Presentation
Right lower extremity pain
Patient Data
![](https://prod-images-static.radiopaedia.org/images/41810467/762aabacdc0e3b2c27d6083508a45a_thumb.jpeg)
![](https://prod-images-static.radiopaedia.org/images/41810451/02a7acb2cc70afb381a9c08056cc9b_thumb.jpeg)
![](https://prod-images-static.radiopaedia.org/images/41810467/762aabacdc0e3b2c27d6083508a45a_big_gallery.jpeg)
A bubble-like lucency at the right inferior pubic ramus most likely represents an "open" ischiopubic synchondrosis. The contralateral left synchondrosis appears normal. No pelvic or proximal femur fracture.
Recommend correlation with site of child's pain.
![](https://prod-images-static.radiopaedia.org/images/41810475/cd825ace546cc2170a5263cdeb580b_big_gallery.jpeg)
Lucent and expansile right ischiopubic synchondrosis (blue line), as compared to normal left synchondrosis (yellow).
Case Discussion
The ischiopubic synchondrosis consists of a hyaline cartilage articulation and typically fuses around the time of puberty. Asymmetric enlargement and lucency of the synchondrosis, often simulating a lytic lesion, is a normal variant which may represent an adaptation to mechanical stress. The lesion resolve with skeletal maturation.
This patient was found to have a spiral fracture of the right tibia (toddler's fracture, not shown), which explained the patient's symptoms.