Posterior vertebral fusion anomalies

Posterior vertebral fusion anomalies are relatively common and should not be mistaken for fractures. They are thought to be both developmental and pathological (e.g. spondylolysis) but are typically asymptomatic and incidental, and considered as anatomical variants. There are six types of posterior vertebral fusion anomalies:

• neurocentral synchondrosis
• retrosomatic/pedicular cleft
• spondylolysis (pars interarticularis defect)
• retroisthmic cleft
• paraspinal cleft (spina bifida occulta)
• spinous cleft (spina bifida occulta)