Ultrasound-guided Deep Iliacus Plane Block (DIPB): Cadaveric Evaluation and Pilot Retrospective Evaluation of Another Novel Fascial Plane Block for Hip Analgesia

Objective: Regional anaesthesia for hip surgery aims to cover both articular and cutaneous nerves. Current techniques often miss components or require multiple injections. We hypothesized that the deep iliacus plane block (DIPB)—which involves injection deep to the iliacus muscle at the anterior inferior iliac spine—could simultaneously target both lumbar plexus branches and articular nerves. Methods: We conducted a cadaveric investigation and a retrospective clinical pilot. Bilateral DIPB was performed on a fresh cadaver (50 mL dye) using 50 mL of dye to assess dye spread. Clinically, 20 hip fracture patients received a single-injection DIPB (30-40 mL of 0.25% bupivacaine). Blocks were performed postoperatively (n = 13) or preoperatively for positioning (n = 7). Primary outcomes included dye spread and opioid consumption. Pain scores were evaluated before and after the block in the positioning subset. Results: Cadaveric dye stained the lateral femoral cutaneous nerve (LFCN), the femoral nerve (FN), and the pericapsular branches. In the clinical cohort (n = 20), the median postoperative numeric rating scale (NRS) score was 1; only one patient required rescue analgesia within 24 hours. In the positioning subset (n = 7), median NRS dropped from 9.0 (7-10) to 1.0 (0-2) 30 minutes post-block (P < 0.001). Conclusion: Preliminary findings suggest that DIPB may provide simultaneous coverage of the LFCN, FN, and pericapsular branches with a single injection. Further prospective studies are required to confirm the safety and efficacy.