METHODS: A Blinded Randomised Controlled Trial was carried out to compare IF and PF injections for LBP. Patients randomised into IF and PF groups. Bilateral L4/5 and L5/S1 levels injected. 40mg of Depo‐Medrone with Lignocaine (total 1ml) in IF group. 80mg of Depo‐Medrone with 1ml of 0.5% Chirocaine (total 3ml) in PF group. Pain visual analogue score (VAS) and analgesic chart ‐ completed till six months.
RESULTS: 88 total, 14 withdrew, 69 feedback available. Sixty‐three (91%) had significant pain relief a week following injection, 86% and 94% in IF & PF groups. Mean duration of pain relief was 12.4 weeks (IF‐12.2, PF‐12.5). Mean change in VAS before & after injection was 4 (IF‐4, PF‐4). Mean change in analgesic use before & after injection was 2 tablets. (IF‐2.9, PF‐2.3). Radiation dose area product (DAP) for IF injections‐ 603 and PF‐ 45 mGy.cm2. 45 (51%) came for repeat injections, 19 & 26 in IF & PF groups.
* Majority had pain relief (91%), more patients in PF group compared to IF group (94% vs. 86%). No statistically significant difference between 2 groups in change in pain severity, duration of pain relief or change in analgesic intake.
* Significant change in VAS after injection in both groups (from 7 to 3). Pain relief for a mean duration of 12.4 weeks.
* PF ‐ technically easier‐ 9 patients randomised to IF group had to have PF injections (facet joint osteophytes).
* Radiation doses much higher for IF injections even in expert hands (P=0.007). It took double the time to perform IF injections compared to PF (30 and 15 minutes).