Table 4.

Intervertebral disk degeneration classified according to a modified version of the microscopic criteria of Vernon-Roberts [25]

Intervertebral disc degeneration assessed by microscopic examination
Grading of degeneration	Reactive chondrocytes “Brutkapseln”	Fissures, clefts, splints	Areals of necrosis	Damage of annular layers
a	Few	Isolated, flat	Isolated, small	0–1 ring
b	Moderate	Ample, flat	Several, focal	1–2 rings
c	Ample	Numerous deep	Multiple, partly confluent	2–3 rings
d	A lot	Numerous very deep	Great, diffuse extended	3–4 rings