Assessing the fusion of the ischiopubic synchondrosis using predictive modeling.

Flaring of the ischiopubic synchondrosis at the time of fusion is a common clinical observation in pediatrics and represents a normal physiological process in skeletal maturation. When presenting unilaterally, this flaring can mimic a range of serious pathological conditions such as osteomyelitis, osteal tumors, and traumatic injury. An improved understanding of ischiopubic synchondrosis fusion is therefore critical to avoid potential misdiagnosis. Retrospective multi-slice computed tomography pelvic scans of Australian individuals aged neonate to 24 years (n = 184) were assessed using a novel five stage morphological classification system of the maturation and fusion of the ischiopubic synchondrosis. Maturation scoring was conducted using both multiplanar formatting views and volume-rendered reconstructions in OsiriX™. Maturational stage was strongly related to age (P < 0.001) with fusion of the ischiopubic synchondrosis observed between the ages of 4 and 9 years in females and 7 and 13 years for males. The highest probability of fusion in our Queensland Australian population based on multinomial regression predictive modeling was between 7 and 10 years of age. We documented three variants of fusion: pubic and ischial outgrowths, appearance of a secondary ossification center, and a fusiform-shaped enlargement. This study provides the first predictive modeling of the timing of fusion of the ischiopubic synchondrosis using a reliable morphological classification system. The significant variation in timing and progression of fusion of the ischiopubic synchondrosis reported in this study, will aid in minimizing misdiagnosis and unnecessary treatment in children presenting with asymmetrical or delayed ischiopubic synchondrosis anomalies. Clin. Anat. 32:851-859, 2019. © 2019 Wiley Periodicals, Inc.

Age estimation based on pelvic ossification using regression models from conventional radiography.

To establish regression models for age estimation from the combination of the ossification of iliac crest and ischial tuberosity. One thousand three hundred and seventy-nine conventional pelvic radiographs at the West China Hospital of Sichuan University between January 2010 and June 2012 were evaluated retrospectively. The receiver operating characteristic analysis was performed to measure the value of estimation of 18 years of age with the classification scheme for the iliac crest and ischial tuberosity. Regression analysis was performed, and formulas for calculating approximate chronological age according to the combination developmental status of the ossification for the iliac crest and ischial tuberosity were developed. The areas under the receiver operating characteristic (ROC) curves were above 0.9 (p < 0.001), indicating a good prediction of the grading systems, and the cubic regression model was found to have the highest R-square value (R (2) = 0.744 for female and R (2) = 0.753 for male). The present classification scheme for apophyseal iliac crest ossification and the ischial tuberosity may be used for age estimation. And the present established cubic regression model according to the combination developmental status of the ossification for the iliac crest and ischial tuberosity can be used for age estimation.

Evolution of the ischio-iliac lordosis during natural growth and its relation with the pelvic incidence.

PURPOSE: Human fully upright ambulation, with fully extended hips and knees, and the body's center of gravity directly above the hips, is unique in nature, and distinguishes humans from all other mammalians. This bipedalism is made possible by the development of a lordosis between the ischium and ilium; it allows to ambulate in this unique bipedal manner, without sacrificing forceful extension of the legs. This configuration in space introduces unique biomechanical forces with relevance for a number of spinal conditions. The aim of this study was to quantify the development of this lordosis between ischium and ilium in the normal growing and adult spine and to evaluate its correlation with the well-known clinical parameter, pelvic incidence. METHODS: Consecutive series of three-dimensional computed tomography scans of the abdomen of 189 children and 310 adults without spino-pelvic pathologies were used. Scan indications were trauma screening or acute abdominal pathology. Using previously validated image processing techniques, femoral heads, center of the sacral endplate and the axes of the ischial bones were semi-automatically identified. A true sagittal view of the pelvis was automatically reconstructed, on which ischio-iliac angulation and pelvic incidence were calculated. The ischio-iliac angle was defined as the angle between the axes of the ischial bones and the line from the midpoint of the sacral endplate to the center of the femoral heads. RESULTS: A wide natural variation of the ischio-iliac angle (3°-46°) and pelvic incidence (14°-77°) was observed. Pearson's analysis demonstrated a significant correlation between the ischio-iliac angle and pelvic incidence (r = 0.558, P < 0.001). Linear regression analysis revealed that ischio-iliac angle, as well as pelvic incidence, increases during childhood (+7° and +10°, respectively) and becomes constant after adolescence. CONCLUSIONS: The development of the ischio-iliac lordosis is unique in nature, is in harmonious continuity with the highly individual lumbar lordosis and defines the way the human spine is biomechanically loaded. The practical parameter that reflects this is the pelvic incidence; both values increase during growth and remain stable in adulthood.

The developing juvenile ischium: macro-radiographic insights.

Despite the importance of the human pelvis as a weight-bearing structure, there is a paucity of literature that discusses the development of the juvenile innominate from a biomechanical perspective. This study aims to add to the limited body of literature pertaining to this topic through the qualitative analysis of the gross architecture of the human ischium during the juvenile period. Macro-radiographs of 55 human ischia ranging from 28 intra-uterine weeks to 14 years of age were examined using intensity-gradient color mapping to highlight changes in gross structural morphology with increasing age. A clear pattern of maturation was observed in the juvenile ischium with increasing age. The acetabular component and ramus of the ischium consistently displayed low bone intensity in the postnatal skeletal material. Conversely the posterior body of the ischium, and in particular the ischial spine and lesser sciatic notch, exhibited increasing bone intensity which first arose at 1-2 years of age and became more expansive in older cohorts. The intensity patterns observed within the developing juvenile ischium are indicative of the potential factors influencing the maturation of this skeletal element. While the low intensity acetabular fossa indicates a lack of significant biomechanical interactions, the posterior increase in bone intensity may be related to the load-bearing nature of the posterior ischium.

Timing of fusion of the ischiopubic ramus from dry bone observations.

There is little information about the age at which the ischiopubic ramus fuses derived from dry bone observations. This study documents the age ranges for union of the ischiopubic ramus in a sample of 148 known sex and age skeletons from Portugal, with ages ranging from birth to 20 years, using a three-stage scheme. The oldest female with an unfused ramus is 11 years old and the oldest male is 8 years old. The youngest male with a completely fused ramus is 7 years old, and the youngest female is 5 years old. Despite the relatively large sample size, partial fusion was a rare event to record as only two individuals were at this stage and these seemed relatively older than expected (12 and 14 years of age). The likely age interval for partial union of the ramus was subsequently estimated from logistic regression, for both sexes separated and combined. In the sex-pooled sample, the inter-quartile range (25th-75th percentile) for the median age of fusion is 7-11 years and the 10th-90th percentile range is 4-15 years. The scarcity of data on the age of ischiopubic fusion may be related to biases in the sample or to fusion occurring rapidly in this anatomical location. Additional studies may be required to assess the accuracy of the ages reported here, but at present this study provides the most comprehensive assessment of timing of fusion at the ischiopubic ramus from observations of dry bone specimens.

The evolution, development and skeletal identity of the crocodylian pelvis: revisiting a forgotten scientific debate.

Unlike most tetrapods, in extant crocodylians the acetabulum is formed by only two of the three skeletal elements that constitute the pelvis, the ilium, and ischium. This peculiar arrangement is further confused by various observations that suggest the crocodylian pelvis initially develops from four skeletal elements: the ilium, ischium, pubis, and a novel element, the prepubis. According to one popular historical hypothesis, in crocodylians (and many extinct archosaurs), the pubis fuses with the ischium during skeletogenesis, leaving the prepubis as a distinct element, albeit one which is excluded from the acetabulum. Whereas the notion of a distinct prepubic element was once a topic of considerable interest, it has never been properly resolved. Here, we combine data gleaned from a developmental series of Alligator mississippiensis embryos, with a revised interpretation of fossil evidence from numerous outgroups to Crocodylia. We demonstrate that the modern crocodylian pelvis is composed of only three elements: the ilium, ischium, and pubis. The reported fourth pelvic element is an unossified portion of the ischium. Interpretations of pelvic skeletal homology have featured prominently in sauropsid systematics, and the unambiguous identification of the crocodylian pubis provides an important contribution to address larger scale evolutionary questions associated with locomotion and respiration.

Differential diagnosis in painful ischiopubic synchondrosis (IPS): a case report.

Synchondroses are temporary joints that only exist during skeletal maturation. Bilateral widening of the ischiopubic synchondrosis (IPS) is a normal growth phenomenon, but when it is unilateral and painful it can become a diagnostic challenge. An eight-year-old child with an enlarged symptomatic unilateral synchondrosis is presented. Failure of conservative treatment and its pseudo-tumoral appearance led us to intervene surgically. Pathology revealed a stress fracture. Based on this clinical case, we made a revision of policy regarding pathology, diagnostic workup and treatment strategies for symptomatic synchondrosis.

Estimating differences in volumetric flat bone growth in pediatric patients by radiation treatment method.

PURPOSE: To estimate potential differences in volumetric bone growth in children with sarcoma treated with intensity-modulated (IMRT) and conformal (CRT) radiation therapy using an empiric dose-effect model. METHODS AND MATERIALS: A random coefficient model was used to estimate potential volumetric bone growth of 36 pelvic bones (ischiopubis and ilium) from 11 patients 4 years after radiotherapy. The model incorporated patient age, pretreatment bone volume, integral dose >35 Gy, and time since completion of radiation therapy. Three dosimetry plans were entered into the model: the actual CRT/IMRT plan, a nontreated comparable IMRT/CRT plan, and an idealized plan in which dose was delivered only to the planning target volume. The results were compared with modeled normal bone growth. RESULTS: The model predicted that by using the idealized, IMRT, and CRT approaches, patients would maintain 93%, 87%, and 84%, respectively (p = 0.06), of their expected normal growth. Patients older than 10 years would maintain 98% of normal growth, regardless of treatment method. Those younger than 10 years would maintain 87% (idealized), 76% (IMRT), or 70% (CRT) of their expected growth (p = 0.015). Post hoc testing (Tukey) revealed that the CRT and IMRT approaches differed significantly from the idealized one but not from each other. CONCLUSIONS: Dose-effect models facilitate the comparison of treatment methods and potential interventions. Although treatment methods do not alter the growth of flat bones in older pediatric patients, they may significantly impact bone growth in children younger than age 10 years, especially as we move toward techniques with high conformity and sharper dose gradient.

Asymmetric closure of ischiopubic synchondrosis in pediatric patients: correlation with foot dominance.

OBJECTIVE: The enlarged ischiopubic synchondrosis is a well-known anatomic structure; however, little is known about its physiology. In early childhood, enlargement of this synchondrosis occurs bilaterally, whereas before complete ossification, it is frequently found unilaterally. In most children, the unilateral enlarged ischiopubic synchondrosis is observed in the left hemipelvis, a finding that was hitherto unexplained. During common athletic activities, increased ground reaction forces are exerted on the weight-bearing nondominant limb, which in up to 87% of the general population is the left leg. The asymmetric exertion of these forces may explain the distinct closure sequence of this temporary joint. The purpose of this study was to correlate unilateral enlarged ischiopubic synchondrosis with foot dominance. MATERIALS AND METHODS: The study cohort comprised 32 children who had undergone unenhanced radiography, CT, or MRI for reasons other than bone disorders and who presented with enlarged ischiopubic synchondroses. In these children, the distribution of enlarged ischiopubic synchondrosis and foot dominance were evaluated either retrospectively (n = 11) or prospectively (n = 21). RESULTS: In this cohort, 78% of patients were right-footed and 22% were left-footed. Nine of the 32 children presented with unilateral enlarged ischiopubic synchondrosis (left, seven [78%] of nine; right, two [22%] of nine). All children with enlarged left ischiopubic synchondrosis were right-footed, and all children with enlarged right ischiopubic synchondrosis were left-footed. CONCLUSION: Unilateral enlarged ischiopubic synchondrosis is closely correlated with foot dominance. The asymmetric ossification pattern of the ischiopubic synchondrosis indicates delayed ossification of this anatomic structure due to asymmetrically applied mechanical forces to the nondominant limb.

Sex and age diagnosis by ischium morphometric analysis.

The growth of four variables of the ischium was analysed by polynomial regression in order to evaluate its significance and its capacity for age and sex determination during and after growth. The material used was 327 specimens ranging from birth to 97 years of age from four documented west European collections. The growth curves were calculated for ischium length and three new variables of the acetabular surface (horizontal diameter of ischium acetabular surface, vertical diameter of ischium acetabular surface and ischium acetabular index). All curves, except those of the female series of vertical diameter of ischium acetabular surface and its index, showed a lineal growth corresponding to vertical variables. All variables studied, except the ischium acetabular index, can be used variables for adult sexual discrimination. Furthermore, ischium length and the horizontal and vertical diameters of the acetabular surface can be useful for sub-adult age determination in archaeological samples, as well as in forensic samples. However, the ischium length is the best variable, as it can be applied to all the growth ages.

Fetal bony pelvis in the bladder exstrophy complex: normal potential for growth?

OBJECTIVES: To provide the first look at the bony histologic features of fetuses with the exstrophy complex, specifically evaluating the endochondral ossification, stage of development, and microscopic potential for normal growth. METHODS: Three fetuses between 28 and 30 weeks of gestation, one with classic bladder exstrophy, one with cloacal exstrophy, and one control, were obtained from France. The bony pelves were dissected and preserved in formalin, and multiple representative sections were sliced from all pelvic areas: pubis, ischium, ilium, and sacrum. These slices were sequentially processed as slides, stained with hematoxylin-eosin, and evaluated microscopically for histologic changes, developmental stage, and degree of endochondral ossification. RESULTS: All slides from the three specimens showed cartilage analogue with endochondral ossification. Histologically the exstrophy specimens were identical to the control and appeared completely normal; bone development was occurring at an expected rate with the potential for continued normal growth. CONCLUSIONS: These new findings illustrate that fetal bone in the exstrophy complex displays normal microscopic growth patterns and unhindered endochondral ossification at 28 weeks of gestation, well beyond the embryologic period. With no evident microscopic bony defect, the gross bony anomalies in exstrophy should be surgically correctable, leading us to conclude that early reapproximation of the physiologic shape of the pelvis could lead to more normal gross bone growth, decreased shortage of bone, and a more appropriate distribution of the mechanical and developmental forces on a closed, normally functioning pelvic ring.

Classificaçäo da ossificaçäo da crista do ísquio na maturidadwe esquelética e sua correlaçäo com o sinal de Risser / Classification of the ossification of the ischium crest in bone maturity and its correlation with Risser sign

Foram analisadas 130 radiografias da bacia de pacientes adolescentes com idade compreendida entre 10 e 19 anos. A ossificaçäo do núcleo do ísquio foi observada e sua evoluçäo classificada em seis grupos (de zero a cinco) de acordo com o período de desenvolvimento da ossificaçäo. A comparaçäo com a ossificaçäo da crista do ilíaco (sinal de Risser) foi realizada, encontrando-se relaçäo direta na ossificaçäo dos núcleos. Os autores concluem que a ossificaçäo da crista do ísquio pode ser um sinal que substitui o sinal de Risser.

Morphometric changes in growth of the rat pelvis after papain administration.

The proteolytic enzyme, papain, was given systematically to evaluate the short- and long-term effects of inhibition of endochondral bone formation on pelvic growth, with emphasis on the innominate bone. Ninety-eight Lewis-strain male rats, used concurrently for craniofacial growth studies, were divided into two groups. Thirty rats from Group I (n = 48) received 2% crude papain i.p. daily from 25-40 days-of-age and were euthanized at 40, 54, and 70 days-of-age. Thirty-five rats from Group II (n = 50) were given papain at the same dose from 25-70 days-of-age and were euthanized at 26, 40, 54, 70, and 120 days. The remaining animals in both groups were the controls. Standardized dorsoventral pelvic radiographs were taken of all 98 animals. Ten linear dimensions were measured on each and the data evaluated statistically. A reduction both in size and rate of growth of the bony pelvis was found. All the anteroposterior and most of the transverse pelvic dimensions were significantly shorter, to a greater extent in the prolonged papain group. Bi-ischial width was increased, perhaps to compensate for pelvic shortening and to accommodate the pelvic contents. The findings may contribute to our better understanding of abnormal endochondral bone growth in the pelvis.

[Van Neck disease or a variation of ischio-pubic synchondrosis development?]. / Choroba Van Necka czy wariant zarastania chrzastkozrostu kulszowo--lonowego.

Diagnostic problems in the case of 9 years old boy with flared ischio-pubic synchondrosis are presented. The condition is differentiated between Van Neck disease and variation od ischio-pubic synchondrosis development.

[Duration of synostosis of the ischiopubic synchondrosis]. / Sroki sinostozirovaniia lonno-sedalishchnogo sinkhondroza

A table of the developmental rate of synostosing pubic-ischiatic synchondrosis is made on the basis of analysis of 305 pelvis roentgenograms of children from 2 till 14 years of age. The obtained data may be used in clinical differential diagnosing between such process and osteochondropathy of pubic-ischiatic synchondrosis as well as for determining the bone age of children