Table 3 Prevalence of four atypical SIJ morphologies, transitional vertebra and disc degenerative changes. Furthermore, BME and/or structural changes in relation to these. N (%) if not otherwise stated

Any atypical SIJ morphology

20 (80%)

53 (90%)

Accessory SIJ

9 (36%)

27 (46%)

 With BME^a

6 (67%)

7 (26%)

 With structural changes^b

4 (44%)

9 (33%)

Iliosacral complex

15 (60%)

35 (59%)

 With BME^a

10 (67%)

5 (14%)

 With structural changes^b

5 (33%)

1 (3%)

Dysmorphic cartilaginous facets

10 (40%)

22 (37%)

 With BME^a

10 (100%)

18 (82%)

 With structural changes^b

9 (90%)

9 (41%)

Bipartite iliac bony plate

1 (4%)*

15 (25%)

 With BME^a

0

1 (7%)

 With structural changes^b

0

0

Transitional vertebra

2 (8%)

3 (5%)

 With BME^a

2 (100%)

1 (33%)

 With structural changes^b

2 (100%)

3 (100%)

Disc degeneration (0–3)

1.6

1.7

Disc extrusion (disc degeneration = 3)

6 (24%)

16 (27%)

Vertebral corner changes (BME/FMD)

3 (12%)*

1 (2%)

Vertebral end plate changes (BME/FMD)

6 (24%)

20 (34%)