Table 1 Inclusion and exclusion criteria

1. Pain located to one or more pelvic joints

1. Known psychiatric diagnosis,

2. Minimum two positive out of five clinical tests:

2. Other spine pathology

 *Posterior Pelvic Pain Provocation test (P4)

3. CT verified ankylosis at baseline

 *Active Straight Leg Raise (ASLR)

4. Body mass index over 30

 *Palpation of the long dorsal SI-ligament

 *Modified Trendelenburg test

 *Palpation of the symphysis

3. High pain and disability score

 *Oswestry Disability Index >40 and/or

 *Visual Analogue Scale >50

4. The patients should have performed adequate physiotherapy over time without positive effect