Resolving residual acetabular dysplasia following successful brace treatment for developmental dysplasia of the hip in infants.

Aims: Radiological residual acetabular dysplasia (RAD) has been reported in up to 30% of children who had successful brace treatment of infant developmental dysplasia of the hip (DDH). Predicting those who will resolve and those who may need corrective surgery is important to optimize follow-up protocols. In this study we have aimed to identify the prevalence and predictors of RAD at two years and five years post-bracing. Methods: This was a single-centre, prospective longitudinal cohort study of infants with DDH managed using a published, standardized Pavlik harness protocol between January 2012 and December 2016. RAD was measured at two years' mean follow-up using acetabular index-lateral edge (AI-L) and acetabular index-sourcil (AI-S), and at five years using AI-L, AI-S, centre-edge angle (CEA), and acetabular depth ratio (ADR). Each hip was classified based on published normative values for normal, borderline (1 to 2 standard deviations (SDs)), or dysplastic (> 2 SDs) based on sex, age, and laterality. Results: Of 202 infants who completed the protocol, 181 (90%) had two and five years' follow-up radiographs. At two years, in 304 initially pathological hips, the prevalence of RAD (dysplastic) was 10% and RAD (borderline) was 30%. At five years, RAD (dysplastic) decreased to 1% to 3% and RAD (borderline) decreased to < 1% to 2%. On logistic regression, no variables were predictive of RAD at two years. Only AI-L at two years was predictive of RAD at five years (p < 0.001). If both hips were normal at two years' follow-up (n = 96), all remained normal at five years. In those with bilateral borderline hips at two years (n = 21), only two were borderline at five years, none were dysplastic. In those with either borderline-dysplastic or bilateral dysplasia at two years (n = 26), three (12%) were dysplastic at five years. Conclusion: The majority of patients with RAD at two years post-brace treatment, spontaneously resolved by five years. Therefore, children with normal radiographs at two years post-brace treatment can be discharged. Targeted follow-up for those with abnormal AI-L at two years will identify the few who may benefit from surgical correction at five years' follow-up.

Effects of lower limb length discrepancy on spinopelvic compensation following total hip arthroplasty in patients with developmental dysplasia of the hip.

BACKGROUND: Limited research has examined the impact of lower limb length discrepancy (LLLD) alteration on spinopelvic compensation in individuals with developmental dysplasia of the hip (DDH). This study aimed to investigate the effects of LLLD on spinopelvic compensation following total hip arthroplasty (THA) and elucidate the complex biomechanical adaptations in the spinopelvic structures. METHODS: A retrospective review of DDH patients undergoing THA from January 2014 to December 2021 categorized individuals with Crowe type I and II into the low dislocation group (LDG, n = 94) and those with Crowe type III and IV into the high dislocation group (HDG, n = 43). Demographic data, as well as preoperative, postoperative, and last follow-up imaging data, including lower limb length (LLL), sacral obliquity (SO), iliac obliquity (IO), hip obliquity (HO), Cobb angle, apical vertebral translation (AVT), and coronal decompensation (CD), were collected for analysis. RESULTS: Patients in the LDG had a significantly higher surgical age and shorter disease duration (P<0.05). In LDG, patients exhibited substantial postoperative reductions in LLLD, SO, IO, and HO (P<0.05), while Cobb Angle, AVT, and CD showed no statistically significant changes (P>0.05). The variation in LLLD correlated significantly with the variations in SO, IO, and HO (P<0.05). Postoperative outcomes in the HDG demonstrated marked decreases in LLLD, SO, IO, HO, and CD (P<0.05), with no significant change in Cobb angle and AVT (P>0.05). The variation in LLLD correlated significantly with the variations in SO, IO, HO, and CD (P<0.05). CONCLUSIONS: THA effectively reduces LLLD in patients with DDH, and the variation in LLLD correlates meaningfully with the recovery of spinopelvic compensatory mechanisms.

Specific pelvic shape in patients with developmental dysplasia of the hip on 3D morphometric homologous model analysis.

PURPOSE: To clarify the morphological factors of the pelvis in patients with developmental dysplasia of the hip (DDH), three-dimensional (3D) pelvic morphology was analyzed using a template-fitting technique. METHODS: Three-dimensional pelvic data of 50 patients with DDH (DDH group) and 3D pelvic data of 50 patients without obvious pelvic deformity (Normal group) were used. All patients were female. A template model was created by averaging the normal pelvises into a symmetrical and isotropic mesh. Next, 100 homologous models were generated by fitting the pelvic data of each group of patients to the template model. Principal component analysis was performed on the coordinates of each vertex (15,235 vertices) of the pelvic homologous model. In addition, a receiver-operating characteristic (ROC) curve was calculated from the sensitivity of DDH positivity for each principal component, and principal components for which the area under the curve was significantly large were extracted (p<0.05). Finally, which components of the pelvic morphology frequently seen in DDH patients are related to these extracted principal components was evaluated. RESULTS: The first, third, and sixth principal components showed significantly larger areas under the ROC curves. The morphology indicated by the first principal component was associated with a decrease in coxal inclination in both the coronal and horizontal planes. The third principal component was related to the sacral inclination in the sagittal plane. The sixth principal component was associated with narrowing of the superior part of the pelvis. CONCLUSION: The most important factor in the difference between normal and DDH pelvises was the change in the coxal angle in both the coronal and horizontal planes. That is, in the anterior and superior views, the normal pelvis is a triangle, whereas in DDH, it was more like a quadrilateral.

An in-depth analysis of young adults with osteonecrosis secondary to developmental dysplasia of the hip who underwent total hip arthroplasty.

BACKGROUND: Patients with osteonecrosis of the femoral head secondary to DDH frequently require total hip arthroplasty (THA), but it is not well understood which factors necessitate this requirement. We determined the incidence of THA in patients who have osteonecrosis secondary to DDH and factors associated with need for THA. METHODS: We included patients who received closed or open reductions between 1995 and 2005 with subsequent development of osteonecrosis. We determined osteonecrosis according to Bucholz and Ogden; osteoarthritis severity (Kellgren-Lawrence), subluxation (Shenton's line); neck-shaft angle; and acetabular dysplasia (centre-edge and Sharp angles). We also recorded the number of operations of the hip in childhood and reviewed case notes of patients who received THA to describe clinical findings prior to THA. We assessed the association between radiographic variables and the need for THA using univariate logistic regression. RESULTS: Of 140 patients (169 hips), 22 patients received 24 THA (14%) at a mean age of 21.3 ± 3.7 years. Associated with the need for THA were grade III osteonecrosis (OR 4.25; 95% CI 1.70-10.77; p = 0.0019), grade IV osteoarthritis (21.8; 7.55-68.11; p < 0.0001) and subluxation (8.22; 2.91-29.53; p = 0.0003). All patients who required THA reported at least 2 of: severe pain including at night, stiffness, and reduced mobility. Acetabular dysplasia and number of previous operations were not associated with the need for THA. CONCLUSIONS: We identified a 14% incidence of THA by age 34 years in patients with osteonecrosis secondary to DDH. Grade III osteonecrosis (global involvement femoral head and neck) was strongly associated with THA, emphasising the importance to avoid osteonecrosis when treating DDH.

Risk factors for avascular necrosis of the femoral head after developmental hip dislocation reduction surgery and construction of Nomogram prediction model.

BACKGROUND: To analyze the risk factors for the development of avascular necrosis (AVN) of the femoral head after reduction surgery in children with developmental hip dysplasia (DDH), and to establish a prediction nomogram. METHODS: The clinical data of 134 children with DDH (169 hips) treated with closure reduction or open reduction from December 2016 to December 2019 were retrospectively analyzed. Independent risk factors for AVN after DDH reduction being combined with cast external immobilization were determined by univariate analysis and multivariate logistic regression and used to generate nomograms predicting the occurrence of AVN. RESULTS: A total of 169 hip joints in 134 children met the inclusion criteria, with a mean age at surgery of 10.7 ± 4.56 months (range: 4-22 months) and a mean follow-up duration of 38.32 ± 27.00 months (range: 12-94 months). AVN developed in 42 hip joints (24.9%); univariate analysis showed that the International Hip Dysplasia Institute (IHDI) grade, preoperative development of the femoral head ossification nucleus, cartilage acetabular index, femoral head to acetabular Y-shaped cartilage distance, residual acetabular dysplasia, acetabular abduction angle exceeding 60°, and the final follow-up acetabular index (AI) were associated with the development of AVN (P < 0.05). Multivariate logistic regression analysis showed that the preoperative IHDI grade, development of the femoral head ossification nucleus, acetabular abduction angle exceeding 60°, and the final follow-up AI were independent risk factors for AVN development (P < 0.05). Internal validation of the Nomogram prediction model showed a consistency index of 0.833. CONCLUSION: Preoperative IHDI grade, preoperative development of the femoral head ossification nucleus, final AI, and acetabular abduction angle exceeding 60° are risk factors for AVN development. This study successfully constructed a Nomogram prediction model for AVN after casting surgery for DDH that can predict the occurrence of AVN after casting surgery for DDH.

The usefulness of universal ultrasound before hospital discharge for early diagnosing hip dysplasia in Korean neonates with breech presentation in a single center: A retrospective study.

Developmental dysplasia of the hip (DDH) is a broad-spectrum disorder. Early diagnosis and treatment are important for improved prognosis and a lower risk of long-term complications. Selecting high-risk infants is important for the early diagnosis of DDH using ultrasonography; however, there are no standard international guidelines. This study aimed to identify the usefulness of universal ultrasound before hospital discharge in breech-born neonates and proposes selective ultrasound for high-risk patients. A retrospective chart review was conducted to identify breech-born neonates who underwent hip ultrasonography before discharge for the detection of DDH between 2019 and 2023. Patients were categorized into DDH and non-DDH groups according to the ultrasound results. We compared sex, gestational age, birth weight, first-born status, twin pregnancy, associated anomalies, presence of symptoms, physical examination results, and timing of the first hip ultrasound. The medical records of the mothers were reviewed to identify the amount of amniotic fluid and duration of breech presentation. This study included 102 patients, of whom 62 and 40 were assigned to the non-DDH and DDH groups, respectively. Congenital anomalies, positive symptoms, and positive physical examination results were significant risk factors. However, female sex, first-born status, and oligohydramnios were not statistically significant. The duration of breech presentation during pregnancy was not significant. Additionally, the risk of Pavlik harnesses was higher in patients who underwent a positive physical examination. Universal ultrasonography before discharge is not recommended for the early diagnosis of DDH in all breech-born neonates because of the high rate of overdiagnosis. We recommend that ultrasonography be performed in patients with congenital anomalies, except for foot problems, or in those with a positive physical examination conducted by trained specialists.

Proximal Femur Guided Growth: A Systematic Review.

Children with cerebral palsy (CP) and those with avascular necosis (AVN) after treatment of developmental hip dysplasia (DDH) are at risk of developing coxa valga. Proximal femur guided growth is a minimally invasive option to correct this deformity. A systematic review of articles that described treatment of coxa valga with proximal femur guided growth (PFGG) and reporting on primary radiographic outcomes, demographic variables, surgical variables and complications. One hundred and seventy-nine hips underwent PFGG (117 with CP and 62 with lateral overgrowth). Average age at surgery was 8.1 years; average follow-up was 52.5 months. Migration percentage improved from 11.2% (p < 0.0001). Neck-shaft angle improved by 11.9° (p < 0.0001). The most common complication was screw growth out of the physis (30% of cases). PFGG can correct coxa valga, improve radiographic parameters, and in children with CP prevent further subluxation. This technique modulates proximal femur growth, induces changes to the acetabulum and can correct valgus deformity. Evidence Level III. (Journal of Surgical Orthopaedic Advances 32(4):049-052, 2024).

Does cranial bone ossification differ in children with developmental dysplasia of the hip?

OBJECTIVES: This study aims to compare cranial bone ossification between patients with developmental dysplasia of the hip (DDH) and healthy individuals. PATIENTS AND METHODS: Between September 2021 and April 2022, a total of 60 healthy female individuals (median age: 24.5 months; range, 18 to 36 months) and 56 female DDH patients (median age: 23 months; range, 18 to 35 months) were included. Age, head circumference, weight, height, and patency of the anterior fontanel were measured in groups. Percentiles were classified as very low, low, normal, high and very high. All patients were female and those with abnormal thyroid function test, vitamin D, calcium, phosphate and alkaline phosphatase values were not included in the study. For those diagnosed with DDH, they were included in the group regardless of the type of treatment. RESULTS: No statistically significant difference was found between the groups in terms of age and weight (p>0.05). The very low and very high head circumferences were more frequent, and the normal head circumferences were less frequent in the DDH group (p<0.05). There was no significant difference between groups in terms of fontanel closure (p>0.05). In open fontanels, no significant difference was found in both groups in terms of age (p>0.05). CONCLUSION: Our study results showed no significant difference between the fontanel ossifications of children with and without DDH; however, we found that the ossification of the skull bones of children with DDH was different compared to healthy children.

2D/4D Finger Length Ratio in the Screening of Developmental Dysplasia of the Hip.

OBJECTIVE: To investigate whether there is a relationship between the 2nd finger and 4th finger length measurement ratios and developmental dysplasia of the Hip (DDH). STUDY DESIGN: Cross-sectional observational study. Place and Duration of the Study: Department of Orthopaedics and Traumatology, Meram Faculty of Medicine Hospital, Konya, Turkiye, from January 2020 to May 2023. METHODOLOGY: Infants were screened for DDH with Graff method for the ultrasounds of both hips. Lengths of the 2nd and 4th fingers of both hands were measured and recorded. Patients with additional risk factors for developmental dysplasia of the hip (breech birth, family history, oligohydramnios, swaddling) were excluded. RESULTS: Two hundred and fifty-six babies were screened including 55.1% (n = 141) girls and 44.9% (n = 115) boys. Their mean age was 2.51 ± 0.80 months. The average lengths were 31.73 ± 3.05 mm, for the left 2nd finger and 34.26 ± 3.48 mm for the left 4th finger. In the hip USG measurements, the mean alpha angles were 62.91 ± 3.12° for the right hip and, 63.20 ± 3.55° for the left hip. Eighteen (7%) of babies who underwent hip ultrasound (USG) had unilateral or bilateral DDH. Among these cases, 2.7% (n = 7) had right, 2.3% (n = 6) had left, and 2% (n = 5) had bilateral DDH. There was no statistically significant correlation between the ratios of right 2/4 finger lengths and the right alpha angle (rs = 0.051; p = 0.421). There was a statistically positive and statistically significant correlation between the ratios of left 2/4 finger lengths and the left alpha angle (rs = 0.154; p = 0.013). CONCLUSION: Only the left-hand finger ratio among the parameters in the model had a statistically significant effect on DDH. Therefore, the left hand 2D/4D finger length may be of value in screening for DDH. KEY WORDS: Developmental dysplasia of the hip, Second to fourth finger digit ratio, Ring finger, Digit ratios.

Routine ultrasound screening for hip dysplasia in children with clubfoot is not supported.

PURPOSE: Despite the existence of guidelines for screening for developmental dysplasia of the hip (DDH), there remains controversy regarding the need for routine ultrasound screening for DDH in patients with clubfoot due to an unclear correlation between the two conditions. The purpose of this study is to determine whether ultrasound screening for DDH in this population improved the diagnostic accuracy of DDH over standard assessment for patient risk factors and physical exam. METHODS: This is a retrospective cross-sectional review of infants diagnosed with idiopathic clubfoot who underwent hip ultrasounds to assess for DDH as identified by keyword search in an institutional radiological database at a tertiary care paediatric hospital. Patient demographics, risk factors for DDH, physical exam findings, and ultrasound results were recorded. RESULTS: Of the 120 patients who met the inclusion criteria between 2003 and 2018, 8 had hip dysplasia confirmed on ultrasound (6.7%). All these patients either had known risk factors for hip dysplasia or had an abnormal physical exam finding suggestive of hip instability or dislocation as performed by an orthopaedic surgeon on their initial consultation. CONCLUSION: A detailed history to determine risk factors and a thorough physical exam are adequate to determine the need for hip ultrasound in infants with idiopathic clubfoot. Routine ultrasound screening of all patients with clubfoot is likely unnecessary and may pose a significant burden on the health care system.

Pioneering a chick embryo model to explore the intrauterine etiology of developmental dysplasia of the hip in oligohydramnios conditions.

OBJECTIVE: To explore the impact of oligohydramnios on fetal movement and hip development, given its association with developmental dysplasia of the hip (DDH) but unclear mechanisms. METHODS: Chick embryos were divided into four groups based on the severity of oligohydramnios induced by amniotic fluid aspiration (control, 0.2 mL, 0.4 mL, 0.6 mL). Fetal movement was assessed by detection of movement and quantification of residual amniotic fluid volume. Hip joint development was assessed by gross anatomic analysis, micro-computed tomography (micro-CT) for cartilage assessment, and histologic observation at multiple time points. In addition, a subset of embryos from the 0.4 mL aspirated group underwent saline reinfusion and subsequent evaluation. RESULTS: Increasing volumes of aspirated amniotic fluid resulted in worsening of fetal movement restrictions (e.g., 0.4 mL aspirated and control group at E10: frequency difference -7.765 [95% CI: -9.125, -6.404]; amplitude difference -0.343 [95% CI: -0.588, -0.097]). The 0.4 mL aspirated group had significantly smaller hip measurements compared to controls, with reduced acetabular length (-0.418 [95% CI: -0.575, -0.261]) and width (-0.304 [95% CI: -0.491, -0.117]) at day E14.5. Histological analysis revealed a smaller femoral head (1.084 ± 0.264 cm) and shallower acetabulum (0.380 ± 0.106 cm) in the 0.4 mL group. Micro-CT showed cartilage matrix degeneration (13.6% [95% CI: 0.6%, 26.7%], P = 0.043 on E14.5). Saline reinfusion resulted in significant improvements in the femoral head to greater trochanter (0.578 [95% CI: 0.323, 0.833], P = 0.001). CONCLUSIONS: Oligohydramnios can cause DDH by restricting fetal movement and disrupting hip morphogenesis in a time-dependent manner. Timely reversal of oligohydramnios during the fetal period may prevent DDH.

Accuracy of portable navigation during THA in patients with severe developmental dysplasia of hip.

INTRODUCTION: Correct cup placement in total hip arthroplasty (THA) for patients with developmental dysplasia of the hip (DDH) is considerably difficult. This study aimed to analyze the orientation accuracy of cup insertion during THA using a portable navigation system in patients with DDH. MATERIALS AND METHODS: In this retrospective cohort study, we analyzed data from 64 patients who underwent THA using infrared stereo camera-matching portable navigation. Patients underwent THA via the anterolateral approach in the lateral decubitus position. Navigation records for intraoperative cup angles, postoperative cup angles measured on computed tomography (CT) images, and cup angle measurement differences were measured and compared between patients with non-DDH/mild DDH and severe DDH. Furthermore, the predictive factors for outliers of accurate acetabular cup placement were analyzed. RESULTS: The average measurement absolute abduction differences (postoperative CT-navigation record) were 3.9 ± 3.5° (severe DDH) and 3.3 ± 2.6° (non-DDH/ mild DDH), and the anteversion differences were 4.7 ± 3.4° (severe DDH) and 2.3 ± 2.1° (non-DDH/ mild DDH). The anteversion difference was different between the two groups. Multivariate analysis showed that the navigation difference (absolute difference in anteversion between postoperative CT and navigation records of > 5°) was significantly associated with severe DDH (odds ratio [OR]: 3.3; p = 0.049, 95% confidence interval [CI]: 1.0-11.1) and posterior pelvic tilt (OR: 1.1; p = 0.042, 95% CI: 1.0-1.27). CONCLUSIONS: In patients with severe DDH, it is important to pay close attention during THA using portable navigation. However, the average difference was < 5º even in patients with severe DDH, and the accuracy may be acceptable in a clinical setting when the cost is considered.

Is AI 3D-printed PSI an accurate option for patients with developmental dysplasia of the hip undergoing THA?

BACKGROUND: In traditional surgical procedures, significant discrepancies are often observed between the pre-planned templated implant sizes and the actual sizes used, particularly in patients with congenital hip dysplasia. These discrepancies arise not only in preoperative planning but also in the precision of implant placement, especially concerning the acetabular component. Our study aims to enhance the accuracy of implant placement during Total Hip Arthroplasty (THA) by integrating AI-enhanced preoperative planning with Patient-Specific Instrumentation (PSI). We also seek to assess the accuracy and clinical outcomes of the AI-PSI (AIPSI) group in comparison to a manual control group. METHODS: This study included 60 patients diagnosed with congenital hip dysplasia, randomly assigned to either the AIPSI or manual group, with 30 patients in each. No significant demographic differences between were noted the two groups. A direct anterior surgical approach was employed. Postoperative assessments included X-rays and CT scans to measure parameters such as the acetabular cup anteversion angle, acetabular cup inclination angle, femoral stem anteversion angle, femoral offset, and leg length discrepancy. Functional scores were recorded at 3 days, 1 week, 4 weeks, and 12 weeks post-surgery. Data analysis was conducted using SPSS version 22.0, with the significance level was set at α = 0.05. RESULTS AND CONCLUSION: The AIPSI group demonstrated greater prosthesis placement accuracy. With the aid of PSI, AI-planned THA surgery provides surgeons with enhanced precision in prosthesis positioning. This approach potentially offers greater insights and guidelines for managing more complex anatomical variations or cases.

Prediction of the Labrum Shape in Patients With Developmental Dysplasia of the Hip Based on Pelvic Radiography.

BACKGROUND: The shape of the labrum is strongly correlated with outcomes of developmental dysplasia of the hip (DDH). Magnetic resonance imaging (MRI) is the generally preferred imaging technique for observing the labrum. PURPOSE: We aimed to find a correlation between the labrum shape and anterior-posterior (AP) pelvic measurements in children with DDH. METHODS: Preoperative AP pelvic x-ray radiographs and MRI of patients with DDH from January 2019 to December 2021 were retrospectively collected and divided into three groups by labrum shape on MRI: everted, partly inverted, and inverted. The acetabular length ratio (RAL) in patients with unilateral DDH and the ratio of acetabular length to interpedicular distance (RALI) in all patients were calculated. T-tests were used to analyze differences between the groups. Receiver operating characteristic curve (ROC) analysis was performed between the everted group and the partly inverted and inverted groups. RESULTS: We found significant differences in RAL between the everted and partly inverted groups, everted and inverted groups, and everted and combined groups. The ROC analysis showed that the best cutoff value for RAL was 0.945 between the everted and combined groups, with an area under the curve (AUC) of 88.4%. The sensitivity at the best RAL value was 0.783, and the specificity was 0.887. Moreover, we observed a significant difference in RALI between the everted, partly inverted, and inverted groups, as well as between the everted and combined groups. The optimal cutoff value for RALI between the everted and combined groups was 0.575, with an AUC of 74.5%. The sensitivity at the best RALI value was 0.765, and the specificity was 0.674. CONCLUSION: The RAL or RALI values on pelvic AP radiographs can be used to predict the shape of the labrum. LEVEL OF EVIDENCE: III.

Comparison of Two Surgical Approaches for Periacetabular Osteotomy: A Retrospective Study of Patients with Developmental Dysplasia of the Hip.

OBJECTIVE: Given the intricate challenges and potential complications associated with periacetabular osteotomy (PAO) for developmental dysplasia of the hip (DDH). Our study aimed to compare the clinical and imaging benefits and drawbacks of two surgical approaches, the modified Stoppa combined iliac spine approach and the modified Smith-Peterson approach, for treating PAO and to provide guidance for selecting clinical approaches. METHODS: A retrospective analysis of 56 patients with 62 DDHs was conducted from June 2018 to January 2022. The experimental group underwent surgery via the modified Stoppa combined iliac spine approach, while the control group underwent surgery via the modified Smith-Peterson approach for periacetabular osteotomy and internal fixation. Basic statistical parameters, including age, sex, BMI, and preoperative imaging data, were analyzed. Differences in surgical time, intraoperative blood loss, and postoperative imaging data were compared, as were differences in preoperative and postoperative imaging data between the two groups. RESULTS: There were 28 hips in the experimental group and 34 in the control group. Moreover, there was no significant difference in the basic parameters between the experimental and control groups. Before and after the operation, for the LCE angle, ACE angle, and Tonnis angle, there was no significant difference in acetabular coverage (p > 0.05). However, there were significant differences between the two groups in terms of the above four indicators before and after the operation (p < 0.05). After the operation, the experimental group exhibited significant increases in both lateral and anterior acetabular coverage of the femoral head. However, the experimental group had longer operation times and greater bleeding volumes than did the control group. Despite this, the experimental group demonstrated significant advantages in protecting the lateral femoral cutaneous nerve compared to the control group. CONCLUSION: The modified Stoppa combined iliac spine approach can be considered a practical approach for PAO and is more suitable for patients with DDH who plan to be treated by one operation than the classic modified Smith-Peterson approach for PAO.

A New Method to Predict Postoperative Stem Anteversion in Total Hip Arthroplasty for Developmental Dysplasia of the Hip.

BACKGROUND: Preoperative evaluation of femoral anteversion to predict postoperative stem anteversion aids the selection of an appropriate prosthesis and optimizes the combined anteversion in total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH). The conventional prediction methods are based on the femoral anteversion measurement at the location of the femoral head and/or neck. However, varied differences between femoral anteversion and postoperative stem anteversion were demonstrated. This study investigated the predictive role of a new method based on the principle of sagittal three-point fixation. METHODS: From January 2017 to December 2018, a total of 133 DDH hips that underwent THA were retrospectively analyzed. There were 76 Crowe type I, 27 type II, and 30 type III hips. The single-wedge stem was used in 49 hips, and the double-wedge stem was used in 84 hips. Preoperative native femoral anteversion at the femoral head-neck junction, anterior cortex anteversion at 2 levels of the lesser trochanter, posterior cortex anteversion at 5 levels of the femoral neck, and postoperative stem anteversion were measured using two-dimensional computed tomography. Predictive anteversion by the new method was calculated as the average anteversion formed by the anterior cortex at the lesser trochanter and the posterior cortex at the femoral neck. RESULTS: For hips with different neck heights, different Crowe types, different stem types, or different femoral anteversions, native femoral anteversion showed widely varied differences and correlations with stem anteversion, with differences ranging from -1.27 ± 8.33° to -13.67 ± 9.47° and correlations ranging from 0.122 (p = 0.705, no correlation) to 0.813. Predictive anteversion formed by the anterior cortex at the lesser trochanter proximal base and posterior cortex 10 mm above the lesser trochanter proximal base showed no significant difference with stem anteversion, with less varied differences (0.92 ± 7.52°) and good to excellent correlations (r = 0.826). CONCLUSION: Adopting our new method, predictive anteversion, measured as the average anteversion of the anterior cortex at the lesser trochanter proximal base and posterior cortex 10 mm above the lesser trochanter proximal base, predicted postoperative stem anteversion more reliably than native femoral anteversion.

Follow-up Value of Hip Medial Ultrasound in Infants and Children With Developmental Dysplasia of the Hip Treated With Reduction and Spica Casting.

OBJECTIVE: Closed or open reduction and spica casting are common treatments for children aged 6 to 18 months, as well as infants aged 0 to 6 months whose harness treatment for developmental dysplasia of the hip (DDH) was unsuccessful. The study aimed to quantify the distance between the femoral head and the acetabulum after closed or open reduction and evaluate the dynamic docking progression of the femoral head using serial hip medical ultrasound. METHODS: We retrospectively reviewed the medical records and hip medial ultrasound images of a consecutive series of patients with DDH who underwent spica casting after reduction and compared images obtained immediately after reduction and at follow-up. The first cast (stage I) was maintained for 2 to 3 months and scheduled for outpatient repeat ultrasound in 4 to 8 weeks. Then the second cast was placed (stage II), lasting for another 2 to 3 months. The triradiate cartilage-femoral head distance (TFD) was measured in the acetabulum coronal mid-sectional plane. The Wilcoxon signed-rank test was used to compare the TFD values. RESULTS: This study included 49 patients. All patients underwent hip medial ultrasound 0 to 3 days after stage I (time 1) and 4 to 8 weeks (time 2) postoperatively, with 24 patients reviewed again 0 to 7 days after stage II. The TFD values in time 1 and time 2 were 6.0 (5.0, 9.0) mm and 5.0 (3.6, 7.0) mm, respectively. There was a statistically significant difference between times 1 and 2 regarding TFD values in 49 close-reduction hips (6.0 vs 5.0 mm, P < 0.001). Similar findings were also observed in 13 open-reduction hips (6.0 vs 5.0 mm, P = 0.023). CONCLUSIONS: Hip medial ultrasonography during the period of cast immobilization after reduction in children with DDH can objectively and quantitatively show the dynamic change of the distance between the femoral head and the acetabulum, and can be used to assess reduction of the hip and progression of femoral head docking. LEVEL OF EVIDENCE: Level II-prognostic study.

Clinical efficacy of greater trochanter osteotomy with tension wire fixation in total hip arthroplasty for Crowe type IV developmental dysplasia of the hip.

OBJECTIVE: The choice of osteotomy in joint replacement surgery for Crowe type IV developmental dysplasia of the hip (DDH) is a challenging and controversial procedure. In this study, we compared the clinical efficacy of a combination of greater trochanter osteotomy and tension wire fixation with that of subtrochanteric osteotomy. METHODS: We performed 15 primary total hip arthroplasty (THA) procedures between January 2016 and July 2020 on 13 patients with a combination of greater trochanter osteotomy and tension wire fixation (the GTT group) and 12 THA procedures in 11 patients using subtrochanteric osteotomy (the STO group). The mean follow-up was 2.8 years (range 2.2-4.5 years) in the GTT group and 2.6 years (range 2.5-4.3 years) in the STO group. Clinical scores and radiographic results were evaluated during the final follow-up for the 15 hips in the GTT group and 12 hips in the STO group. RESULTS: Postoperative Harris hip scores, implant position, and the surgery time did not differ between the treatment groups. There were no differences in preoperative leg length discrepancy LLD (P = 0.46) and postoperative LLD (P = 0.56) between the two groups. Bone union occurred within 6 months after surgery in 12 hips in the GTT group (92.3%) and in 9 hips (81.8%) in the STO group. One case in the GTT group and two cases in the STO group had nonunion, and additionally, there was one case of postoperative nerve injury in the STO group, while no symptoms of nerve damage were observed in the GTT group. CONCLUSION: The GTT method demonstrated many advantages and reliable clinical results for Crowe type IV DDH patients undergoing THA. This is a surgical method that warrants further development and promotion clinically.