- Discuussion:
- axillary nerve (
C5,
C6) originates from and passes backward from
posterior cord of
brachial plexus - at level of axilla;
- it arises immediately posterior to the coracoid process and conjoined tendon;
- it crosses the inferolateral surface of the
subscapularis, 3-5 mm medial to the musculotendinous border;
- sweeping a finger from superior to inferior along the anterior aspect of subscapularis will catch the axillary nerve;
- it courses along inferior border of the shoulder capsule, & then thru
quadrangular space below lower border of
teres minor,
where it passes around posterior and lateral humerus on deep surface of the
deltoid muscle;
- after passing thru quadrilateral space (at inferior border of subscapularis muscle and posterior aspect of the humeral neck) it divides into
anterior and posterior trunks;
- anterior trunk:
- branches supply the middle and anterior deltoid as it winds around the inner surface of deltoid;
- posterior trunk:
- branch to the
teres minor muscle
- posterior part of the
deltoid muscle (lie deep in deltoid);
- terminal branches: superior lateral brachial cutaneous nerve
- references:
-
The Posterior Branch of the Axillary Nerve: An Anatomic Study.
-
Anatomical basis of the variable aspects of injuries of the axillary nerve (excluding the terminal branches in the deltoid muscle).
-
The position of the axillary nerve in the deltoid muscle. A cadaveric study.
- Anterior Dislocation of Shoulder:
- because of its relatively fixed position at
posterior cord and at
deltoid, any downward subluxation of proximal humerus can result in traction
and injury to the nerve;
- also because of its close relationship to the inferior capsule makes it suseptible to injury with anterior dislocations;
- in pts w/ axillary nerve injuries following anterior dislocation, sensory exam over the lateral shoulder will be normal;
- injury causes loss of shoulder abduction & external rotation;
- Axillary Nerve and Shoulder Reconstruction:
- references:
-
Anatomy of the axillary nerve and its relation to inferior capsular shift.
-
The axillary nerve and its relationship to common sports medicine shoulder procedures.
-
Prevention of Axillary Nerve Injury in Anterior Shoulder Reconstructions. Use of a Subscapularis Muscle-Splitting Technique and a Review of the Literature.
-
The Anatomic Relationship of the Brachial Plexus and Axillary Artery to the Glenoid. Implications for Anterior Shoulder Surgery.
-
The Relationship of the Axillary Nerve to Arthroscopically Placed Capsulolabral Sutures. An Anatomic Study.
-
Determining the Relationship of the Axillary Nerve to the Shoulder Joint Capsule from an Arthroscopic Perspective.
- Axillary Nerve Injury during Rotator Cuff Surgery:
- if
deltoid is split anteriorly for > 5 cm, branches of axillary nerve will be damaged, rendering corresponding portion of deltoid ineffective;
- in smaller patients, the deltoid should not be split more than 4 cm;
- smallest split possible should be made in deltoid to permit sufficient exposure of the
rotator cuff;
- arm can be passively moved into various positions to allow this exposure without creating a larger muscle split than is necessary;
- Axillary Nerve and Proximal Interlocking Screws for IM Nailing: (see
IM nailing)
- references:
-
Relationship of the axillary nerve to the proximal screws of a flexible humeral nail system: an anatomic study.
-
Antegrade locked nailing for humeral shaft fractures.
-
Percutaneous Pinning of the Proximal Part of the Humerus. An Anatomic Study.
-
Anatomic considerations of locked humeral nailing.
The sub-deltoid approach to the metaphyseal region of the humerus.
Repair of isolated axillary nerve lesions after infraclavicular brachial plexus injuries: case reports.
Suprascapular neuropathy in the differential diagnosis of rotator cuff injuries.
Isolated and combined lesions of the axillary nerve. A review of 146 cases.
Surgical anatomy of the axillary nerve.
Is There a Safe Area for the Axillary Nerve in the Deltoid Muscle?
The anatomic relationships of the axillary nerve and surgical landmarks for its localization from the anterior aspect of the shoulder.
