DX: Asymmetric Ischiopubic Synchondrosis (van Neck-Odelberg disease)

This is an important variant that we as radiologists have to take in consideration. The ischiopubic synchondrosis (IPS) is the junction between the inferior ischial and pubic rami and is principally composed of hyaline cartilage. Is a temporal joint occurring in childhood prior to fusion of the ischial and pubic bones. With skeletal maturation, like all synchondroses, it becomes thinner and then obliterates, either due to bony union or synostosis.

Here is the spot image:

There is an expansile lesion of the inferior ischial and pubic rami that resembles a lytic bone mass (chondroid matrix). But in this group age, before a bone neoplasm arrises as a differential we have to discard first normal variants or infectious ethiology. Osteomyelitis is a good possibility but there is no history of previous limb or skin infection. Neither there's no history of malnourishment that can induce such infection. 

Therefore, IPS is our main consideration. It can be asymmetric also. But why pain?...if pain presents, we called it Van Neck-Odelberg disease and treat it as a growing pain. Also is good to consider that this disease has correlation with foot dominance.

Here are some examples in literature:

http://www.ijri.org/article.asp?issn=0971-3026%3Byear%3D2011%3Bvolume%3D21%3Bissue%3D2%3Bspage%3D107%3Bepage%3D110%3Baulast%3DMacarini
http://uiortho.com/ioj/2010/08cases.pdf
http://www.virtualpediatrichospital.org/providers/PAP/MSDiseases/IschiopubSynchon.shtml
http://www.ajronline.org/content/182/2/361.full.pdf+html


Thanks for your participation in FB groups.

Until next year!!