Modic type I change may predict rapid progressive, deforming disc degeneration: a prospective 1-year follow-up study

Abstract

Introduction: This prospective magnetic resonance imaging (MRI) study in chronic low-back pain (CLBP) patients evaluated the natural course of degenerative lumbar spine changes in relation to Modic 1 type changes (M1) within 1 year.

Materials and methods: From 3,811 consecutive CLBP patients referred to lumbar spine MRI 54 patients with a large M1 were selected using strict exclusion criteria to exclude specific back disorders. Follow-up MRI was obtained within 11-18 months.

Results: At baseline M1 was associated with an adjacent endplate lesion in 96% of the cases. In follow-up, an unstable M1 was associated both with an increase of endplate lesions, decrease of disc height and change in disc signal intensity, most found at L4/5 or L5/S1. In disc spaces without M1, progression of degenerative changes was rare.

Conclusion: Endplate deformation, decreasing disc height and change of disc signal intensity appear essential features of accelerated degenerative process associated with M1.

Figures

Fig. 1

On T1-weighted image, a “dark spot” type focal subchondral hypointensity (arrow) surrounded by a mixed type (M1/M2) signal abnormality adjacent to the upper endplate of L3/4 disc

Fig. 2

On T1-weighted image, irregularity of the both endplates and defects in the adjacent subchondral bone surrounded by M1 type hypointensities in L5/S1 disc with decreased disc height and posterior bulge (arrow)

Fig. 3

a At baseline on T1-weighted image, the L5/S1 disc has a decreased disc height and an anterior bulge (broad arrow). There is an M1 type hypointensity adjacent to the both endplates and only slight depression in the upper endplate of L5/S1 disc (thin arrow). b After 1-year follow-up, on T1-weighted image, M1 has enlarged and there is still an anterior bulge. A focal defect has appeared in the upper endplate of L5/S1 disc anteriorly (arrow)

Fig. 4

a At baseline, there is M1 adjacent to the both endplates and a bony endplate defect (broad arrow) adjacent to the upper endplate of L4/L5 disc on T2-weighted image. The L4/L5 disc has a posterior (thin black arrow) and anterior (thin white arrow) bulge and a decreased disc signal intensity. b After 1 year, both M1s and the endplate defect have enlarged (thin arrow). Disc height has decreased, anterior and posterior bulge have increased and the disc signal intensity has increased (turned to black/white)

Fig. 5

a On T1-weighted image at baseline, L4/L5 disc has an anterior (thin arrow) and posterior (thick arrow) extrusion and a large hypointensity (M1) in the subchondral bone adjacent to the both endplates with irregularities posteriorly. b After follow-up, M1 type hypointensity adjacent to the both endplates has changed into a mixed type (M1/M2) subchondral hypo- and hyperintensity (small arrows). Disc height and extrusions have decreased and irregularities of the endplates have increased