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.


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.


CONCLUSIONS
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.
Herneth
Andreas M
AM
Department of Radiology, Stanford University School of Medicine, Medical Center S056, Stanford, CA 94305-5105, USA.
Philipp
Marcel O
MO
Pretterklieber
Michael L
ML
Balassy
Csilla
C
Winkelbauer
Friedrich W
FW
Beaulieu
Christopher F
CF
D000293:Adolescent; D000367:Age Factors; D002356:Cartilage / Q000254:growth & development / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005528:Foot; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007512:Ischium / Q000254:growth & development / Q000473:pathology*; D008297:Male; D010012:Osteogenesis; D011630:Pubic Bone / Q000254:growth & development / Q000473:pathology*; D013314:Stress, Mechanical; D016474:Weight-Bearing