Syndesmophytes are seen in -
Syndesmophytes 

Syndesmophytes are thin, slender vertical radiodense spicules bridging the vertebral bodies, giving the spine `bamboo' appearance. They are actually ossification of outer fibres of annulus fibrosus.

Syndesmophytes are seen in :

Ankylosing spondylitis
Psoriatic arthritis
Reiter's disease
Arthritis associated with Inflammatory bowel disease
AS
RA
OA
All