Table 2.

BME and structural lesions on MRI-sacroiliac joint of patients from the Devenir des Spondyloarthropathies Indifférenciées Récentes cohort over 5 years of follow-up

	Baseline mean (SD) (n=150)*	2 years’ mean (SD) (n=136)	5 years’ mean (SD) (n=150)*	Change over 5 years’ mean (SD)		P value†
BME lesions (scores)
Mean SPARCC score‡ (0–72)	3.8 (7.2)	2.8 (5.8)	2.4 (4.7)	−1.4 (6.5)		0.009
Structural lesions (scores)
Mean number of erosions‡ (0–40)	1.0 (1.9)	1.1 (2.0)	1.2 (2.1)	0.2 (1.4)		0.085
Mean number of fatty lesions‡ (0–40)	1.1 (2.6)	1.7 (4.0)	1.9 (4.1)	0.8 (2.2)		<0.001
Mean number of fatty lesions and/or erosions‡ (0–80)	2.1 (3.9)	2.8 (5.0)	3.1 (5.1)	1.0 (2.6)		<0.001
Mean total number of lesions‡§ (0–144)	2.6 (4.5)	3.3 (6.2)	3.9 (6.5)	1.3 (3.1)		<0.001

	Baseline n (%) (n=150)*	2 years n (%) (n=136)	5 years n (%) (n=150)*	Positive change over 5 years n (%)	Negative change over 5 years n (%)	Net change n (%)
BME lesions (cut-off)
ASAS definition*	44 (29.3)	30 (22.1)	32 (22.0)	10 (6.7)	21 (14.0)	−11 (−7.3)

	Baseline n (%)	2 years n (%) (n=136)	5 years n (%)	Positive change over 5 years n (%)	Negative change over 5 years n (%)	Net change n (%)
Structural lesions (cut-offs)
≥3 erosions¶	20 (13.3)	21 (15.4)	21 (13.9)	8 (5.3)	7 (4.6)	1 (0.7)
≥3 fatty lesions¶	20 (13.3)	26 (19.1)	32 (21.2)	12 (8.0)	0 (0.0)	12 (8.0)
≥5 fatty lesions and/or erosions¶	23 (15.2)	32 (23.5)	33 (21.9)	12 (8.0)	2 (1.3)	10 (6.6)

*Missing MRI short tau inversion recovery sequence in one case at 5 years.

†Paired samples t-test comparing baseline versus 5 years.

‡Mean of three readers.

§Fatty lesions, erosions, sclerosis and partial ankylosis/total ankylosis.

¶Agreement of ≥2 out of 3 readers.

ASAS, Assessment of Spondyloarthritis International Society; BME, bone marrow oedema; SPARCC, Spondyloarthritis Research Consortium of Canada.