Residual Acetabular Dysplasia Research Articles

Dynamic and Static Splinting for Treatment of Developmental Dysplasia of the Hip: A Systematic Review.

Background: Developmental dysplasia of the hip (DDH) is one of the most common pediatric conditions. The current gold-standard treatment for children under six months of age with a reducible hip is bracing, but the orthopedic literature features several splint options, and each one has many advantages and disadvantages. The aim of this review is to analyze the available literature to document the up-to-date evidence on DDH conservative treatment. Methods: A systematic review of PubMed and Science Direct databases was performed by two independent authors (C.d.C. and A.V.) using the keywords “developmental dysplasia hip”, “brace”, “harness”, “splint”, “abduction brace” to evaluate studies of any level of evidence that reported clinical or preclinical results and dealt with conservative DDH treatment. The result of every stage was reviewed and approved by the senior investigators (V.P. and G.T.). Results: A total of 1411 articles were found. After the exclusion of duplicates, 367 articles were selected. At the end of the first screening, following the previously described selection criteria, we selected 29 articles eligible for full text reading. The included articles mainly focus on the Pavlik harness, Frejka, and Tubingen among the dynamic splint applications as well as the rhino-style brace, Ilfeld and generic abduction brace among the static splint applications. The main findings of the included articles were summarized. Conclusions: Dynamic splinting for DDH represents a valid therapeutic option in cases of instability and dislocation, especially if applied within 4–5 months of life. Dynamic splinting has a low contraindication. Static bracing is an effective option too, but only for stable hips or residual acetabular dysplasia.

What is the association between MRI and conventional radiography in measuring femoral head migration?

Background and purpose — Pelvic radiographs are traditionally used for assessing femoral head migration in residual acetabular dysplasia (RAD). Knowledge of the heightened importance of cartilaginous structures in this condition has led to increased use of MRI in assessing both osseous and cartilaginous structures of the pediatric hip. Therefore, we assessed the relationship between migration percentages (MP) found on MRI and conventional radiographs. Second, we analyzed the reliability of MP in MRI and radiographs. Patients and methods — We retrospectively identified 16 patients (mean age 5 years [2–8], 14 girls), examined for RAD during a period of 2½ years. 4 raters performed blinded repeated measurements of osseous migration percentage (MP) and cartilaginous migration percentage (CMP) in MRI and radiographs. Pelvic rotation and tilt indices were measured in radiographs. Bland–Altman (B–A) plots and intraclass correlation coefficients (ICC) were calculated for agreement and reliability. Results — B–A plots for MPR and MPMRI produced a mean difference of 6.4 with limits of agreement –11 to 24, with higher disagreements at low average MP values. Mean MPR differed from mean MPMRI (17% versus 23%, p < 0.001). MPR had the best interrater reliability with an ICC of 0.92 (0.86–0.96), compared with MPMRI and CMP with ICC values of 0.61 (0.45–0.70) and 0.52 (0.26–0.69), respectively. Intrarater reliability for MPR, MPMRI and CMP all had ICC values above 0.75 and did not differ statistically significantly. Differences inMPMRI and MPR showed no correlation to pelvic rotation index, pelvic tilt index, or interval between radiograph and MRI exams. Interpretation — Pelvic radiographs underestimated MP when compared with pelvic MRI. We propose CMP as a new imaging measurement, and conclude that it has good intrarater reliability but moderate interrater reliability. Measurement of MP in radiographs and MRI had mediocre to excellent reliability.

Timing for closed reduction procedure for developmental dysplasia of the hip and its failure analysis

BackgroundIt remains controversial whether the older age to perform closed reduction (CR) procedure for developmental dysplasia of the hip (DDH), the higher incidence of complications. The aim of this study is to evaluate the midterm outcome of CR for DDH among different age groups, and to analyze and identify risk factors for the failure of this procedure.MethodsClinical data of 107 DDH patients, who received CR, were retrospectively reviewed. Data were divided into three groups according to initial treatment age (Group I: younger than 12 months; Group II: 12 months to less or equal to18 months; Group III: older than 18 months). The presence of avascular necrosis (AVN), residual acetabular dysplasia (RAD), re-dislocation, and further surgeries (FS) were observed. The risk factors were identified for those outcomes aforementioned using univariable logistic regression models. For identified risk factor age, pre-op acetabular index (AI) and post-op AI, their prediction of CR failure were evaluated by receiver operating characteristics curve (ROC).ResultsA total of 107 patients (156 hips) undergoing CR procedure were evaluated with a median age at initial reduction of 13.0 ± 5.4 months (range, 4 to 28 mo). Mean follow-up time in this study was 6.7 ± 0.8 years (range, 3–8 years). The incidence of AVN, RAD and re-dislocation was 15.4% (24/156), 17.3% (27/156) and 14.7% (23/156) respectively. For AVN, RAD and re-dislocation, the significant risk factors are pre-op IHDI IV (p = 0.033), age ≥ 18 months (p = 0.012), and pre-op IHDI IV (p = 0.004) and walking (p = 0.011), respectively. The areas under the ROC curve of each type of failures were 0.841 (post-op AI), 0.688 (pre-op AI) and 0.650 (age).ConclusionsSevere DDH patients older than 18 months with CR procedure may result in a high risk of RAD complication. Re-dislocation is significantly associated with pre-op IHDI IV and walking. Patients, who are older than 12.5 months or have a pre-op AI of 38.7° or a post-op AI of 26.4°, are also more likely to fail of CR procedure.

Acetabular Dysplasia in Children with Cerebral Palsy: Can Isolated Femoral Varus Osteotomies Help?

Purpose: The remodeling potential of the dysplastic acetabulum in children with neuromuscular disorders is not clear and how to address residual acetabular dysplasia after femoral osteotomy in children with cerebral palsy remains unknown. The purpose of this study is to 1) quantify acetabular remodeling in patients with CP who received a femoral osteotomy without an acetabular osteotomy and 2) to determine the impact of age and Gross Motor Function …

Early open reduction of dislocated hips using a modified Smith-Petersen approach in arthrogyposis multiplex congenita

BackgroundArthrogryposis multiplex congenita (AMC) is a rare syndrome with multiple joint contractures. Within the medical community, there is controversy surrounding AMC in terms of the ideal surgical approach and age for performing a reduction of dislocated hips. The purpose of this retrospective study was to evaluate the clinical outcomes of early open reduction of infant hip dislocation with arthrogryposis multiplex congenita following a modified Smith-Petersen approach that preserves the rectus femoris.MethodsFrom 2010 to 2017, we performed this procedure on 28 dislocated hips in 20 infants under 12 months of age with AMC. The clinical and radiology data were reviewed retrospectively. The mean age at surgery was 6.9 ± 5.1 months, with a mean follow-up of 42.4 ± 41.1 months.ResultsAfter open reduction, the average hip acetabular index (AI), the international hip dysplasia institute classification (IHDI), and the hip range of motion significantly improved (all P < 0.001). After the surgery, 16 patients were community walkers, and four patients were home walkers. Three hips in two patients required secondary revision surgery for residual acetabular dysplasia with combined pelvic osteotomy and femoral osteotomy. Seven of the hips that had been operated on showed signs of avascular necrosis (AVN). Among them, four were degree II, two were degree III, and one was degree IV. Multiple linear regression analysis demonstrated that greater age (in months) heightened the risk for secondary revision surgery (P = 0.032).ConclusionsThe modified Smith-Petersen approach preserving the rectus femoris is an encouraging and safe option for treating hip dislocation in young AMC patients (before 12 months). If surgery takes place at less than 12 months of age for patients with AMC, this earlier open reduction for hip dislocation may reduce the chances of secondary revision surgery.Level of evidenceIV, retrospective non-randomized study.

Developmental dysplasia of the hip: update of management.

The term ‘developmental dysplasia of the hip’ (DDH) includes a wide spectrum of hip alterations: neonatal instability; acetabular dysplasia; hip subluxation; and true dislocation of the hip.DDH alters hip biomechanics, overloading the articular cartilage and leading to early osteoarthritis. DDH is the main cause of total hip replacement in young people (about 21% to 29%).Development of the acetabular cavity is determined by the presence of a concentrically reduced femoral head. Hip subluxation or dislocation in a child will cause an inadequate development of the acetabulum during the remaining growth.Clinical screening (instability manoeuvres) should be done universally as a part of the physical examination of the newborn. After two or three months of life, limited hip abduction is the most important clinical sign.Selective ultrasound screening should be performed in any child with abnormal physical examination or in those with high-risk factors (breech presentation and positive family history). Universal ultrasound screening has not demonstrated its utility in diminishing the incidence of late dysplasia.Almost 90% of patients with mild hip instability at birth are resolved spontaneously within the first eight weeks and 96% of pathologic changes observed in echography are resolved spontaneously within the first six weeks of life. However, an Ortolani-positive hip requires immediate treatment.When the hip is dislocated or subluxated, a concentric and stable reduction without forceful abduction needs to be obtained by closed or open means. Pavlik harness is usually the first line of treatment under the age of six months.Hip arthrogram is useful for guiding the decision of performing a closed or open reduction when needed.Acetabular dysplasia improves in the majority due to the stimulus provoked by hip reduction. The best parameter to predict persistent acetabular dysplasia at maturity is the evolution of the acetabular index.Pelvic or femoral osteotomies should be performed when residual acetabular dysplasia is present or in older children when a spontaneous correction after hip reduction is not expected.Avascular necrosis is the most serious complication and is related to: an excessive abduction of the hip; a force closed reduction when obstacles for reduction are present; a maintained dislocated hip within the harness or spica cast; and a surgical open reduction.Cite this article: EFORT Open Rev 2019;4:548-556. DOI: 10.1302/2058-5241.4.180019

Effect of age on radiographic outcomes of patients aged 6-24 months with developmental dysplasia of the hip treated by closed reduction.

This study aimed to investigate the effect of age on the rates of redislocation, avascular necrosis (AVN) of the femoral head, and final radiographic outcomes in patients with developmental dysplasia of the hip (DDH) treated with closed reduction. A total of 308 hips (276 patients) with DDH treated with closed reduction were included and divided into three groups according to age (<12, 12-18, 18-24 months). Tönnis grade, rate of redislocation and AVN, Severin radiographic grade, and risk of surgery were evaluated on radiographs. Tönnis grade significantly increased with age (P < 0.001). Redislocation occurred in 17 (5.5%) and AVN occurred in 36 (11.7%) hips. The rate of redislocation and AVN was similar among the three age groups in all Tönnis grades. However, redislocation rate significantly increased with Tönnis grade (P = 0.027). Overall, 246 hips (79.9%) had satisfactory final outcomes, and 62 hips (20.1%) had unsatisfactory outcome; no difference was observed among three age groups. A total of 103 hips (33.4%) were found to be at risk for secondary surgery. The surgical risk (25%) in patients younger than 12 months was lower than that of older patients (12-18 months: 34.4%; 18-24 months: 37.9%). Logistic regression analysis also confirmed that age was not a risk factor for redislocation, AVN, or poor radiographic outcome. In conclusion, age has no significant impact on redislocation and AVN in patients aged 6-24 months with DDH treated by closed reduction. Although older patients have a higher risk developing residual acetabular dysplasia, secondary pelvic surgery provides favorable outcomes in most patients.

Comparison of arthroscopic and open reduction of conservatively irreducible dislocated hips of children.

PurposeChildren with sonographic grade IV hip dysplasia according to Graf and with failed conservative treatment usually need surgical reduction afterwards. Surgical reduction of the hip can lead to severe complications, the occurrence of residual acetabular dysplasia, osteonecrosis, redislocation and other postoperative complications. This paper investigates whether arthroscopic reduction is a promising alternative to open reduction.MethodsWe retrospectively examined 66 patients (78 hips) who were not older than two years at the first time of surgery. Arthroscopic reduction was performed on 17 children (19 hips) and open reduction on 49 children (59 hips). Patient records were used to determine redislocation, postoperative complication and residual dysplasia. Radiographs were used to determine Tönnis classification for osteonecrosis and pathological acetabular (AC) angle for residual dysplasia. We considered data up to a two-year follow-up. Statistical evaluation was performed with binary logistic regression.ResultsAfter arthroscopic reduction, 6% showed osteonecrosis, compared with 20% with open reduction (p = 0.334). Redislocation was not observed after arthroscopic reduction but for 29% after open reduction (p = 0.005). An improvement of femoral head coverage was achieved with residual dysplasia of 23.5% after arthroscopic reduction, compared with 62% after open reduction (p = 0.002).ConclusionThe arthroscopic procedure represents a meaningful alternative to the open procedure due to a lower complication rate, a safe setting, a lower rate of residual dysplasia, no observed redislocation and occurrence of osteonecrosis only once in the arthroscopic group of developmental dysplasia of the hip. The arthroscopic procedure should be tested in further studies and in other clinics in order to broaden the empirical base.Level of Evidence:Level III (retrospective cohort study)

Evaluation of cartilage coverage with magnetic resonance imaging in residual dysplasia and its impact on surgical timing

ObjectiveThe aim of this study was to measure the cartilaginous coverage of the acetabulum using magnetic resonance imaging (MRI) and to analyze its effect on the timing and necessity of secondary operations in residual acetabular dysplasia (RAD). MethodsThe MRI results of 33 children (30 girls and 3 boys) aged between 5 and 9 years who were operated on unilaterally via a posteromedial limited approach were compared with the radiographical findings of acetabular dysplasia at follow-up. The acetabular index (AI) and the center-edge (CE) angles were measured. MRI was used to measure the osseous acetabular index (OAI), cartilage acetabular index (CAI), and cartilaginous center-edge angles (CCE). The Children's Hospital's Oakland Hip Evaluation Score (CHOHES) was used for the assessment of clinical and functional results. The Severin scoring system was used to evaluate the radiographic results. The Mann-Whitney U test and Spearman correlation tests were used for statistical analysis. ResultsIn all, 30 (90.9%) girls and 3 (9.1%) boys with an average age of 7.4 years (range: 5–9 years) and a mean follow-up period of 6.1 years (range: 4–8 years) were included. While there was a significant difference between non-dislocated hips and operated hips in 3 measurements (AI, Wiberg CE, and Ogata CE) using X-rays (p < 0.05), no significant difference was found in the MRI measurements (OAI, CAI, and CCE) (p > 0.05). The CAI values were lower than the AI measured on X-ray (p = 0.035). The mean CCE was higher than the mean CE (p = 0.022). The mean CHOHES score was 83.1 (range: 52–100) and the score of 62% patients was above 90. There was no significant difference in terms of CHOHES score according to age at the time of operation (p = 0.43). Three (9.1%) patients were Severin class I, 8 (24.3%) patients were class II, 12 (36.3%) patients were class III and 10 (30.3%) patients were class IV. There was no correlation between preoperative hip dislocation and Severin score (p = 0.056). No significant difference was found between the ambulatory and non-ambulatory groups in terms of Severin classification (p = 0.063). ConclusionCartilaginous acetabulum should be taken into account in RAD measurements. MRI may be a more appropriate option for the evaluation of acetabular cartilaginous coverage in the evaluation of RAD and the decision to perform surgery, though X-rays are currently the most used method. The results revealed no effect on functional or radiological scores as a result of being of walking age. Level of studyLevel III, Diagnostic Study.

Is male gender a prognostic factor for developmental dysplasia of the hip? Mid-long-term results of posteromedial limited surgery

ObjectiveThe aim of this study was to determine if male sex is a poor prognostic factor for developmental dysplasia of the hip (DDH) and to determine the mid-long-term radiological and clinical results of male patients in comparison with female patients following an open reduction with posteromedial limited approach. MethodsWe examined 54 hips of 41 male patients (12.38 ± 4.82 months) and 96 hips of 82 female patients (11.11 ± 4.93 months) with DDH. All the patients underwent open reduction with posteromedial limited approach. The average follow-up time was 108 months for the male patients and 110 months for the female patients. The Tönnis grade, acetabular index, Kalamchi and MacEwen classification, and Severin classifications were determined for all patients. The Mc Kay classification system was used to evaluate the functional results. ResultsFrom the total, 25 (60%) male and 70 (85%) female patients had satisfactory radiographic outcomes (Severin Ia, Ib, or II) according to the Severin classification. There was a significant difference between the two groups in terms of the Severin classification (P = 0.04). Residual acetabular dysplasia (RAD) was observed in 12 (15%) female and 17 (41%) male patients (P = 0.001). Grade 2 or higher osteonecrosis was observed in 7 (9%) patients in female and 6 (15%) patients in male group. The clinical outcomes in terms of the Mc Kay classification showed satisfactory outcomes in 72 (87%) female and 34 (82%) male patients. Further, 8 (9.7%) female patients and 6 (14.6%) male patients underwent a second operation. However, there was no difference between the two groups in terms of postoperative osteonecrosis presence (P = 0.982), functional outcomes (P = 0.571), and secondary operation rates (P = 0.298). Male sex was associated with poor outcomes in terms of the Severin classification (P = 0.04) and RAD (P = 0.001). ConclusionAlthough our results indicated that male sex is a poor prognostic factor for radiological results and RAD, there was no difference between male and female patients in terms of osteonecrosis, redislocations, and functional outcomes. Secondary surgical interventions should not be delayed in the absence of the spontaneous development of acetabulum. Level of evidenceLevel III, prognostic study.

Tönnis triple pelvic osteotomy for the management of late residual acetabular dysplasia: mid-term to long-term follow-up study of 54 patients.

The authors reviewed 54 (58 hips) patients with acetabular dysplasia following developmental dislocation of the hip (DDH), treated by triple pelvic osteotomy according to the Tönnis technique. The aim of our study was to report the long-term clinical and radiographic results of the operation at a mean follow-up of 12 years (from 7 to 20). At diagnosis, all the hips were painful, the Wiberg angle measured less than 20°, and no radiographic signs of osteoarthritis were present. At follow-up, 82.7% of the operated hips showed either excellent or good results, according to Harris, and the Wiberg angle measured an average of 34° (from 26° to 45°). We encountered five complications: one acetabular malrotation and four asymptomatic ischial nonunions. In conclusion, we believe that, although Bernese periacetabular osteotomy is nowadays considered the gold standard for the surgical treatment of the dysplastic hip following DDH, Tönnis osteotomy represents a good treatment option: it is technically easy, enables direct visualization of the three osteotomies, leads to few complications, and its learning curve is short. The absence of radiographic signs of osteoarthritis and hip congruency before surgery are the basic requirements to achieve a successful result.

Radiographic outcome of children older than twenty-four months with developmental dysplasia of the hip treated by closed reduction and spica cast immobilization in human position: a review of fifty-one hips.

This study aimed to investigate the radiographic outcomes, rate of redislocation, and avascular necrosis of proximal femoral epiphysis (AVN) in patients aged 24 to 36months with developmental dysplasia of the hip (DDH) treated by closed reduction (CR) and spica cast immobilization in human position. We reviewed the medical records of 39 patients (51 hips) aged 24 to 36months with DDH treated by CR and spica cast immobilization in human position. The Tönnis grade, rate of redislocation and AVN, acetabular index (AI), centre-edge angle (CEA), and Severin radiographic grade were evaluated on plain radiographs. Among the included 39 patients (51 hips), 15 hips (29.4%) were Tönnis grade II, 24 hips (47.1%) were grade III, and 12 hips (23.5%) were grade IV. In 47 hips (92.2%), the ossific nucleus was present at the time of CR. Stable reduction was achieved by CR in 39/51 hips (76.5%) and redislocation occurred in 12/51 hips (23.5%). Among the 12 hips that redislocated, 11 underwent open reduction and one repeated CR. Two out of 40 hips (5%) treated by CR developed AVN. Overall, 54.6% of the hips had satisfactory outcomes (39.2% Severin type I and 17.6% type II), while 45.4% had unsatisfactory outcomes (39.2% Severin type III and 3.9% type IV). Of the 40 hips treated by CR, 57.5% and 42.5% of cases had satisfactory outcomes and residual acetabular dysplasia, respectively. Six out of 11 hips (54.6%) treated by open reduction and pelvic osteotomy had satisfactory outcomes. Our study showed that stable CR could be achieved in 76.5% of patients aged 24 to 36months with DDH at the time of index procedure. Satisfactory outcomes can be expected in 56.4% of the cases (5.0% AVN rate), although late acetabular dysplasia may develop in 43.6% of the hips.

Effectiveness of abduction orthosis for the treatment of acetabular dysplasia.

This study aims to evaluate the effectiveness of full-time bracing in residual acetabular dysplasia (RAD) and the effect of previous Pavlik harness usage on the results of treatment with abduction orthosis. We retrospectively reviewed 80 patients (9 males, 71 females; mean age 6±0.8 months; range, 5 to 7 months) with developmental dysplasia of the hip (119 dysplastic hips) treated with hip abduction orthosis. Patients with an acetabular index (AI) measurement of 30° and over who used full-time hip abduction brace for six months were included in the study. Acetabular index values were measured at the initiation, third, and sixth months of treatment and the effectiveness of abduction orthosis was evaluated. The patients were analyzed for the effect of prior Pavlik harness application on abduction orthosis treatment. Mean AI value of the dysplastic hips (n=119) was 33.4°±2.6°, which decreased to 28.5°±2.6° after treatment (p<0.001). The AI improvement in the first three-month period was significantly faster than the second three-month period (2.9°±1.9° vs. 1.9°±1°; p=0.013). No difference was observed in AI development between patients with or without prior Pavlik treatment (p=0.1). In patients with unilateral dysplasia, dysplastic hips improved significantly faster than normal hips (p<0.001). As a result of a mean follow-up duration of 20.2±9.8 months from the onset of brace treatment, 32 (32%) hips were grouped as normal, 49 (48%) as mildly dysplastic, and 22 (20%) as severely dysplastic based on Tönnis criteria. Hip abduction orthosis may be used in patients with RAD between 6 to 12 months of age. Acetabular index improvement was faster in the first three months of brace treatment. Dysplastic hips improved faster than normal hips, and prior Pavlik harness treatment did not alter the effectiveness of orthosis.

The Role of the Assessment of Cartilage Acetabulum with Magnetic Resonance Imaging in the Management of Residual Acetabular Dysplasia Patients

The Role of the Assessment of Cartilage Acetabulum with Magnetic Resonance Imaging in the Management of Residual Acetabular Dysplasia Patients

Graf Type-IV Hips Have a Higher Risk of Residual Acetabular Dysplasia at 1 Year of Age Following Successful Pavlik Harness Treatment for Developmental Hip Dysplasia.

We asked whether patient-specific factors and ultrasound (US) measurements of hip dysplasia severity at initial examination influence short-term residual acetabular dysplasia in patients successfully treated with Pavlik harness for developmental hip dysplasia. After IRB approval, 134 hips (84 patients) successfully treated by the Pavlik method between August 2011 and October 2014 with follow-up at 12 months of age were identified. Early successful treatment was defined as normal examination and US after approximately 12 weeks of Pavlik treatment. Multivariate linear and logistic regression models were used to identify factors associated with acetabular index (AI) measurements at 12 months as well as factors associated with an increase in AI between the 6- and 12-month timepoints (dysplastic progression). The study consisted of 134 hips (84 patients). The distribution of dysplastic, Barlow, and Ortolani hips was 44.8% (N=60), 30.6% (N=41), and 24.6% (N=33), respectively. The crude incidence of residual dysplasia at the 6-month visit (AI>30 degrees) was 11.7% (12/102). The incidence of residual dysplasia at the 12-month visit (AI>28 degrees) was 11.8% (13/111). Graf type was the only variable associated with AI values at the 12-month visit (mean difference: Graf type-IV-Other, 2.6; 95% confidence interval, 0.3-4.9; P=0.026). The risk of residual acetabular dysplasia after normal hip US following Pavlik treatment is not negligible. Radiographic surveillance is warranted to monitor and screen for dysplasia progression. Patients with dislocated Graf type-IV hips at diagnosis are at increased risk of residual acetabular dysplasia at 1 year after successful treatment with the Pavlik method. Level III-therapeutic study.

Diagnostic and treatment preferences for developmental dysplasia of the hip: a survey of EPOS and POSNA members.

PurposeThe aim of this study was to elucidate developmental dysplasia of the hip (DDH) diagnosis and treatment preferences among members of the Pediatric Orthopaedic Society of North America (POSNA) and European Paediatric Orthopaedic Society (EPOS).MethodsA 54-question survey on DDH diagnosis and treatment preferences was distributed to POSNA and EPOS members. Descriptive statistics were performed.ResultsA total of 459 responses were analyzed. Ultrasound was the preferred modality for diagnosing DDH in infants less than six months old; few surgeons preferred radiographs. In all, 57% of POSNA members had radiology technicians perform ultrasounds, only 7% of EPOS members did. The percent coverage defining a dislocated hip varied greatly, the most frequent response being < 20% for POSNA and < 40% for EPOS members. Pavlik harnesses were the most popular harness/brace, used by 90% of POSNA and 71% of EPOS members. POSNA members were more likely than EPOS members to use a rigid abduction brace following initial harness/brace failure. For residual acetabular dysplasia, POSNA members were twice as likely as EPOS members to institute hip abduction bracing. Most surgeons would not perform closed reduction at less than three months of age or open reduction at less than six months of age. Most EPOS ­members used traction prior to reduction; few POSNA members did. Few POSNA and EPOS members believed that reduction should be delayed until the ossific nucleus was visible.ConclusionThere is great variation in the preferred methods for diagnosing and treating DDH. This survey is the largest transcontinental survey to compile diagnostic and treatment preferences for DDH. With wide variations in practice, there is room for quality improvement.Level of Evidence II

Anterior and lateral overcoverage after triple pelvic osteotomy in childhood for developmental dislocation of the hip with acetabular dysplasia: Frequency, features, and medium-term clinical impact.

Triple pelvic osteotomy (TPO) is a treatment option in children and adolescents with residual acetabular dysplasia after developmental dislocation of the hip (DDH). However, TPO to redirect the acetabulum is often blamed for anterior and lateral overcoverage of the femoral head. The main objectives of this study were to assess the potential clinical impact, frequency, and radiological features of acetabular overcorrection. Evidence of post-operative remodelling and associations linking younger age at surgery and/or dysplasia severity to the existence and magnitude of overcorrection were sought. Acetabular overcorrection has little or no clinical impact. TPO was performed on 41 hips in 31 patients at a mean age of 6.3 years (range, 3.0-15.2 years). Mean follow-up was 13.8 years (range, 5.4-28.7 years) and mean age at last re-evaluation was 22.1 years (range, 13-39 years). Clinical outcomes were assessed based on the Harris Hip Score (HHS) and Postel-Merle d'Aubigné (PMA) score. Radiographs were used to look for a cross-over sign (CO+) and to measure the vertical-centre edge (VCE) and vertical-centre anterior (VCA) angles and the acetabular index (AI). Overcorrection was defined as AI≤0° and/or VCE≥35° and/or VCA≥40° and/or CO+. The HHS and PMA score values were good or excellent for 39 (94%) hips. One or more parameters indicated overcorrection of 33 (80.5%) hips. No significant differences were found between the overcorrected hips and the hips with normal parameters. TPO effectively corrects residual acetabular dysplasia. Overcorrection is common in all three planes but has little clinical impact in young adults. The high frequency of overcorrection mandates a careful pre- and intra-operative evaluation of acetabular version. IV, retrospective study.

Acetabular index is the best predictor of late residual acetabular dysplasia after closed reduction in developmental dysplasia of the hip.

Our objective was to find the best predictor of late residual acetabular dysplasia in developmental dysplasia of the hip (DDH) after closed reduction (CR) and discuss the indications for secondary surgery. We retrospectively reviewed the records of 89 patients with DDH (mean age 16.1 ± 4.6months; 99 hips) who were treated by CR. Hips were divided into three groups according to final outcomes: satisfactory, unsatisfactory and operation. The changes in the acetabular index (AI), centre-edge angle of Wiberg (CEA), Reimer's index (RI) and centre-head distance discrepancy (CHDD) over time among groups were compared. The power of predictors for late residual acetabular dysplasia of AI, CEA, RI and CHDD at different time points was analysed by logistic regression analysis. Receiver operating characteristics (ROC) curve analysis was used to determine cutoff values and corresponding sensitivity, specificity and diagnostic accuracy for these parameters. Both AI and CEA improved in all groups of patients following CR. In the satisfactory group, AI progressively decreased until seven to eightyears, while CEA increased until nine to tenyears (P < 0.05). In the unsatisfactory group, AI and CEA ceased to improve three and twoyears after CR, respectively (P < 0.05). CEA and RI were significantly better in the satisfactory group compared with the unsatisfactory group at all time points (P < 0.05). Following CR, both RI and CHDD remained stable over time in all groups. Final outcome following CR could be predicted by AI, CEA and RI at all time points (P < 0.01). Cutoff values of AI, CEA and RI were 28.4°, 13.9° and 34.5%, respectively, at oneyear and 25°, 20° and 27%, respectively, at two to fouryears post-CR. A total of 80-88% of hips had an unsatisfactory outcome if AI > 28.4° and >25 at one and two to fouryears following CR, respectively. However, if CEA was less than or RI was larger than the cutoff values at each time point, only 40-60% of hips had an unsatisfactory outcome. Mean sensitivity (0.889), specificity (0.933) and diagnostic accuracy (92.1%) of AI to predict an unsatisfactory outcome were significantly better compared with CEA (0.731; 0.904; 78.2%) and RI (0.8; 0.655; 70.8%) (P < 0.05). Satisfactory and unsatisfactory hips show different patterns of acetabular development after reduction. AI, CEA and RI are all predictors of final radiographic outcomes in DDH treated by CR, although AI showed the best results. AI continues to improve until seven years after CR in hips with satisfactory outcomes, while it ceases to improve three to fouryears after CR in hips with unsatisfactory outcomes. According to our results, surgery is indicated if AI >28° 1year following CR or AI >25° two to fouryears after CR. CEA and RI should be used as a secondary index to aid in the selection of patients requiring surgery.

The management of residual acetabular dysplasia: updates and controversies

Residual acetabular dysplasia is a frequent cause of secondary osteoarthritis of the hip and its management is still controversial. The aim of this review is to describe residual acetabular dysplasia, to estimate the age limit above which surgical management is needed, and to emphasize the role of assistive imaging in evaluating predictive parameters for future acetabular development. A decision-making algorithm is presented.

Does Orientation of the Femoral Head Affect Acetabular Development? An Experimental Study in Lamb

Derotational osteotomy of the proximal femur has proved to be effective in the treatment of residual acetabular dysplasia. However, the reason why this osteotomy is effective remains debatable. The purpose of this study is to investigate if an alteration of femoral head orientation affects acetabular growth. A proximal femoral osteotomy was performed in 21 lambs aged 3 months: 5 varus osteotomies (110 degrees), 4 valgus osteotomies (150 degrees), and 12 derotation osteotomies. Results were compared with a control group (5 animals). Osteotomy was fixed with a screw-plate device. Version was controlled intraoperatively with K-wires. Animals were killed 3 months after surgical procedure. A morphometric study of both proximal femur and acetabulum was performed, including deepness, volume and diameters of the acetabulum, neck-shaft angle and femoral version. The average neck-shaft angle for the normal, anteversion, and retroversion groups was 129 degrees, whereas it was 110 degrees for the varus group and 149 degrees for the valgus group. The average femoral version for the normal, valgus, and varus groups was 21 degrees of anteversion, whereas it was 38 degrees of anteversion for the so-called anteversion group and 17 degrees of retroversion for the retroversion group. Nor the neck-shaft angle, nor the femoral version correlated with the acetabular anteroposterior diameter (P=0.698, 0.6, respectively), the acetabular inferosuperior diameter (P=0.083, 0.451, respectively) or the acetabular deepness (P=0.14, 0.371, respectively). The neck-shaft angle correlated significantly with acetabular volume (P=0.023), so that the lower the neck-shaft angle, the higher the acetabular volume (r=-0.453). The femoral version did not correlated with acetabular volume (P=0.381). Decreasing the neck-shaft angle provokes an increase in acetabular volume, whereas changes in femoral version do not affect the acetabular growth. Extra-articular osteotomies that alter femoral orientation affect intra-articular gross morphology. Level II-therapeutic study.