Impact of Adjacent Facet Joint Osteoarthritis on Adjacent Segment Degeneration after Short-Segment Lateral Lumbar Interbody Fusion for Indirect Decompression: Minimum 5-Year Follow-Up

Figure 2

Facet joint osteoarthritis grade. (a) Grade 1 (normal): facet joint space is preserved, and there is no osteosclerosis or facet hypertrophy. (b) Grade 2 (mild): facet joints with mild osteoarthritis. Joint space narrowing, sclerosis, and facet hypertrophy are present. (c) Grade 3 (moderate): facet joints with moderate osteoarthritis. Osteophytes (white arrow), subchondral cysts (black arrow), and vacuum phenomenon are present. (d) Grade 4 (severe): facet joints with severe arthritis. Overall narrowing of the joint space, large osteophytes (white arrow), facet hypertrophy, subchondral cysts (black arrow), and vacuum phenomenon (gray arrow) are present.

(a)

(b)

(c)

(d)