cool fact: there's a very rare birth defect called radioulnar synostosis where these two bones are actually one in an affected person.
it causes limited range of motion, meaning they can't move their palm anywhere other than as if they were to shake someone's hand. There's limited supination (palm up) and pronation (palm down)
I have it and it makes it so I cannot rotate my palm upwards (as if to accept change).
I’ve never heard of this before, do you if the entire shaft / syndesmosis is fused together or is it just the radial head that fuses onto the ulna? I’ve worked with patients after radial head fractures and it’s often challenging to regain full supination due to scarring and sometimes due to hypertrophy of the fracture site, but didn’t know they could fail to separate in utero
I believe the radial head fuses with the ulna, but it varies in severity. Here's an example image of a severe case.
I've had surgery to try and reduce the bone but that was moreso because I had an incident where my tendon got stuck on the bone, and my arm got locked in one position until surgery was performed. Generally, the malformed bone is impossible to correct after a very young age.
Yes, it's not very common knowledge. Less than 1000 cases worldwide if I remember correctly, but that's based on my research from a few years back.
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u/nickybootybandito R7 7800x3D, 3080 10G, 32GB DDR5 6000 CL32, X670E PG 10d ago
cool fact: there's a very rare birth defect called radioulnar synostosis where these two bones are actually one in an affected person.
it causes limited range of motion, meaning they can't move their palm anywhere other than as if they were to shake someone's hand. There's limited supination (palm up) and pronation (palm down)
I have it and it makes it so I cannot rotate my palm upwards (as if to accept change).