Background: Pain following open reduction and internal fixation of distal radius fracture (DRF) can be significant. This study compared the intensity of pain up to 48 hours after volar plating for DRF, associated to either an ultrasound guided distal nerve block (DNB) or surgical site infiltration (SSI).
Methods: In this prospective single blind randomized study, 72 patients scheduled for DRF surgery under 1.5% lidocaine axillary block were allocated to receive, at the end of surgery, either an ultrasound-guided median and radial nerves block with ropivacaine 0.375% (DNB) performed by the anesthesiologist or a SSI with the same drug regimen, performed by the surgeon. Primary outcome was the duration between analgesic technique (H0) and pain reappearance (Numerical Rating Scale (NRS 0-10)>3). Secondary outcomes were the quality of analgesia, the quality of sleep, the magnitude of motor blockade, and the patient satisfaction. The study was built on a statistical hypothesis of equivalence.
Results: Fifty-nine patients were included in the final per-protocol analysis (DNB=30, SSI=29). Time to reach NRS>3 was (in median [95%CI]) 267 min [155;727] and 164 min [120;181] respectively after DNB and SSI (difference=103 min [-22;594] - rejection of equivalence hypothesis). Pain intensity throughout the 48 hours, quality of sleep, opiate consumption, motor blockade and patient satisfaction was not significantly different between groups.
Conclusions: Although DNB provides a longer analgesia than SSI, both techniques gave comparable level of pain control during the first 48 hours after surgery, without any difference in the incidence of side effects or patient satisfaction.