Accuracy of ultrasound-guided versus ‘blind’ injection of the tibial nerve

In order to get a dependable block on the tibial nerve several US guided injections need to be infused around the nerve.
DrO

Cadaveric comparison of the accuracy of ultrasound-guided versus ‘blind’ perineural injection of the tibial nerve in horses
Vet J. 2021 Mar;269:105603.
Authors
Maylin van der Laan 1 , Els Raes 2 , Maarten Oosterlinck 3
Affiliations

1 Department of Veterinary Medical Imaging and Small Animal Orthopedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; Department of Surgery and Anaesthesiology of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium. Electronic address: maylin@live.nl.
2 Department of Veterinary Medical Imaging and Small Animal Orthopedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
3 Department of Surgery and Anaesthesiology of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.

Abstract

During diagnostic evaluation of hindlimb lameness in horses the tibial nerve block is traditionally performed based on anatomical reference points, but it can be difficult to achieve effective local anaesthesia using this blind technique. Ultrasound (US)-guided injection could increase the accuracy of injection. The aim of this study was to compare the accuracy of both techniques. Twenty-one paired sets of cadaver hindlimbs were injected with 1 mL methylene blue using the blind or US-guided technique. There was no significant difference in stain width and length and in coloured nerve length between techniques. However, the successful rate of nerve staining was 85.7% and 47.6% for the US-guided and blind technique, respectively (P = 0.02; odds ratio 6.6; 95% confidence interval, 1.5-29.4). This study suggests that the US-guided technique is more accurate than the blind technique. However, in the treated sample, a single US-guided injection did not consistently result in nerve staining.