the Danish participants mentioned this challenge.

CONCLUSION

Our findings elucidate the diverse range of hopes and expectations in individuals undergoing PAO, and how these relate to their perceived challenges. In particular, the findings highlight the importance of aligning expectations between individuals and clinicians when designing the rehabilitation.

Fate of acetabular dysplasia after closed and open reduction of hips in children with developmental hip dislocation

Acetabular underdevelopment (acetabular dysplasia) is a common finding in children with hip dislocation, and residual acetabular dysplasia can remain after hip reduction. Residual dysplasia leads to unsatisfactory long-term outcomes and osteoarthritis. Dynamics of acetabular dysplasia [measured as Acetabular Index (AI)] in a pediatric cohort that underwent open (OR) or closed reduction are reported. Retrospective data from six tertiary pediatric orthopedic centers were gathered. Hips were classified as having 'Critical', 'Monitoring', or 'Normal' acetabular dysplasia based on age-adjusted normative AI measurements. From 193 hips, 108 (56%) underwent open reduction. Children younger than 24 months had a strong AI decline but children > 24 months did not. Among 78 hips with critical dysplasia at time of OR, 36 (46.2%) remained critical and 19 (24.4%) underwent an acetabular osteotomy (AO) during follow-up. CR hips had a similar AI decline in patients younger and older than 12 months. Among 51 hips with critical dysplasia at the time of CR, 13 (25.5%) remained critical and 21 (41.2%) underwent AO during follow-up. Acetabular dysplasia improves with AI decreasing in children who undergo OR and CR under the age of 2 years with slower acetabular remodeling afterwards. Around 2/3 of patients with AI in the critical range at CR or OR either underwent AO or had significant acetabular dysplasia at final follow-up. Our data supports considering simultaneous AO at the time of OR for hips with AI in the critical range or children who undergo hip open reduction after 24 months of age. Level of Evidence: Level III.

Factors influencing outcomes of pelvic osteotomy for residual acetabular dysplasia following closed reduction in patients with developmental dysplasia of the hip

To investigate the factors influencing outcome of pelvic osteotomy (PO) for residual acetabular dysplasia (RAD) following closed reduction (CR) in patients with developmental dysplasia of the hip (DDH). We retrospectively reviewed 91 patients (95 hips) with DDH who underwent PO for RAD. Tönnis grade, Acetabular index, Center Edge Angle, Reimer's Index (RI), and avascular necrosis of the femoral head (AVN) were assessed. Hips were divided into satisfactory (Severin I/II) and unsatisfactory group (Severin III/IV). Finally, 87 hips (91.5%) had satisfactory and 8 (8.5%) unsatisfactory outcomes. The RI before PO was significantly higher in unsatisfactory (49.6 ± 9%) than in satisfactory group (30.6%±11.8%). All patients without AVN had satisfactory outcome, while it was 78.9% of patients with AVN. Logistic regression analysis showed that higher AVN grade and RI before PO were risk factors for unsatisfactory outcome. Satisfactory outcome was obtained in all hips with RI < 33% before PO, while it was 79.5% if RI > 33% before PO (79.5%). There was no difference in the satisfactory rate between patients undergoing open reduction (66.7%) and those not undergoing (83.3%). The rate of satisfactory outcome in patients undergoing femoral osteotomy (63.6%) was lower than those without it (100%). In patients with RAD following CR, good outcome can be expected after PO alone. AVN and preoperative RI > 33% are risk factors for poor outcome. Additional open reduction and femoral osteotomy do not significantly improve outcome of PO in patients with preoperative RI > 33%.

Study on the efficacy of brace therapy for developmental dysplasia of the hip with Graf IIc and greater severity

To assess changes in the α and β angle with brace treatment in DDH classified as Type Graf IIc, D, III, and IV; to study the α angle threshold that can predict the treatment effect; to analyze the effective rate in different groups. A retrospective study was conducted on children from 2013 to 2018 with Graf type IIc and greater diagnosed with ultrasound (US). Brace therapy was applied to 356 patients, with 423 affected hips (Graf IIc: 202 hips; Graf D: 17 hips; Graf III: 118 hips; and Graf IV: 86 hips). For follow-up efficacy analyses using US, X-ray and clinical examination, based on the success of early treatment of the brace, the outcomes were divided into 'effective' and 'noneffective' groups. The statistical results showed that the α angle increased ( P  < 0.05) and the β angle decreased ( P  < 0.05). When α≥43°, the accuracy of success with early treatment was 95.95%. The overall effective rate of bracing treatment was 74.70%. Children with α ≥ 43° are recommended to receive brace therapy as soon as possible and demonstrate the best effects. The effective rate varies across different Graf types and the age at treatment initiation. Brace therapy is more effective for Graf IIc and D hips compared to Graf III and IV.

Deciphering the pathogenic role of rare RAF1 heterozygous missense mutation in the late-presenting DDH

Background

Developmental Dysplasia of the Hip (DDH) is a skeletal disorder where late-presenting forms often escape early diagnosis, leading to limb and pain in adults. The genetic basis of DDH is not fully understood despite known genetic predispositions.

Methods

We employed Whole Genome Sequencing (WGS) to explore the genetic factors in late-presenting DDH in two unrelated families, supported by phenotypic analyses and in vitro validation.

Results

In both cases, a novel de novo heterozygous missense mutation in RAF1 (c.193A>G [p.Lys65Glu]) was identified. This mutation impacted RAF1 protein structure and function, altering downstream signaling in the Ras/ERK pathway, as demonstrated by bioinformatics, molecular dynamics simulations, and in vitro validations.

Conclusion

This study contributes to our understanding of the genetic factors involved in DDH by identifying a novel mutation in RAF1. The identification of the RAF1 mutation suggests a possible involvement of the Ras/ERK pathway in the pathogenesis of late-presenting DDH, indicating its potential role in skeletal development.

Plasma metabolomics signatures of developmental dysplasia of the hip in Tibet plateau

BACKGROUND

Developmental dysplasia of the hip (DDH) is a common childhood health complaint, whose etiology is multifactorial. The incidence of DDH is variable and higher in Tibet plateau. Here, we collected plasma samples and studied the metabolomics signatures of DDH.

METHODS

Fifty babies were enrolled: 25 with DDH and 25 age-matched non-DDH healthy controls (HC group). We collected plasma samples, laboratory parameters and conducted untargeted metabolomics profiling.

RESULTS

There are many differential metabolites among patients with DDH, including 4-β-hydroxymethyl-4-α-methyl-5-α-cholest-7-en-3-beta-ol, β-cryptoxanthin, α-tocopherol, taurocholic acid, glycocholic acid, 2-(3,4-dihydroxybenzoyloxy)-4,6-dihydroxybenzoate, arabinosylhypoxanthine, leucyl-hydroxyproline, hypoxanthine. The main differential metabolic pathways focused on primary bile acid biosynthesis, arginine and proline metabolism, phenylalanine metabolism, histidine metabolism, purine metabolism.

CONCLUSIONS

To our knowledge, this is the first report of metabolomics profile in babies with DHH. By combining the α-tocopherol and taurocholic acid, we could achieve the differential diagnosis of DDH.

Treatment of developmental hip dysplasia with manual therapy following Pavlik harness failure: a case report with long-term follow-up

BACKGROUND

Developmental dysplasia of the hip (DDH) is a common musculoskeletal disorder in newborns, ranging from mild dysplasia to complete dislocation. Early detection and intervention are crucial for managing DDH. However, in some cases, standard orthopedic treatments such as the Pavlik harness fail, and alternative approaches are needed. Our study explores the possibility that manual therapy, specifically the Mézières-Bertelè Method (MBM), could be beneficial in cases of DDH that are resistant to conventional treatments.

CASE DESCRIPTION

We present a case of a 20-month-old female who had been suffering from persistent DDH (Graf's type IIIC on the left), pain and limping, despite previous conventional treatments, including the Pavlik harness. The patient received daily MBM sessions for six months, followed by maintenance sessions every two months.

OUTCOMES

After undergoing the MBM treatment, the patient showed clinical improvements, such as normal neuromotor development and restored hip joint parameters. We observed normal walking and running abilities, and X-ray parameters returned to normal levels. The patient sustained positive outcomes during long-term follow-up until the age of 7.

CONCLUSION

The MBM manual therapy was used to treat a challenging case of DDH resistant to conventional treatment. This case report suggests a possible correlation between manual therapy and improved outcomes in resistant DDH and highlights the potential relevance of addressing the inherent musculoskeletal components of the condition.

Use of the flat panel detector fluoroscope reduces radiation exposure during periacetabular osteotomy

The Periacetabular Osteotomy is a technically demanding procedure that requires precise intraoperative evaluation of pelvic anatomy. Fluoroscopic images pose a radiation risk to operating room staff, scrubbed personnel, and the patient. Most commonly, a Standard Fluoroscope with an Image Intensifier is used. Our institution recently implemented the novel Fluoroscope with a Flat Panel Detector. The purpose of this study was to compare radiation dosage and accuracy between the two fluoroscopes. A retrospective review of a consecutive series of patients who underwent Periacetabular Osteotomy for symptomatic hip dysplasia was completed. The total radiation exposure dose (mGy) was recorded and compared for each case from the standard fluoroscope (n = 27) and the flat panel detector (n = 26) cohorts. Lateral center edge angle was measured and compared intraoperatively and at the six-week postoperative visit. A total of 53 patients (96% female) with a mean age and BMI of 17.84 (± 6.84) years and 22.66 (± 4.49) kg/m2 (standard fluoroscope) and 18.23 (± 4.21) years and 21.99 (± 4.00) kg/m2 (flat panel detector) were included. The standard fluoroscope averaged total radiation exposure to be 410.61(± 193.02) mGy, while the flat panel detector averaged 91.12 (± 49.64) mGy (p < 0.0001). The average difference (bias) between intraoperative and 6-week postoperative lateral center edge angle measurement was 0.36° (limits of agreement: - 3.19 to 2.47°) for the standard fluoroscope and 0.27° (limits of agreement: - 2.05 to 2.59°) for the flat panel detector cohort. Use of fluoroscopy with flat panel detector technology decreased the total radiation dose exposure intraoperatively and produced an equivalent assessment of intraoperative lateral center edge angle. Decreasing radiation exposure to young patients is imperative to reduce the risk of future comorbidities.

Comparison of quality and interpretation of newborn ultrasound screening examinations for developmental dysplasia of the hip by basically trained nurses and junior physicians with no previous ultrasound experience

BACKGROUND

We are obliged to give babies the chance to profit from a nationwide screening of developmental dysplasia of the hip in very rural areas of Mongolia, where trained physicians are scarce. This study aimed to compare the quality and interpretation of hip ultrasound screening examinations performed by nurses and junior physicians.

METHODS

A group of 6 nurses and 6 junior physician volunteers with no previous ultrasound experience underwent Graf's standard training in hands-on practice. Newborns were examined before discharge from the hospital, according to the national guideline. Two standard documentation images of each hip were saved digitally. The groups were compared on the proportion of good quality of sonograms and correct interpretation. Two Swiss supervisors' agreed diagnosis according to Graf was considered the final reference for the study purposes.

RESULTS

A total of 201 newborns (402 hips or 804 sonograms) were examined in the study, with a mean age of 1.3±0.8 days at examination. Junior physicians examined 100 newborns (200 hips or 400 sonograms), while nurses examined 101 newborns (202 hips or 404 sonograms). The study subjects of the two groups were well balanced for the distribution of baseline characteristics. The study observed no statistically significant difference in the quality of Graf's standard plane images between the providers. Eventually, 92.0% (92) of the physician group and 89.1% (90) of the nurse group were correctly diagnosed as "Group A" (Graf's Type 1 hip) or "Non-Group A" hips (p = 0.484). The most common errors among the groups were a missing lower limb, wrong measurement lines, and technical problems.

CONCLUSION

Our study provides evidence that while there might be a trend of slightly more technical mistakes in the nurse group, the overall diagnosis accuracy is similar to junior physicians after receiving standard training in Graf's hip ultrasound method. However, after basic training, regular quality control is a must and all participants should receive refresher trainings. More specifically, nurses need training in the identification of anatomical structures.

Community Awareness About Developmental Dysplasia of the Hip (DDH) in the Western and Southern Regions of Saudi Arabia

BACKGROUND

Developmental dysplasia of the hip (DDH) is a disorder in which the hip joint does not develop normally in the pediatric age group. It is caused by a confluence of hereditary and environmental factors. We aimed to examine knowledge and awareness of DDH among the general population of the southern and western regions of Saudi Arabia.

METHODOLOGY

A cross-sectional survey-based study was conducted in the western and southern regions of Saudi Arabia. This study included adult male and female participants above 18 years of age. Data were collected using a validated electronic questionnaire that was disseminated via social media platforms. All data were analyzed using IBM SPSS Statistics for Windows, Version 23.0 (IBM Corp., Armonk, NY).

RESULTS

In this study, 1,232 participants were surveyed in Saudi Arabia. The majority were between 21 and 30 years old (663, 53.8%), unmarried (690, 56%), and had a baccalaureate or diploma certificate (886, 71.9%). Regarding knowledge of DDH, 86.4% of participants had poor knowledge of the causes of DDH, and 740 (60%) had poor overall knowledge of DDH. However, 492 (40%) participants had good knowledge. Respondents with a higher monthly income, those who were mothers, and those who obtained information from social media had a better awareness level. Concerning treatment, 531 (43.1%) participants were unsure about the best treatment for DDH, and 850 (69%) believed that early treatment was better.

CONCLUSIONS

According to our literature, DDH is highly prevalent among Saudi populations. However, our findings indicate that the majority of the Saudi population residing in the western and southern regions of Saudi Arabia lacks basic knowledge of DDH. All capable facilities, such as medical schools, hospitals, and primary healthcare centers, must impart cultural education about DDH to address this awareness gap.

Comparison of outcomes of different Graf grades of developmental dysplasia of the hip in infants treated with Tubingen splint versus Pavlik harness - A systematic review

This systematic review was designed to compare the outcomes of the two braces against each other classified by the Graf method. The databases sources included PubMed, Embase, and Google Scholar. The keywords included "DDH Tubingen versus Pavlik" and Tubingen and Pavlik separately. Included papers provided specific data regarding success and failure rate, avascular necrosis (AVN), duration, and age of intervention. The excluded studies discussed surgeries, diagnosis and mechanism, and ones that weren't in English. Total of 20 papers were included, resulting in 1243 Tubingen and 420 Pavlik samples. It was seen that the Tubingen splint had a statistically significant greater success rate and lower failure rate for Graf 2, D, and 3 hips, while both braces were not very successful for Graf 4 at success rates less than 60 %. Tubingen also had a lower incidence of AVN. Both braces shared similar ages of intervention, duration, and time per day. Both braces are very comparable to each other, each having better success rates for lower Graf grades, which points to the importance of bracing earlier to improve the success rates. The Tubingen splint had a higher success rate, lower failure rate, and lower AVN rate compared to the Pavlik harness. This points to the Tubingen splint potentially being the preferred option for bracing in infants.

Transgluteal Ultrasonography in Spica Cast in the Post-reduction Assessment of Hip Developmental Dysplasia

OBJECTIVE

Concentric circle reduction is one of the outcomes after reduction of developmental dysplasia of the hip (DDH). Radiography and magnetic resonance imaging (MRI) are used to confirm the reduction results. In this study, we evaluated the reduction results of the coronal section of the hip using transgluteal ultrasonography.

METHODS

We enrolled 46 children admitted to our hospital for closed or open reduction plaster fixation of DDH between January 2021 and December 2022. Thirty-eight patients had unilateral DDH, and eight patients had bilateral DDH. Transgluteal ultrasonography, radiography and MRI were done on the patients during the 7 d after reduction, and the results were interpreted by different radiologists. The covering of the femoral head and the distance between the medial margin of the femoral head and the acetabulum (HSD) were measured after calculating the maximum coronal surface of the iliac bone. MRI is regarded as the gold standard for determining hip reduction or dislocation. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of ultrasound and radiography were determined and compared.

RESULTS

The sensitivity, specificity, PPV and NPV of transgluteal ultrasonography were 100% (confidence interval [CI]: 69.2%-100%), 97.7% (CI: 88%-99.9%), 90.9% (CI: 59%-98.6%) and 100%, respectively, higher than those of radiography, which were 50% (CI: 18.7%-81.3%), 86.4% (CI: 72.6%-94.8%), 45.5% (CI: 24%-68.7%) and 88.4% (CI: 80.2%-93.5%), respectively. Ultrasonography had a higher sensitivity (100% vs. 50%, p < 0.01) and positive predictive rate (90.9% vs. 45.5%, p < 0.01) than radiography. Ultrasonography revealed that a distance between the head and socket (HSD) >8 mm indicated a strong suspicion for a poor reduction.

CONCLUSION

Transgluteal coronal ultrasound scan with semiquantitative assessment of acetabular femoral head coverage and measurement of HSD can effectively monitor the reduction relationship between the two in children after DDH reduction.

Hip arthrogram parameters predict radiographic outcomes of patients with developmental dysplasia of the hip treated by closed reduction

Objective

This study aimed to investigate the relationship between intraoperative hip arthrogram parameters and residual acetabular dysplasia (RAD) and avascular necrosis of the femoral head (AVN) in children with developmental dysplasia of the hip (DDH) treated by closed reduction.

Methods

We retrospectively analyzed the data of 102 patients (110 hips; mean age, 14.6 months ± 4.7 months) with DDH treated by closed reduction. A hip arthrogram was routinely performed during the operation. The femoral head coverage rate (FHC), medial pool distance of the hip (MPD), labral inversion, and reduction quality classification were evaluated under the hip arthrogram. The presence of RAD and AVN was assessed on radiographs at the last follow-up. The relationship between each arthrogram parameter and RAD as well as AVN was investigated using a t-test, chi-square test, and logistic regression.

Results

The overall FHC and medial pool distance of the hip (MDP) averaged 42.2% ± 12% and 8.1% ± 11.7%, respectively. There were 80 hips (72.7%) with labral inversion and 30 hips (27.2%) without. The reduction quality was type A in 57 hips (51.8%), type B in 28 hips (25.4%), and type C in 25 hips (22.7%). A total of 32 hips (29%) were in the RAD group, and 78 hips (71%) were in the recovered group according to whether pelvic osteotomy was performed or not and according to the last Severin grade. The FHC was significantly higher in the recovered group than that in the RAD group (P = 0.014). No significant difference was observed in sex, age at reduction, side, preoperative acetabular index, International Hip Dysplasia Institute classification, follow-up time, quality of reduction, MDP, and proportion of labral inversion between the recovered and RAD groups. Logistic regression analysis showed that only the FHC was a risk factor for RAD. The incidence of AVN above type II was 11.8% in this group of patients, and the incidence of AVN was significantly higher in patients with labral inversion (23.2%) than that in those without (7.5%; P = 0.041). Logistic regression analysis showed that labral inversion was a risk factor for AVN.

Conclusion

The FHC measured under arthrogram can predict the occurrence of RAD after closed reduction of DDH, whereas MDP, reduction quality classification, and labral inversion are of little significance. Labral inversion is a risk factor for AVN.

The Optimal Age for Surgical Management of DDH Differs by Treatment Method

BACKGROUND

There is a lack of consensus on the optimal age for specific surgical interventions for developmental dysplasia of the hip. We compared radiographic and clinical outcomes among patients who were treated with closed reduction (CR), open reduction (OR), and open reduction with concomitant pelvic osteotomy (ORP) for the treatment of a dislocated hip. We sought to identify the optimal age at treatment within each of these groups.

METHODS

We retrospectively reviewed 256 hips (n=195 patients) who underwent CR (n=96), OR (n=116), or an ORP (n=44) as their index procedure at a single institution between January 1, 2004 and September 23, 2020. Radiographic outcomes included acetabular index, The International Hip Dysplasia Institute classification, and acetabular depth ratio. The incidence of further corrective surgery (FCS), defined as the need for an additional femoral and/or pelvic osteotomy before skeletal maturity, and the optimal age cutoffs for index surgery within each surgical group were determined.

RESULTS

After adjusting for age and sex, the incidence of FCS was 13.8% in the CR group, 29.2% in the OR group, and 9.2% in the ORP group. Earlier surgery was protective against FCS in the CR and OR groups. In contrast, patients in the ORP group who were older at index procedure were less likely to undergo FCS. Optimal age at surgery was 9.9 months (CR), 11.5 months (OR), and 21.4 months (ORP). Compared with older patients, younger patients were associated with a larger average decrease in the acetabular index and a larger average increase in acetabular width during the first 5 years post surgery.

CONCLUSIONS

Age at index surgical procedure was correlated with both clinical and radiographic outcomes. Age at index procedure did impact the risk of subsequent FCS, particularly in the CR and ORP groups. Based on our analysis, CR should be considered before 9.9 months of age and OR considered before 11.5 months of age to minimize the risk of FCS during childhood. This work highlights the importance of considering age-related heterogeneity in developmental dysplasia of the hip treatment outcomes.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Efficacy of post-surgery family-based participatory cluster pain care in children with developmental dislocation of hip

BACKGROUND

Developmental dislocation of the hip (DDH) is a common congenital deformity of the skeletal system in children.

OBJECTIVE

To investigate the efficacy of post-surgery cluster nursing in children with DDH.

METHODS

A total of 60 children with DDH who underwent hip joint orthopedic surgery in our hospital from September 2021 to September 2022 were enrolled as the research participants in this prospective study, and divided into the control group and the observation group according to the numerical table method, with 30 patients in each group. The control group was given routine pain care, and the observation group was given cluster pain care. The hip joint function scores, pain scores, self-rating anxiety score (SAS) were compared between the two groups and between before intervention and after intervention in the two groups.

RESULTS

The pain score of the children and the SAS of the primary caregivers after the intervention in the observation group were lower than those in the control group (P< 0.05), and the hip joint function score and family satisfaction degree were higher than those in the control group (P< 0.05).

CONCLUSION

Family-based cluster pain care can reduce pain in children with DDH after surgery, promote hip joint functional recovery, reduce the negative emotions of caregivers, and improve family satisfaction, and has clinical popularization value.

Comparison Static and Dynamic Ultrasound Techniques of DDH: The Role of the Patient's Position

Objectives

The ultrasound examination of the hip joint is performed in the static (Graf) technique in the lateral recumbent position and in the dynamic technique in the supine position. This study compares the two static and dynamic techniques and assesses the role of the patient's position in the examination of DDH.

Methods

This cross-sectional study was conducted in 2020-2021 at Akbar Hospital, Mashhad University of Medical Sciences, Iran. 126 patients suspected of having DDH (199 hip) infants were enrolled in the study. All ultrasound examinations were performed with two static and dynamic techniques by a pediatric radiologist.

Results

In the static and dynamic ultrasound examinations, the average alpha angle was 51.57 ± 6.41 degrees, and 53.41 ± 6.94 degrees, respectively. These changes were not statistically significant (P = 0.312). The relationship and agreement between instability with dynamic technique and instability with static technique (IIC unstable, D, III, and IV) were investigated. Significant agreement (Kappa=0.77 (95% CI: 0.66-0.87) with excellent clinical significance was obtained between the two ultrasound examination method. Also, in terms of DDH types in the static method with instability types in the dynamic method, a substantial agreement was found between the two examination methods (Kappa =0.67; (95% CI: 0.59-0.75) with good clinical significance.

Conclusion

In the ultrasound examination of DDH with static and dynamic techniques, the change in the alpha angle was not statistically significant. Therefore, the hand of the radiologist is open in measuring alpha angles and there is no need to emphasize a specific position. The type of DDH in the static technique completely corresponded to the type of stability or instability in the dynamic technique.

The utility of ultrasound and plain radiographs in the management of developmental dysplasia of the hip

The purpose of this study is to assess the utility of follow-up radiological imaging in the management of developmental dysplasia of the hip (DDH) in patients successfully treated with the Pavlik harness. A retrospective review was conducted on all children under 6 months diagnosed with DDH at a tertiary pediatric hospital between January 2004 and December 2018. Inclusion criteria included successful Pavlik harness treatment following a standardized protocol with complete radiological documentation at 2 years of age. Ultrasonography was reviewed to measure the α and β angles and Graf classification. Anteroposterior pelvic radiographs were evaluated for the acetabular index and residual acetabular dysplasia. Seventy-eight hips from 57 infants were included in this study. The mean 6-month, 12-month and 2-year acetabular index of Graf I, IIa and IIc hips on ultrasound at 12 weeks were within the normal range according to age. There were no Graf IIb, IId, III and IV hips. All infants had normal radiographs at 2 years follow-up. The 6- and 12-month residual dysplasia rates in patients with DDH normalization at 12 weeks and 6 months range from 2.5 to 8.82%. Regardless of when the acetabular index normalized, all patients eventually had normal hip radiographs at 2 years of age. Following a standardized protocol, patients undergoing Pavlik harness treatment for DDH with Graf I and IIa hips at 12 weeks are likely to have normal plain radiographs at discharge. The incidence of residual dysplasia is very low and hence, radiographic surveillance is probably unnecessary until discharge at 2 years. Level II, retrospective study.

Developmental Dysplasia of the Hip - Part 1

Developmental dysplasia of the hip (DDH) is a condition characterized by changes in joint formation within the last months of intrauterine life or the first months after birth. Developmental dysplasia of the hip presentation ranges from femoroacetabular instability to several stages of dysplasia up to complete dislocation. Early diagnosis is essential for successful treatment. Clinical screening, including appropriate maneuvers, is critical in newborns and subsequent examinations during the growth of the child. Infants with suspected DDH must undergo an ultrasound screening, especially those with a breech presentation at delivery or a family history of the condition. A hip ultrasound within the first months, followed by pelvic radiograph at 4 or 6 months, determines the diagnosis and helps follow-up. Treatment consists of concentric reduction and hip maintenance and stabilization with joint remodeling. The initial choices are flexion/abduction orthoses; older children may require a spica cast after closed reduction, with or without tenotomy. An open reduction also can be indicated. After 18 months, the choices include pelvic osteotomies with capsuloplasty and, eventually, acetabular and femoral osteotomies. The follow-up of treated children must continue throughout their growth due to the potential risk of late dysplasia.

Acetabular index as an indicator of Pavlik harness success in grade I developmental dysplasia of the hip: A retrospective study

Purpose

Some articles have focused on the effectiveness of the Pavlik harness treatment for unstable and dislocated hips, yet data on monitoring its effectiveness with the acetabular index remains elusive. Therefore, this study aimed to assess Pavlik harness effectiveness in infants ≤6 months diagnosed with grade I developmental dysplasia of the hip using acetabular index improvement and identify the possible predictors of successful Pavlik harness treatment.

Methods

A retrospective review of infants with grade I acetabular dysplasia treated with a Pavlik harness and monitored with anteroposterior pelvis X-rays at presentation and follow-up. Successful treatment was defined as achieving an acetabular index <30°.

Results

A total of 231 infants with acetabular dysplasia were treated with a Pavlik harness. A successful outcome was achieved in 135 infants (58.4%). Younger age, lower initial acetabular index, and patients with unilateral developmental dysplasia of the hip were significant predictors of a successful outcome. An age of 4.5 months or older was found to be the threshold for an unsuccessful result following Pavlik harness treatment, with a sensitivity of 65.2% and specificity of 57.3%. An initial acetabular index of 35.5° was found to be the threshold for an unsuccessful result, with a sensitivity of 83.7% and specificity of 61.5%.

Conclusion

Pavlik Harness's success in correcting the acetabular index in acetabular dysplasia patients was related to unilateral cases, a younger age at presentation, and a lower initial acetabular index. The thresholds for unsuccessful treatment were an age of 4.5 months or greater and an acetabular index of 35.5° or higher.

A novel approach for screening standard anteroposterior pelvic radiographs in children

Anteroposterior pelvic radiography is the first-line imaging modality for diagnosing developmental dysplasia of the hip (DDH). Nonstandard radiographs with pelvic malposition make the correct diagnosis of DDH challenging. However, as the only method available for screening standard pelvic radiographs, traditional manual assessment is relatively laborious and potentially erroneous. We retrospectively collected 3,247 pelvic radiographs. There were 2,887 radiographs randomly selected to train and optimize the AI model. Then 362 radiographs were used to test the model's diagnostic performance. Its diagnostic accuracy was assessed using receiver operating characteristic (ROC) curves and measurement consistency using Bland-Altman plots. In 362 radiographs, the AI model's area under ROC curves, accuracy, sensitivity, and specificity for quality assessment was 0.993, 99.4% (360/362), 98.6% (138/140), and 100.0% (222/222), respectively. Compared with clinicians, the 95% limits of agreement (Bland-Altman analysis) for pelvic tilt index (PTI) and pelvic rotation index (PRI), as determined by the model, were -0.052-0.072 and -0.088-0.055, respectively.

CONCLUSIONS

The artificial intelligence-assisted method was more efficient and highly consistent with clinical experts. This method can be used for real-time validation of the quality of pelvic radiographs in current picture archiving and communications systems (PACS).

WHAT IS KNOWN

• Nonstandard pediatric radiographs with pelvic malposition make the correct diagnosis of developmental dysplasia of the hip (DDH) challenging. • Traditional manual assessment remains the only method available for screening standard pediatric pelvic radiographs, which is relatively laborious and potentially erroneous.

WHAT IS NEW

• This study proposed an artificial intelligence-assisted model to assess the quality of pediatric pelvic radiographs accurately and efficiently. • We recommend the integration of the model into current picture archiving and communications systems (PACS) for real-time screening of standard pediatric pelvic radiographs.

Natural progression of the pubofemoral distance with age and its correlation with future acetabular index

OBJECTIVES

This study investigated the progression of pubofemoral distance (PFD) with age and assessed the correlation between PFD and late acetabular index (AI) measurements.

METHODS

This prospective observational study was conducted between January 2017 and December 2021. We enrolled 223 newborns who underwent the first, second, and third hip ultrasounds, and pelvis radiograph at a mean age of 18.6 days, 3.1 months, 5.2 months, and 6.8 months, respectively. The difference between PFD measured at serial ultrasounds and the correlation with AI were analyzed.

RESULTS

The PFD increased significantly (p < 0.001) at serial measurements. The mean PFD at the first, second, and third ultrasounds were 3.3 (2.0-5.7), 4.3 (2.9-7.2), and 5.1 (3.3-8.0) mm, respectively. The PFD at three ultrasounds were all significantly (p < 0.001) and positively correlated with AI, with the Pearson correlation coefficients being 0.658, 0.696, and 0.753 for the first, second, and third ultrasounds, respectively. Using AI as reference, the diagnostic ability of PFD was calculated by the areas under the receiver operating characteristic curve, which was 0.845, 0.902, and 0.938 for the first, second, and third PFD, respectively. For the first, second, and third ultrasounds, PFD cutoff values of ≥ 3.9, ≥ 5.0, and ≥ 5.7 mm, respectively, yielded the greatest sensitivity and specificity in predicting late abnormal AI.

CONCLUSION

The PFD naturally progresses with age and is positively correlated with AI. The PFD has potential for predicting residual dysplasia. However, the cutoff for abnormal PFD values may require adjustment according to the patient's age.

KEY POINTS

• The pubofemoral distance measured in hip ultrasonography naturally increases as the infant's hips mature. • The early pubofemoral distance demonstrates a positive correlation with late acetabular index measurements. • The pubofemoral distance may help physicians predict abnormal acetabular index. However, the cutoff for abnormal pubofemoral distance values may require adjustment according to patient's age.

Identification of screw spacing on pediatric hip locking plate in proximal femoral osteotomy

This study describes a computational analysis technique for evaluating the effect of screw spacing and angle on the pediatric hip locking plate system in proximal femoral osteotomy in pediatric patients having DDH with an aberrant femoral head and femoral angle. Under static compressive load conditions, the stresses of the screw and bone were examined as the screw spacing and angle changed. The spacing and angle of various screws were specifically considered as variables in this study based on the pile mechanism studied in civil engineering. As with the group pile mechanism, the tighter the screw spacing under static compressive loads, the more the overlapping effect between the bone stresses and the screws develops, increasing the risk of injuring the patient's bone. Therefore, a series of simulations was performed to determine the optimal screw spacing and angles to minimize the overlapping effect of bone stress. In addition, a formula for determining the minimum screw spacing was proposed based on the computational simulation results. Finally, if the outcomes of this study are applied to pediatric patients with DDH in the pre-proximal femoral osteotomy stage, post-operative load-induced femur damage will be reduced.

How Ready are Pediatricians and Family Physicians in Saudi Arabia to Perform Clinical Screening of Developmental Dysplasia of the Hip?

Background

Developmental dysplasia of the hip (DDH) is one of the most common hip pathologies in pediatric age group and late diagnosis remains a major concern in Saudi Arabia.

Objective

The aim of this study is to examine the ability of Saudi Arabian pediatricians and family physicians to conduct clinical screening for (DDH) by estimating their clinical knowledge and skills and analyzing the gaps therein to determine whether there is potential to launch a national screening protocol for DDH in Saudi Arabia.

Methods

This is a multicenter cross-sectional study from three major regions in Saudi Arabia (Central, Eastern and Western provinces). The assessed aspects are risk factors, age of screening, incidence in Saudi Arabia, physical signs and diagnostic markers, and treatment, along with their 'clinical knowledge and skills' score.

Results

Half of the participants were pediatricians, while the rest were family physicians. More than a third of the participants were considered to have adequate knowledge, ie, above the mean score. Dimensions with the most significant knowledge gaps included the incidence of DDH in Saudi Arabia, adverse effects of swaddling, and the management of a high-risk infants presenting with a negative physical examination. Additionally, there were relatively low rates of awareness regarding positive risk factors as well as a generally poor ability to identify physical signs. Clinical knowledge and skill levels were significantly lower among family physicians.

Conclusion

Pediatricians and family physicians in Saudi Arabia still need further training to improve their clinical skills for DDH screening. The proper administration of training programs could eventually enable the gradual implementation of a national systematic screening program.

A Novel Technique for Autograft Preparation Using Patient-Specific Instrumentation (PSI) Assistance in Total Hip Arthroplasty in Developmental Dysplasia of Hip (DDH)

Due to the change in the structure of the proximal femur and acetabulum in patients with developmental dysplasia of the hip, total hip arthroplasty (THA) was difficult to perform for surgeons. To elevate the acetabular coverage rate, we developed a technique in the use of a patient-specific instrumentation (PSI) graft in patients with developmental dysplasia of hip (DDH) undergoing surgery. This study aims to evaluate the peri-operative outcomes of THA with PSI graft in patients with DDH. This study recruited 6 patients suffering from Crowe I DDH with secondary Grade IV osteoarthritis. All the patients underwent THA with PSI graft performed by a well-experienced surgeon. Perioperative outcomes included surgical procedures, blood loss during operation, the volume of blood transfusion, length of hospitalization, complications, and the mean difference in hemoglobin levels before and after surgery. All the outcomes analyzed were assessed by mean and standard deviation. The average duration of the surgical procedure was found to be 221.17 min, with an SD of 19.65 min. The mean blood loss during the operation was 733.33 mL, with an SD of 355.90 mL. The mean length of hospital stay was calculated to be 6 days, with an SD of 0.89 days. Furthermore, the mean difference between the pre- and postoperative hemoglobin levels was 2.15, with an SD of 0.99. A total of three patients received 2 units of leukocyte-poor red blood cells (LPR) as an accepted blood transfusion. There were no reported complications observed during the admission and one month after the operation. This study reported the peri-operative outcomes in the patients with DDH who underwent THA with PSI graft. We found that THA with PSI graft would provide a safe procedure without significant complications. We assumed that the PSI graft in THA may increase the coverage rate of the acetabulum, which may increase the graft union rates. Further cohort studies and randomized controlled trials were needed to confirm our findings.

Are the outcomes of single-stage open reduction and Dega osteotomy the same when treating DDH in patients younger than 8 years old? A prospective cohort study

BACKGROUND

The primary objective was to report our early results after a one-stage procedure [open reduction (OR), Dega pelvic osteotomy (DPO), and femoral osteotomy (FO) when needed] for surgical management of a cohort of patients with developmental dysplasia of the hip (DDH). The secondary objective was to compare the functional, radiological, and complications among patients younger and older than 30 months.

MATERIALS AND METHODS

This prospective cohort study included 71 hips with DDH in 61 patients with a mean age of 34.3 ± 19.5 months. All patients underwent one-stage surgical procedures, including OR + DPO and FO, if needed. Functional and radiographic assessment at the last follow-up was conducted using the modified Severin grading system and the Severin classification system, respectively, in addition to assessing the acetabular index (AI), osteotomies healing, and presence of complications. We divided patients into two groups, younger than 30 months (group I) and older than 30 months (group II).

RESULTS

We included 35 hips in group I and 36 in group II. All hips received OR + DPO, while 25 (69.4%) hips in group II had FO. The operative time was significantly longer in group II (103.19 ± 20.74 versus 72.43 ± 11.59 min, p < 0.001). After a mean follow up of 21.3 ± 2.3 months, the functional outcomes were satisfactory in 62 (87.3%) hips (94.3% in group I and 80.6% in group II, p = 0.35). There was a significant improvement in the AI in all patients compared with preoperative values (27.2° ± 2.9 versus 37° ± 4.2, p < 0.05). Furthermore, 63 (88.7%) hips had satisfactory radiographic outcomes (94.3% in group I and 83.3% in group II, p = 0.26), and all osteotomies showed radiographic healing. The overall complications incidence was significantly lower in group I compared with group II (5.7% versus 30.6%, p < 0.05), and avascular necrosis occurred in 4 (5.6%) hips, all in group II (p = 0.06).

CONCLUSION

One-stage procedure entailing open reduction, Dega pelvic osteotomy, and femoral osteotomy when needed for managing DDH in patients younger than eight years old revealed acceptable clinical and radiological outcomes. However, there was a higher need for a concomitant femoral osteotomy in patients older than 2.5 years, and complications were more frequent.

LEVEL OF EVIDENCE III

Treatment perspective after failed open reduction of congenital hip dislocation. A systematic review

Background

Failure of open reduction of developmental hip dislocation is a serious complication and revision surgery appear to be technically demanding with high complication rates. Little attention has been given in literature to patients in whom open reduction of developmental hip dislocation has failed. We present a systematic review about current perspectives and timing when to perform surgical revision after failed open reduction of developmental hip dislocation in children.

Methods

Following the recommendations of the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) statements we performed a comprehensive search of the PubMed and Google Scholar bibliographic database in order to select all studies published between 1980 and 2022. Studies were screened for the reasons for failure of open reduction, timing when revision surgery was performed, and for the surgical techniques used for revision.

Results

A total of 10 articles including 252 patients and 268 hips has been recorded. The most common causes of re-dislocation after open reduction are inadequate exposure and failure to release the obstructing soft tissues inside and around the hip. In 90% of the cases the anterolateral approach was performed for revision surgery. Avascular necrosis occurred in 5%-67% of cases and was the most encountered complication.

Conclusion

Redislocation of developmental hip dislocation after an open reduction has poor long-term outcomes mainly due to a high rate of avascular necrosis of the femoral head. It is mandatory to obtain a stable reduction at the second surgery combining soft tissue release, capsulorrhaphy, pelvic and femoral osteotomies.

The tension of the iliopsoas tendon more than doubles during extension of the dysplastic hip in open reduction

The role of the iliopsoas as an obstructing and re-dislocating factor in developmentally dislocated hips is unclear. The purpose of this article is to determine the change in the iliopsoas' tension during flexion and extension when performing an open reduction. We evaluated 34 hips undergoing an anterior open reduction for a developmental dislocation. At the time of surgery, we identified the iliopsoas, and before sectioning it as part of the open reduction, we measured the tension while cycling the reduced hip through flexion and extension. We performed statistical analysis using Pearson and Spearman correlation tests. We created an initial tension artificially at 20 N with the hip held in 90º of flexion, which then doubled to a mean of 42 N when placed in extension. We found a significant increase in tension when the hip went below 20º of flexion. We also found the correlation between the angle of the hip and the force of tension to be statistically significant ( P  = 0.003). This study provides quantitative support that the tension of the iliopsoas tendon increases significantly in extension when performing an open reduction of a developmentally dislocated hip.

Intraoperative medial wall disruption in Dega pelvic osteotomy: Does it effect the radiographic outcome at medium-term?

OBJECTIVES

To compare the radiographic outcomes of our patients who encountered medial wall disruption, with those who did not while undergoing Dega osteotomy.

METHODS

We retrospectively reviewed the records of 95 hips with developmental dysplasia of the hip who were treated with Dega pelvic osteotomy. Hips were divided into 2 groups according to medial wall disruption: group A included the hips with medial wall disruption, while group B included the hips without disruption. Preoperative, immediate postoperative, 12 weeks and last follow-up anteroposterior radiographs of the pelvis were reviewed for changes in the acetabular index (AI) between groups.

RESULTS

There were 22 hips in group A and 73 hips in the group B. Preoperative (34.6 versus [vs] 37.2, p=0.231), postoperative (17.9 vs 18.4, p=0.682), 12th week (18 vs 18, p=0.504) and last follow-up (13.3 vs 15.1, p=0.097). The acetabular index measurements were comparable between the groups. Corrections achieved during surgery, and during the follow-up period were also comparable between the two groups, indicating no loss of radiographic correction caused by medial wall disruption. Ninety one percent of the patients in group A and 90% of group B achieved good or excellent results according to the Severin classification (p=0.944).

CONCLUSION

Our study shows that disruption of the medial wall did not have a significant detrimental effect on radiographic correction when performing Dega osteotomy.

Ultrasound Imaging of Hip Displacement in Children With Cerebral Palsy

OBJECTIVE

An approach to estimation of hip displacement on ultrasound (US) images is described. Its accuracy is validated through numerical simulation, an in vitro study with 3-D-printed hip phantoms and pilot in vivo data.

METHODS

A diagnostic index, migration percentage (MP), is defined by the ratio of acetabulum-femoral head distance to femoral head width. The acetabulum-femoral head distance could be measured directly on hip US images, while the femoral head width was estimated from the diameter of a best-fit circle. Simulation was performed to evaluate the accuracy of circle fitting with noiseless and noisy data. Surface roughness was also considered. Nine hip phantoms (three different sizes of femur head × three MP values) and 10 US hip images were used in this study.

RESULTS

The maximum diameter error was 16.1 ± 8.5% when the roughness and noise were 20% of the original radius and 20% of the wavelet peak, respectively. In the phantom study, the percentage errors of MPs between the 3-D-design US and X-ray US were 0.3%-6.6% and 0.0%-5.7%, respectively. From the pilot clinical trial, the mean absolute difference between the X-ray-US MPs was 3.5 ± 2.8% (1%-9%).

CONCLUSION

This study indicates that the US method can be used to evaluate hip displacement in children.

Investigation of Igf-1, Igf-Bp3 and Igf-Bp5 levels in umbilical cord blood of infants with developmental dysplasia of the hip

BACKGROUND

IGF-1 (insulin-like growth factor-1) is an important regulator of bone formation. Its deficiency has been associated with fetal growth disorders and hip dysplasia. The aim of this study was to evaluate whether IGF-1, IGF-BP3 (insulin like growth factorbinding protein 3), and IGF-BP5 levels in the umbilical cord blood can be predictive for early diagnosis of DDH.

METHODS

Umbilical cord blood samples were collected from 860 mothers with pregnancies at high risk for DDH between October 2020 and January 2021. Mothers at 37-42 weeks of gestation, with risk factors for DDH, who delivered healthy infants were included. Blood samples were collected during delivery. Each eligible infant was medically followed up and underwent a hip ultrasound in the postnatal 2nd or 3rd month. Infants diagnosed with DDH were matched with a healthy cohort in terms of sex, birth weight, maternal age, and gestational week, and the IGF-1, IGF-BP3 and IGF-BP5 levels were studied and compared.

RESULTS

Evaluation was made of 20 infants diagnosed with DDH and 60 healthy infants. Of the total 80 infants, 72.5% were female.The umbilical cord blood levels of IGF-1 and IGF-BP3 were similar in both groups. The IGF-BP5 values were significantly lower in the DDH patient group. Except for DDH diagnosis, the other categorical variables of the study did not appear to influence the levels of any of the IGFs.

DISCUSSION

Umbilical blood samples could potentially help diagnose DDH. The levels of IGF-BP5 were shown to be significantly lower in infants with DDH.

The Impact of Maternal Age and Educational Level on Developmental Dysplasia of the Hip Diagnosis and Screening: A Descriptive Comparative Study

Background

Early and proper screening for developmental dysplasia of the hip (DDH) is very critical to prevent catastrophic complication on the developing hip joint. Many factors (either maternal or child-related) that hinder timely DDH screening have been previously investigated.

Methods

A cross-sectional descriptive study design was adopted. 175 babies presented for DDH screening coming with their mothers were investigated. Maternal age, age group, and educational level were recorded. In addition, multiple child-related variables such as age of screening, gender, positive family history, preterm delivery, and mode of delivery were recorded as well. Analysis for association between delayed vs. early screening was made against the maternal and the child-related variables.

Results

A total number of 175 children with their mothers were investigated. The mean maternal age was 27.9 years, about one third of the mothers had a graduate level of education (36.3%), while 41.1% had high school education, and 22.3% had middle school education. On the other hand, 40.0% of the investigated babies were first born and two thirds of our sample babies were females (66.9%). Of the included babies, 100 (57.1%) were screened at the appropriate 4-month age, while 75 (42.9%) missed the 4-month screening. Chi-square analysis showed that delayed DDH screening was associated with a lower maternal educational level (P ≤ 0.001), younger maternal age (P ≤ 0.001), and first born baby (P ≤ 0.001). Positive family history was protective against delayed DDH screening (P = 0.032).

Conclusion

The lower maternal educational level, younger maternal age group, and first born babies are risk factors for delayed DDH screening.

Analysis of the results of hip ultrasonography in 48 666 infants and efficacy studies of conservative treatment

PURPOSE

This study aimed to investigate the detection rate of developmental dysplasia of the hip (DDH) by ultrasound. To obtain the distribution characteristics of the different types (I-IV) and the role of ultrasound in the evaluation of infants with DDH (type IIc and above) receiving conservative treatment.

METHODS

A retrospective analysis was performed. The chi-square test was used for comparisons between count-data groups. Two-sided tests were used for all analyses. The results of ultrasound follow-up after conservative treatment are described.

RESULTS

Among the 48 666 infants examined, the detection rates were as follows: type I, 95.42%; IIa, 3.18%; IIb, 0.91%; IIc, 0.22%; D, 0.01%; III, 0.14%; and IV, 0.12%. There were 4456 hips with IIa and above, more left (54.65%) than right (45.35%) hips, and more females (82.60%) than males (17.40%). The detection rate of type IIa and above was 4.58%, and that of type IIb and above was 1.40%. After the treatment, the α value increased, and β value decreased. The cure rate of the less-than-42-days group was higher than that of the other groups.

CONCLUSION

The ultrasound detection rate of DDH is high. DDH was more likely to occur on the left side and in females. It is recommended that the infants should be treated within 42 days.

Diagnostic accuracy of a deep learning model using YOLOv5 for detecting developmental dysplasia of the hip on radiography images

Developmental dysplasia of the hip (DDH) is a cluster of hip development disorders and one of the most common hip diseases in infants. Hip radiography is a convenient diagnostic tool for DDH, but its diagnostic accuracy is dependent on the interpreter's level of experience. The aim of this study was to develop a deep learning model for detecting DDH. Patients younger than 12 months who underwent hip radiography between June 2009 and November 2021 were selected. Using their radiography images, transfer learning was performed to develop a deep learning model using the "You Only Look Once" v5 (YOLOv5) and single shot multi-box detector (SSD). A total of 305 anteroposterior hip radiography images (205 normal and 100 DDH hip images) were collected. Of these, 30 normal and 17 DDH hip images were used as the test dataset. The sensitivity and the specificity of our best YOLOv5 model (YOLOv5l) were 0.94 (95% confidence interval [CI] 0.73-1.00) and 0.96 (95% CI 0.89-0.99), respectively. This model also outperformed the SSD model. This is the first study to establish a model for detecting DDH using YOLOv5. Our deep learning model provides good diagnostic performance for DDH. We believe our model is a useful diagnostic assistant tool.

Effects of different pelvic osteotomies on acetabular morphology in developmental dysplasia of hip in children

Developmental dysplasia of hip seriously affects the health of children, and pelvic osteotomy is an important part of surgical treatment. Improving the shape of the acetabulum, preventing or delaying the progression of osteoarthritis is the ultimate goal of pelvic osteotomies. Re-directional osteotomies, reshaping osteotomies and salvage osteotomies are the three most common types of pelvic osteotomy. The influence of different pelvic osteotomy on acetabular morphology is different, and the acetabular morphology after osteotomy is closely related to the prognosis of the patients. But there lacks comparison of acetabular morphology between different pelvic osteotomies, on the basis of retrospective analysis and measurable imaging indicators, this study predicted the acetabular shape after developmental dysplasia of the hip pelvic osteotomy in order to help clinicians make reasonable and correct decisions and improve the planning and performance of pelvic osteotomy.

Closed reduction evaluation in dysplastic hip with the Ömeroğlu system in children aged 24 to 36 months

Closed reduction (CR) as an initial treatment for developmental hip dysplasia of the hip (DDH) in children aged 24 to 36 months is debatable; however, it could have better results than open reduction (OR) or osteotomies, because it is minimally invasive. The purpose of this study was to evaluate the radiological results in children (24-36 months) with DDH initially treated with CR. Initial, subsequent, final anteroposterior pelvic radiological records were retrospectively analyzed. The International Hip Dysplasia Institute was used to classify the initial dislocations. To evaluate the final radiological results after CR (initial treatment) or additional treatment (CR failed), the Ömeroğlu system was used (6 points excellent, 5 good, 4 fair-plus, 3 fair-minus, and ≤2 poor). The degree of acetabular dysplasia was estimated using the initial acetabular index and the final acetabular index, Buchholz-Ogden classification was used to measure avascular necrosis (AVN). A total of 98 radiological records were eligible, including 53 patients (65 hips). Fifteen hips (23.1%) were redislocated, OR with femoral osteotomy and pelvic osteotomy was the preferred surgical treatment 9 (13.8%). The initial acetabular index versus final acetabular index in total population was (38.9º ± 6.8º) and (31.9º ± 6.8º), respectively (t = 6.5, P < .001). The prevalence of AVN was 40%. Overall AVN in OR, femoral osteotomy and pelvic osteotomy were 73.3% versus CR 30%, P = .003. Unsatisfactory results ≤ 4 points on the Ömeroğlu system were observed in hips that required OR with femoral and pelvic osteotomy. Hips with DDH treated with CR initially might had better radiological results than those treated with OR and femoral and pelvic osteotomies. Regular, good, and excellent results, ≥4 points on the Ömeroğlu system, could be estimated in 57% of the cases, in whom CR was successful. AVN is frequently observed in hips with failed CR.

Developmental dysplasia of the hip: A systematic review of susceptibility genes and epigenetics

BACKGROUND

Developmental dysplasia of the hip (DDH) is a complex developmental deformity whose pathogenesis and susceptibility-related genes have yet to be elucidated. This systematic review summarizes the current literature on DDH-related gene mutations, animal model experiments, and epigenetic changes in DDH.

METHODS

We performed a comprehensive search of relevant documents in the Medline, Scopus, Cochrane, and ScienceDirect databases covering the period from October 1991 to October 2021. We analyzed basic information on the included studies and summarized the DDH-related mutation sites, animal model experiments, and epigenetic changes associated with DDH.

RESULTS

A total of 63 studies were included in the analysis, of which 54 dealt with the detection of gene mutations, 7 presented details of animal experiments, and 6 were epigenetic studies. No genetic mutations were clearly related to the pathogenesis of DDH, including the most frequently studied genes on chromosomes 1, 17, and 20. Most gene-related studies were performed in Han Chinese or North American populations, and the quality of these studies was medium or low. GDF5 was examined in the greatest number of studies, and mutation sites with odds ratios > 10 were located on chromosomes 3, 9, and 13. Six mutations were found in animal experiments (i.e., CX3CR1, GDF5, PAPPA2, TENM3, UFSP2, and WISP3). Epigenetics research on DDH has focused on GDF5 promoter methylation, three microRNAs (miRNAs), and long noncoding RNAs. In addition, there was also a genetic test for miRNA and mRNA sequencing.

CONCLUSIONS

DDH is a complex joint deformity with a considerable genetic component whose early diagnosis is significant for preventing disease. At present, no genes clearly involved in the pathogenesis of DDH have been identified. Research on mutations associated with this condition is progressing in the direction of in vivo experiments in animal models to identify DDH susceptibility genes and epigenetics analyses to provide novel insights into its pathogenesis. In the future, genetic profiling may improve matters.