Sacro-iliac Joint Arthrodesis or Non-operative Care for Treatment of Chronic Pelvic Pain. A Randomized Study.

Background: Pelvic pain is common during pregnancy and usually subsides after delivery. Some women, however, experience severe and long-standing pelvic pain, judged to emanate from the Sacro-iliac joints (SI-joints). Radiological correlates are absent and there are diverging opinions regarding the value of different clinical testing procedures and the use of anaesthetic blocks to reveal SI-joint origin of the pain. In case of slight or moderate pain the situation may be solved by the use of analgetics and physical therapy, but in case of severe pain the situation might end up in a discussion whether surgery with arthrodesis of the SI joint might be of value. To our knowledge, however, the results from surgical treatment has not been compared with non-surgical treatment in a randomized study.

Aim: The investigators´ hypothesis is that

1. there exists a specific identifiable subgroup of patients within the chronic low back pain (CLBP) group in whom the pain emanates from the sacro-iliac (SI) joints, and that
2. patients in this subgroup may be selected based on thorough symptom analysis, and
3. that arthrodesis of the actual joint/s may reduce the pelvic pain. Methods: A RCT with parallel group design with pre- and post-treatment data. Inclusion of women 18-55 years old with pronounced pelvic pain for at least 2 years and having tried ordinary physical therapy without improvement and being on sick leave at least 50 percent. Operation by posterior approach with bone transplantation between the iliac bone and the sacrum, using microsurgical technique. Patients in both groups, the surgical (S) and non-surgical (NS) were all treated by formal physiotherapy at a five days stay at the Clinic and instructed to continue their training at home according to the lines given at the Clinic.

Outcome: The primary outcome was perceived pelvic pain according to the assessments on the validated Balanced Inventory for Spinal Disorders questionnaire (BIS) and on a Visual Analogue Scale (VAS) before treatment and at follow-up one year after treatment. The perceived change in pain was also assessed on a transitional scale in the follow-up version of the BIS.

Secondary patient reported outcome measures (PROM) were pain related functions assessed on the Oswestry Disability Index questionnaire (ODI), the BIS and the Roland-Morris questionnaire. Health related quality of life was assessed by using the Short-Form 36 (SF-36) and Euro-Quol (EQ-5D) questionnaires.