Validity and Reliability of Diagnostic Findings of SI Joint Blocking

Subjects with suspected SI joint pain will undergo 3 SI joint blocks, 2 with local anesthetic
and 1 sham block.

The sequence of blocks is randomly assigned. This study examines both the test-retest
reliability of response to diagnostic sacroiliac (SI) joint injection and the specificity of
response to local anesthetic or sham block. The goal of the study is to validate the use of
diagnostic SI joint block.

Subjects with pain suspected to be generated by one SI joint will undergo three diagnostic SI
joint blocks each separated by one week. Two blocks will be with local anesthetic (LA) and
one will be a sham block (SB). Both the Coordinator (collecting pain assessments) and subject
will be blinded to the sequence of blocks (LA or SB each time). The sequence of blocks will
be randomly assigned for each subject on study. The subject's participation in the study is
complete after 6-month post-procedure assessment.

Inclusion Criteria:

1. Age 21-75 at time of screening.

2. Patient has buttocks, groin and/or leg pain suspected to be from one SI joint (left or
right).

3. Patient has positive Fortin finger test*.

4. Patient has a current average SI joint pain rating of at least 5 on 0-10 numerical
rating scale**.

5. Patient has at least 3 positive physical SI joint examination findings in the targeted
SI joint.

6. Investigator believes that diagnostic SI joint block is indicated now, and that no
other (hip/back, etc.) diagnostic test is required at this time.

7. Patient has signed study-specific informed consent form.

8. Patient has the necessary mental capacity to participate and is physically able to
comply with study protocol requirements (including avoiding taking pain medication 8
hours prior to and 4 hours after each scheduled block).

Exclusion Criteria:

1. Patient has history of any surgical procedure of the targeted SI joint (except for
prior RF ablation of the SI joint).

2. Patient has suspected bilateral SIJ pain and bilateral injections are indicated.

3. Patient has history of chronic pain syndrome (e.g., fibromyalgia).

4. Patient has any medical or other condition that would interfere with study
participation or data validity.

5. Patient is currently pregnant.

6. Patient has known allergy to contrast used or local anesthetic used (bupivacaine).

7. Patient has had one or more steroid SI joint injection(s) of the targeted side in the
last 3 months.

8. Patient is a prisoner or a ward of the state.

9. Patient is participating in another investigational study related to back or SI joint
pain (Exclude if participating in trials other than the SIFI study (NCT01640353) or
the INSITE Study (NCT01681004). Subjects on these two SI-BONE sponsored trials may be
eligible for VaReFi.)

10. Patient is known or suspected drug or alcohol abuser.

11. Patient has known or suspected psychiatric disease (e.g., schizophrenia, major
depression, personality disorders) that could interfere with study participation .

12. Patient is unable to isolate suspected SI joint pain to the SI joint but rather has
generalized pain.

13. Patient has known or suspected alternative cause for pain at/near SI joint (e.g.,
lumbar disc degeneration, lumbar facet arthropathy, hip osteoarthritis or labral tear)