Figure 3.

(A) Elastin fibers were organized in the regular arrangement in a patient who underwent surgery due to LDH. Rich normal elastin fibers (grade 0, elastin degradation) were organized in a strictly parallel arrangement, as indicated by the blue lines. (B) The grade of elastin degradation was very high (grade 4) in a patient who underwent surgery due to lumbar spinal canal stenosis (LSCS). An irregular arrangement of elastin fibers was seen, as indicated by the blue lines. (C) Most of the area was stained pink, indicating a normal, nonfibrotic state (grade 0 fibrosis by Masson trichrome staining). (D) A high grade of fibrosis of the ligamentum flavum in a patient who underwent surgery due to LSCS. Most of the area was stained blue, indicating that most of the area was fibrotic (grade 3 fibrosis by Masson trichrome staining).