A longitudinal cohort study of adolescent elite footballers and controls investigating the development of cam morphology.

Cam morphology describes an asphericity of the femoral head that develops during adolescence, is highly prevalent in athletes, and predisposes individuals to future osteoarthritis. However, it's aetiology remains poorly understood. The aim of this study was to perform 3-year longitudinal follow-up of a control population and football club academy cohort to compare the change in hip and growth plate anatomy between athletes and controls. MRI and questionnaires were used to characterise change in hip and growth plate anatomy and quantify activity levels. 121 male academy footballers and 107 male and female controls participated at baseline. Footballers experienced significantly greater increases in femoral head asphericity (4.83 degrees (95% CI: 2.84 to 6.82), p < 0.001) than controls. A positive correlation existed between activity levels and change in femoral head morphology (coefficient 0.79, p ≤ 0.001). Greatest morphological change occurred in individuals aged 11-12 years at baseline, with no significant change in individuals aged 14 years and older at baseline. Cam morphology development was secondary to soft tissue hypertrophy and lateral growth plate extension. In conclusion, excessive loading of the hip joint through exercise prior to 14 years of age may result in growth plate adaptations causing cam morphology. Potential interventions may include training type and load modification in young adolescent football players.

Secreted frizzled-related protein 3 was genetically and functionally associated with developmental dysplasia of the hip.

BACKGROUND: Developmental dysplasia of the hip (DDH) is the most common joint disease in child orthopedics. Secreted Frizzled-Related Protein 3 (FRZB) plays an important role in joint development. however, no direct association between FRZB and DDH has been demonstrated. METHODS: Analysis of genotype distribution and allele frequency for detected single nucleotide polymorphisms (SNP) of FRZB was performed. FRZB expression was assayed in DDH joint tissues. Further experiments to identify the chondrogenic properties of FRZB were conducted. Potential upstream miRNAs for FRZB were assayed in DDH. RESULTS: Significant difference in genotype distribution for rs3768842 (OR=1.46, P=0.0081) and rs2242040 (OR=0.65, P=0.0067) was found. DDH joint tissues showed significantly higher FRZB expression. FRZB demonstrated chondrogenic and anti-hypertrophic properties in vitro. FRZB modulated cell adhesion pathway and cell spreading by regulating integrins expressions. Upstream miRNAs regulating FRZB expression were identified in DDH synovial fluid. Experiments indicated that downregulated miRNA-454 caused FRZB upregulation in DDH joint. CONCLUSION: Dysregulated FRZB and its loci were associated with DDH. As a Wnt antagonist with chondrogenic properties, FRZB modulated cell adhesion pathway and cell spreading by regulating integrins expressions. FRZB in multiple DDH joint tissues might be mediated by the dysregulated miRNA expression profiles in the joint synovial fluid.

A Cam Morphology Develops in the Early Phase of the Final Growth Spurt in Adolescent Ice Hockey Players: Results of a Prospective MRI-based Study.

BACKGROUND: Cam morphologies seem to develop with an increased prevalence in adolescent boys performing high-impact sports. The crucial question is at what age the cam morphology actually develops and whether there is an association with an aberration of the shape of the growth plate at the cam morphology site. QUESTIONS/PURPOSES: (1) What is the frequency of cam morphologies in adolescent ice hockey players, and when do they appear? (2) Is there an association between an extension of the physeal growth plate and the development of a cam morphology? (3) How often do these players demonstrate clinical findings like pain and lack of internal rotation? METHODS: A prospective, longitudinal MRI study was done to monitor the proximal femoral development and to define the appearance of cam morphologies in adolescent ice hockey players during the final growth spurt. Young ice hockey players from the local boys' league up to the age of 13 years (mean age 12 ± 0.5 years) were invited to participate. From 35 players performing on the highest national level, 25 boys and their parents consented to participate. None of these 25 players had to be excluded for known disease or previous surgery or hip trauma. At baseline examination as well as 1.5 and 3 years later, we performed a prospective noncontrast MRI scan and a clinical examination. The three-dimensional morphology of the proximal femur was assessed by one of the authors using radial images of the hip in a clockwise manner. The two validated parameters were: (1) the alpha angle for head asphericity (abnormal > 60°) and (2) the epiphyseal extension for detecting an abnormality in the shape of the capital physis and a potential correlation at the site of the cam morphology. The clinical examination was performed by one of the authors evaluating (1) internal rotation in 90° of hip and knee flexion and (2) hip pain during the anterior impingement test. RESULTS: Cam morphologies were most apparent at the 1.5-year follow-up interval (10 of 25; baseline versus 1.5-year follow-up: p = 0.007) and a few more occurred between 1.5 and 3 years (12 of 23; 1.5-year versus 3-year follow-up: p = 0.14). At 3-year follow-up, there was a positive correlation between increased epiphyseal extension and a high alpha angle at the anterosuperior quadrant (1 o'clock to 3 o'clock) (Spearman correlation coefficient = 0.341; p < 0.003). The prevalence of pain on the impingement test and/or restricted internal rotation less than 20° increased most between 1.5-year (1 of 25) and the 3-year follow-up (6 of 22; 1.5-year versus 3-year follow-up: p = 0.02). CONCLUSION: Our data suggest that a cam morphology develops early during the final growth spurt of the femoral head in adolescent ice hockey players predominantly between 13 to 16 years of age. A correlation between an increased extension of the growth plate and an increased alpha angle at the site of the cam morphology suggests a potential underlying growth disturbance. This should be further followed by high-resolution or biochemical MRI methods. Considering the high number of cam morphologies that correlated with abnormal clinical findings, we propose that adolescents performing high-impact sports should be screened for signs of cam impingement, such as by asking about hip pain and/or examining the patient for limited internal hip rotation. LEVEL OF EVIDENCE: Level I, prognostic study.

Prediction of adolescent pelvis development using femoral head and acetabulum growth in a longitudinal radiographic study.

INTRODUCTION: Adolescent total hip arthroplasty (THA) is guarded partially due unclarity as to when pediatric hip joints reach full development. This study sought to identify when maximum acetabular and femoral head diameters are achieved with relation to chronological and skeletal age. MATERIALS AND METHODS: Consecutive femoral head and acetabular diameters were measured in a random sample of 54 female and 78 male subjects, which were queried from a historical collection of annual radiographs of children. Femoral head and triradiate physeal plates were scored according to Oxford bone parameters. RESULTS: At 14 years females had femoral diameters of 4.16 +/- 0.23 cm and acetabular diameters of 5.15 +/- 0.30 cm. At 16 years males had femoral diameters of 4.85 +/- 0.30 cm and acetabular diameters of 5.90 +/- 0.35 cm. In the year following maximal femoral Oxford scores, no significant change was seen in femur and acetabulum diameters in females and in femur diameters in males. In the year following maximal acetabular Oxford scores, there was a significant increase in both femur and acetabulum diameters in both females and males. CONCLUSIONS: Females on average reach maximum pelvis maturity at 14 years and males reach maximum pelvis maturity at 16 years. A closed femoral head was found to be a good marker of full hip growth, while a closed triradiate was not. This study provides anatomical data for surgeons to consider in assessing risk factors of THA failure in adolescents.

Hip Structural Analysis Reveals Impaired Hip Geometry in Girls With Type 1 Diabetes.

CONTEXT: Among patients with type 1 diabetes (T1D), the risk of hip fracture is up to 6-fold greater than that of the general population. However, the cause of this skeletal fragility remains poorly understood. OBJECTIVE: To assess differences in hip geometry and imaging-based estimates of bone strength between youth with and without T1D using dual-energy x-ray absorptiometry (DXA)-based hip structural analysis. DESIGN: Cross-sectional comparison. PARTICIPANTS: Girls ages 10 to 16 years, including n = 62 with T1D and n = 61 controls. RESULTS: The groups had similar age, bone age, pubertal stage, height, lean mass, and physical activity. Bone mineral density at the femoral neck and total hip did not differ in univariate comparisons but was lower at the femoral neck in T1D after adjusting for bone age, height, and lean mass. Subjects with T1D had significantly lower cross-sectional area, cross-sectional moment of inertia, section modulus, and cortical thickness at the narrow neck, with deficits of 5.7% to 10.3%. Cross-sectional area was also lower at the intertrochanteric region in girls with T1D. Among those T1D subjects with HbA1c greater than the cohort median of 8.5%, deficits in hip geometry and strength estimates were more pronounced. CONCLUSIONS: DXA-based hip structural analysis revealed that girls with T1D have unfavorable geometry and lower estimates of bone strength at the hip, which may contribute to skeletal fragility and excess hip fracture risk in adulthood. Higher average glycemia may exacerbate effects of T1D on hip geometry.

Physical Activity Throughout Adolescence and Peak Hip Strength in Young Adults.

Importance: Peak bone strength, which occurs in early adulthood, is an important marker of the future risk of osteoporosis. It is therefore important to identify modifiable early life factors that are associated with the attainment of peak hip strength. Objective: To investigate the association of time spent in moderate to vigorous-intensity and light-intensity physical activity throughout adolescence with peak hip strength in adulthood. Design, Setting, and Participants: The Avon Longitudinal Study of Parents and Children is a prospective birth cohort study that initially recruited all pregnant women residing within the catchment area of 3 health authorities in southwest England who had an expected delivery date between April 1, 1991, and December 31, 1992. In total, 15 454 eligible pregnant women were enrolled, and 15 589 infants were delivered. Of those, 14 901 infants were alive at age 1 year. The present analysis examined 2569 healthy offspring who had valid physical activity measurements obtained during a clinical assessment for at least 1 age (12, 14, 16, and/or 25 years), with up to 4 repeated accelerometer assessments performed (1 per age-associated clinical visit). Data were analyzed from June 2019 to June 2020. Exposures: Trajectories of accelerometer-assessed time spent in moderate to vigorous-intensity and light-intensity physical activity at ages 12, 14, 16, and 25 years (measured in minutes per day) were identified using latent trajectory modeling. Moderate to vigorous-intensity and light-intensity physical activity were determined using established thresholds of acceleration counts per minute. Main Outcomes and Measures: Femur neck bone mineral density (BMD; measured in g/cm2) at age 25 years assessed by dual-energy radiography absorptiometry scans of the hip. Results: A total of 2569 participants (1588 female participants [62%]) were included in the analysis. Male participants spent more time in moderate to vigorous-intensity activity at each age and had greater adult femur neck BMD than female participants. For each sex, 3 moderate to vigorous-intensity trajectory subgroups and 3 light-intensity trajectory subgroups were identified. With regard to the moderate to vigorous-intensity trajectories, most male participants (85%) were in the low adolescent subgroup, with only 6% and 9% in the high early-adolescent and high mid-adolescent subgroups, respectively. Moderate to vigorous-intensity trajectories in female participants were divided into low adolescent-low adult (73%), low adolescent-high adult (8%), and high adolescent (19%) subgroups. Light-intensity physical activity trajectories were classified into low nonlinear, moderate decreasing, and high decreasing subgroups for both sexes. Femur neck BMD in male participants was greater in the high early-adolescent subgroup (0.38 g/cm2; 95% CI, 0.11-0.66 g/cm2) and the high mid-adolescent subgroup (0.33 g/cm2; 95% CI, 0.07-0.60 g/cm2) compared with the low adolescent (reference) subgroup. Femur neck BMD in female participants was greater in the high adolescent subgroup (0.28 g/cm2; 95% CI, 0.15-0.41 g/cm2) but not in the low adolescent-high adult subgroup (-0.12 g/cm2; 95% CI, -0.44 to 0.20 g/cm2) compared with the low adolescent-low adult (reference) subgroup. A sensitivity analysis using a negative-outcome control variable to explore unmeasured confounding supported these findings. The light-intensity trajectories were not associated with femur neck BMD; for example, differences in femur neck BMD between the high decreasing and low nonlinear subgroups were 0.16 g/cm2 (95% CI, -0.08 to 0.40 g/cm2) in male participants and 0.20 g/cm2 (95% CI, -0.05 to 0.44 g/cm2) in female participants. Conclusions and Relevance: Supporting high-intensity physical activity throughout early life may help to maximize peak hip strength and prevent osteoporosis in later life. Replication of our findings in independent studies will be important.

Age- and sex-specific morphologic changes in the metaphyseal fossa adjacent to epiphyseal tubercle in children and adolescents without hip disorders.

The epiphyseal tubercle plays an important role in epiphyseal stabilization. While the majority of studies have focused on tubercle morphology, there is a paucity of information on the morphological features of the metaphyseal fossa, where the tubercle sits on the metaphysis. The goal of this study was to determine the developmental changes in the capital femoral metaphyseal fossa. Computed tomography of the pelvis from 80 children and adolescents 8-15 years old were used to create three-dimensional models of the proximal femur. Depth, width, length, and surface area of the metaphyseal fossa were measured and the impact of age and sex on fossa morphology was assessed using the linear regression and two-way analysis of variance, respectively. The metaphyseal fossa was located in the posterosuperior quadrant of the metaphysis without any variations in the location with increasing age (P > .1). However, with increasing age, there was a reduction in all metaphyseal fossa measurements including the depth, length, width, and surface area (P < .01). No significant differences were noted for the metaphyseal fossa measurements between males and females (P > .1). The metaphyseal fossa reduces in size from 8 to 15 years of age in a similar fashion in males and females. As the metaphyseal fossa adjacent to the tubercle matches the area where a focal radiolucency has been observed in early slipped capital femoral epiphysis (SCFE), further studies should clarify the mechanisms by which the interlocking interaction of the epiphyseal tubercle and its fossa contributes to or is affected by SCFE.

Radiographic study of the development of the pelvis and hip and the femorotibial joints in domestic cats.

OBJECTIVES: The aims of the present study were to monitor, by radiographic examination, the skeletal development of the pelvis and the femorotibial joints of the domestic cat from the first week of life until the closing of the growth plates. METHODS: Radiographic examinations were collected from 15 domestic cats at weekly intervals during the first month and every 2 weeks from the second to the fourth month of age. After that, examinations were performed monthly until the age of 18 months. RESULTS: The ischiopubic growth plate closed at 2 months of age, followed by the fusion of the iliopubic, ilioischial, proximal femoral, greater trochanter and proximal fibular growth plates. The distal femur and proximal tibial growth plates were the last to close, with fusion occurring at 18 months. The mean time to closure of the iliopubic, ilioischial and distal femoral growth plates was shorter in females. The ossification centers first appeared, in ascending order, beginning with the lesser trochanter, followed by the greater trochanter, proximal fibular epiphysis, tibial tuberosity, patella, ischial tuberosity and lateral sesamoid of the popliteus muscle. CONCLUSIONS AND RELEVANCE: The complete closure of the growth plates of domestic cats occurs at approximately 18 months of age. Skeletal maturation at approximately 18 months of age is an important parameter to be considered in radiographic evaluation of certain skeletal changes, evolution of fractures and nutritional imbalance.

Discrepancy between ultrasonographic and radiographic findings in patients treated for developmental dysplasia of the hip; hip maturation on ultrasonography may not be consistent with radiographic hip maturation.

Currently, hip sonography is used for early diagnosis and for monitoring developmental dysplasia of the hip (DDH) treatment in many countries. An early pioneer of ultrasonography for early diagnosis of DDH was Graf. Based on the Graf approach, hip ultrasonography is more sensitive and specific than radiography for the diagnosis of DDH, because of its capability to show cartilaginous structures of the hip joint. The aim of this study was to compare radiographic and ultrasonographic findings in patients treated for DDH. This study included 88 infants (98hips) treated for DDH. Radiography was simultaneously used for treatment and follow-up evaluation in addition to ultrasonography after six months of age. A retrospective evaluation was made of the ultrasonographs and radiographs of these infants. Of the total 98 hips, 28 were normal both ultrasonographically and radiographically, and a pathologic hip was demonstrated in 32 hips both sonographically and radiographically. Hip ultrasonography showed abnormal development in 32 hips, while radiography showed abnormal development in 70 hips. In 38 hips, the findings were normal according to ultrasonography but pathological according to radiography. There were no hips that were normal radiographically but pathological sonographically. When radiography is accepted as the standard imaging method in our study patients, the sensitivity and specificity of hip ultrasonography were determined as 45.7% [95% confidence interval (CI): 41.5-45.7] and 100% (95% CI: 89.4-100), respectively. These findings suggest that hip maturation apparent on ultrasonography may not be consistent with radiographic hip development in infants treated for DDH.

Physiologic and Pathologic Development of the Infantile and Adolescent Hip Joint: Descriptive and Functional Aspects.

The basic law of mechanobiology states that the external form and internal architecture of the skeleton and joints follow the functional stimuli that act upon them. Radiographs and magnetic resonance imaging reflect the loading history of the growing child, enabling an experienced radiologist to analyze the clinical functioning of patients by interpreting imaging studies. Concerning the hip joint, the physes of the coxal femoral end, the coxal femoral epiphysis with its epiphyseal growth plate, as well as the apophysis of the greater trochanter with its trochanteric growth plate, are the essential organ structures subject to internal forces. They determine the definitive geometric shape of the proximal femur. Indirectly they influence the appearance of the acetabulum and the centration of the hip joint.

Acetabular Version Increases During Adolescence Secondary to Reduced Anterior Femoral Head Coverage.

BACKGROUND: Acetabular version influences joint mechanics and the risk of impingement. Cross-sectional studies have reported an increase in acetabular version during adolescence; however, to our knowledge no longitudinal study has assessed version or how the change in version occurs. Knowing this would be important because characterizing the normal developmental process of the acetabulum would allow for easier recognition of a morphologic abnormality. QUESTIONS/PURPOSES: To determine (1) how acetabular version changes during adolescence, (2) calculate how acetabular coverage of the femoral head changed during this period, and (3) to identify whether demographic factors or hip ROM are associated with acetabular development. METHODS: This retrospective analysis of data from a longitudinal study included 17 volunteers (34 hips) with a mean (± SD) age of 11 ± 2 years; seven were male and 10 were female. The participants underwent a clinical examination of BMI and ROM and MRIs of both hips at recruitment and at follow-up (6 ± 2 years). MR images were assessed to determine maturation of the triradiate cartilage complex, acetabular version, and degree of the anterior, posterior, and superior acetabular sector angles (reflecting degree of femoral head coverage provided by the acetabulum anteriorly, posteriorly and superiorly respectively). An orthopaedic fellow (GG) and a senior orthopaedic resident (PJ) performed all readings in consensus; 20 scans were re-analyzed for intraobserver reliability. Thereafter, a musculoskeletal radiologist (KR) repeated measurements in 10 scans to test interobserver reliability. The intra- and interobserver interclass correlation coefficients for absolute agreement were 0.85 (95% CI 0.76 to 0.91; p < 0.001) and 0.77 (95% CI 0.70 to 0.84), respectively. All volunteers underwent a clinical examination by a senior orthopaedic resident (PJ) to assess their range of internal rotation (in 90° of flexion) in the supine and prone positions using a goniometer. We tested investigated whether the change in anteversion and sector angles differed between genders and whether the changes were correlated with BMI or ROM using Pearson's coefficient. The triradiate cartilage complex was open (Grade I) at baseline and closed (Grade III) at follow-up in all hips. RESULTS: The acetabular anteversion increased, moving caudally further away from the roof at both timepoints. The mean (range) anteversion angle increased from 7° ± 4° (0 to 18) at baseline to 12° ± 4° (5 to 22) at the follow-up examination (p < 0.001). The mean (range) anterior sector angle decreased from 72° ± 8° (57 to 87) at baseline to 65° ± 8° (50 to 81) at the final follow-up (p = 0.002). The mean (range) posterior (98° ± 5° [86 to 111] versus 97° ± 5° [89 to 109]; p = 0.8) and superior (121° ± 4° [114 to 129] to 124° ± 5° [111 to 134]; p = 0.07) sector angles remained unchanged. The change in the anterior sector angle correlated with the change in version (rho = 0.5; p = 0.02). The change in version was not associated with any of the tested patient factors (BMI, ROM). CONCLUSIONS: With skeletal maturity, acetabular version increases, especially rostrally. This increase is associated with, and is likely a result of, a reduced anterior acetabular sector angle (that is, less coverage anteriorly, while the degree of coverage posteriorly remained the same). Thus, in patients were the normal developmental process is disturbed, a rim-trim might be an appropriate surgical solution, since the degree of posterior coverage is sufficient and no reorientation osteotomy would be necessary. However, further study on patients with retroversion (of various degrees) is necessary to characterize these observations further. The changes in version were not associated with any of the tested patient factors; however, further study with greater power is needed. LEVEL OF EVIDENCE: Level II, prognostic study.

Exploración ecográfica de las caderas del bebé en mochilas de porteo / Evaluation by ultrasound of the hips of babies carried in baby carriers

Antecedentes y objetivo: La displasia de cadera se ha asociado con factores de riesgo como la presentación de nalgas, el sexo femenino o los antecedentes familiares. Sin embargo, factores externos, como los sistemas de porteo, parecen influir en el desarrollo de la cadera en los primeros meses de vida. El objetivo del presente trabajo es valorar por imagen ecográfica la posición de las caderas en bebés colocados en diferentes tipos de mochilas portabebés. Método: Se ha realizado un estudio ecográfico de las caderas de bebés sanos entre 1,5 y 3,5meses de edad, cuando el niño es porteado en tres diferentes mochilas portabebés que proporcionan diferentes grados de sujeción de los muslos del bebé. Todas las caderas eran tipoI de Graf. Se han valorado tres parámetros ecográficos: el ángulo alfa de Graf, la cobertura acetabular y la distancia a pubis en situación basal (mesa de exploración) y en las tres diferentes mochilas de porteo. Resultados: En todos los casos los bebés mostraron valores de normalidad en los tres parámetros estudiados, sin diferencias estadísticamente significativas entre ninguna de las situaciones. Tampoco se encontraron diferencias en los parámetros ecográficos relacionadas con el sexo, la edad o el peso del bebé. Conclusiones: La cadera derecha del bebé mantiene unos parámetros ecográficos de normalidad cuando es colocada en cualquiera de los modelos de mochila estudiados

Background and objective: Hip dysplasia has been associated with risk factors such as breech presentation, female gender or family history. However, external factors, such as the use of baby carriers, seem to influence the development of the hip in the first months of life. The aim of this study is to evaluate the position of the hips of babies placed in different types of baby carriers by ultrasound image. Method: An ultrasound study of the hips of healthy babies between 1.5 and 3.5 months of age was carried out, when the children were carried in three different baby backpacks, which provide different degrees of support for the babies' thighs. All hips were typeI according to the Graf classification. Graf's alpha angle, acetabular coverage and distance to the pubis were assessed at baseline (examination table) and when the children were carried in the three different backpacks. Results: In all cases, the babies showed normal values in the three studied parameters, without statistically significant differences between any of the situations. There were also no differences in the ultrasound parameters related to the sex, age or weight of the baby. Conclusions: The right hip of the babies shows normal ultrasound parameters when placed in any of the baby carriers studied

Abnormal expression of Pappa2 gene may indirectly affect mouse hip development through the IGF signaling pathway.

INTRODUCTION: Developmental dysplasia of the hip (DDH) is a major cause of disability in children, and the genetic mechanism of this disease remains unclear. In our previous study, we found that pregnancy-associated plasma protein-A2 (PAPP-A2) was associated with DDH significantly. OBJECTIVES: The aim of this study was to investigate the insulin-like growth factor (IGF) expression and collagen synthesis as well as cartilage proliferation-related proteins in the case of abnormal expression of Pappa2 in mice to research the relationship between PAPP-A2 and the pathological changes of DDH. METHODS: In vivo animal experiments, the mice were directly injected with 50 µl of Cas9/PAPP-A2 sgRNA lentiviruses around the hip to downregulate the Pappa2 gene expression and injected with control lentiviruses on the other side, then to observe the expression and localization of related proteins. And in an in vitro experiment, mice fibroblasts and primary chondrocytes were cultured with insulin-like growth factor binding protein-5 (IGFBP-5) protein, PAPP-A2 protein and Cas9/PAPP-A2 sgRNA lentiviruses to detect of related proteins and mRNA expression. RESULTS: Cartilage proliferation-related proteins demonstrated a significant decrease in the PAPP-A2 knockdown hips acetabulum and femoral head cartilage, meanwhile the IGF expression was also downregulated in the soft tissue around the acetabulum compared with the control hips. Furthermore, the role PAPP-A2 played in chondrocytes and fibroblasts was the same as in the in vivo experiments, downregulation of PAPP-A2 expression or upregulation of IGFBP-5 expression can reduce collagen synthesis and cartilage proliferation. CONCLUSIONS: PAPP-A2 may be involved in the development of the mouse hip joint by interfering the fibrous and cartilaginous metabolism via IGF pathway-associated proteins pathway.

Evaluation by ultrasound of the hips of babies carried in baby carriers. / Exploración ecográfica de las caderas del bebé en mochilas de porteo.

BACKGROUND AND OBJECTIVE: Hip dysplasia has been associated with risk factors such as breech presentation, female gender or family history. However, external factors, such as the use of baby carriers, seem to influence the development of the hip in the first months of life. The aim of this study is to evaluate the position of the hips of babies placed in different types of baby carriers by ultrasound image. METHOD: An ultrasound study of the hips of healthy babies between 1.5 and 3.5 months of age was carried out, when the children were carried in three different baby backpacks, which provide different degrees of support for the babies' thighs. All hips were typeI according to the Graf classification. Graf's alpha angle, acetabular coverage and distance to the pubis were assessed at baseline (examination table) and when the children were carried in the three different backpacks. RESULTS: In all cases, the babies showed normal values in the three studied parameters, without statistically significant differences between any of the situations. There were also no differences in the ultrasound parameters related to the sex, age or weight of the baby. CONCLUSIONS: The right hip of the babies shows normal ultrasound parameters when placed in any of the baby carriers studied.

Gene expression in hip soft tissues in incipient canine hip dysplasia and osteoarthritis.

Canine hip dysplasia and developmental dysplasia of the human hip share demographic, phenotypic, and clinical features including the predisposition to develop osteoarthritis in affected joints. To support the results of genetic mapping studies for CHD and its concomitant osteoarthritis with functional information, we performed RNA-seq on hip capsule and teres ligament of affected and unaffected dogs. RNA seq showed that expressed genes segregated according age, capsule or ligament, and hip phenotype. Expression of HHIP, DACT2, and WIF1 was significantly higher in capsule from control hips than dysplastic hips indicating a disruption of the hedgehog signaling pathway. Expression of SPON 1, a key component of the WNT pathway, was increased significantly in both dysplastic capsule and ligament while FBN2 and EMILIN3 were significantly increased in dysplastic capsule. Of genes associated with human hip osteoarthritis, expression of ACAN, IGF1, CILP2, COL11A1, COL8A1, and HAPLN was increased significantly in dysplastic capsule. The significant increase in expression of PLA2F, TNFRSF, TMEM, and IGFBP in dysplastic capsule indicated an injury response. Gene set enrichment analysis revealed that genes involved in extracellular matrix structure, epithelial to mesenchymal transition, myogenesis, growth factor signaling, cancer and immune pathways were enriched in dysplastic capsule. For teres ligament from dysplastic joints, genes in retinoic signaling pathways and those encoding extracellular matrix molecules, but not proteoglycans, were enriched. Hip tissues respond to abnormal mechanics early in dysplastic hip development and these pathways present targets for intervention in the early synovitis and capsulitis secondary to canine and human hip dysplasia. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:313-324, 2019.

The early radiological effects of Dega and Pemberton osteotomies on hip development in children aged 4-8 years with developmental dysplasia of the hip.

We aimed to investigate the early radiological effects of Dega and Pemberton iliac osteotomies that were performed in patients aged 4-8 years with developmental dysplasia of the hip on development of hip joint. Dega osteotomy or Pemberton osteotomy was performed in 76 hips of 58 patients because of developmental dysplasia of the hip between September 2011 and June 2015 and were evaluated retrospectively. Of a total of 76 hips, Pemberton osteotomy was performed on 39 (19 unilateral) and Dega osteotomy was performed on 37 (21 unilateral). In all hips, the acetabular index, acetabular depth ratio, centre-edge angle of Wiberg, and Reimer's index values were recorded preoperatively and at the final follow-up. We measured the surface areas of the femoral head ossific nucleus in patients with unilateral dysplastic hips and compared results before both osteotomy procedures and at the final follow-up. There were no statistically significant differences between the groups in terms of the acetabular index and acetabular depth ratio values (P>0.05) preoperatively and at the final follow-up, but the mean centre-edge angle of Wiberg and Reimer's index values showed significant statistical differences in favor of the Dega procedure (P<0.05). There was a statistically significant difference in favor of the Pemberton procedure when the mean ratio of the surface area of the femoral head ossific nucleus on the dysplastic side in relation to the normal side was compared preoperatively (P=0.042) and at the final follow-up (P=0.027) in unilateral hips. Although Dega and Pemberton osteotomies produce satisfactory radiological outcomes at early stages in children aged 4-8 years with developmental dysplasia of the hip, a higher rate in the surface area of the femoral head ossific nucleus was observed in the Pemberton osteotomy group, which also had a lower mean age than the Dega osteotomy group.

Radiological Outcomes of Overhead Traction Therapy for Developmental Dysplasia of the Hip in Non-ambulatory Children.

BACKGROUND: Infants with a dislocated and unstable hip that does not lend itself to stabilisation may be treated using overhead traction to achieve gradual reduction of the hip joint. The aim of this paper was to analyse the radiological outcomes of overhead traction therapy and the effect of duration of traction on the occurrence of complications and final treatment outcomes. Material and methodd. A retrospective analysis of medical records of 26 children (34 affected hips) involved three independent observers assessing radiological parameters before the surgery and at follow-up visits at least two years after the therapy. RESULTS: Overhead traction was used for an average of 35 days (range: 15-43 days). Twenty six hips were treated solely with reduction and immobilisation in a 'human position' plaster cast. Three hips were qualified for surgery immediately after a preliminary traction period. Five hips showed a suboptimal result following the immobilisation period. A MANOVA model revealed that the following factors had a significant effect on the treatment outcome: superior centring ratio of Smith (with the lowest values recorded in patients with residual hip dysplasia, p = 0.001) and acetabular angle of Sharp (with the lowest values found in patients requiring surgery, p = 0.01). Statistical tests did not show a correlation between the duration of traction and disturbance of proximal femoral metaphysis growth assessed according to Bucholz and Ogden classification. Fifteen hips were classified as type I, eight hips were graded as type II and also eight hips as type III. CONCLUSIONS: The lowest values of acetabular angle of Sharp were recorded in patients requiring surgery and the lowest superior centring ratio of Smith was found in those with residual hip dysplasia. The duration of overhead traction did not directly correlate with the final outcome; it only seemed to be an indicator of the severity of hip dysplasia. Routine use of overhead traction before undertaking closed reduction does not probably decrease the incidence of proximal femoral growth disturbance.

Magnetic resonance imaging evaluation of the labrum to predict acetabular development in developmental dysplasia of the hip: A STROBE compliant study.

Recently, more attention has been paid to the role of the acetabular labrum. Therefore, we designed a retrospective cohort study of patients with residual hip dysplasia (RHD) who underwent magnetic resonance imaging (MRI). The objective of this study was to investigate an association between the MRI appearance of the labrum before school age and the natural history of RHD.We retrospectively investigated 45 hips of 40 patients who underwent MRI at about 3 and 4 years of age for RHD and were conservatively followed up with until 6 years of age or older. We evaluated the extent of eversion with a new method that measures the ß angle (MRI ß angle) using landmarks of the Graf method on MRI T2*-weighted images. The outcome measure was the Severin classification at the final follow-up. We compared the radiographic and MRI parameters at approximately 3 and 4 years of age between the good and poor outcome groups. The Student t test or one-way analysis of variance was used to compare the quantitative variables between groups. The Chi-square test was used to perform a ratio comparison.Although there was a significant difference in the center-edge (CE) angle, there was no significant difference in the acetabular index and the ratio of the presence of femoral head necrosis and the break in Shenton line between the good and poor groups. The MRI ß angle was significantly greater in the poor outcome group than in the normal and good outcome groups. The cut-off value of the MRI ß angle to differentiate the good and poor outcome groups was 65°, and its specificity and sensitivity were 92% and 53%, respectively.There was labral eversion on MRI scans in patients with RHD. Acetabular development before adolescence was poorer with greater labral eversion on MRI scans. The specificity for poor acetabular development was high when the MRI ß angle was 65° or more. The MRI ß angle has the potential to predict acetabular development.

Asymmetrical lumbosacral transitional vertebrae in dogs may promote asymmetrical hip joint development.

OBJECTIVES: This study examines the relationship between the morphology of the lumbosacral transitional vertebra (LTV) and asymmetrical development of the hip joints in dogs. METHODS: A total of 4000 dogs which had been consecutively scored for canine hip dysplasia were checked for the presence of a LTV. A LTV was noted in 138 dogs and classified depending on the morphology of the transverse processes and the degree of contact with the ilium. RESULTS: In dogs with an asymmetrical LTV, the hip joint was significantly more predisposed to subluxation and malformation on the side of the intermediate or sacral-like transverse process (p <0.01), on the side of the elevated pelvis (p <0.01), or when an asymmetrical LTV resulted in pelvic rotation on its long axis (p <0.01), whereas hip joint conformation was less affected on the side featuring a free transverse process (p <0.01). CLINICAL SIGNIFICANCE: The results support our hypothesis that an asymmetrical LTV favours pelvic rotation over its long axis, resulting in inadequate femoral head coverage by the acetabulum on one side. Inadequate coverage of the femoral head favours subluxation, malformation of the hip joint, and secondary osteoarthritis. Asymmetrical hip conformation may therefore be the sequela of a LTV and mask or aggravate genetically induced canine hip dysplasia.

Normal radiological unossified hip joint space and femoral head size development during growth in 675 children and adolescents.

Evaluation of hip joint space width during child growth is important to aid in the early diagnosis of hip pathology in children. We established reference values for hip joint space and femoral head size for each age. Hip joint space development during growth was retrospectively investigated medial and cranial in 1350 hip joints of children using standard anteroposterior supine plain pelvic radiographs. Maximum capital femoral epiphysis diameter and femoral radii were further more investigated. Hip joint space values show a slow decline during growth. Joint space was statistically significantly (p < 0.006) larger in boys than girls. Our hip joint space measurements on supine subjects seem slightly larger than those reported by Hughes on standing subjects. Evaluation of the femoral head diameter and the radii showed a size curve quite parallel to the known body growth charts. Radii medial and perpendicular to the physis are not statistically significantly different. We recommend to compare measurements of hip joint space at two locations to age dependent charts using the same imaging technique. During growth, a divergence in femoral head size from the expected values or loss of the spherical shape should raise the question of hip disorder. Clin. Anat. 30:267-275, 2017. © 2016 Wiley Periodicals, Inc.