The sequelae of open reduction of developmental and/or syndromic hip dislocations include osteonecrosis/proximal femoral growth disturbance and residual dysplasia. There is limited information comparing the rates of these sequelae in patients with developmental dysplasia of the hip (DDH) and arthrogryposis multiplex congenita (AMC). We performed a dual-center retrospective cohort study to compare rates of proximal femoral growth disturbance and residual dysplasia between patients with DDH and AMC who had undergone open hip reduction for the treatment of non-traumatic hip dislocations.

We identified patients <18 years of age who had undergone open reduction for the treatment of hip dislocation between 1981 and 2020 at 2 tertiary pediatric hospitals. Patients with AMC were matched by age against patients with DDH in a 1:2 ratio. Preoperative data included demographic characteristics, the severity of dislocation according to the International Hip Dysplasia Institute (IHDI) classification system, and the acetabular index. Outcomes included the acetabular index at 2 years postoperatively, the IHDI classification at the time of final follow-up, and the presence and grade of proximal femoral growth disturbance according to the Salter criteria at 2 years postoperatively and according to the Kalamchi and MacEwen (KM) classification system at the time of final follow-up.

Eighty-two patients (98 hips) with DDH were matched against 39 patients (49 hips) with AMC. The mean follow-up was 107 months (range, 24 to 443 months). There was no difference in the mean age at surgery (1.5 ± 0.7 versus 1.4 ± 1.3 years; p = 0.86), preoperative IHDI classification, acetabular index, or spica cast duration (p > 0.05 for all), but the DDH cohort had more females (83% versus 56%; p = 0.003). Postoperatively, the prevalence of proximal femoral growth disturbance was higher in the AMC group than in the DDH group according to the Salter criteria at 2 years (57% versus 21%; p < 0.001) and according to the KM criteria at the time of final follow-up (59% versus 16%; p < 0.001). At 2 years postoperatively, there was no difference between the DDH and AMC groups in terms of the acetabular index (31° ± 6.2° versus 29° ± 6.9°; p = 0.3) or reoperation rate (24% versus 20%; p = 0.68), but the AMC cohort had more IHDI grade II-IV hips than the DDH cohort (24% versus 9%; p = 0.02), reflecting re-subluxation/dislocation.

Open reduction for hip dislocation in patients with AMC was associated with a significantly higher rate of proximal femoral growth disturbance and re-subluxation/dislocation compared with that in patients with DDH, despite similar preoperative characteristics. This information may guide perioperative counseling for families of patients with AMC.

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Hip dysplasia (HD) at skeletal maturity can result from residual developmental dysplasia of the hip (DDH) treated in childhood or from primary adolescent-onset HD (AOHD). This study aims to compare the pathomorphology of these two HD subtypes with that of a normal control group.

This retrospective study reviewed patients who underwent periacetabular osteotomy for symptomatic HD between 2013 and 2020. The study included 27 residual HD patients (32 hips) following a previous pelvic osteotomy and 39 AOHD patients (68 hips), compared to 29 age- and sex-matched healthy individuals. Acetabular morphology was assessed using plain radiographs, measuring the lateral and anterior center-edge angle (LCEA/ACEA), Sharp angle, Tönnis angle (TA), acetabular depth ratio (ADR), acetabular head index (AHI), and head lateralization index (HLI). On 2D axial and frontal CT scans, we measured acetabular version (AV), anterior and posterior acetabular sector angle (AASA/PASA), femoral neck shaft angle (NSA) and femoral anteversion (FAV).

Both HD groups presented frontal and sagittal acetabular dysplasia with lower LCEA (p < 0.001), lower ACEA (p < 0.001), and lateral subluxation, indicated by lower AHI (p < 0.001) and higher HLI (p < 0.001). Compared to AOHD, residual HD demonstrated greater lateralization, with a higher HLI (p = 0.028). In the axial plane, both HD groups had similar deficient anterior coverage, with lower AASA (p < 0.001). However, residual HD exhibited poorer posterior coverage, with a lower PASA (p < 0.001) and a lower AV (p = 0.006). NSA did not differ between groups, but residual HD had excessive FAV compared to the other groups (p < 0.001).

Although both residual HD and AOHD demonstrated anterior and lateral acetabular deficiencies, residual HD was further characterized by reduced acetabular version, more femoral head lateralization, poorer posterior acetabular support, and excessive FAV.

Reoperation is a major adverse event following surgical treatment but has yet to be used as a primary outcome measure in population studies to assess current treatments for developmental dysplasia of the hip (DDH). The purpose of the present study was to explore the risk factors associated with reoperations following procedures under anesthesia ("operations") for DDH in patients between the ages of 1 and 3.00 years, with the goal of deriving treatment recommendations.

This retrospective birth cohort study included children who had undergone closed reduction, open reduction, or osteotomy for the treatment of unilateral DDH between the ages of 1 and 3.00 years, identified using the Taiwan National Health Insurance Research Database. The children were followed until 10 years of age for reoperations, excluding implant removal and sequential closed reduction within 3 months postoperatively. A comparison between patients with and without reoperations was conducted, and binary logistic regression was used to identify factors associated with reoperation. Patients were further stratified by age and procedure for developing treatment recommendations.

Among 2,261,455 live births from 2000 to 2009, 701 patients underwent operations for unilateral DDH between 1 and 3.00 years of age (an incidence of 31.0 per 1,000 live births). The initial operations included closed reduction (n = 86; mean age, 1.34 years), open reduction (n = 73; mean age, 1.53 years), pelvic osteotomy (n = 405; mean age, 1.59 years), femoral osteotomy (n = 93; mean age, 1.76 years), and pelvic osteotomy plus femoral osteotomy (n = 44; mean age, 1.84 years). Reoperations were performed in 91 patients (13%) at a mean age of 3.80 years. Comparison between patients with and without reoperations revealed the operative procedure as a significant factor. Logistic regression revealed that closed reduction was associated with a 1.8 to 9.0 times higher reoperation risk than open reduction, depending on age, whereas pelvic osteotomy was associated with 0.34 times the risk of reoperation than open reduction in patients 1.5 to 2.0 years of age.

Reoperations may not be directly linked to radiographic and functional outcomes but are important from the patient's perspective and in terms of cost-effectiveness. To reduce the risk of reoperation, the findings of the present study support open reduction to properly reduce the hip joint at walking age and additional pelvic osteotomy for patients beyond 1.5 years of age.

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Patients with developmental dysplasia of the hip (DDH) undergo curved periacetabular osteotomy (CPO) to prevent progressive osteoarthritis. The acetabulum's morphology varies with in each DDH type. Therefore, developing a three-dimensional preoperative plan is important in CPO. However, the optimal rotation angle of the osteotomized bone remains unclear. This study aimed to examine the contact pressure (CP) of the acetabular cartilage in each DDH type using the finite element analysis and the optimal rotation angle of the osteotomized bone in surgical simulation.

This study included 23 patients (24 hips) with DDH who underwent CPO. The DDH type was determined based on a previously reported DDH type classification using radar charts. Four patients, with each patient presenting with one deficiency type, were selected for analysis. The preoperative computed tomography scan data of each patient were analyzed using a finite element analysis software. Based on each DDH type, the following CPO models were established: the preoperative model, the model rotated 10°, 20°, 30°, and 40° laterally, each lateral rotation model with 10° anterior rotation, and each lateral rotation model with 10° external rotation. Furthermore, the acetabular cartilage and the femoral head cartilage were created. The mesh model based on a 4-mm tetrahedron was generated from the CPO model. The load was set in the one-leg standing position (femur: 500 N, grater trochanter: 1000 N). The medial pubic bone, distal femur, and superior rim of the ilium were constrained. The CP of the acetabular cartilage and the number of contact surfaces in each model were evaluated. The rotation angle that was most effective in reducing the CP was examined.

According to the mean CP, the optimal rotation angles of the osteotomized bone in mild, anterior, posterior, and global type deficiencies were 20° laterally, 30° laterally, 30° laterally with 10° anterior rotation, and 30° laterally with 10° anterior rotation, respectively. Based on the contour diagram, the CPO models rotated anteriorly or externally increased the contact surface. The CP of the models rotated 40° laterally did not improve to greater extent than that of the models rotated 30° laterally.

The optimal rotation angle of the osteotomized bone should be determined based on the DDH type.

The aim of this study was to compare the effects of two types of cast immobilization (human position cast and dynamic cast) on hip development in children with Developmental dysplasia of the hip (DDH) after closed reduction (CR).

A retrospective study of 60 children (64 hips) with DDH who underwent CR and cast immobilization between January 2015 and December 2016 at our Institution was performed. The average age at the time of CR was 14.6 months (range, 6.1-23.5). Fifty-seven females and 3 males were included. According to the technique of cast immobilization, two groups of patients could be identified: patients with DDH managed by human position cast immobilization (group A: 32 patients, 34 hips) and patients with DDH treated by dynamic cast immobilization (group B: 28 patients, 30 hips). Hip joint distance (HJD) after CR was measured on MRI. Acetabular Index (AI) and Acetabular Depth Radio (ADR) were measured of anterior-posterior (AP) radiographs before and 3 months after CR; AI and central edge angle (CEA) were measured last follow-up AP radiographs. The presence of subluxation or dislocation and avascular necrosis (AVN) at the last follow-up visit was also evaluated.

The patients were comparable regarding to sex, side, age, Tönnis degree, AI, and ADR before the reduction between two groups. There was no significant difference in HJD improvement between the two groups 6 weeks following closed reduction. The AI (27.5±5.1°) of group B was significantly lower than those of group A (31±4.9°) (P=0.03) when cast was removed 3 months after CR. At the last follow-up, the incidence of AVN was similar between the two groups of patients (group A: 11.8% versus group B: 13.3%), and the incidence of subluxation or dislocation (group A: 8.8% versus group B: 10%). At last follow-up visit, the AI (23.7±5.4°) in group B was significantly lower than in group A (26.9±4.1°) (P=0.02).

Dynamic cast immobilization promotes acetabular development following CR in patients aged 6 to 24 months with DDH. Dynamic cast immobilization does not increase the risk of dislocation or subluxation, nor of AVN.

Patients with developmental dysplasia of the hip (DDH) are at risk for residual acetabular dysplasia even after successful closed reduction. The aim of this study was to identify predictors of long-term outcomes in order to guide prognostication and management.

Patients who were treated for DDH at 2 institutions between 1970 and 2010 and had follow-up until skeletal maturity were screened for inclusion. Hips that underwent open reduction were excluded to reduce iatrogenic confounding. Syndromal (including neuromuscular and arthrogrypotic) hip instability with collagenopathies were excluded. Demographic characteristics, Tönnis grade, age at the time of the reduction, surgical treatment, acetabular index, lateral center-edge angle, residual dysplasia graded using the Severin classification, and the presence and type of proximal femoral growth disturbance categorized using the Bucholz and Ogden classification were assessed. In addition, the the acetabular angle was recorded at the latest follow-up before secondary procedures, and the Oxford Hip Score and 5-level EuroQoL (EQ)-5 Dimension score were recorded at the latest follow-up. To account for repeated measures, generalized estimating equations (GEE) logistic regression was utilized for the multivariable analysis. A support vector machine model and a receiver operating characteristic curve analysis were utilized to identify prognostication thresholds.

One hundred and seven hips (96 female, 11 male) that were followed to skeletal maturity, with a mean follow-up of 20 years (range, 10 to 54 years), were included in the analysis. Eighty-nine hips (83%) demonstrated a good outcome at skeletal maturity, with a Severin grade of I or II. Major growth disturbances of Bucholz and Ogden types II, III, or IV were present in 13 hips (12%). At the latest follow-up after skeletal maturity (before any secondary procedures), the mean acetabular angle was 45° ± 4° and the mean lateral center-edge angle was 26° ± 8°. The mean Oxford Hip Score and EQ visual analog scale values were 47 and 86, respectively. A GEE logistic regression analysis of 1,135 observations revealed that the acetabular index (odds ratio [OR], 1.16 per degree; p < 0.001) and age (OR, 1.20 per year; p = 0.003) were significant predictors of a poor outcome (i.e., Severin grade III, IV, or V). Significant differences in acetabular indices across all age groups were found between hips with a good outcome and those with a poor outcome. Age-specific acetabular index prognostication cutoff values are presented.

This long-term follow-up study demonstrated that the age-specific acetabular index remains an important predictor of residual dysplasia at skeletal maturity. The proposed prognostication chart and thresholds herein can help to guide orthopaedic surgeons and parents when contemplating the use of an intervention versus surveillance to optimize long-term outcomes.

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Despite the success rate of the Pavlik method in the treatment of developmental dislocation of the hip, there is a subset of hips that do not reduce with harness use. The purpose of this study was to determine the outcomes after closed reduction (CR), open reduction (OR) and combined open reduction and pelvic osteotomy (OR+PO) in patients with infantile hip dislocations who initially failed the Pavlik method.

This was a retrospective cohort study of patients with infantile hip dislocations who failed the Pavlik method and subsequently underwent a secondary procedure for persistent hip dislocation. The primary outcome measure was the Severin classification of the involved hip 3 years after the secondary procedure. Other outcomes assessed included rates of redislocation, residual acetabular dysplasia and proximal femoral growth disturbance.

Twenty-three patients were included; seven subsequently underwent CR, three underwent isolated OR and 13 proceeded directly to OR+PO. The overall successful outcome rate at final follow-up (as determined by radiographic Severin class I or II) was 11/23 (48%). However, patients undergoing OR+PO had significantly higher rates of successful outcomes (77%) compared with CR (15%) and OR (0%), P  < 0.05. The rate of residual acetabular dysplasia and proximal femoral growth disturbance was significantly lower in patients treated with OR+PO compared with CR and isolated OR, P  < 0.05.

Patients with dislocated hips who failed Pavlik harness treatment had better radiographic outcomes 3 years after OR+PO in comparison to patients undergoing CR or isolated OR.

To assess the efficacy of arthroscopic debridement and reduction through two medial portals for the treatment of developmental dislocation of the hip (DDH) with failure of initial closed reduction and to explore key pathological structures obstructing reduction.

Forty-eight children with 58 irreducible dislocated hips treated by arthroscopic reduction between January 2017 and December 2020 were retrospectively evaluated. Arthroscopic reduction was performed via two medial portals located in the superior and inferior adductor longus. All intra-articular obstacles were eliminated via arthroscopy, followed by manual reduction and spica cast immobilization. The surgical duration, extent of improvement in the safe zone, and extent of secondary surgical treatment were noted. All the children were followed up for > 24 months. Hip function and radiographic outcomes were evaluated.

All 58 hips showed safe zone improvement and concentric reduction after arthroscopic debridement. Hypertrophic ligamentum teres and thickened pulvinars were detected and resected in all hips. Constrictive capsules preventing reduction were observed in 15 hips, which needed to be further released. No inverted labrum was observed. Secondary surgery was performed in four hips with redislocation and seven hips with subluxation during follow-up. The remaining 47 hips (81.03%) maintained their reduction at the last follow-up. Excellent and good clinical outcomes were achieved in 95.74% of patients according to McKay's criteria. Two hips, three hips, and one hip were diagnosed with grade I, II, and III osteonecrosis of the femoral head, respectively.

This study demonstrated that arthroscopic debridement and reduction is a safe and feasible choice for treating irreducible DDH.

To evaluate mid-long term radiological outcomes following early medial approach open reduction (MAOR) performed for developmental dysplasia of the hip (DDH) in infants aged ≤6 months old at time of surgery, specifically incidence of clinically significant avascular necrosis (AVN), Severin outcomes and rates of further surgery.

This is a single centre retrospective study of patients treated from 1999 to 2017. Only infants aged ≤6 months old at time of MAOR, and aged at least 6 years old at latest follow-up were included (minimum 5.5 years follow-up). Data was collected from electronic healthcare records and serial radiographs reviewed to assess outcomes. AVN was classified according to Kalamchi and MacEwen, with types 2-4 considered clinically significant. Severin classes I (excellent) and II (good) were considered satisfactory outcomes, and classes III + considered unsatisfactory.

MAOR was performed on 48 hips in 44 patients. Mean age at time of surgery was 4 months (SD 1.4, range 2-6), with mean follow-up of 9.8 years (SD 2.7, range 6.2-16.2). Clinically significant AVN developed in 9/48 hips (19 %), all of which were type 2. Only 1/48 hips (2 %) required a subsequent pelvic osteotomy due to residual dysplasia with subluxation at 2 years post MAOR. At final follow-up, 81 % of patients had excellent or good radiological outcomes (Severin I/II). No statistically significant predictors for developing AVN, including age and presence of ossific nucleus, were identified.

Early MAOR in infants aged ≤6 months was associated with a very low rate of significant residual dysplasia requiring further surgery, yet was not associated with unacceptable rates or severe forms of AVN. We therefore recommend MAOR is performed early to optimise acetabular remodelling potential and minimise the need for concurrent or subsequent bony procedures.

Background: This retrospective cross-sectional study investigated the cutoff values (COVs) for developmental dysplasia of the hip (DDH) using a three-dimensional (3D) pelvic model reconstructed using computed tomography (CT). We included 107 healthy Japanese participants and 73 patients who had undergone curved periacetabular osteotomy (CPO) for DDH between 2012 and 2017. Methods: The hip CT images were adjusted to the anterior pelvic plane (APP), functional pelvic plane (FPP), sagittal anterior center-edge angle (ACEA), and sagittal posterior center-edge angle (PCEA). The lateral center-edge angle (LCEA), acetabular roof obliquity (ARO), anterior acetabular sector angle (AASA), and posterior acetabular sector angle (PASA) were measured. Receiver operating characteristic (ROC) curves were used to calculate the COVs, and the association between the parameters was analyzed using multiple logistic regression. Results: The ARO (≥10.2°) and LCEA (≤22.2°) were independent influencing factors for the APP, whereas the AASA (≤53.1°) and LCEA (≤24.5°) were independent influencing factors for the FPP. Conclusions: The 3D criteria for the diagnosis of DDH in Japanese individuals can identify DDH with insufficient anterior coverage, which anteroposterior plain radiographs cannot visualize, and can help determine indications for acetabular osteotomy.

The current published evidence for the treatment of developmental dysplasia of the hip (DDH) with failed closed reduction (CR) following failed Pavlik harness (PH) treatment is still limited. This study aimed to determine whether an one-stage open reduction (OR) would lead to a similar outcome to a two-stage OR in these patients. Meanwhile, the occurrence of femoral head avascular necrosis (AVN) and further surgery (pelvic osteotomy, PO) within the follow-up period was investigated.

A consecutive series of DDH patients who failed CR following failed PH treatment and received OR finally between January 2008 and December 2020 were studied. The patients were divided into two groups. One group of which received OR immediately after failed CR (one-stage OR group, Group A), and the other received a delayed OR (two-stage OR group, Group B). The McKay's criteria, acetabular index (AI) and the degree of dislocation of the hips were evaluated for the final outcomes.

At the last follow-up, 54 (84.4%) of the 64 hips in Group A and 26 (83.9%) of 31 hips in Group B were in excellent or good condition. Comparison between the two groups revealed that there were no differences in terms of McKay grading (P = 0.950), AI (P = 0.783), incidence of AVN (P = 0.745), and also incidence of PO (P = 1.000). However, a significant lower mean AI was found in Group A, when the OR was performed in Group B (31.06 ± 4.45° vs. 33.87 ± 4.12°, P = 0.004).

Both of the one- and two-stage OR may acheive favorable outcomes. Moreover, one-stage OR is of without the general anesthesia risk associated with two-stage OR. We therefore advocate that an OR should be performed in appropriate DDH patients during the same session once a failed CR is detected.

This study aims to demonstrate the use of the cartilaginous to osseous acetabular angle ratio (AAR) in surgical decision-making for hip dysplasia.

Data were collected from patients who underwent an MRI of the hip after conservative treatment for developmental dysplasia of the hip between August 2019 and 2022. The data included demographic information as well as an anteroposterior pelvic radiograph. The osseous acetabular index (OAI) was measured using x-ray, while the cartilaginous acetabular index (CAI) and the cartilaginous acetabulum head index (CAHI) were measured using MRI. The square of the CAI to OAI, AAR, was calculated. The patients in the residual hip dysplasia (RHD) group were categorized as having an OAI above 20°. During the postoperative follow-up, we evaluated the patients in this group who underwent Bernese triple pelvic osteotomy. Data on surgical patients with an observation period that exceeded 1 year were collected and analyzed. The distribution of the AAR among the different groups was analyzed. A receiver operating characteristic (ROC) predictive model was constructed using the AAR of the patients in the normal and surgical groups to evaluate the need for surgery.

It was found that there was a significant difference in the OAI, CAI, CAHI, and AAR between the RHD group (OAI 26.15 ± 3.90°, CAI 11.71 ± 4.70°, CAHI 79.75 ± 6.27%, and AAR 5.88 ± 4.24) and the control group patients (OAI 16.77 ± 5.39°, CAI 6.16 ± 3.13°, CAHI 85.05 ± 4.91%, and AAR 2.71 ± 2.08) (p < 0.001). A total of 93.5% of the control group patients had an AAR ≤5, while only 6.5% had an AAR >5. The results of postoperative imaging follow-up were "excellent" in 52 patients and "good" in 3, while the functional follow-up results were excellent in 53 and good in 2. In 15 patients, the observation period exceeded 1 year. The mean observation period was 633.1 ± 259.6 days and the preoperative CAHI was 71.7 ± 4.8%. Of the patients with an AAR >5, a substantial 94.8% (55/58) of them were reported to have undergone surgery, while all patients with an AAR less than or equal to 5 did not undergo surgery (91/91). Based on the ROC, a cutoff value of 5.09 was identified for the need for surgery in children with RHD.

A surgical decision for residual hip dysplasia can be based on the AAR. An AAR >5 may be a potential indicator for surgical intervention in patients with RHD.

Developmental dysplasia of the hip is prevalent and is associated with dysplasia of both the femoral head and acetabulum. There is a paucity of literature describing femoral head remodeling after surgical reduction of developmentally dislocated hips. The purpose of this study was to describe and quantify changes in femoral head sphericity after closed or open reduction for developmental dysplasia of the hip.

A retrospective cohort study was performed including patients with typical developmental hip dislocations who underwent closed or open reduction from 2009 to 2022 at a single institution and had immediate postoperative and average 3-week follow-up magnetic resonance imaging (MRI) scans. A subset of patients also had 3-year follow-up MRI scans. Patients with insufficient imaging or bony procedures at the time of reduction were excluded. We developed a technique to quantify femoral head "sphericity" by comparing differences in measured radii of the femoral head on axial and coronal plane MRI slices. We then calculated the variance of the radii for each plane and averaged these to calculate a combined variance. The variance was used to represent "sphericity," with a larger variance indicating a wider distribution of radii and thus a less spherical shape.

A total of 74 patients (69 females) with 96 hips were included in this series. The median age of the child at the time of reduction was 8.7 months [interquartile range (IQR): 2.2]. Over half (58.3%) of the hips had a closed reduction, whereas the remaining were open reduced (41.7%). Immediately postoperatively, at the 3-week time point, and at the 3-year time point the median combined variance was 1.1 (IQR: 3.93), 0.51 (IQR: 1.32), and 0.31 (IQR: 0.50), respectively, indicating improved sphericity over time.

Sphericity of the femoral head in developmental hip dislocations improves in both the immediate postoperative period, as well as the first few years after reduction. Further research is needed to evaluate the mechanism of remodeling, the ideal timing of reduction, and the relationship between femoral head and acetabular remodeling.

Level IV-case series, therapeutic study.

Developmental dysplasia of the hip (DDH) joint is a complex condition that may lead to severe problems. Ultrasound scan (USS) in the first four-to-six weeks of life is considered the gold-standard for diagnosis while the Pavlik harness (PH) is a widely utilized method as first-line treatment. The purpose of this study is to compare clinical outcomes of infants with DDH in relation to the timing and frequency of USS following application of the PH.

Retrospective data were collected over a 5-year period from February 2017 to February 2022. We included patients who underwent the first USS post-diagnosis and PH application in two, three, four and six weeks. Two-hundred-twenty-five patients were included and divided in four groups according to timing of the first follow-up: week-2, n = 13; week-3, n = 66; week-4, n = 95; and week-6, n = 51. For every patient Graf classification, treatment length and number of follow-ups were documented.

Week-3 and week-4 groups displayed a statistically significant shorter treatment length compared to week-6 group (p value < 0.001), while also demonstrating a lower number of sonographic follow-ups per patient compared to both week-6 (p value < 0.001) and week-2 (p value = 0.002 vs week-3; p value < 0.001 vs week 4). Week-4 group presented the highest treatment completion (56%) on first visit post-diagnosis. Conservative treatment with PH failed in 1.8% (4/225) and displayed no significant difference among all subgroups.

Differences in timing of first USS post-DDH diagnosis and initiation of treatment can lead to discrete outcomes with implications to the clinical outcome and cost effectiveness.

There is limited evidence supporting the value of morphological parameters on post-reduction magnetic resonance imaging (MRI) to predict long-term residual acetabular dysplasia (RAD) after closed or open reduction for the treatment of developmental dysplasia of the hip (DDH).

We performed a retrospective study of 42 patients (47 hips) undergoing open or closed reduction with a minimum 10 years of follow-up; 39 (83%) of the hips were in female patients, and the median age at reduction was 6.3 months (interquartile range [IQR], 3.3 to 8.9 months). RAD was defined as additional surgery with an acetabular index >2 standard deviations above the age- and sex-specific population-based mean value or Severin classification grade of >2 at last follow-up. Acetabular version and depth-width ratio, coronal and axial femoroacetabular distance, cartilaginous and osseous acetabular indices, transverse ligament thickness, and the thickness of the medial and lateral (limbus) acetabular cartilage were measured on post-reduction MRI.

At the time of final follow-up, 24 (51%) of the hips had no RAD; 23 (49%) reached a failure end point at a median of 11.4 years (IQR, 7.6 to 15.4 years). Most post-reduction MRI measurements, with the exception of the cartilaginous acetabular index, revealed a significant distinction between the group with RAD and the group with no RAD when mean values were compared. The coronal femoroacetabular distance (area under the receiver operating characteristic curve [AUC], 0.95; 95% confidence interval [CI], 0.90 to 1.00), with a 5-mm cutoff, and limbus thickness (AUC, 0.91; 95% CI, 0.83 to 0.99), with a 4-mm cutoff, had the highest discriminatory ability. A 5-mm cutoff for the coronal femoroacetabular distance produced 96% sensitivity (95% CI, 78% to 100%), 83% specificity (95% CI, 63% to 95%), 85% positive predictive value (95% CI, 65% to 96%), and 95% negative predictive value (95% CI, 76% to 100%). A 4-mm cutoff for limbus thickness had 96% sensitivity (95% CI, 78% to 100%), 63% specificity (95% CI, 41% to 81%), 71% positive predictive value (95% CI, 52% to 86%), and 94% negative predictive value (95% CI, 70% to 100%).

Coronal femoroacetabular distance, a quantitative metric assessing a reduction's concentricity, and limbus thickness, a quantitative metric assessing the acetabulum's cartilaginous component, help to predict hips that will have RAD in the long term after closed or open reduction.

Diagnostic Level IV . See Instructions for Authors for a complete description of levels of evidence.

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.

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.

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.

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.

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.

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.

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.

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 III-retrospective comparative study.

This systematic review and meta-analysis aimed to compare the outcomes of total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH) and those with osteoarthritis (OA).

Four databases were searched from inception till February 2023 for original studies that compared the outcomes of THA in DDH and OA. The primary outcome was the revision rate; the secondary outcomes were dislocation and failure modes (i.e. aseptic loosening, PJI, instability, and periprosthetic fractures), hospital stay and costs. This review was conducted as per PRISMA guidelines, and the risk of bias was assessed using the Newcastle-Ottawa scale.

A total of 9 observational studies with 575,255 THA (469,224 hips) were included, with a mean age of 50.6 years and 62.1 years for DDH and OA groups, respectively. There was a statistically significant difference in revision rate between DDH and OA patients in favour of OA (OR, 1.66; 95% CI 1.11-2.48; p-value, 0.0251). However, dislocation rate (OR, 1.78, 95% CI 0.58-5.51; p-value, 0.200), aseptic loosening (OR, 1.69; 95% CI 0.26-10.84; p-value, 0.346) and PJI (OR, 0.76; 95% CI 0.56-1.03; p-value, 0.063) were comparable across both groups.

A higher revision rate following total hip arthroplasty was associated with DDH compared with osteoarthritis. However, both groups had similar dislocation rates, aseptic loosening and PJI. Consideration of confounding factors, such as patient age and activity level, is crucial when interpreting these findings. LEVEL OF EVIDENCE : III.

PROSPERO registration: CRD42023396192.

Residual acetabular dysplasia in children after reduction of hip dislocation is often treated using Salter innominate osteotomy to prevent future osteoarthritis. Preventive surgery for asymptomatic patients, which could result in overtreatment, should be carefully applied with consideration of patients' opinions. In this study, we aimed to describe opinions on Salter innominate osteotomy as preventive surgery for children among adult patients who had undergone periacetabular osteotomy for hip pain due to hip dysplasia.

A mail-in questionnaire survey was conducted with 77 patients who underwent periacetabular osteotomy. Participants responded whether they would recommend Salter innominate osteotomy as preventive surgery for children and the reason for their opinion. We also performed a patient-based evaluation using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire and assessed clinical outcome measures with the Japanese Orthopedic Association score. Their recommendations and reasons were evaluated, and associations between their opinions and demographic and clinical characteristics were analyzed.

Forty-three patients (56%) responded to the questionnaire. Of these, 10 (23%) patients recommended undergoing Salter innominate osteotomy, 28 (65%) patients did not, and 5 (12%) patients responded they were undecided. No significant association was observed between their opinions and demographic/clinical characteristics evaluated in the survey. The most frequent reason for why they do not recommend Salter innominate osteotomy was related to uncertainty about future hip pain.

In total, 65% of the study participants did not recommend Salter innominate osteotomy for children with risk of dysplasia in the future. Participants' preferences regarding preventive surgery were not influenced by demographic and clinical characteristics.

After the successful reduction of developmental dysplasia of the hip, residual hip dysplasia may persist and lead to early osteoarthritis. Femoral and/or acetabular osteotomy has been used to address this problem. The purpose of this study is to determine the indication of femoral versus combined femoral-acetabular osteotomy in the management of residual hip dysplasia.

Fifty-five patients with unilateral dislocated-type dysplasia of the hip, who had residual hip dysplasia after reduction, underwent femoral osteotomy with or without acetabular osteotomy before 8 years of age, and were followed for more than 2 years and over 8 years of age, were the subjects of this retrospective study. Twenty-eight patients underwent femoral osteotomy only at a median age of 34 months (group F), and 27 underwent combined femoral-Dega osteotomy at a median age of 49 months (group C). Seventeen patients in group F and 4 in group C had an additional osteotomy due to persistent hip dysplasia. Acetabular index (AI), lateral center-edge angle, and center-head distance difference were measured on serial radiographs. The z-value of AI (Z AI ) was calculated. At the latest follow-up, patients in group F with Severin I/II who did not have an additional osteotomy were considered satisfactory, and patients with Severin III/IV or those who had an additional osteotomy were considered unsatisfactory. Preoperative variables were tested for the difference between satisfactory and unsatisfactory cases. Receiver operating characteristic analysis was performed to delineate a cutoff value of a significant parameter dividing the outcome.

AI and Z AI before index osteotomy were significant parameters predicting a satisfactory outcome in group F. Receiver operating characteristic analysis returned a cutoff value of Z AI 2.6 (Area Under the Curve=0.86, P =0.001). Eight of 12 cases (66.7%) with Z AI <2.6 in group F achieved a satisfactory outcome, whereas only 2 of 14 cases with Z AI ≥2.6 in group F did ( P =0.02).

Z AI 2.6 may serve as a threshold to combine acetabular osteotomy with femoral osteotomy in the management of residual hip dysplasia before 8 years of age.

Therapeutic III.

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.

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).

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).

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.

Although there are several predominantly single-center case series in the literature, relatively little prospectively collected data exist regarding the outcomes of open hip reduction (OR) for infantile developmental dysplasia of the hip (DDH). The purpose of this prospective, multi-center study was to determine the outcomes after OR in a diverse patient population.

The prospectively collected database of an international multicenter study group was queried for all patients treated with OR for DDH. Minimum follow-up was 1 year. Proximal femoral growth disturbance (PFGD) was defined by consensus review using Salter's criteria. Persistent acetabular dysplasia was defined as an acetabular index >90th percentile for age. Statistical analyses were performed to compare preoperative and operative characteristics that predicted re-dislocation, PFGD, and residual acetabular dysplasia.

A cohort of 232 hips (195 patients) was identified; median age at OR was 19 months (interquartile range 13 to 28) and median follow-up length was 21 months (interquartile range 16 to 32). Re-dislocation occurred in 7% of hips (n=16/228). The majority (81%; n=13/16) occurred in the first year after initial OR. Excluding patients with repeat dislocation, 94.5% of hips were IHDI 1 at most recent follow-up. On the basis of strict radiographic review, some degree of PFGD was present in 44% of hips (n=101/230) at most recent follow-up. Seventy-eight hips (55%) demonstrated residual dysplasia compared with established normative data. Hips that had a pelvic osteotomy at index surgery had about half the rate of residual dysplasia (39%; n=32/82) versus those without a pelvic osteotomy with at least 2 years follow-up (78%; n=46/59).

In the largest prospective, multicenter study to date, OR for infantile DDH was associated with a 7% risk of re-dislocation, 44% risk of PFGD, and 55% risk of residual acetabular dysplasia at short term follow-up. The incidence of these adverse outcomes is higher than previous reports. Patients treated with concomitant pelvic osteotomy had lower rates of residual dysplasia. These prospectively collected, multicenter data provide better generalizable information to improve family education and appropriately set expectations.

Level II, prospective comparative study.

The long-term prognosis of acetabular dysplasia without subluxation in developmental dislocation of the hip (DDH) is uncertain. The aim of this study was to assess the consequence of having acetabular dysplasia at skeletal maturity on the need for having a total hip arthroplasty (THA) up to the age of 60 years.

Inclusion criteria were age at diagnosis 0.5-3.0 years, initial treatment with skin traction to obtain closed reduction during 1958-1962, and no acetabular procedures to improve femoral head coverage. 48 patients (57 hips) met these criteria, 41 girls and 7 boys. Hip dysplasia was defined as a center-edge (CE) angle at skeletal maturity of 10-19°, and hips with CE angles in the range 20-25° were termed borderline dysplastic.

At skeletal maturity, 18 hips had acetabular dysplasia with a mean CE angle of 15.8° (10-19), whereas 19 hips were borderline with CE angles 20-25°, and 20 hips were normal (CE angles ≥ 26°). During the follow-up period 16 hips had undergone THA, 11 of 18 hips with dysplasia, 4 of 19 with borderline dysplasia, and 1 of 20 hips without dysplasia (p < 0.001). Hip survival in the 18 dysplastic hips, with THA as the endpoint, was 100% up to patient age 40 years; thereafter survival fell to 83% at 50 years and 39% at 60 years. There was no significant correlation between CE angle at skeletal maturity and age at THA (p = 0.2). The mean age at the last follow-up in patients without THA was 62 years (60-64).

Acetabular dysplasia without subluxation was a risk factor for THA, but less than one-fifth of the hips had undergone THA up to patient age 50 years.

This study was designed to analyze the cartilaginous predictors of residual acetabular dysplasia (RAD) after early treatment of developmental dysplasia of the hip and their diagnostic accuracy.

Databases such as PubMed, Embase, Cochrane, and Web of science were searched to screen the literature. The quality of the literature was assessed by the QUADAS-2 tool. Qualitative and quantitative synthesis of literature were performed based on extracted data. For quantitative synthesis studies, the sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve with corresponding confidence intervals were calculated.

For the cartilaginous acetabular index (CAI) group, the combined values of sensitivity, specificity, and DOR were 0.80 (95% CI = 0.54-0.93), 0.73 (95% CI = 0.57-0.84), and 10.62 (95% CI = 3.96-28.53), respectively. The corresponding values in the cartilaginous center-edge angle (CCE) group were 0.71 (95% CI = 0.57-0.82), 0.78 (95% CI = 0.66-0.87), and 8.64 (95% CI = 3.08-24.25), respectively. The area under the curve (AUC) of SROC was 0.82 (95% CI = 0.78-0.85) and 0.80 (95% CI = 0.76-0.83) for the CAI and CCE groups. The CAI group had higher sensitivity, DOR, and AUC than the CCE group.

Both of these two groups have good diagnostic accuracy, and CAI/L-AI has a little edge over CCE/L-CEA. However, there is still more research needed to determine whether they can be used as independent indications for secondary orthopedic surgery.Systematic review registration: [https://www.crd.york.ac.uk/PROSPERO/], identifier: [CRD42022338332].

A new, supposedly more reproducible radiographic classification, set to replace the Tönnis classification of hip dislocations, was proposed in 2015: the International Hip Dysplasia Institute (IHDI) classification.

To compare the IHDI classification with the Tönnis classification when evaluating the severity of hip dislocations as well as their respective inter- and intra-observer reliability.

Since January 2000, Swedish-born children with a hip dislocation were prospectively registered. From this registry, radiographs of 97 hips in 79 patients (91% girls; median age = 7 months), born in 2000-2009, were analyzed. Two observers, one consultant and one resident, classified each hip both by IHDI and Tönnis twice.

The IHDI classification had a more even distribution of grades with the majority in grade 2-3. The Tönnis classification graded the majority (77%) of the patients as grade 2 and equally among the other grades. There was moderate inter-observer agreement using both methods calculated with Kappa, 0.61 (95% confidence interval [CI] = 0.44-0.79) for Tönnis and 0.62 (95% CI = 0.49-0.74) for IHDI. The resident calculated Tönnis with weak intra-observer reliability of 0.57 (95% CI = 0.40-0.74) compared to high intra-observer reliability of 0.86 (95% CI = 0.74-0.98) for the consultant. Both observers graded IHDI with high intra-observer reliability.

IHDI is more discriminative than the Tönnis classification when evaluating the severity of a hip dislocation in infants.

Developmental dysplasia of the hip represents a spectrum of deformity. Residual dysplasia at 2 years of age is associated with an increased risk for osteoarthritis and functional limitations. We compared the prognostic value of 6-month imaging modalities and aimed to identify optimal diagnostic metrics for the prediction of residual dysplasia.

After IRB approval, patients who underwent Pavlik treatment between 2009 and 2018 with 2-year follow-up were identified. Sonographs [ultrasound (US)] and radiographs (x-ray) were obtained at 6-month and 2-year-old visits. Dysplasia at 2 years was defined as an acetabular index (AI) >24 degrees. Receiver operating characteristic curves were constructed to quantitatively compare the prognostic ability of US and x-ray-based measures at 6 months. Youden's index [(YI) (values range from 0 (poor test) to 1 (perfect test)] was used to evaluate existing cutoffs at 6 months of age (normal measurements: alpha angle (AA) ≥60 degrees, femoral head coverage (FHC) ≥50%, and AI <30 degrees) relative to newly proposed limits.

Fifty-nine patients were included, of which 28.8% of patients (95% CI: 17.3 to 40.4%) had acetabular dysplasia at 2 years. After adjusting for sex, AA [Area under the Curve (AUC): 80] and AI (AUC: 79) at 6 months of age were better tests than FHC (AUC: 0.77). Current diagnostic cutoffs for AA (YI: 0.08), AI (YI: 0.0), and FHC (YI: 0.06) at 6 months had poor ability to predict dysplasia at 2 years. A composite test of all measures based on proposed cutoffs (AA ≥73 degrees, FHC > 62% and AI ≤24 degrees) was a better predictor of dysplasia at 2 years (Youden's index (YI): 0.63) than any single metric.

The rate of residual dysplasia remains concerning. The 6-month x-ray and US both play a role in the ongoing management of the developmental dysplasia of the hip. The prediction of dysplasia is maximized when all metrics are considered collectively. Existing parameters were not accurate; We recommend the following cutoffs: AA ≥73 degrees, FHC > 62%, and AI ≤24 degrees. These cutoffs must be validated.

Prognostic Level II.

Long-term outcomes of surgical treatment for pediatric developmental dysplasia of the hip (DDH) are not well defined. The purpose of this study was to report long-term radiographic and clinical outcomes, survivorship free of total hip arthroplasty (THA), and predictors of subsequent THA following childhood treatment of DDH. This study was a single-institution retrospective review of hips treated for DDH with closed or open reduction at a minimum 10-year follow-up. 107 patients (119 hips) were included with a mean patient age of 3.3 years at childhood treatment. At mean 30.5 years follow-up, 24 hips had undergone THA (20%). Mean patient age at time of THA was 33.5 years. None of the hips treated with closed reduction alone required THA, whereas 8 hips treated with open reduction (25%) underwent THA. Hips with patient age > 4 years at the time of treatment had lower survivorship at 35 years follow-up (50% vs. 85%; p < 0.001). Additionally, femoral osteotomy (OR 2.0, p < 0.001), and previous treatment elsewhere (27% vs. 16%; p < 0.01) were associated with subsequent THA. Early referral and appropriate intervention may prove important, as age and prior treatment were predictive of subsequent THA.

Residual acetabular dysplasia of the hip after open reduction can complicate the treatment of developmental dysplasia of the hip (DDH) due to the potential need for corrective surgery. This retrospective study aimed to determine the predictive factors for acetabular development using postoperative radiographs and magnetic resonance imaging (MRI).

We retrospectively investigated 74 hips of patients with DDH who underwent open reduction after reaching walking age and were followed up radiologically until skeletal maturity. We evaluated the cartilaginous acetabulum and labrum using a new method that measures the cartilaginous and labral landmarks on coronal and axial MR T2*-weighted images in patients aged 5 years. The mean age at the time of surgery was 22 months and that at the final survey was 20 years. Severin classification was determined at the final follow-up. Groups with good (53 hips) and poor (21 hips) outcomes were compared using the postoperative radiographic and MRI parameters recorded at 5 years of age. Factors predicting acetabular development were identified using univariate and multiple logistic analyses.

There were no significant differences in the bony-acetabular index (AI) and centre-edge (CE) angle between the good and poor outcome groups. However, the poor outcome group had significantly larger cartilaginous- and labral-AIs but significantly smaller cartilaginous- and labral-CE angles than the good outcome group (both p < 0.05). Multiple logistic regression analysis showed that labral-AI and labral-CE angle were predictors of acetabular development after open reduction for DDH, and their optimal cut-offs were 4° (77% sensitivity, 76% specificity) and 37° (68% sensitivity, 85% specificity), respectively.

Normal cartilaginous acetabulum development occurs in childhood, and evaluation using only radiographs is difficult. However, labral-AI ⩾4° and labral-CE angle <37° on MRI at 5 years of age offer useful indications for corrective surgery in patients with DDH.

The purpose of this study was to examine whether measurement accuracy is impacted with a low radiation radiograph technique. Treatment decisions for hip dysplasia require serial radiographs to monitor acetabular anatomy. However, radiation use creates concern for future malignancy. Standard radiograph technique utilizes a grid to enhance clarity, but requires a larger X-ray dose. We hypothesized grid removal would lower radiation exposure without decreasing measurement accuracy. This is a retrospective cohort study of patients with idiopathic DDH and neuromuscular hip displacement at a single institution from 2019 to 2020 receiving surveillance radiographs. A cohort receiving modified technique radiographs (grid removed) was compared to an age-matched cohort receiving standard technique radiographs. Four examiners measured radiographs on two separate occasions, a minimum of 2 weeks apart. Migration percentage (MP) was measured for neuromuscular patients and acetabular index (AI) for idiopathic DDH. Intraclass correlation coefficient (ICC) with a 95% confidence interval (CI) was used to evaluate inter-observer and intra-observer agreement for measurements. Average radiation dose for both techniques. A total of 134 age-matched patients were included for measurement of MP. Thirty age-matched patients were included for AI measurements. Inter and intra-rater reliability of MP and AI were not different with or without use of the grid. There was a 50-75% decrease in radiation dose per radiograph following grid removal, dependent on patient size. The adjusted radiograph technique showed no significant difference in MP or AI reliability. A slight decrease in picture contrast did not jeopardize measurement reliability and decreased radiation exposure for the patient significantly. This simple technique can be useful for patients requiring multiple radiographs over time.

Salter innominate osteotomy (SIO) provides favorable results for treating residual acetabular dysplasia in young children. In this study, we examined the midterm results of SIO according to the age at surgery to determine the optimal timing of this procedure.

We retrospectively examined 50 hips of 42 patients (8 boys and 34 girls) with acetabular dysplasia who underwent SIO and were followed up until skeletal maturity. The center-edge angle (CEA) was measured based on the anteroposterior radiographs of the hip obtained before surgery, 5 weeks after surgery, and at the latest follow-up. Severin classification was evaluated at the latest follow-up. Patients were categorized into 3 groups according to age at surgery: younger than 7 years of age (group A), 7 to 8 years of age (group B), and 9 years of age or older (group C).

The mean preoperative CEA level of 0.9 degrees improved to 17.1 degrees postoperatively, which was increased to 28.1 degrees at the latest examination. Overall, 45 hips (90%) were classified as Severin I or II, with 96% in group A, 94% in group B, and 57% in group C. In group C, postoperative acetabular coverage was similar to that in the other groups (16.6 degrees in group A, 14.8 degrees in group B, and 18.1 degrees in group C), although the final outcome was unsatisfactory. The average improvement in CEA from postoperative to skeletal maturity was significantly smaller in group C than in the other groups (12.7 degrees in group A, 11.3 degrees in group B, and 3.0 degrees in group C).

SIO showed favorable outcomes with satisfactory acetabular coverage at skeletal maturity. However, satisfactory acetabular coverage could not be obtained in some older patients because of limited postoperative remodeling capacity and smaller secondary improvement of CEA. We recommend that SIO should be performed in patients aged 8 years or younger.

Level III-retrospective comparative study.

Developmental dysplasia of the hip (DDH) describes the abnormal development of a hip in childhood, ranging from complete dislocation of the hip joint to subtle immaturity of a hip that is enlocated and stable within the socket. DDH occurs in around 10 per 1000 live births, though only one per 1000 are completely dislocated. There is variation in treatment pathways for DDH, which differs between hospitals and even between clinicians within the same hospital. The variation is related to the severity of dysplasia that is believed to require treatment, and the techniques used to treat dysplasia.

To determine the effectiveness of splinting and the optimal treatment strategy for the non-operative management of DDH in babies under six months of age.

We searched CENTRAL, MEDLINE, Embase, seven other electronic databases, and two trials registers up to November 2021. We also checked reference lists, contacted study authors, and handsearched relevant meetings abstracts.

Randomised controlled trials (RCTs), including quasi-RCTs, as well as non-RCTs and cohort studies conducted after 1980 were included. Participants were babies with all severities of DDH who were under six months of age. Interventions included dynamic splints, static splints or double nappies (diapers), compared to no splinting or delayed splinting.

Two review authors independently selected studies, extracted data and performed risk of bias and GRADE assessments. The primary outcomes were: measurement of acetabular index at years one, two and five, as determined by radiographs (angle): the need for operative intervention to achieve reduction and to address dysplasia; and complications. We also investigated other outcomes highlighted by parents as important, including the bond between parent and child and the ability of mothers to breastfeed.

We included six RCTs or quasi-RCTs (576 babies). These were supported by 16 non-RCTs (8237 babies). Five studies had non-commercial funding, three studies stated 'no funding' and 14 studies did not state funding source. The RCTs were generally at unclear risk of bias, although we judged three RCTs to be at high risk of bias for incomplete outcome data. The non-RCTs were of moderate and critical risk of bias. We did not undertake meta-analysis due to methodological and clinical differences between studies; instead, we have summarised the results narratively. Dynamic splinting versus delayed or no splinting Four RCTs and nine non-RCTs compared immediate dynamic splinting and delayed dynamic splinting or no splinting. Of the RCTs, two considered stable hips and one considered unstable (dislocatable) hips and one jointly considered unstable and stable hips. No studies considered only dislocated hips. Two RCTs (265 babies, very low-certainty evidence) reported acetabular index at one year amongst stable or dislocatable hips. Both studies found there may be no evidence of a difference in splinting stable hips at first diagnosis compared to a strategy of active surveillance: one reported a mean difference (MD) of 0.10 (95% confidence interval (CI) -0.74 to 0.94), and the other an MD of 0.20 (95% CI -1.65 to 2.05). Two RCTs of stable hips (181 babies, very low-certainty evidence) reported there may be no evidence of a difference between groups for acetabular index at two years: one study reported an MD of -1.90 (95% CI -4.76 to 0.96), and another study reported an MD of -0.10 (95% CI -1.93 to 1.73), but did not take into account hips from the same child. No study reported data at five years. Four RCTs (434 babies, very low-certainty evidence) reported the need for surgical intervention. Three studies reported that no surgical interventions occurred. In the remaining study, two babies in the dynamic splinting group developed instability and were subsequently treated surgically. This study did not explicitly state if this treatment was to achieve concentric reduction or address residual dysplasia. Three RCTs (390 babies, very low-certainty evidence) reported no complications (avascular necrosis and femoral nerve palsy). Dynamic splinting versus static splinting One RCT and five non-RCTs compared dynamic versus static splinting. The RCT (118 hips) reported no occurrences of avascular necrosis (very low-certainty evidence) and did not report radiological outcomes or need for operative intervention. One quasi-RCT compared double nappies versus delayed or no splinting but reported no outcomes of interest. Other comparisons No RCTs compared static splinting versus delayed or no splinting or staged weaning versus immediate removal.

There is a paucity of RCT evidence for splinting for the non-operative management of DDH: we included only six RCTs with 576 babies. Moreover, there was considerable heterogeneity between the studies, precluding meta-analysis. We judged the RCT evidence for all primary outcomes as being of very low certainty, meaning we are very uncertain about the true effects. Results from individual studies provide limited evidence of intervention effects on different severities of DDH. Amongst stable dysplastic hips, there was no evidence to suggest that treatment at any stage expedited the development of the acetabulum. For dislocatable hips, a delay in treatment onset to six weeks does not appear to result in any evidence of a difference in the development of the acetabulum at one year or increased risk of surgery. However, delayed splinting may reduce the number of babies requiring treatment with a harness. No RCTs compared static splinting with delayed or no splinting, staged weaning versus immediate removal or double nappies versus delayed or no splinting. There were few operative interventions or complications amongst the RCTs and the non-randomised studies. There's no apparent signal to indicate a higher frequency of either outcome in either intervention group. Given the frequency of this disease, and the fact that many countries undertake mandatory DDH screening, there is a clear need to develop an evidence-based pathway for treatment. Particular uncertainties requiring future research are the effectiveness of splinting amongst stable dysplastic hips, the optimal timing for the onset of splinting, the optimal type of splint to use and the need for 'weaning of splints'. Only once a robust pathway for treatment is established, can we properly assess the cost-effectiveness of screening interventions for DDH.

Although normal anterior acetabular coverage provides stability to the hip, acetabular retroversion leads to femoroacetabular impingement related to hip osteoarthritis. Previous studies have focused on acetabular version and anteroposterior coverage in children with developmental dysplasia of the hip (DDH); however, the correlation between anteroposterior coverage and acetabular development is unclear. We measured anteroposterior acetabular coverage in DDH patients using transverse magnetic resonance imaging (MRI) and subsequent bony acetabular growth, and evaluated the correlation of those findings.

We evaluated 37 DDH (dislocations) in 36 patients who underwent MRI at 2 years of age. The mean age was 2.2±0.3 years at the time of MRI (1.6±0.4 y after reduction) and 6.0±0.1 years at the time of plain radiography for the Severin classification. On MRI scans, we measured the cartilaginous center-edge angle (CCEA) and cartilaginous acetabular-head index (CAHI) in the coronal plane and the anterior and posterior cartilaginous center-edge angles (AC-CEA and PC-CEA, respectively) in the transverse plane. Severin I or II was defined as a good outcome and III or IV as a poor outcome.

In the evaluations conducted at 2 years of age, the mean CCEA, CAHI, AC-CEA, and PC-CEA were 14±9 degrees, 66%±10%, 39±8 degrees, and 77±7 degrees, respectively; the CEA at 6 years of age was 13±7 degrees. Twelve and 25 hips were classified in the good and poor outcome groups, respectively. Although CCEA, CAHI, and AC-CEA were significantly associated with the outcome in a single regression analysis ( P <0.05), only AC-CEA was significant in the multiple regression analysis with a stepwise selection method ( P =0.018). The cutoff AC-CEA value for a good outcome was 38 degrees (sensitivity, 67%; specificity, 68%) using a receiver operating characteristic curve.

Among MRI findings for acetabular cartilaginous morphology, AC-CEA was strongly associated with the outcome. Anteroposterior coverage was correlated with bony acetabular growth in childhood, and anterior coverage was particularly important for subsequent acetabular growth.

Level IV-case series.

Universal ultrasonographic screening for developmental dysplasia of the hip (DDH) has gained increasing popularity despite the lack of benefit in terms of reducing the rates of late-detected cases (age ≥12 weeks) in randomized clinical trials.

To report the reported incidence of DDH in the English scientific literature and compare rates of late-detected cases in settings with different DDH screening strategies.

PubMed, Scopus, and Web of Science databases were searched on November 25 and 27, 2021. No time filters were used in the search.

All observational studies reporting the incidence of early-detected or late-detected (age ≥12 weeks) DDH were included. Non-English reports were excluded if the abstract did not include enough information to be included for analysis.

The number of newborns screened and the detection rates were extracted. Meta-analysis calculated the pooled incidence of DDH per 1000 newborns with 95% CIs using a random- or fixed-effects model. This study is reported according to the PRISMA and MOOSE guidelines.

The main outcome measures were early detection, early treatment, late detection, and operative treatment incidences.

A total of 1899 studies were identified, 203 full texts were assessed, and 76 studies with 16 901 079 infants were included in final analyses. The early detection rate was 8.4 (95% CI, 4.8-14.8) infants with DDH per 1000 newborns with clinical screening, 4.4 (95% CI, 2.4-8.0) infants with DDH per 1000 newborns with selective ultrasonographic screening, and 23.0 (95% CI, 15.7-33.4) infants with DDH per 1000 newborns with universal ultrasonographic screening. Rates for nonoperative treatment were 5.5 (95% CI, 2.1-14) treatments per 1000 newborns with clinical screening, 3.1 (95% CI, 2.0-4.8) treatments per 1000 newborns with selective ultrasonographic screening, and 9.8 (95% CI, 6.7-14.4) treatments per 1000 newborns with universal ultrasonographic screening. The incidence of late-detected DDH was 0.5 (95% CI, 0.2-1.5) infants with DDH per 1000 newborns with clinical screening, 0.6 (95% CI, 0.3-1.3) infants with DDH per 1000 newborns with selective ultrasonographic screening, and 0.2 (95% CI, 0.0-0.8) infants with DDH per 1000 newborns with universal ultrasonographic screening. The corresponding incidences of operative treatment were 0.2 (95% CI, 0.0-0.9) operations per 1000 newborns with clinical screening, 0.5 (95% CI, 0.4-0.7) operations per 1000 newborns with selective ultrasonographic screening, and 0.4 (95% CI, 0.2-0.7) operations per 1000 newborns with universal ultrasonographic screening.

This meta-analysis found that early detection rates and nonoperative treatments were higher with universal screening. The late detection and operative treatment rates with universal screening were similar to those among selectively and clinically screened newborns. Based on these results, universal screening may cause initial overtreatment without reducing the rates of late detection and operative treatment.

The acetabular morphology varies greatly among individuals, and hypoplasia is more common in Asia than in Europe. Dislocation after bipolar hip arthroplasty (BHA) for femoral neck fracture occurs at a constant rate, and is affected by the acetabular morphology. This study aimed to clarify individual differences in the acetabula of Asian patients with displaced femoral neck fractures.

Fifty patients with displaced femoral neck fractures were assessed (50 fractured hips, 50 non-fractured hips). On CT corrected by the anterior pelvic plane, the 100 hips were assessed regarding acetabular coverage (six parameters), acetabular depth (two parameters), and acetabular opening angle (four parameters). Additional parameters related to the fracture and sex were examined. The percentile of each parameter was shown for all hips.

There was no patient with hip dysplasia defined as superior acetabular sector angle (SASA) less than 110° Compared with men, women had a significantly smaller anterior acetabular sector angle (AASA) (p = 0.016), and significantly larger acetabular inclination angle (p = 0.006) and acetabular index angle (p = 0.034). In the group with a normal SASA, seven hips (7.3%) had an anterior wall defect (AASA<50°) and five hips (5.2%) had a posterior wall defect (posterior acetabular sector angle<90°).

Older adults with femoral neck fractures can have anterior wall and posterior wall defects, even if their SASA is normal. Hidden acetabular dysplasia may be related to post-BHA dislocation. So, our results suggest that is important to accurately evaluate the acetabulum of patients with femoral neck fracture before surgery.

Many aspects of developmental hip dysplasia (DDH) care and evaluation are still active areas of debate. Recent studies have provided more insight into these topics such as strategies for reducing osteonecrosis, assessing hip reduction after closed and open reduction, and the management of residual acetabular dysplasia.

The presence of the ossific nucleus at the time of reduction does not alter the risk of osteonecrosis. The risk of osteonecrosis may be higher when hips are immobilized in excessive abduction. Limited sequence MRI may be the best choice for assessing hip reduction after closed and open reduction; however, new technologies are emerging such as 3D fluoroscopy and perfusion MRI. The treatment of residual acetabular dysplasia with bracing has been shown to be effective and the decision to perform a pelvic osteotomy is based on patient-specific factors. The spectrum of DDH treatment has evolved over the past several decades. Recent studies have provided insights into strategies for osteonecrosis prevention, hip evaluation during after reduction, and the management of residual acetabular dysplasia. However, there is ample room for additional and more rigorous studies guiding advanced imaging for assessing hip reduction such as 3D fluoroscopy and perfusion MRI, as well as the management of residual acetabular dysplasia.

We aimed to compare the outcomes between closed reduction (CR) and open reduction (OR) in children aged 6-24 months with developmental dysplasia of the hip (DDH) who could be reduced safely and stably by the closed reduction operation.

We retrospectively reviewed the medical records of 77 patients who underwent CR or OR for DDH. Fifty-one patients (56 hips) underwent CR, 26 (29 hips) underwent OR. The demographic data, International Hip Dysplasia Institute classification and acetabular index (AI) before reduction and the centre-edge angle (CEA), AI, Alsberg angle (AA), Reimer's migration index (RMI), and height-to-width index (HWI) of the epiphysis were compared between two groups at the final follow-up. The percentage of coxa magna > 15% of the normal side and AA > 81° were calculated.

At the final follow-up, the mean AA in the CR and OR groups were 77.66° (60°-89°) and 81.97° (73°-91°) (p = 0.001), respectively, there were 32.14% and 58.62% of the hips with an AA > 81° (p = 0.019). The frequency of coxa magna > 15% of the normal side was higher in the OR group (60.9%) than in the CR group (6.5%) (p < 0.001). There was no difference in the improvement of AI, CEA, HWI, and RMI.

In children aged 6-24 months with DDH, if a stable and safe CR can be obtained but with medial joint space up to 6mm, CR should be attempted first.

Traditionally graft displacement following Pemberton and Dega acetabuloplasties involves internal fixation for treatment of developmental dysplasia of hip (DDH). This study was performed to assess the acetabular remodeling by conservative management of graft displacement among patients with DDH. This was a retrospective study of 20 patients 17 (85%) women and 3 (15%) men; mean age 22.90 ± 6.96 months with DDH who underwent Pemberton and Dega acetabuloplasties at King Khalid University Hospital, Riyadh between January 2013 and January 2018. All patients after losing acetabular correction during immediate postoperative period were treated by conservative management. The management involved application of Spica cast for 6 weeks that was trimmed to broomstick cast for an extended period of time and finally replaced by nocturnal abduction brace until normal acetabular index (AI) was achieved. The patients were followed up for a mean period of 44.60 ± 12.36 months. Out of the total, 18 (90%) patients with DDH were successfully treated by conservative management. The mean preoperative AI of 43.70° ± 5.91° improved to 21.35o ± 6.32o at the final follow-up (P < 0.001) which was no different when compared to the mean of unaffected hips (19.70o ± 2.96o; P < 0.44). The mean preoperative CEA of all the patients was negative that improved during the conservative treatment to 29.20° ± 10.0° which was no different when compared with the mean of unaffected (31.70° ± 4.64o; P = 0.32) hips at the final follow-up. doption of less aggressive approach for management of displaced, rotated or impacted autograft following acetabuloplasties among children with DDH was not only a useful conservative approach for remodeling of hips but also obviated the need for additional surgical intervention.

Following open or closed reduction for children with developmental dysplasia of the hip, there remains a significant risk of residual acetabular dysplasia which can compromise the long-term health of the hip joint. The purpose of this study was to use postoperative in-spica magnetic resonance imaging (MRI) data to determine factors predictive of residual acetabular dysplasia at short-term follow-up.

We retrospectively reviewed 63 hips in 48 patients which underwent closed or open reduction and spica casting for developmental dysplasia of the hip. MRI performed in-spica at ∼3-week follow-up were used to assess 11 validated metrics and 2 subjective factors. Acetabular index (AI) was measured on anteroposterior pelvic radiographs at 2-year postoperative follow-up. Binary logistic regression was then used to identify variables predictive of residual dysplasia, defined as an AI greater than the 90th percentile for age based on historic normative data.

Average age at surgical reduction was 9.3±3.2 months. 58.7% (37/63) of reductions were open. A total of 43 (68.3%) hips demonstrated residual acetabular dysplasia at 2 years postoperatively based on normative values. In those with persistent dysplasia, patients were on average older at the time of reduction (10.0 mo±3.2 vs. 8.0 mo±2.8, P=0.010) and more likely female (88.4% vs. 60.0%, P=0.010). Patients with residual dysplasia were more likely to have mild subluxation on postoperative MRI (40.0% vs. 10.5%, P=0.022). Hips with a cartilaginous acetabular index (CAI) of >23 degrees were 7.6 times more likely to develop residual dysplasia. Type of reduction (ie, closed vs. open) did not appear to influence the rate of residual dysplasia (P=0.682).

In this series, the rate of residual dysplasia after surgical reduction was higher than most previous reports, with no appreciable difference between closed and open reductions. Older age, female sex, and a higher CAI were associated with a greater risk of persistent radiographic dysplasia. In particular, hips with a CAI >23 degrees were 7.6 times more likely to be dysplastic at 2-year follow-up.

Level III.

The purpose of this study was to investigate whether presence of an infolded limbus on hip arthrogram at index closed reduction was associated with increased residual dysplasia or secondary surgery.

We retrospectively reviewed all patients who underwent closed reduction for dysplasia of the hip with a minimum 2-year follow-up between 1980 and 2016. Demographic data was obtained including the age at reduction and severity of dislocation based on the International Hip Dysplasia Institute (IHDI) classification. Arthrograms performed at time of closed reduction were separately reviewed by 3 fellowship-trained pediatric orthopaedic surgeons to evaluate for an infolded limbus. The primary radiographic outcome was acetabular indices at 2 and 4 years postreduction. We also assessed the presence of avascular necrosis and rate of secondary reconstructive surgery for residual dysplasia.

A total of 182 hips in 165 patients underwent closed reduction at a mean age of 9.8±4.5 mo and were followed a mean of 9.0±4.9 y. An infolded limbus was identified in 20.3% (37/182) hips with substantial agreement among the 3 graders (Fleiss κ=0.75). The frequency of labral infolding increased with the severity of dislocation (8.8%% of IHDI II, 26.7% IHDI III, and 25.0% of IHDI IV hips; P=0.03). Hips with infolded limbus were older at reduction (12.4±5.3 vs. 9.2±5.8 mo, P=0.001). The mean acetabular index was higher in hips with infolded limbus than hips without at 2 years postreduction (34.8±4.8 vs. 32.6±5.8 degrees, respectively; P=0.04). However, multivariate analysis revealed that only the severity of dislocation predicted dysplasia at 2 years postreduction. No significant difference in acetabular index was seen at 4 years postreduction (27.2±7.4 vs. 25.4±6.5 degrees, P=0.24). There was no difference in avascular necrosis between groups (P=0.74). There was no difference in rate of secondary surgery between hips with labral infolding and those without (35% vs. 30%, respectively; P=0.52).

An infolded limbus was more common in older patients with more severe dislocations. However, it is not associated with increased residual dysplasia or secondary surgery and may have limited utility in decision-making during closed reduction.

Level II-prognostic study.

Residual acetabular dysplasia (RAD) is a major problem of developmental dysplasia of the hip (DDH) after closed reduction (CR). Several parameters have been investigated as ways of predicting RAD; however, prediction of RAD remains controversial. The purpose of this study was to evaluate the radiographic sign of teardrop and sourcil line (TSL) in pediatric patients with DDH to enable prediction of RAD after CR.

One hundred and twenty-five hips with DDH treated with CR and followed up for at least 2 years were included in this study. The mean age at CR was 18.3 months (range, 9 to 32 months) and the average follow-up time was 50.2 months (range, 24 to 89 months). The acetabular index (AI) was measured at different time points. The cases were divided into two groups according to whether TSL became continuous or not. The relationships among TSL, AI and RAD were analyzed.

The RAD incidence was 73.6% (92/125) at the last follow-up. AI at CR and TSL were the prognostic factors for RAD (P=0.017 and 0.001, respectively). Thirty-four hips showed a continuous TSL. There was a lower RAD rate in the TSL continuous group (P<0.001). There was no statistical difference in the AI at CR between the TSL continuous and discontinuous groups; however, the level of AI after CR was lower in the TSL continuous group. The TSL of 74% (20/27) hips became continuous after acetabular osteotomy surgery.

The TSL continuous group had a lower AI and incidence of RAD than the discontinuous group. The TSL can be a predictive factor of RAD in DDH after CR and restore the continuous of TSL maybe a potential parameter that can help surgeons to make a judgment intra-operation.

Dislocation following total hip arthroplasty (THA) is a well-known complication. However, there is little data on its rate and predictors in patients with developmental dysplasia of the hip (DDH). The current study is aimed to determine the rate and specific risk factors of dislocation following THA in DDH patients.

All the medico-surgical records of primary THAs from January 2014 to January 2019 were retrospectively reviewed. They were categorized into three main groups: primary OA, DDH, and others. Pre-operative and post-operative radiographs, past medical and surgical history, and surgical notes were reviewed in DDH cases.

In a total of 171 patients with DDH, 21 suffered from dislocation after THA (12%) which was significantly more frequent than those with primary OA. In univariate analysis, higher grade of dysplasia, smaller head size, intra-operative fracture, Wagner Cone stem, failure of offset restoration, and implanting the cup outside the Lewinnek's safe zone were identified as predictors of dislocation. In multiple regression analysis, however, only higher Crowe grade, intra-operative fracture, and post-operative acetabular offset less than 16 mm were independent predictors of dislocation.

Dysplastic hips can be more prone to post-THA dislocation than those with primary OA. Higher grades of dysplasia, failure of offset restoration, and intra-operative fracture can increase the rate of dislocation in this group of patients.

Residual acetabular dysplasia occurs in up to a third of patients treated successfully for developmental dysplasia of the hip (DDH) and has been found to be a significant risk factor for early hip osteoarthritis (OA).

Age at the time of initial reduction and the initial severity of DDH have been linked to residual acetabular dysplasia. An anteroposterior pelvic radiograph is the main diagnostic modality, but MRI also provides valuable information, particularly in equivocal cases. The literature supports intervening when significant residual acetabular dysplasia persists at 4-5 years of age, and common surgical indications include acetabular index (AI) > 25°-30°, lateral center-edge angle (LCEA) < 8°-10°, and a broken Shenton's line on radiographs; and a cartilaginous acetabular angle (CAI) > 18°, cartilaginous center-edge angle (CCE) < 13°, and/or the presence of high-signal intensity areas on MRI. Surgical options include redirectional pelvic osteotomies and reshaping acetabuloplasties, which provide comparable radiographic and clinical results.

RAD is common after treatment of DDH and requires regular follow-up for diagnosis and appropriate management to decrease the long-term risk of OA. Long-term outcomes of patients treated with pelvic osteotomies are generally favorable, and the risk of OA can be decreased, although the risk of total hip replacement in the long-term remains.

This study aimed to explore the docking of the femoral head into the acetabulum after gradual reduction (GR) using traction for developmental dysplasia of the hip (DDH) and the impact on subsequent acetabular development.

A total of 40 patients with DDH (42 hips) undergoing GR using overhead traction and spica casting were retrospectively reviewed. The presence of inverted labrum and the coronal and axial femoral-acetabular distances (FADs) were compared between MRI immediately and five weeks after spica casting. The change in the acetabular index on anteroposterior pelvic radiographs were compared between hips with inverted labrum (residual group) and with normally-shaped labrum (normalized group) on follow-up MRI.

The mean age at reduction was 13.1 months (7 to 33) and the mean follow-up duration was 7.7 years (4 to 11). The rate of inverted labrum and the FADs significantly decreased between the MRI scans (all p-values < 0.001), and previous Pavlik harness failure had no negative effect on these decreases. The acetabular indices at the ages of three and five years in the residual group were significantly larger than those in the normalized group (both p-values < 0.001). Residual acetabular dysplasia was seen in 84.2% of the residual group compared with 34.8% of the normalized group (p = 0.002).

The docking phenomenon can occur during spica casting following GR using traction in children with DDH between the ages of six months and three years. The remaining inverted labrum at the cast removal may negatively affect subsequent acetabular development.

III - retrospective comparative study.

Early prediction of future acetabular development is important to determine an additional surgery for developmental dysplasia of the hip (DDH). The purpose of this study was to investigate the predictive factors of acetabular development using MRI. We retrospectively investigated dislocated 40 hips and 34 normal hips in 37 pediatric patients (9 males and 28 females) with DDH who underwent open reduction after walking age. We evaluated the cartilaginous acetabulum and labrum of the patients using coronal MRI T2*-weighted images at 5 years of age. The mean age at the time of surgery was 22 months, and the mean age at the final survey was 19 years. We divided patients into two groups in accordance with the Severin classification at the final follow-up. Groups with good outcomes (affected 26 hips and unaffected 27 hips) and poor outcomes (14 hips and 7 hips) were compared using the MRI parameters on each side. Predictive factors of acetabular development were identified using univariate and multiple logistic regression analyses. Using multiple logistic regression analysis, labral acetabular roof depth and labral hip center distance at 5 years of age represented predictors after open reduction (odds ratio 0.27, P = 0.035; odds ratio 3.4, P = 0.028, respectively) on the affected side, and bony hip center distance represented a predictor on the unaffected side (odds ratio 2.6, P = 0.049). Acetabular development in the unaffected side could be predicted by bony assessment, while acetabular development in the affected side had to be assessed by labrum using MRI.

Developmental dysplasia of hip joint (DDH) is a dynamic progressive pathology which can tilt either way. The term strictly applies to primary dysplasia, where etiology is not clearly known. Secondary dysplasia can be due multiple causes, such as neuromuscular disorders, connective tissue disorders or skeletal syndromes.

The etiology being multifactorial, it needs a multidisciplinary team to address the issue at hand. The management starts antenatally with a detailed history of any risk factors and a dedicated ultrasound of the foetus, since forewarned is forearmed. At birth, a paediatrician having a keen sense of DDH will perform Barlow's or Ortolani's manoeuvre and can be the first one to sound the alarm in the event of positive findings. How and when a Radiologist needs to step in will depend on inter-departmental discussions between the paediatrician and the orthopedician.

In the presence of positive clinical screening tests, and non-availability of ultrasound, a preliminary X ray pelvis AP view including both hip joints should be the requisitioned in a child of any age, particularly, if belonging to the high-risk group. If ultrasound is available, a screening exam till 6 months of age is recommended to rule out DDH.

India is known for its vast numbers and little babies with occult diseases are the first to bear the brunt of conditions which have very few symptoms to start with. DDH is one such condition which most unfortunately expresses itself as a symptom only when it's too late, i.e., most often when the child begins to walk. Ultrasound is the modality of choice in neonates; however, since India is a country of modest means, in majority of the regions, radiographs still remain the first line of investigation.

The growth and development of the acetabulum in children with developmental dysplasia of hip (DDH) depends upon the extent of concentric reduction. Children in walking age often need open reduction with or without additional osteotomies to obtain congruous, stable reduction. The purpose of this study was to evaluate acetabular development in late diagnosed DDH treated by open reduction with or without femoral osteotomy.

This is a retrospective study of 29 children (40 hips) with idiopathic DDH, previously untreated managed by open reduction with or without femoral osteotomy. We analyzed preoperative and yearly postoperative radiographs up to 6 years of age for acetabular development by measuring acetabular index. Acetabular remodeling was assessed with a graphical plot of serial mean acetabular index. Those with AI < 30° at outcome measure point of 6 years of patient age were considered to have satisfactory acetabular remodeling.

Mean age of surgery was 26.8 months. Open reduction alone was done in 14 hips and open reduction with concurrent femoral osteotomy done in 26 hips. The mean acetabular index pre operatively was 36.6° ± 5.9° which reduced to 29.7° ± 6° at 1-year follow-up and to 26.6° ± 5.9° at 2-year follow-up. 28 out of 40 hips were available for evaluation at outcome measure point of 6 years of age, which showed satisfactory remodeling in 24 hips with mean AI of 22.7° ± 5.7°. Maximum acetabular development was seen at 2 years post-surgery and better remodeling was seen in children operated at less than 2 years of age. 5 hips had changes of avascular necrosis of femoral head. There was no incidence of redislocation/subluxation at latest follow-up.

Open reduction in late-diagnosed developmental dysplasia of hip has potential for favourable acetabular development. Femoral osteotomy when required along with open reduction may suffice to address acetabular dysplasia found in the initial years of management of DDH.

Developmental dysplasia of the hip (DDH) is a disabling pathology leading to hip problems, such as painful arthritic hip, unstable hip, etc. Total hip arthroplasty (THA) is an effective treatment modality for this condition. Obesity has been shown to be associated with increased rates of complications following orthopaedic surgeries (Journal of Arthroplasty 20:46-50). The hypothesis of this study was that patients with a body mass index (BMI) greater than 30 (obese), who undergo total hip arthroplasty for dysplastic hip, are associated with longer operative and anaesthetic times, longer hospital stays and higher re-admission rates within 30 days.

All the cases of total hip arthroplasty in patients with high-riding dysplastic hips were reviewed. Evaluation was made of a total of 68 patients comprising 64 females and 4 males, classified into two groups. Patients with BMI < 30 kg/m2 formed the non-obese group and patients with BMI ≥ 30 kg/m2 the obese group.

The mean age was 44.67 ± 6.49 years. BMI was < 30 in 44 (64.7%) patients and > 30 in 24 (35.3%) patients. The data analysis showed that mean surgical time, anaesthesia duration and re-admission rate were significantly higher in the group with BMI ≥ 30(obese) as compared to the group with BMI < 30 (non-obese) (p < 0.01). The complication rate was determined to be higher in the obese group (p < 0.05).

Obese patients performed with total hip arthroplasty for high-riding dysplastic hips had more complications and higher rates of re-admission to hospital compared with the non-obese patients.