Distal subsartorial compartment block of the saphenous nerve - A dissection study and a patient case series

Anne E Jensen; Siska Bjørn; Thomas D Nielsen; Bernhard Moriggl; Romed Hoermann; Michael Vaeggemose; Thomas F Bendtsen

doi:10.1016/j.jclinane.2023.111315

Distal subsartorial compartment block of the saphenous nerve - A dissection study and a patient case series

J Clin Anesth. 2024 Feb:92:111315. doi: 10.1016/j.jclinane.2023.111315. Epub 2023 Nov 3.

Authors

Anne E Jensen¹, Siska Bjørn², Thomas D Nielsen³, Bernhard Moriggl⁴, Romed Hoermann⁴, Michael Vaeggemose⁵, Thomas F Bendtsen⁶

Affiliations

¹ Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark.
² Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark; Department of Anesthesiology, Aarhus University Hospital, Aarhus, Denmark.
³ Department of Anesthesiology, Aarhus University Hospital, Aarhus, Denmark.
⁴ Institute of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria.
⁵ GE Healthcare, Brøndby, Denmark; MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
⁶ Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark; Department of Anesthesiology, Aarhus University Hospital, Aarhus, Denmark. Electronic address: tfb@dadlnet.dk.

PMID: 37926063
DOI: 10.1016/j.jclinane.2023.111315

Abstract

Study objective: A saphenous nerve block is an important tool for analgesia after foot and ankle surgery. The conventional midthigh approach to saphenous nerve block in the femoral triangle may impede ambulation by impairing quadriceps motor function.

Primary objective: Developing a selective saphenous nerve block targeting the nerve distal to its emergence from the adductor canal in the subsartorial compartment.

Design: This study consists of A) a dissection study and B) Data from a clinical case series.

Setting: A) Medical University of Innsbruck, Austria (dissection of 15 cadaver sides) and. B) Aarhus University Hospital, Denmark (5 patients).

Interventions: A) Five mL of methylene blue was injected into the subsartorial compartment distal to the intersection of the saphenous nerve and the tendon of the adductor magnus guided by ultrasound. B) Five patients undergoing major hindfoot and ankle surgery had a subsartorial compartment block with 10 mL of local anesthetic in addition to a popliteal sciatic nerve block.

Measurement: A) The frequencies of staining the saphenous and medial vastus nerves. B) Assessment of postoperative pain by NRS score (0-10) and success rate of saphenous nerve block by presence of cutaneous anesthesia in the anteromedial lower leg, and motor impairment by ability to ambulate.

Main results: A) The saphenous nerve was stained in 15/15 cadaver sides. A terminal branch of the medial vastus nerve was stained in 2/15 cadaver sides. B) All patients were fully able to ambulate without support. No patients had any post-surgical pain from the anteromedial aspect of the ankle and foot (NRS score 0). The success rate of saphenous nerve block was 100%.

Conclusion: The saphenous nerve can be targeted in the subsartorial compartment distal to the intersection of the nerve and the tendon of the adductor magnus. The subsartorial compartment block provided efficient analgesia without quadriceps motor impairment.

Keywords: Distal subsartorial compartment block; Foot and ankle surgery; Saphenous nerve.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cadaver
Humans
Leg
Nerve Block* / methods
Pain, Postoperative / etiology
Pain, Postoperative / prevention & control
Peripheral Nerves
Thigh / innervation