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.

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.

[Duration of synostosis of the ischiopubic synchondrosis]

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

The effect of a single neonatal sex hormone injection on the growth of the rat pelvis

On the 26th day post-copulation (p. c.) male rats were injected with 100 μg Hexoestrol® and females were injected with 1.25 mg testosterone propionate. The growth of the pelvis of these animals was then measured from radiographs taken longitudinally from 23 days p. c. until 140 days p.c.

Generally the effect of neonatal sex hormone injection was to diminish, but not abolish, the sex differences in pelvic size. The magnitude of the effect differed according to measurement and sex. Thus ilium length was diminished more in males than it was augmented in females, while ischial length and bi-acetabular width were only slightly diminished in males but considerably increased in females. The effects were greatest in bi-iliac width where both treated groups came to be exactly intermediate between normal males and females.

A radiographic study of the growth of the rat pelvis

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The growth of the caudal half of the pelvis in the rat

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