Hand - bone deformities

Hi,
This is probably a really wierd question and I am going to speak to my daughters physiotherapist when school resumes but in the mean time I thought I would ask here.

My daughter had a bite on the side of her thumb (on the bottom knuckle) and when I looked at her hand I noticed the knuckles doesn' t move properly, after my first little "oh no whats wrong" I checked the other hand and found her other knuckle is the same.

Does anyone elses child/ren have hand bone deformities that could cause this??

I dont know if it makes any difference but her bone age is approx 11yrs old. I dont know what it has taken so long to pick up on it (she is 15yrs old).

Sjl