Cheatography
https://cheatography.com
Presentation, management, etc
Axillary Nerve
- Posterior cord of the brachial plexus, anterior to the subscapularis muscle
- Travels inferior to the glenohumeral joint capsule
- Passes through quadrangular space
- Axillary nerve splits into anterior and posterior division
- Anterior division = motor innervation to anterior and middle heads of deltoid
- Posterior division = motor innervation to posterior deltoid and teres minor
- Terminates as the superior lateral cutaneous nerve (innervates lateral shoulder)
- C5-C6
Causes
- Skiiers, footballers, rugby, baseball, hockey, soccer, weight lifting, wrestling |
- Chronic compression occurs in young adults who are overhead throwers |
- Carrying a heavy backpack/ misuse of crutches |
- Overdeveloped or hypertrophic muscles forming quadrangular space |
- Ganglion/paralabral cyst |
- More common in the dominant shoulder |
- Brachial Neuritis (Parsonage-Turner Syndrome) |
- Rare in isolation |
- Older people with GH dislocation more predisposed |
Presentation
- Dull, poorly localises shoulder ache |
- Can be after sporting event or blunt force to the shoulder (shoulder dislocation can be related to AN) |
- Vague deltoid numbness or parasthesia |
- Sensory symptoms often worse at night |
- Deltoid weakness may be present ( rapid fatigue with overhead throwing) |
- Excaerbated by arm abduction and external rotation |
- Point tenderness of quadrangular space |
- Weakness in abduction, external rotation |
- Deltoid atrophy if chronic |
- Assess for changes in limb (cyanosis, pallor, splinter haemorrhages) for lesions pressing on posterior circumflex artery as it exits the quadrangular space (Quadrangular space syndrome (QSS) |
- Assess ipsilateral neck and upper extremity |
- Assess other nerves (Spinal accessory, suprascapular, long thoracic, musculocutaneous, radial) |
DDx
- Cx radiculopathy |
- TOS |
- Rotator cuff tear |
- Brachial plexopathy |
- QSS |
- Brachial neuritis |
- GH f#/dislocation |
- Subacromial impingement syndrome |
- Herpes Zoster |
Imaging
- X-ray rule out bony pathology/ if trauma
- MRI to rule out lesions and look for atrophy of teres minor/deltoid
- EMG gold standard
- MRI if compressive/inflammatory causes
Management
Selective rest and modifications |
ROM exercises |
Cross friction massage / myofascial release to muscles of quadrangular space |
- GH mobilisation |
- Cross body and posterior capsule stretching |
- Rotator cuff strengthening |
- Avoidance of positions that place axillary nerve in traction |
- NSAIDs |
- If failure to restore function in 3-6 months , consider surgical referral |
- Traumatic cases can be managed non-surgically (reduction, immobilised for 4-6 weeks in the young and 7-10 days in the elderly then a rehab program - muscle strength and shoulder mobility) but there is a risk of permanent paralysis |
-Neuropraxic patients expect recovery within 6-12 months
- Axonotmesis recovery is high, but can take many months, if no signs of recovery within 6-9 months, consider surgery
- Neurotmesis patients should have surgery |
Prognosis
- Low grade + GH dislocation recovery within 7 months |
Complications: Permanent numbness to the lateral shoulder region, atrophy of the deltoid and teres minor muscles and chronic neuropathic pain |
|
Created By
Metadata
Comments
No comments yet. Add yours below!
Add a Comment
Related Cheat Sheets
More Cheat Sheets by Siffi