Sacro-iliac Joint Arthrodesis or Non-operative Care for Treatment of Chronic Pelvic Pain. A Randomized Study.
Condition: Pelvic Pain; Low Back Pain
MeSH terms: Low Back Pain; Pelvic Pain
Study type: Interventional

Summary: 
      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.
    

Detailed description: 
      Study description

        1. a. Title Sacro-iliac joint arthrodesis or non-operative care for treatment of chronic
           pelvic pain.

           A randomized study.

           Introduction Background and objectives

        2. a. 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 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.

      2 b. 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.

           3 a. A RCT with parallel group design with pre- and post-treatment data. 3 b. No changes
           were made after trial commencement.

           Participant 4 a. Inclusion criteria 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.

           4 b. Eligible outpatients at the Clinic of Spinal Surgery, Strängnäs, Sweden, were
           informed about the study and those who consented to participate were included. The other
           women received ordinary treatment. Data were collected at the Clinic of Spinal Surgery,
           Strängnäs, Sweden.

           Interventions 5. A percutaneous mechanical provocation test was developed to obtain
           information regarding the possible pain origin in the SI joints. Injections with saline
           or local anaesthetics blind for the patients were performed against the posterior
           aspects of the SI joints, not intra-articular, to analyse the pain response at needle
           contact with the joint capsule, the pain reaction during injection and also the pain
           situation during the first hour after injection.

           Operation was performed by posterior approach with bone transplantation between the
           iliac bone and the sacrum, using microsurgical technique. Internal fixation was used.

           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.

           6 a. The primary outcome was perceived pelvic pain according to the assessments on the
           validated Balanced Inventory for Spinal Disorders questionnaire (BIS) and on a 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 SF-36 and EQ-5D questionnaires.

           6 b. No changes in the trial were made during the study.

           Sample size The sample size estimation was performed before study start by the
           statistician (ES). It was based on our previous experience of improvements in 55-60 % of
           the patients undergoing SI-joint arthrodesis compared to 10 % following physiotherapy.
           Assuming similar results of improvements a total sample size of 34 (17 + 17) will detect
           such a difference with the statistical power of 80 % (p < 0.05) when using statistical
           methods designed for change in rating scale assessments.

           7b. No interim analysis was performed.

           Randomization 8 a and b. A randomization scheme balanced for surgery /non-surgery
           patients was performed by using random permuted blocks in order to reduce
           predictability. A set of closed envelopes in numbered order with the message "operate"
           or "do not operate" was delivered to the Clinic by the statistician (ES) not involved in
           the treatment of the patients.

           Allocation concealment mechanism 9. The patients were consecutively included in the
           study according to the randomization envelopes.

           Implementation 10. A statistician not involved in the treatment of the patients
           generated the random allocation sequence. The surgeon enrolled the participants and a
           research nurse at the Clinic performed the practical assignment, i.e. opened the closed
           envelopes in consecutive order.

           Blinding 11 a. In accordance with the treatment alternatives the participants and the
           care givers could not be blinded to group assignment.

           11 b. Patients in both groups, the surgical and non-surgical, received equal treatment
           with formal physiotherapy. Besides, the patients in the surgical group were operated
           with arthrodesis.

           Statistical methods 12 a and b. The patients reported outcome variables (PROMs) were
           assessed on rating scales that generate ordered categorical data. Characteristic
           features are the ordered structure with lack of information regarding size and
           inter-categorical distances. Non-parametric rank-based statistical methods that take
           account of these limited mathematical properties of ordered categorical data are used
           for description and analysis. Frequency distribution, proportions, bar charts, median
           and quartiles are used for statistical descriptions. Statistical analysis of difference
           in outcomes assessed by transitional scales in the BIS by the two groups of patients was
           performed by the Wilcoxon-Mann-Whitney test. Statistical evaluation of change in the
           paired assessments made before treatment and on the follow-up occasion was made by
           Svensson´s methods for paired ordinal data that provides measures of systematic change
           in common for the group and additional measure of individual variability. The measures
           and the 95% confidence intervals of systematic change in position (RP), and in
           concentration (RC), and the measure of additional individual variability (RV) will be
           calculated as well as the differences in these measures between the two treatment
           groups. This statistical approach has been found to have a high power of detecting
           differences in small samples.

           Results 13. All patients in both groups received the allocated treatment and all
           patients in both groups were also seen at follow-up.

           Recruitment 14 a. Recruitment started October 22, 2008 and ended when the last patient
           was included in the study November 19, 2011.

           The follow-up took place from October 27, 2009 to November 19, 2012. 14 b. The trial was
           performed as planned but stopped after 3 years when 19 patients were included because of
           difficulties in recruiting eligible patients within reasonable time.

           16. The analyses will be carried out on the complete groups of 9 patients in the Surgery
           group and 10 patients in the NonSurgery group.

           17 a and b. The analyses are ongoing.

           Ancillary analysis 18. None.

           Harms 19. Will be reported when the analyses are completed.

           Comment Limitation 20. There was a small sample size because of difficulties in
           recruiting eligible patients, but a good research team and the choice of appropriate
           statistical analysis shows the power of this study.

           Generalizability 21. Provided that the patients being selected according to the same
           criteria as in the present study and the surgery being performed in the same way our
           results may be generalizable.

           22. During the last few years a remarkable increase is seen in the number of articles
           published concerning arthrodesis in case of presumed SI-joint pain, this due to the use
           of minimal invasive techniques. This increase in SI-joint surgery, however, is not a
           result of a better pre-operative evaluation of the patients. To our knowledge our study
           is the first RCT.

           Other information Registration 23. The study protocol was approved by the Regional
           Ethics Committee, Stockholm, (reference number 2008/289-31/3). In accordance with the
           Declaration of Helsinki, all patients were thoroughly informed concerning all parts of
           the study, both verbally and in written text, and gave their written informed consent.

           24. Then full trial protocol can be accessed via Bo Nyström, Clinic of Spinal Surgery,
           Strängnäs, Sweden, present address Regementsgatan 20 B, 64533 Strängnäs, Sweden.

           25. The study had no funding support.
    

Intervention name(s): Surgery; Non-surgery
Intervention type(s): Procedure; Other
Intervention description(s): Arthrodesis of SI-joints, Physiotherapy; Physiotherapy
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment