Improvement of analgesic efficacy for total hip arthroplasty by a modified ultrasound-guided supra-inguinal fascia iliaca compartment block.

Background: Fascia iliaca compartment block (FICB) is an anterior approach to the lumbar plexus block and provides the effective adjunctive analgesia for total hip arthroplasty (THA).

Methods: As a case series study, 28 patients (≥ 65 years old) with THA were received a modified in-plane ultrasound-guided supra-inguinal (S-FICB) as an analgesic adjunct to evaluate the analgesic effectiveness and the local anesthetic diffusion with magnetic resonance imaging (MRI). A combination of propofol and sufentanil was administered to conduct target-controlled infusion.

Results: The pain scores were 1 (0-4), 2 (1-5), 3 (1-6) and 3 (1-6) at 4, 8, 12, and 24 h. The cumulative opioids were 8 (8-12), 18 (16-32), 28 (24-54) and 66 (48-104) mg of i.v. morphine equivalents at 4, 8, 12, and 24 h. The patient-controlled analgesia (PCA) times were 0 (0-1), 1 (0-2), 2 (0-5) and 5 (3-8) at 4, 8, 12, and 24 h. In lateral, anterior and medial part of thigh, the sensory blockade in 28 patients was 23 (82 %), 21 (75 %) and 19 (68 %) at 5 min; 28 (100 %) at 10 and 20 min. Motor blockade of femoral nerve (FN) and obturator nerve (ON) was present in 13 (46 %) and 3 (11 %) patients at 5 min, 24 (86 %) and 9 (32 %) at 10 min, 26 (93 %) and 11 (39 %) at 20 min. Injectate permeated to the FN and extended superiorly over the surface of iliac muscle (IM) and pectineus muscle (PM) in all patients.

Conclusions: The modified S-FICB has provided an effective postoperative analgesic adjunct after THA with the satisfactory blockade of femoral (FN), obturator (ON) and sciatic (SN) nerves, especially for ON, when compared with the existing techniques.