Residual Acetabular Dysplasia Research Articles

Residual Acetabular Dysplasia at Walking Age: A Study of 470 Hips Treated With Pavlik Harness.

This study aims to report on the acetabular indices of walking age children following successful DDH treatment with Pavlik harness and investigate risk factors for residual acetabular dysplasia (RAD). We retrospectively reviewed the data for children treated for DDH at a single centre between 2015 and 2020. Acetabular indices (AI) measured on pelvic radiographs taken at 2- and 4-year follow-up visits were referenced against age-matched and sex-matched normal data. Values ≥90th percentile were considered to represent RAD. A total of 305 children with 470 hips were suitable for inclusion. The mean age at treatment initiation was 7.0±4.5 weeks and mean treatment duration was 15.9±4.3 weeks. Overall, 27% and 19% of hips were found to have RAD at 2- (n=448) and 4-year (n=206) follow-up, respectively. The χ2 test for independence demonstrated that the difference in the proportion of hips with RAD at both time points was significant (P=0.032). Patients with RAD at 2 years were found to have been treated for longer (P=0.028) and had lower alpha angles on final ultrasound assessment (P<0.001). Patients with RAD at 4 years were older at initiation of treatment (P=0.041), had lower alpha angles on final ultrasound assessment (P<0.001) and were more likely to have had RAD at 2 years (P<0.001). Multivariate analysis identified lower alpha angles on final ultrasound to be predictive for RAD at 2 years (P=0.011), and presence of RAD at 2 years to be predictive for RAD at 4 years (P<0.001). The risk of RAD beyond walking age in children successfully treated with Pavlik harness is not negligible. However, we observed that a significant proportion of children with RAD at 2-year follow-up had spontaneously improved without any intervention. This data suggests that routine long-term radiologic follow-up of children treated with Pavlik harness is necessary, and surgical intervention to address RAD should be delayed until at least 4 years of age. Level III-case-control study.

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

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.

Modified triple pelvic osteotomy for residual acetabular dysplasia through double incisions: Technical note and review of short-term results.

To assess validity, safety, and efficacy of the modified triple pelvic osteotomy (TPO) approach for correction of residual acetabular dysplasia. This is a retrospective case series conducted on 15 hips in 15 patients from 2019 to 2023 with residual acetabular dysplasia treated by modified TPO as described by Tonnis with two modifications. The first modification is using a single medial incision for pubic and ischial cuts (the Vladimirov modification). The second modification is having the ischial cut closer to the acetabulum (Li modification) allowing free movement of the acetabular fragment for better femoral head coverage. The mean age at the time of surgery was 11.85years, (range 8-23). Cases presenting were 10 males (66.7%) and 5 females (33.3%). The mean follow-up period was 36.533 months (24-60 months). Our study revealed significant clinical and radiological improvement. The CE angle improved from a mean value of 10° (range 2-17) pre-operatively to 32.785° (range 18°-40°) post-operatively. The AI improved from a mean value of 32° pre-operatively to a mean value of 13.89° post-operatively. HHS increased from a preoperative mean value of 74.80° to a post-operative mean value of 90.67°. Also, there was a significant improvement in ROM (abduction and internal rotation). LLD improved from a mean value of 2.60cm preoperatively to a mean value of 0.37cm postoperatively. Delayed union was found in 3 cases. No cases of osteonecrosis or neurovascular complication were encountered in our study. The modified TPO technique using dual incisions can be considered safe and effective, providing adequate coverage of the femoral head in acetabular dysplasia with less surgical time, satisfactory functional outcomes, and minimal complications. IV.

Outcomes of treatment for developmental dislocation of the hip when the Pavlik method has failed.

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.

Bilateral Involvement in Developmental Dislocation of the Hip: Analysis of 561 Patients Operated on Using the Limited Posteromedial Approach.

Our objective was to scrutinize the risk factors related to bilateral involvement in the developmental dysplasia of the hip (DDH) and to inspect the impact of bilaterality on the enduring results of the DDH. All patients, aged between 6 and 18 months, who underwent surgery using the limited posteromedial approach (734 hips from 561 patients), were included in this study. The number of births, birth type, history of consanguineous marriage, family history, and swaddling were analyzed. Physical examination and complaints of the patients were evaluated, and direct radiographs were examined in terms of the redislocation, avascular necrosis, and residual acetabular dysplasia. Among the 561 patients, bilateral DDH was observed in 173 patients (30.8%). The use of swaddling was found to be statistically significant between groups (p = 0.012). The use of swaddling for more than one month was associated with a higher odds ratio for bilaterality (p = 0.001, OR = 1.56, 95% CI: 1.2-2.0). Furthermore, bilaterality was associated with a higher risk for redislocation in DDH (p = 0.001, OR = 4.25, 95% CI: 1.6-11.2). The study concludes that swaddling for over a month is strongly linked with the bilateral involvement in DDH. It is important to note that bilaterality plays a crucial role in the development of redislocation after open reduction in DDH.

Hip Morphology on Post-Reduction MRI Predicts Residual Dysplasia 10 Years After Open or Closed Reduction.

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.

Twelve to Twenty-year Follow-up of Dega Acetabuloplasty in Patients With Developmental Dysplasia of the Hip: Is it as Effective as Expected?

Although Dega acetabuloplasty is widely used for the treatment of developmental dysplasia of the hip, there is a paucity of data on long-term outcomes. The purpose of the study was to evaluate the rate of residual acetabular dysplasia after Dega acetabuloplasty. Patients of a previously reported consecutive series of 35 patients (43 hips) operated by a single surgeon were recontacted for long-term follow-up. Of these, 25 patients (32 hips) consented, with a follow-up rate of 71% (74% of hips). The mean age at the time of surgery was 35 (18 to 65) months. The presence of residual dysplasia was noted according to the lateral center-edge angle of Wiberg, femoral head extrusion index, and Tönnis angle. The latest radiographic outcome was evaluated according to the Severin classification and patients were clinically evaluated according to the modified McKay criteria. The mean follow-up duration of 16.5 (12 to 20) years yielded an average age of 19.2 (14 to 23) years at the time of analysis. According to lateral center-edge angle, femoral head extrusion index, and Tönnis angle, 5 (15.6%) hips were dysplastic and 2 (6.3%) hips were reoperated for resubluxation. Thus, a total of 7 hips (21.9%) were considered to have residual dysplasia. With the exception of 2 hips that underwent further osteotomies, no other hips were re-subluxated or redislocated. Overcoverage was noted in 6 (18.7%) hips. There were 26 Severin group I and II (81.3%), 4 Severin group III (12.5%), and 2 Severin group IV (6.2%) hips. According to modified McKay criteria, 20 (62.5%) hips were excellent, 7 (21.9%) hips were good, and 5 (15.6%) were fair. Severin classification and modified McKay criteria were correlated with dysplasia ( P < 0.05). Seventy-eight percent of the hips treated by Dega acetabuloplasty for developmental dysplasia of the hip did not have acetabular dysplasia at a mean follow-up of 16 years. Even in well-treated asymptomatic hips, patients should be followed regularly, especially for residual dysplasia. Level IV.

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

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

Triple Innominate Osteotomy in Management of Residual Acetabular Dysplasia in Young Adolescent Patients (Systematic Review and Meta-Analysis)

Background: Aim of the Work The aim of this work is to provide cumulative data about the effic cy and safety of triple innominate osteotomy in management of residual acetabular dysplasia in young adolescent patients. Methods This review was done using standard methodology outlined in the Cochrane Handbook and reported the findings in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses Results We found that; the total number of patients in all the included studies was 631 patients; while their average follow up time was (7.2 ± 4.6 years); with longest follow up time of 14.5 years. The average age of all patients was (12.67 ± 3.7 years); with youngest mean age of 7.5 years. Regarding Pre-operative assessment, the average CE angle was (10.4 ± 7.2) degrees, and the average HHS score was (77.7 ± 17.69) degrees. Regarding Post-operative sequel, the overall complications rate was (184/631) (29.1%), and the overall AVN rate was (123/631) (19.5%). Regarding 1 ry efficacy outcome measures, Conclusion Acetabular dysplasia is among the anatomical abnormalities seen in developmental dyplasia of the hip (DDH). One of the goals of surgical treatment during childhood is to achieve optimal femoral head coverage by correcting this architectural flaw, thereby preventing osteoarthritis. Pelvic osteotomy is a treatment option in children and adolescents with residual acetabular dysplasia after developmental dyplasia of the hip.

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

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

Developmental Dysplasia of the Hip (DDH): Etiology, Diagnosis, and Management.

Developmental dysplasia of the hip (DDH) is a complex disorder that refers to different hip problems, ranging from neonatal instability to acetabular or femoral dysplasia, hip subluxation, and hip dislocation. It may result in structural modifications, which may lead to early coxarthrosis. Despite identifying the risk factors, the exact aetiology and pathophysiology are still unclear. Neonatal screening, along with physical examination and ultrasound, is critical for the early diagnosis of DDH to prevent the occurrence of early coxarthrosis. This review summarizes the currently practised strategies for the detection and treatment of DDH, focusing particularly on current practices for managing residual acetabular dysplasia (AD). AD may persist even after a successful hip reduction. Pelvic osteotomy is required in cases of persistent AD. It could also be undertaken simultaneously with an open hip reduction. Evaluation of the residual dysplasia (RD) of the hip and its management is still a highly active area of discussion. Recent research has opened the door to discussion on this issue and suggested treatment options for AD. But there is still room for more research to assist in managing AD.

Residual acetabular dysplasia after Pavlik harness treatment for Graf type II hips.

To evaluate the residual acetabular dysplasia in Graf type II hips after Pavlik harness treatment with a radiographic follow-up at 2 years of age. We retrospectively reviewed the developmental dysplasia of the hip patients who were treated with the Pavlik harness between March 2018 and February 2022. Patients with Graf type II hip dysplasia who had at least one radiographic follow-up after 2 years of age were included. The following information, sex, laterality, affected side, age at harness initiation, treatment duration, α angle, and the morphology of bony roof, was collected and studied. We evaluated the radiographic acetabular index at the last follow-up and defined the value of greater than 2 standard deviations as residual acetabular dysplasia. A total of 33 patients (53 hips) met the criteria. The mean initial α angle was 53.4°; the mean age at Pavlik harness initiation was 10.9 weeks. The mean treatment duration was 10 weeks. The mean α angle at the last ultrasound follow-up was 64.9°. The mean age of the last radiographic follow-up was 2.6 years, and 26 hips had a residual acetabular dysplasia with acetabular indexes greater than 2 standard deviations above the mean. The morphology of the acetabular bony rim (odds ratio = 4.333, P = 0.029) and age of initial treatment <12 weeks (odds ratio = 7.113, P = 0.014) were seen as significant predictors for a higher acetabular index more than 2 years of age. A notable incidence of residual acetabular dysplasia after Pavlik harness treatment in Graf type II hips, wherein the acetabular bony roof with a blunt rim at the end of treatment and initial age after 12 weeks were independent predictors associated with residual acetabular dysplasia. Therapeutic studies, IV.

Defining the Incidence of Residual Acetabular Dysplasia After Successful Reduction With a Harness

Background: The purpose of this study was to evaluate the rate of residual acetabular dysplasia (RAD), defined as an acetabular index (AI) of &gt;90th percentile of age and sex-matched controls, in a cohort of infants successfully treated with the Pavlik harness (PH). Methods: We retrospectively studied typically developing infants at a single center, with at least 1 dislocated hip, that was successfully treated with a PH and had a minimum of 48 months follow-up. Hip dislocation was defined as &lt;30% femoral head coverage at rest on pretreatment ultrasound or IHDI grade 3 or 4 on the pretreatment radiograph. Results: Forty-six dislocated hips (41 infants) were studied (4 males and 37 females). Brace treatment was initiated at an average age of 1.8 months (range: 2 d to 9.3 mo) and was maintained for an average of 10.2 months (range: 2.3 to 24.9 mo). All hips achieved IHDI grade 1 reduction. Five of 46 hips (11%) had an AI &gt;90th percentile at the conclusion of bracing. Average follow-up was 6.5 years (range: 4.0 to 15.2 y). We found a 30% incidence of RAD (14/46 hips) on final follow-up radiographs. Of these hips, 13/14 (93%) had AI &lt;90th percentile at the end of brace treatment. Comparing children with and without RAD, there were no differences in age at the initial visit or brace initiation, total follow-up, femoral head coverage at the initial visit, alpha angle at the initial visit, or total time in the brace (P &gt; 0.09). Conclusion: In a single-center cohort of infants with dislocated hips treated successfully with a PH, we observed a 30% incidence of RAD at a minimum 4.0-year follow-up. Normal acetabular morphology at the end of brace treatment did not result in normal acetabular morphology at the final follow-up in 13/41 hips (32%). We recommend that surgeons should pay close attention to the year-over-year change in both the AI and AI percentile. Level of Evidence: Level IV: case series.

Cartilaginous predictors of residual acetabular dysplasia (RAD) in developmental dysplasia of the hip following closed or open reduction: A systematic review and meta-analysis.

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].

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

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

Management and effects of residual limbus inversion following closed reduction in developmental hip dysplasia: Protocol for a multicenter randomized controlled trial.

Closed reduction is a common treatment method for developmental dysplasia of the hip (DDH) in children aged 6-18 months. Residual acetabular dysplasia (RAD) is the most common complication associated with closed reduction. Residual limbus inversion (RLI) is a common condition following DDH closed reduction. Previously, we confirmed that when limbus inversion exceeds 32.2% of the acetabular depth after closed reduction, RLI persists and leads to RAD; however, this was based on a small cohort with a short-term follow-up period. The long-term fate of RLI and the correlation between RLI and RAD have yet to be verified. Therefore, this multicenter clinical study protocol was designed in three parts to investigate the effect of RLI on acetabular development after closed reduction of DDH (a multicenter retrospective cohort study), effect of RLI clearance on acetabular development (a multicenter retrospective and prospective randomized controlled study), and influence of inverted limbus clearance on acetabular development during DDH reduction (a multicenter prospective cohort study). Statistical analysis was performed by assessing the basic measures of acetabular development including the acetabular index and central-edge angle using frontal pelvic radiographs; the magnitude of limbus inversion, cartilaginous acetabular index, and T1ρ mapping values were measured using magnetic resonance imaging. The multicenter retrospective cohort studies required 5 years of follow-up period at minimum, and the prospective randomized controlled studies required reviews of frontal pelvic radiographs every 6 months as well as data pooling every 2 years to compare the short- and mid-term outcomes of hip joint morphological development between the two groups of pediatric patients. This research program is expected to verify that RLI following closed reduction of DDH can affect acetabular development and that limbus excision during DDH reduction can improve postoperative RAD. Therefore, the indication and timing of surgical intervention for RLI after closed reduction of DDH provide a basis for revising the acceptable criteria for utilizing closed reduction of DDH to reduce the incidence of osteoarthritis caused by RAD following DDH treatment. Clinical Trial: http://www.chictr.org.cn/showproj.aspx?proj=35045 (ChiCTR1900020996).

MRI hip morphology is abnormal in unilateral DDH and increased lateral limbus thickness is associated with residual DDH at minimum 10-year follow-up.

The purpose of the study was to compare the post-reduction magnetic resonance imaging morphology for hips that developed residual acetabular dysplasia, hips without residual dysplasia, and uninvolved contralateral hips in patients with unilateral developmental dysplasia of the hip undergoing closed or open reduction and had a minimum 10-year follow-up. Retrospective study of patients with unilateral dysplasia of the hip who underwent open/closed hip reduction followed by post-reduction magnetic resonance imaging. Twenty-eight patients with a mean follow-up of 13 ± 3 years were included. In the treated hips, residual dysplasia was defined as subsequent surgery for residual acetabular dysplasia or for Severin grade > 2 at latest follow-up. On post-reduction, magnetic resonance imaging measurements were performed by two readers and compared between the hips with/without residual dysplasia and the contralateral uninvolved side. Magnetic resonance imaging measurements included acetabular version, coronal/ axial femoroacetabular distance, acetabular depth-width ratio, osseous/cartilaginous acetabular indices, and medial/lateral (limbus) cartilage thickness. Fifteen (54%) and 13 (46%) hips were allocated to the "no residual dysplasia" group and to the "residual dysplasia" group, respectively. All eight magnetic resonance imaging parameters differed between hips with residual dysplasia and contralateral uninvolved hips (all p < 0.05). Six of eight parameters differed (all p < 0.05) between hips with and without residual dysplasia. Among these, increased limbus thickness had the largest effect (odds ratio = 12.5; p < 0.001) for increased likelihood of residual dysplasia. We identified acetabular morphology and reduction quality parameters that can be reliably measured on the post-reduction magnetic resonance imaging to facilitate the differentiation between hips that develop with/without residual acetabular dysplasia at 10 years postoperatively. level III, prognostic case-control study.

Appropriate Surgical Timing of Salter Innominate Osteotomy for Residual Acetabular Dysplasia in Children.

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.

Universal Digital Model of a Child's Pelvis

Summary. Relevance. Developmental dysplasia of the hip (DDH) is a common hip joint pathology in pediatric orthopedist’s practice. Untreated DDH or residual acetabular dysplasia in walking patients usually requires surgery (pelvic osteotomy is one of the surgical options). During pelvic osteotomies, plastic changes take place in so-called 'hinge points'. These hinge points are described in the literature; however, there are some contradictions regarding the classical locations of these hinge points.&#x0D; Objective: to develop a digital pelvic model that can be used for various pelvic osteotomies modeling.&#x0D; Materials and Methods. Pelvic CT scans of a 6-year-old child were obtained, and a virtual model of pelvic bones was created. Pemberton pelvic osteotomy was simulated, material properties were assigned, and pelvic ligaments were added. Simulation of the Pemberton osteotomy was performed, and biomechanical changes during this intervention were assessed.&#x0D; Results. The digital pelvic model of a 6-year-old child was created, Pemberton pelvic osteotomy was simulated, and biomechanical changes during this surgery were evaluated. It was found that there is no single hinge point during this surgery (as believed previously); the main stress generation took place in triradiate cartilage anterior and posterior arms. Pelvic ligaments’ role during Pemberton pelvic osteotomy was assessed (sacrospinous and sacrotuberous ligaments were the main constraints during the lower iliac fragment movement). Also, the possibility of simultaneous bilateral application of Pemberton pelvic osteotomy or its combination with other pelvic osteotomies in 6 years old patients was biomechanically justified.&#x0D; Conclusions. The development of a digital pelvic model with subsequent pelvic osteotomies modeling according to the method described in this article allows to evaluate biomechanical changes during these osteotomies.

Does a Graf Type-I Hip Justify the Discontinuation of Pavlik Harness Treatment in Patients with Developmental Dislocation of the Hip?

Background: To analyze the clinical data of patients aged < 6 months with developmental dislocation of the hip (DDH) treated with Pavlik Harness (PH) in order to identify the best time to terminate PH treatment. Method: Fifty-four patients (47 females, 7 males; 63 hips) met the inclusion criteria and were included in the study; there were 33 (61.1%) left, 12 (22.2%) right and 9 (16.7%) bilateral DDH. The mean age at diagnosis was 11.8 ± 5.9 weeks (range, 1.4–25.5). All patients underwent fulltime PH treatment for about three months. At completion of PH treatment, patients were then divided into Group A, including patients with clinically stable hip joint and Graf type-I hip on ultrasound (US), and Group B, including patients with clinically stable hip joint and well-reduced hip on anterior-posterior (AP) radiographs without acetabular dysplasia. Six months after completion of PH treatment, the presence/absence of residual acetabular dysplasia (RAD) was evaluated on AP pelvis radiographs. The t-test and chi-square test were used to compare the differences in age, gender, side, Graf classification and RAD rate between the two groups of patients. Results: At completion of PH treatment, 45 hips were in Group A and 18 in Group B. There were no significant differences in age, gender, side, preoperative alpha angle and Graf classification between the two groups. Six months after discontinuation of PH, the AI in Group A (27.1° ± 6.8°) was significantly higher than that in Group B (21.9° ± 3.5°; p = 0.001); moreover 23 hips (51.1%) in Group A developed RAD compared to one hip in Group B (5.6%; p = 0.001). Among Group A patients, those with RAD were significantly older (13.7 ± 4.9 weeks) than those with normal hips (7.6 ± 3.8 weeks; p < 0.001); the incidence of RAD was significantly lower in patients with Graf type-II D hips (22.2%) than in patients with Graf type-III (70%) and type-IV hips (71.4%; p = 0.006). However, logistic regression analysis identified age as the only risk factor for RAD. All 24 hips with RAD (24/63, 38.1%) were treated with abduction braces. At final follow-up, AI in Group A (20.5° ± 3.3°) was not significantly different from that in Group B (21.9° ± 3.3°; p = 0.132). At the last follow-up visit, five hips (11.1%) in Group A still had RAD, compared to none in Group B (p = 0.31). Conclusions: In patients with DDH treated by PH, Graf type-I on US is not an absolute timing to terminate PH treatment. In addition, patients ≥ 13 weeks had a high risk of RAD despite PH treatment as 51.1% of infants developed RAD during follow up. Follow-up radiographs should be requested in all patients achieving Graf type-I hips at completion of PH treatment.