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.

Whole exome sequencing of 28 families of Danish descent reveals novel candidate genes and pathways in developmental dysplasia of the hip.

Developmental dysplasia of the hip (DDH) is a common condition involving instability of the hip with multifactorial etiology. Early diagnosis and treatment are critical as undetected DDH is an important cause of long-term hip complications. Better diagnostics may be achieved through genetic methods, especially for patients with positive family history. Several candidate genes have been reported but the exact molecular etiology of the disease is yet unknown. In the present study, we performed whole exome sequencing of DDH patients from 28 families with at least two affected first-degree relatives. Four genes previously not associated with DDH (METTL21B, DIS3L2, PPP6R2, and TM4SF19) were identified with the same variants shared among affected family members, in more than two families. Among known association genes, we found damaging variants in DACH1, MYH10, NOTCH2, TBX4, EVC2, OTOG, and SHC3. Mutational burden analysis across the families identified 322 candidate genes, and enriched pathways include the extracellular matrix, cytoskeleton, ion-binding, and detection of mechanical stimulus. Taken altogether, our data suggest a polygenic mode of inheritance for DDH, and we propose that an impaired transduction of the mechanical stimulus is involved in the etiopathological mechanism. Our findings refine our current understanding of candidate causal genes in DDH, and provide a foundation for downstream functional studies.

Greater hip abductor size in prearthritic patients with developmental dysplasia of the hip versus femoroacetabular impingement.

Developmental dysplasia of the hip (DDH) and femoroacetabular impingement (FAI) are common hip pathologies and important risk factors for osteoarthritis, yet the disease mechanisms differ. DDH involves deficient femoral head coverage and a shortened abductor moment arm, so this study hypothesized that the cross-sectional area (CSA) of the gluteus medius/minimus muscle complex and the stabilizing iliocapsularis muscle would be larger in DDH versus FAI, without increased fatty infiltration. A longitudinal cohort identified prearthritic patients with DDH or FAI who underwent imaging before surgery. Patients with DDH and FAI (Cam, Pincer, or Mixed) were 1:1 matched based on age, sex, and body mass index. Magnetic resonance imaging was used to measure the gluteus medius/minimus complex and iliocapsularis in two transverse planes. Amira software was used to quantify muscle and noncontractile tissue. Paired samples t-tests were performed to compare muscle size and composition (p < 0.05). There were no differences in the iliocapsularis muscle. Patients with DDH had significantly larger CSA of the gluteus medius/minimus complex at both transverse planes, and the noncontractile tissue proportion did not differ. The mean difference in overall muscle CSA at the anterior inferior iliac spine was 4.07 ± 7.4 cm2 (p = 0.005), with an average difference of 12.1%, and at the femoral head this was 2.40 ± 4.37 cm2 (p = 0.004), with an average difference of 20.2%. This study reports a larger CSA of the gluteus medius/minimus muscle complex in DDH compared to FAI, without a difference in noncontractile tissue, indicating increased healthy muscle in DDH.

ARTHROPLASTY IN DYSPLSATIC COXARTHROSIS.

Objective - to justify the use of hip endoprosthesis techniques in dysplastic coxarthrosis depending on the type of dysplasia according to Crowe JF. The study is based on the analysis of hip replacement in 390 patients with dysplastic coxarthrosis, who underwent 436 endoprosthetics. There were 192 patients with type 1 dysplasia according to Crowe, type II - 142, type III - 38 and type IV - 18 patients. The age of patients ranged from 15 to 61 years and averaged 43 years. Pathology was prevalent in women, which accounted for 90 %. Preference was given to prostheses with a cementless type of fixation, which accounted for 89 %. An important task of the surgeon during hip replacement in patients with dysplastic coxarthrosis is to install the acetabulum component of the prosthesis in an anatomical position in compliance with the recommendations of spatial location, especially in types III and IV of dysplasia. Endoprosthetics in types 1 and II of hip dysplasia did not present any difficulties. The amount of bone tissue of the acetabulum of the pelvis is sufficient for the use of cups with primary press-fit fixation. Usually, acetabular components of small size were used. In type III dysplasia, there was a significant deficit of bone tissue of the anterior, posterior columns and acetabular roof. In such cases, bone grafting is used. Shortening of the limb in type III dysplasia, as a rule, does not exceed 4 cm, so the surgery may be performed in one stage and without a shortening osteotomy. In type IV dysplasia with shortening of the lower limb to 4 cm, a single stage endoprosthetics is performed it is possible to perform a shortening osteotomy of the proximal femur. Іn patients with a unilateral process and shortening of the limb more than 4 centimeters, we used the two-stage surgery method. At the first stage, we applied a rod device for external fixation with the introduction of rods into the pelvis and hip, then gradually performed hip traction in order to lower the femoral head to the level of the acetabulum, after which the device was dismantled and at the second stage hip replacement was performed. The acetabular component in hip replacement in Crowe type III or IV dysplasia should be placed in the anatomical position of the acetabulum. If the cranial displacement of the femoral head is less than 4 cm, hip replacement should be performed in one stage. In a unilateral cranial displacement of the femoral head of more than 4 cm, in order to avoid neurovascular bundle traction damage and facilitate the reduction of the prosthesis, preparation should be performed with the reduction of the femoral head to the level of the anatomical acetabulum using an external fixation rod device. It is possible to use a shortening osteotomy of the proximal femur, but then the length of the limb is not restored.

[Treatment strategies for the combination of hip dysplasia, femoroacetabular impingement and malrotation of the proximal femur : How much should be corrected?] / Therapieentscheidung bei Kombinationspathologien Dysplasie ­ FAI ­ Fehlrotation : Wann und wieviel sollte korrigiert werden?

BACKGROUND: Hip dysplasia, FAI and femoral malrotation often occur together, resulting in mixed symptoms and severe biomechanical limitations of the hip. OBJECTIVES: To report on the current recommendations for the best possible diagnosis and treatment strategies of combination pathologies in hip-preserving surgery. METHODS: Review and discussion of the relevant literature with consideration of own experience in the treatment of complex combined pathomorphologies of the hip. RESULTS: Patient history and a thorough clinical examination are key for determining the predominant pathomorphologies causing the symptoms. Standardized conventional ap pelvic and axial images of the hip are the basis for the radiological assessment of the hip, supplemented with MRI, CT and animations of the hip, depending on the case. As the pathologies influence each other functionally, a stepwise approach to treatment is recommended. The functionally most relevant pathology is treated first, followed by further corrections as needed. The primary goal is to achieve a stable hip with normal acetabular coverage, followed by an impingement-free range of motion and normalized musculoskeletal function. Care must be taken in the choice of surgical method to ensure that all pathologies can be adequately treated. CONCLUSION: Complex, combined pathologies of the hip can be treated sufficiently with hip-preserving surgery. A thorough diagnosis is important in order to recognize the functional interaction of the different pathologies. The goal of the surgical therapy is a correctly covered, stable hip with a normal range of motion.

Identification of KANSL1 as a novel pathogenic gene for developmental dysplasia of the hip.

Developmental dysplasia of the hip (DDH) is a common anomaly leading to adult osteoarthritis. Environmental and genetic factors contribute to DDH, but its exact genetic mechanism is unclear. In this study, we used whole exome sequencing to identify the causative gene of a DDH pedigree. A rare missense variant in KANSL1 (c.C767T; p.S256F) was identified as the pathogenic cause of DDH. Subsequent mutation screening showed another missense variant in 1 of 200 sporadic patients. Kansl1-mutated mice showed reduced chondrocytes in the acetabulum and a decrease in the cartilage matrix, which may be DDH phenotype-related abnormalities. Furthermore, functional studies showed that cell proliferation was delayed and Mmp13 expression was abnormally upregulated in chondrocytes differentiated from Kansl1 mutant mouse embryonic stem cells. In conclusion, our findings suggest that KANSL1 is a novel pathogenic gene for DDH. The identification of KANSL1 variants has great diagnostic value for identifying individuals with DDH. KEY MESSAGES: Developmental dysplasia of the hip (DDH) is a common anomaly causing adult osteoarthritis. Environmental and genetic factors contribute to DDH, but its exact genetic mechanism is unclear. Using high-throughput whole exome sequencing, we found a novel variant in KANSL1 that was co-inherited by all severely affected individuals diagnosed with DDH from a three-generation family. Further analysis revealed that a Kansl1 variant in mice reduced the number of chondrocytes and decreased cartilage matrix, and mouse embryonic stem differentiation assay showed cartilage defects. These findings indicate a direct association between KANSL1 and hip development, expanding the pathogenic gene spectrum in DDH and providing insight into potential new targets for diagnosing and treating hip dysplasia.

Surgical Treatment of Acetabular Dysplasia With Labral Tears.

Acetabular dysplasia results in abnormal forces across the hip joint and can result in both labral tears and cartilage degeneration. A continuum exists from classic dysplasia to normal acetabular morphology. Diagnosis is aided by several radiographic measurements and parameters including a lateral center edge angle of less than 20°, an anterior center edge angle of less than 20°, a Sharp's angle of greater than 42°, and a Tonnis angle of greater than 10°, or version abnormalities. When patients with acetabular dysplasia present with intra-articular hip pain, skeletal maturity, and preserved radiographic joint space, a periacetabular osteotomy (PAO) is considered as a surgical treatment option when conservative measures have failed. The Bernese PAO was developed in 1984 as a way for reorienting the acetabulum to restore more normal femoral head coverage and orientation. The long-term results of this procedure have been promising with 10-year and 20-year survivorships of approximately 85% and 60%, respectively. When dysplasia is coupled with a labral tear or other intra-articular pathology including focal chondral damage, ligamentum teres tears, or capsular defects, hip arthroscopy and PAO are performed. Although there is a paucity in the literature of the long-term evidence for the combined procedure, early results indicate improved patient reported outcome measures. Appropriate treatment of borderline hip dysplasia remains controversial.

MRI Predictors of Residual Dysplasia in Developmental Dysplasia of the Hip Following Open and Closed Reduction.

BACKGROUND: Following open or closed reduction for children with developmental dysplasia of the hip, there remains a significant risk of residual acetabular dysplasia which can compromise the long-term health of the hip joint. The purpose of this study was to use postoperative in-spica magnetic resonance imaging (MRI) data to determine factors predictive of residual acetabular dysplasia at short-term follow-up. METHODS: We retrospectively reviewed 63 hips in 48 patients which underwent closed or open reduction and spica casting for developmental dysplasia of the hip. MRI performed in-spica at ∼3-week follow-up were used to assess 11 validated metrics and 2 subjective factors. Acetabular index (AI) was measured on anteroposterior pelvic radiographs at 2-year postoperative follow-up. Binary logistic regression was then used to identify variables predictive of residual dysplasia, defined as an AI greater than the 90th percentile for age based on historic normative data. RESULTS: Average age at surgical reduction was 9.3±3.2 months. 58.7% (37/63) of reductions were open. A total of 43 (68.3%) hips demonstrated residual acetabular dysplasia at 2 years postoperatively based on normative values. In those with persistent dysplasia, patients were on average older at the time of reduction (10.0 mo±3.2 vs. 8.0 mo±2.8, P=0.010) and more likely female (88.4% vs. 60.0%, P=0.010). Patients with residual dysplasia were more likely to have mild subluxation on postoperative MRI (40.0% vs. 10.5%, P=0.022). Hips with a cartilaginous acetabular index (CAI) of >23 degrees were 7.6 times more likely to develop residual dysplasia. Type of reduction (ie, closed vs. open) did not appear to influence the rate of residual dysplasia (P=0.682). CONCLUSION: In this series, the rate of residual dysplasia after surgical reduction was higher than most previous reports, with no appreciable difference between closed and open reductions. Older age, female sex, and a higher CAI were associated with a greater risk of persistent radiographic dysplasia. In particular, hips with a CAI >23 degrees were 7.6 times more likely to be dysplastic at 2-year follow-up. LEVEL OF EVIDENCE: Level III.

Residual acetabular dysplasia in congenital hip dysplasia.

Residual hip dysplasia may exist despite appropriate treatment of congenital hip dysplasia (CHD). The abnormalities chiefly affect the acetabulum and can lead to premature osteoarthritis. Although the main cause is delayed treatment of CHD, primary lesions are also possible and may be worsened by the initial treatment itself. Residual hip dysplasia must be detected during the follow-up of patients with CHD. The antero-posterior radiograph of the pelvis is the main diagnostic tool. However, the importance of non-ossified anatomical structures requires additional investigations such as arthrography and magnetic resonance imaging. The risk of premature osteoarthritis is difficult to predict based only on the imaging-study findings. Hip dysplasia is best treated before 5 years of age. The work-up at this age should allow determination of the best treatment. Surgery is required but should not be performed unnecessarily. The decision rests on the absence of improvement in the radiographic criteria and on the findings from additional imaging studies. The usual treatment is Salter's osteotomy, during which excessive anterior displacement should be avoided. At adolescence, the information provided by radiography in the coronal plane should be completed by a three-dimensional evaluation of the acetabulum and an assessment of the quality of the labrum. The shelf procedure has been proven to relieve pain and to significantly postpone the need for hip arthroplasty, when performed early, before the development of visible osteoarthritis, and on a congruent hip. Chiari's osteotomy has a role to play in complex dysplasia affecting both the acetabulum and the femur. Periacetabular osteotomy is getting more used thanks to cooperation between paediatric and adult orthopaedic surgeons. This osteotomy provides optimal correction in all three dimensions.

Bone defect map of the true acetabulum in hip dysplasia (Crowe type II and III) based on three-dimensional image reconstruction analysis.

The high hip center technique (HHC) is considered to be feasible for acetabular reconstruction in patients with DDH, but there is little in-depth study of its specific impact on Crowe type II and III DDH. The purpose of this study was to simultaneously analyze the effect of HHC on bone coverage of the cup (CC) in the acetabular reconstruction of type II and III DDH patients and to propose a map of acetabular bone defects from the perspective of the cup. Forty-nine hip CT data of 39 patients with DDH (Crowe type II and III) were collected to simulate acetabular reconstruction by cup models of different sizes (diameter 38mm-50 mm, 2 mm increment) with the HHC technique. The frequency distribution was plotted by overlapping the portions of the 44 mm cups that were not covered by the host bone. The mean CC of cups with sizes of 38 mm, 40 mm, 42 mm, 44 mm, 46 mm, 48 mm, and 50 mm at the true acetabula were 77.85%, 76.71%, 75.73%, 74.56%, 73.68%, 72.51%, and 71.75%, respectively, and the maximum CC increments were 21.24%, 21.58%, 20.86%, 20.04%, 18.62%, 17.18%, and 15.42% (P < 0.001), respectively, after the cups were elevated from the true acetabula. The bone defect map shows that 95% of type II and III DDH acetabula had posterosuperior bone defects, and approximately 60% were located outside the force line of the hip joint. Acetabular cups can meet a CC of more than 70% at the true acetabulum, and approximately 60% of Crowe type II and III DDH patients can obtain satisfactory CC at the true acetabulum by using a 44-mm cup without additional operations.

Rare and de novo variants in 827 congenital diaphragmatic hernia probands implicate LONP1 as candidate risk gene.

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly that is often accompanied by other anomalies. Although the role of genetics in the pathogenesis of CDH has been established, only a small number of disease-associated genes have been identified. To further investigate the genetics of CDH, we analyzed de novo coding variants in 827 proband-parent trios and confirmed an overall significant enrichment of damaging de novo variants, especially in constrained genes. We identified LONP1 (lon peptidase 1, mitochondrial) and ALYREF (Aly/REF export factor) as candidate CDH-associated genes on the basis of de novo variants at a false discovery rate below 0.05. We also performed ultra-rare variant association analyses in 748 affected individuals and 11,220 ancestry-matched population control individuals and identified LONP1 as a risk gene contributing to CDH through both de novo and ultra-rare inherited largely heterozygous variants clustered in the core of the domains and segregating with CDH in affected familial individuals. Approximately 3% of our CDH cohort who are heterozygous with ultra-rare predicted damaging variants in LONP1 have a range of clinical phenotypes, including other anomalies in some individuals and higher mortality and requirement for extracorporeal membrane oxygenation. Mice with lung epithelium-specific deletion of Lonp1 die immediately after birth, most likely because of the observed severe reduction of lung growth, a known contributor to the high mortality in humans. Our findings of both de novo and inherited rare variants in the same gene may have implications in the design and analysis for other genetic studies of congenital anomalies.

Acetabular development and fate of inverted limbus in rabbits: Experimental observation from an animal model.

Using an animal model, we aimed to investigate the effects of an inverted limbus on acetabular development following closed reduction of developmental dysplasia of the hip (DDH). We interpositioned the menisci of 5-week-old rabbits (n = 40) into the hip joints to simulate limbus inversion following closed reduction for DDH. The acetabular index (AI) on anteroposterior pelvic radiographs and magnetic resonance imaging were used to evaluate acetabular development. Animals were euthanized at 4 and 8 weeks after surgery. Histological sections of the acetabular cartilage were stained and scored in accordance with the modified Mankin system. Scanning electron microscopy and transmission electron microscopy were used to examine the ultrastructure of the acetabular cartilage. Terminal deoxynucleotidyl transferase dUTP nick end-labeling staining was used to evaluate chondrocyte apoptosis. Immunohistochemistry and Western blot analyses were used to examine the expression of type X collagen (Col-X) and matrix metalloproteinase 13 (MMP-13) in the acetabular cartilage. AI values increased over a period and were higher in the experimental group than in the sham group. In the experimental group, the acetabular surface had become rough and had split in some cases. Chondrocytes within the acetabular cartilage had become hypertrophic, gradually forming clusters, and taking on an apoptotic appearance. Col-X and MMP-13 expression also increased with time. Our findings suggest that residual limbus inversion following closed reduction for DDH can cause progressive dysplasia of the acetabulum, apoptosis of acetabular chondrocytes, accelerated cartilage degeneration, and even early-stage osteoarthritis.

Novel 3D printed integral customized acetabular prosthesis for anatomical rotation center restoration in hip arthroplasty for developmental dysplasia of the hip crowe type III: A Case Report.

RATIONALE: Exact restoration of the rotation center in total hip arthroplasty (THA) is technically challenging in patients with end-stage osteoarthritis due to developmental dysplasia of the hip (DDH), especially in the Crowe type II and III procedures. The technical difficulty is attributable to the complex acetabular changes. In this study, a novel 3-dimensional (3D) printed integral customized acetabular prosthesis for anatomical rotation restoration in THA for DDH Crowe type III was developed using patient-specific Computer-aided design and additive manufacturing (AM) methods. PATIENT CONCERNS: A 69-year-old female patient had developed left hip joint pain and restricted movement for 40 years; the symptoms had increased in the past 5 months. Pain, limited motion of the left hip joint, and lower limb length discrepancy were noted during physical examination. DIAGNOSIS: The patient was diagnosed with left hip end-stage osteoarthritis secondary to DDH (Crowe type III). INTERVENTION: A 3D printed acetabulum model was manufactured and a simulated operation was performed to improve the accuracy of reconstruction of the rotation center and bone defect. A 3D printed titanium alloy integral customized acetabular prosthesis was designed according to the result of simulated operation. The integral customized prothesis was implanted subsequently via the posterolateral approach. Radiography of the pelvis and Harris score assessment were performed during the perioperative period as well as at the 6- and 12-month follow-up. OUTCOMES: The 3D printed integral customized acetabular prosthesis matched precisely with the reamed acetabulum. The rotation center was restored and the bone defect was exactly reconstructed. There were no signs of prosthetic loosening at the 12-month follow-up. The Harris score gradually improved during the follow-up period. LESSONS: Satisfactory results of hip rotation restoration and bone defect reconstruction could be achieved by using 3D printed integral customized acetabular prosthesis, which provides a promising way to reconstruct the acetabulum in patients with DDH anatomically and rapidly for THA.

Developmental dysplasia of the hip.

Developmental dysplasia of the hip encompasses a range of hip abnormalities in which the femoral head and acetabulum fail to develop and articulate anatomically. Developmental dysplasia of the hip is a clinically important condition, with a prevalence of 1-2/1000 in unscreened populations and 5-30/1000 in clinically screened populations. The pathology is incongruence between the femoral head and the acetabulum, which can be caused by an abnormally shaped femoral head, acetabulum, or both. This results in a spectrum of different hip abnormalities. The precise aetiology behind developmental dysplasia of the hip is unclear, but there are a number of established risk factors. In the UK, universal clinical examination of newborns and 6-8-week-old babies is performed under the national UK newborn screening programme for developmental dysplasia of the hip (part of the Newborn and Infant Physical Examination). The physical examination of the newborn hip involves initial inspection of the infant for any of the clinical features of developmental dysplasia of the hip, followed by hip stability tests (Barlow's and Ortolani's tests). Hip ultrasound is the gold standard diagnostic and monitoring tool for developmental dysplasia of the hip in newborns and infants under 6 months of age, or until ossification of the femoral head. Some mild cases of developmental dysplasia of the hip (and the immature hip) resolve without requiring intervention; however, there are a number of treatments, both non-operative and operative, that may be used at various stages of this condition.

Sacral protuberance with cleft lip and palate: Prenatal presentation of 3MC syndrome.

3MC syndromes are rare heterogeneous autosomal recessive conditions previously designated as Mingarelli, Malpuech, Michels, and Carnevale syndromes, characterized by dysmorphic facial features, facial clefts, growth restriction, and intellectual disability. 3MC is secondary to mutations in the MASP1, MASP3, COLEC11, and COLEC10 genes. The number of patients with 3MC syndrome with known mutations in the COLEC11 or MASP1 is, to date, less than 50. At the time this case presented (2015), the only gene identified in Online Mendelian Inheritance in Man to be associated with 3MC syndrome was MASP1. We present, to the best of our knowledge, the first prenatal report of 3MC syndrome, secondary to a homozygous variant in MASP1. Fetal findings included bilateral cleft lip and palate, abnormality of the sacral spine, a right echogenic pelvic kidney, and brachycephaly. 3MC syndrome should be considered as part of the differential diagnosis when fetal ultrasound detects facial clefts and spinal defects, as the risk of recurrence is significant and a molecularly confirmed diagnosis allows for alternate reproductive options.

Larger Acetabular Labrum Is Associated With Hip Dysplasia, Joint Incongruence, and Clinical Symptoms.

PURPOSE: To evaluate the association of labral length with acetabular morphology and clinical symptoms. METHODS: Patients treated at our hip joint clinic between January 2015 and December 2018 were retrospectively enrolled in the study. Our sample included patients who received a diagnosis of one or more of the following: hip labral tear, femoroacetabular impingement (FAI), and developmental dysplasia of the hip. Patients with osteoarthritis and/or osteonecrosis were excluded. Bilateral labral length was measured as the distance from the acetabular rim to the edge of the labrum at the level of the central coronal T1-weighted magnetic resonance imaging scan cross-referenced to the axial plane (3- to 9-o'clock position). The lateral center-edge angle (LCEA) and acetabular roof obliquity (ARO) were evaluated with plain radiographs. An LCEA of 25° or less was defined as developmental dysplasia of the hip, whereas a positive crossover sign in the presence of an LCEA of 30° or greater, an LCEA greater than 40°, or acetabular inclination lower 0° was defined as pincer FAI. An alpha angle greater than 50° or head-neck offset lower 8 mm was considered cam FAI. The severity of hip symptoms was evaluated bilaterally using the Japanese Orthopaedic Association pain scale, on which hips scoring full points (i.e., a perfect score) were defined as asymptomatic whereas hips with all other scores were considered symptomatic. We used simple linear regression to examine the correlations of labral length with the LCEA and ARO. Labral length was also compared according to patient hip symptom status using the Mann-Whitney U test. RESULTS: The study included 102 patients (14 with bilateral symptoms and 88 with unilateral symptoms). Labral length was strongly correlated with the LCEA (r = -0.612, P < .001) and ARO (r = 0.635, P < .001). Additionally, patients with symptomatic hips had significantly larger labra (9.5 ± 3.0 mm) than those with asymptomatic hips (7.9 ± 2.1 mm, P = .004). CONCLUSIONS: Acetabular labral length is significantly greater in dysplastic, irregularly congruent, symptomatic hips. LEVEL OF EVIDENCE: Level Ⅳ, retrospective cross-sectional study.

Correlation of tilt of the anterior pelvic plane angle with anatomical pelvic tilt and morphological configuration of the acetabulum in patients with developmental dysplasia of the hip: a cross-sectional study.

BACKGROUND: It was previously reported that pelvises with developmental dysplasia of the hip are tilted anteriorly, which increases bony coverage of the femoral head. This study aimed to investigate the correlation between anatomical parameters of the pelvis such as pelvic incidence and anatomical pelvic tilt and functional parameters of the spine and pelvis such as tilt of the anterior pelvic plane. METHODS: We examined 84 female patients with bilateral developmental dysplasia of the hip who had undergone curved periacetabular osteotomy at author's institution. Radiographs of the thoracic to lumbar spines and the pelvis were obtained in the standing position to measure spino-pelvic parameters before surgery. Morphological parameters of the acetabulum such as the anterior center-edge (CE) angle, posterior CE angle, lateral CE angle, and acetabular anteversion were measured using a preoperative three-dimensional pelvic model reconstructed from computed tomography images. Pearson's correlation analysis was conducted to evaluate the relationship of these parameters. RESULTS: With regard to correlations between pelvic incidence (PI) and other parameters, the sacral slope (SS) value (r = 0.666) was the highest among functional parameters and the anatomical-SS value (r = 0.789) was the highest among morphological parameters. There were moderate correlations of the anterior pelvic plane angle (APPA) with pelvic tilt (PT) (r = - 0.594) and anatomical-PT (r = 0.646). With regard to correlations between spino-pelvic parameters and bony morphological parameters of the acetabulum, there was a moderate correlation between anatomical-PT and acetabular anteversion (AA) (r = 0.424). There were moderate correlations of APPA with the anterior CE angle (r = - 0.478), posterior CE angle (r = 0.432), and AA (r = 0.565). APPA had a stronger correlation with anatomical-PT (r = 0.646) than with AA. CONCLUSIONS: The tilt of the pelvis may be more dependent on anatomical-PT, a morphological parameter of the pelvis, than the lateral CE angle, anterior CE angle, posterior CE angle, and acetabular anteversion on bony coverage of the acetabulum. This study is the first to investigate the correlation between functional parameters of the pelvis and spine and morphological parameters of the pelvis and acetabulum besides PI.

Are there clinically relevant anatomical differences of the proximal femur in patients with mild dysplastic and primary hip osteoarthritis? A CT-based matched-pairs cohort study.

AIM: To investigate the three-dimensional anatomy and shape of the proximal femur, comparing patients with secondary osteoarthritis (OA) due to mild developmental dysplasia of the hip (DDH) and primary hip OA. MATERIALS AND METHODS: This retrospective radiographic computed tomography (CT)-based study investigated proximal femoral anatomy in a consecutive series of 84 patients with secondary hip OA due to mild DDH (Crowe type I&II/Hartofilakidis A) compared to 84 patients with primary hip OA, matched for gender, age at surgery, and body mass index. RESULTS: Men with DDH showed higher neck shaft angles (127±5° vs. 123±4°; p<0.001), whereas women with DDH had a larger femoral head diameter (46±4 vs. 44±3 mm; p=0.002), smaller femoral offset (36±5 vs. 40±4 mm; p<0.001), decreased leg torsion (25±13° vs. 31±16°; p=0.037), and a higher neck shaft angle (128±7° vs. 123±4°; p<0.001) compared to primary OA patients. Similar patterns of the three-dimensional endosteal canal shape of the proximal femur, but a high inter-individual variability for femoral canal torsion at the meta-diaphyseal level were found for DDH and primary OA patients. CONCLUSION: Standard cementless stem designs are suitable to treat patients with secondary hip OA due to mild DDH; however, high patient variability and subtle anatomical differences in the proximal femur should be respected.

Volumetric measurement of the acetabular cavity in patients with unilateral neglected developmental dysplasia of the dislocated hip operated in a single time.

BACKGROUND: Plain radiography is the most often imaging method used for postoperative assessment of inveterate developmental dysplasia of the hip. This technique does not permit to achieve an accurate diagnose of intra-articular changes, specifically articular congruity. OBJECTIVE: analyze the morphological changes of the acetabular volume by computed tomography, in patients operated by medium adductor myotomy, psoas tenotomy, open hip reduction, diaphysectomy, varus osteotomy and derotating and Dega-type acetabuloplasty. METHOD: A pilot clinical trial was conducted including six patients with unilateral inveterate dysplasia admitted to the Rehabilitation National Institute. Computed tomography were analyzed using an engineering design software. RESULTS: It was found that in all cases analyzed, operated acetabular volume was greater than the contralateral (8 to 48%), however, no significant difference between the volumes was found (p = 2.46). Significant difference between the volume and the age of patients, in multifactorial ANOVA tests (p = 0.006), Cochran's (p = 0.00019) and Kruskal-Wallis (p = 2.925 × 10-8) was found. CONCLUSION: It is clear that the proposed measurement technique is able to identify differences between volumes (operated and contralateral). The clinical monitoring of these patients can validate the results obtained by this measurement technique, and it will serve to estimate the effectiveness of the surgical technique applied in patients.

ANTECEDENTES: El método más utilizado para la evaluación posquirúrgica de la displasia del desarrollo de la cadera inveterada es la radiografía convencional, lo que impide medir con precisión cambios intraarticulares. OBJETIVO: Analizar los cambios morfológicos del volumen acetabular mediante tomografía computarizada en pacientes operados con miotomía de aductor mediano, tenotomía de psoas, reducción abierta de cadera, diafisectomía, osteotomía varizante y desrotadora, y acetabuloplastia tipo Dega. MÉTODO: Se realizó un estudio piloto en el que se analizaron tomografías de seis pacientes del Instituto Nacional de Rehabilitación con displasia inveterada unilateral, por medio de software de diseño para determinar el volumen acetabular. RESULTADOS: Se encontró que el volumen acetabular operado fue mayor que el contralateral (8 vs. 48%), pero no se halló diferencia significativa entre los volúmenes (p = 2.46). Se encontraron diferencias significativas entre los volúmenes y la edad de los pacientes, evaluadas mediante ANOVA multifactorial (p = 0.006), Cochran (p = 2.925 × 10−8) y Kruskal-Wallis (p = 0.00019). CONCLUSIÓN: Es claro que la técnica de medición propuesta permite identificar diferencias entre volúmenes (operado y contralateral). El seguimiento clínico de estos pacientes podrá validar los resultados obtenidos por este método y servirá para poder estimar la eficacia de la técnica quirúrgica aplicada en los pacientes.