a We can see the fibrous adherence to the dura in the study group at 4 weeks (stain, hematoxylin and eosin; original magnification, ×40). M spinal marrow, D dura mater and F fibrosis. b We can observe the fibrous adherence to the dura in the control group at 4 weeks (stain, hematoxylin and eosin; original magnification, ×40). M spinal marrow, D dura mater and F fibrosis