Sacroiliac joint pain is contributor to chronic low back pain, accounting for 15-30% of cases. It is a synovial and syndesmotic articulation plays a role in load transfer between spine and lower extremities. Its limited mobility, strong ligaments makes it susceptible to pain generation in cases of inflammation and degeneration.
The innervation of the SIJ is derived from the dorsal sacral rami (S1-S3), with contributions from L4-L5 dorsal rami. This explains the variability in pain distribution. Patients present with low back pain that may radiate to buttock, groin, or posterior thigh.
The diagnosis of SIJ pain relies on diagnostic blocks. At least 70-75% pain relief following intra-articular injection . However, diagnostic blocks have limitations, including false-positive rates and variability in technique .
Management for SIJ pain include conservative, interventional, and surgical approaches. Conservative treatment consists of physical therapy, NSAIDs, and activity modification.While a significant proportion progress to interventional therapies due to persistent pain .
RFA is as an effective minimally invasive treatment. Monopolar RFA was initially used; however, its efficacy was limited by small lesion size and anatomical variability .
Bipolar radiofrequency were developed, allowing the creation of larger and continuous lesions. This has been associated with improved outcomes .
Cooled radiofrequency represents an advancement in RFA . By internally cooling the electrode, CRF prevents tissue charring allowing for greater energy delivery, resulting larger lesions.
Randomized controlled trials demonstrated that CRF provides significant pain relief at 6 and 12 months .