Radiofrequency denervation for treatment of sacroiliac joint pain-comparison of two different ablation techniques

The radiofrequency treatment (RFD) for sacroiliac joint pain (SIP) is well-established, but there is still scarce evidence on its clinical outcome. The classical monopolar RFD is limited by a high recurrence rate. This might be caused by an incomplete denervation of the dorsal rami. The Simplicity III probe was invented to optimise pain fibre recruitment by its multi-electrode design. However, the clinical superiority of this procedure was never proven. The aim of this study was to illustrate the effectiveness of RFD and to compare both denervation techniques. One hundred twenty-one patients were included, and their clinical course was analysed. Fifty-seven patients received conventional treatment with multiple percutaneous monopolar RFDs (monolesion probe group, MoLG) and 64 patients with the Simplicity III probe (multilesion probe group, MuLG). All patients were followed 1, 3, 6 and 12 s after RFD. Clinical outcome scores were analysed (numeric pain rating scale (NPRS), Roland-Morris Disability Questionnaire, Oswestry Disability Index (ODI), Odom's criteria, Short Form 36 score). The MuLG showed a clearly advanced improvement concerning the clinically relevant pain relief (≥ 50%) (1 month/3 months /6 months/12 months = 72%, 55%, 36%, 27% vs. 1 month/3 months/6 months/12 months = 39%, 28%, 16%, 11%) as well as an advanced improvement of pain-associated disability and a higher satisfaction rating compared to the MoLG (NPRS_MuLG__preop = 8,3; NPRS_MuLG__12months = 5.8; NPRS_{MoLG_preop} = 7,7; NPRS_{MoLG_12months} = 5.8; ODI_{MuLG_preop} = 52; ODI_{MuLG_12months} = 42; ODI_{MoLG_preop} = 52; ODI_{MoLG_12months} = 47; ODOMS_{MuLG_good/excellent} = 54%; ODOMS_{MoLG_good/excellent} = 28%). RFD of the SIP with the Simplicity III probe is effective and delivers a distinct pain reduction even after 1 year of treatment. This technique shows clear advantages compared to the conventional monolesion technique and is a useful treatment for patients with recurrent SIP.