Hansen's classification

Hansen's classification

a system of describing intervertebral disk protrusions. Type I is a complete rupture of the annulus with an extrusion of the nucleus pulposus into the vertebral canal. Seen in chondrodystrophoid breeds in which there is chondroid metaplasia of the intervertebral disk. Type II protrusions occur in nonchondrodystrophoid breeds, usually as a feature of advancing age, are the result of fibrinoid metaplasia, and consist of partial rupture of the annular bands and a domelike bulging of the dorsal annulus.