Thermal versus cooled radiofrequency in patients with sacroiliac joint pain: a systematic review of the literature and pooled analysis of clinical outcomes.

INTRODUCTION: Chronic low back pain (LBP) can be caused by sacroiliac joint (SIJ) disease. Many conditions could cause SIJ dysfunction. The lateral branches of the L4-S3 dorsal rami are responsible for the primary innervation of the posterior SI joint. Radiofrequency (RF) denervation represent an emerging promising treatment for refractory sacroiliac joint pain. There are different types of RF denervation such as thermal or cooled. Use of irrigation cooled electrodes allows targeted tissues to reach the neuroablative temperatures slowly, preventing collateral damage of adjacent tissue. EVIDENCE ACQUISITION: We conducted electronic database (PubMed, Medline, Cochrane and Google Scholar) research (time frame: January 1st, 2010 to May 31st, 2021) for clinical studies that had tested conventional radiofrequency (RFT) and cooled radiofrequency (RFC) to treat sacroiliac joint pain. These studies were evaluated according to Level of Evidence. Quantitative assessment of qualifying studies was done using the random effects model. We calculated the pooled size effect using standardized mean difference (SMD) as the main effect measure. EVIDENCE SYNTHESIS: We identified nine studies, with a total of 276 patients affected by sacroiliac joint pain and treated with radiofrequency. The analysis revealed a small and non-significant difference in pain reduction and an improvement in quality of life in RFT subgroup (Pain measured in Visual Analogic Scale: RFT subgroups SMD=-3.643 (95% CI -4.478, -2.807), RFC subgroup SMD=-3.285 (95% CI -4.428, -2.141), P=0.587; Quality of Life measured in Oswestry Disability Index: RFT subgroup SMD=-35.969 (95% CI -53.993%, -17.945%), RFC subgroup SMD=-20.589% (95% CI -33.424%. -7.754%), P=0.123). Publication bias was found in quality-of-life assessment due to the low number and high heterogeneity of studies. Two techniques showed no major complications. CONCLUSIONS: Current evidence indicates no statistical difference between two techniques examined. The literature is currently lacking, and well-constructed randomized clinical trials are necessary to evaluate this deficient aspect.

Epidemiology, diagnosis and management of Baastrup's disease: a systematic review.

INTRODUCTION: Baastrup's disease (BD) is a common cause of low back pain which is often underdiagnosed. It is characterized by adjacent interspinous processes contact and it can be associated with cystic lesions. The aim of this review was to evaluate the epidemiology, diagnosis, and treatment options of patients with BD. EVIDENCE ACQUISITION: The present study is performed according to PRISMA statement. Medline via PubMed and Embase, Scopus, Cochrane Library database were searched using the keywords: "Baastrup," "kissing spines," "syndrome," "disease." A total of 35 papers met our inclusion criteria. Full texts were reviewed for demographic, clinical data and treatment. EVIDENCE SYNTHESIS: 1308 patients were included in the studies. The mean age of the enrolled patients was 59.6 years. The M:F ratio was 1.3:1. Population-based studies demonstrated a decade on decade increase in the incidence. Standard and dynamic flexion-extension radiographs of the lumbar spine were performed in 213 (16.2%) of cases. MRI was performed in 735 patients (56.2%) whereas FDG PET/CT was used to demonstrate BD in 77 included cases (5.9%). CT scan was performed in 574 cases (43.9%). Twenty-six studies reported the treatment choice for a total of 277 patients. Anti-inflammatory drugs and physical therapy were chosen in 99 cases (35.7%). Percutaneous infiltrations and surgical decompression in 80 (28.9%) and 196 (70.7%) patients respectively. CONCLUSIONS: Baastrup's disease is a common cause of low back pain. Proper diagnosis needs for imaging investigations and dynamic flexion-extension radiographs. Conservative and surgical therapies are available but there is a need for randomized clinical trials.