Effect of suprainguinal fascia iliaca compartment block on postoperative opioid consumption and functional recovery in posterolateral-approached total hip arthroplasty: a single-blind randomized controlled trial.

Introduction: Posterolateral-approached total hip arthroplasty (PLTHA) is followed by moderate to severe postoperative pain. Suprainguinal fascia iliaca compartment block (SFICB) has been proposed as a promising analgesia technique.

Methods: Data from 86 patients scheduled for PLTHA with spinal anesthesia were analyzed in this prospective randomized controlled trial. Patients were randomly divided into two groups of 43 patients each. As opposed to the control group (group C), ropivacaine group (group R) received additional SFICB using 40 mL of 0.375% ropivacaine. As primary endpoint, blind observers noted total morphine consumption at postoperative 48 hours. Secondary endpoints were pain at rest and mobilization on 0-10 Numeric Rating Scale (rest and dynamic NRS) at fixed time points (1 hour and 6 hours after surgery, and at day 1 and day 2 at 8:00, 13:00 and 18:00 hours), walking performance at day 1 and day 2; postoperative complications including morphine-related side effects or orthostatic intolerance symptoms such as dizziness, nausea, blurred vision or vasovagal syncope.

Results: A 48-hour morphine consumption (mg; median (IQR)) was significantly lower in group R than in group C (11 (8.5-15.5)) vs 26 (21-33.5), p<0001), as well as incidence of morphine-related side effects such as nausea at day 1 (p=0.04) and day 2 (p<0.01). Rest and dynamic NRS were globally significantly lower in group R than in group C (p<0.01). Group R showed less orthostatic intolerance at day 1 (p<0.001) and day 2 (p<0.01) and better functional walking performance at day 1 (<0.001) and day 2 (<0.001).

Discussion: In PLTHA, SFICB provides opioid sparing, improved postoperative pain control, and enhanced functional recovery.

Trial registration number: NCT04574479.