Ultrasound Imaging of the Axillary Nerve and its Role in the Diagnosis of Traumatic Impairment

Abstract

Purpose: The axillary nerve (AN) is frequently injured during shoulder trauma and imaging is required to define the site and extent of nerve injury. However, the AN has a rather complex course through several soft tissue compartments of the shoulder and axilla. Therefore, imaging of the nerve with MRI and sonography is troublesome. Thus detection and sonographic assessment bases on thorough knowledge of local topography.

Materials and Methods: This investigation aimed at defining reliable anatomical landmarks for AN-sonography in 5 volunteers and later validating the proposed sonographic examination protocol in 10 unselected patients.

Results: With strict adherence to the proposed examination algorithm, sonography of the AN was feasible in all volunteers and patients. Furthermore, sonographic findings correlated nicely with the golden standard “surgical exploration” concerning severity and topography of neural impairment.

Conclusion: Based on our study results we propose our algorithm for AN-sonography as the first-line imaging tool for the assessment of axillary nerve trauma.

Zusammenfassung

Ziel: Der N. axillaris wird relativ häufig im Rahmen von Schulterverletzungen lädiert und die Bildgebung sollte dazu dienen, die exakte Lokalisation und das Ausmaß der Schädigung zu definieren. Der Nerv zeichnet sich allerdings durch einen ziemlich komplizierten Verlauf durch mehrere Kompartimente des Schultergürtels und der Axilla aus. Daher ist die Darstellung des Nervens sowohl mit MRT als auch Sonografie schwierig und basiert auf profunder Kenntnis der lokalen Topografie.

Material und Methode: Diese Studie zielte einerseits darauf ab klare Landmarken für die Sonografie des Nervus axillaris an 5 Probanden zu definieren und deren Nutzen anschließend an 10 unselektierten Patienten zu verifizieren.

Ergebnisse: Bei strikter Befolgung des etablierten Untersuchungs-Algorithmus war eine Beurteilung des N. axillaris in allen Probanden und Patienten möglich. Darüber hinaus zeigte sich eine gute Korrelation der sonografischen Befunde mit dem goldenen Standard „chirurgische Exploration“ sowohl bezüglich Schwere als auch Topografie des neuralen Schadens.

Schlussfolgerungen: Basierend auf unseren Studienergebnissen empfehlen wir den vorgestellten Untersuchungsalgorithmus für die Sonografie des N. axillaris als Methode der ersten Wahl in der Abklärung einer Nervus axillaris Verletzung.

Key words

nervous-peripheral - ultrasound - trauma

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