II. Pathophysiology
- Suprascapular nerve impingement (typically by ligament at the Scapular notch)
III. Causes
-
Clavicle Fracture
- Suprascapular Nerve runs posterior to clavicle and subject to injury
- Repetitive overhead activity
- Risk of Stretching injury at the suprascapular notch and the spinoglenoid notch
-
Glenoid Labrum Tear with secondary cyst formation
- May entrap and compress the suprascapular nerve
IV. Symptoms
- Infraspinatus weakness
- Weak external rotation at the Shoulder
- Supraspinatus weakness (variably involved)
- Weak arm elevation overhead
V. Differential Diagnosis
- Rotator Cuff Injury
-
Brachial Plexus Injury
- Suprascapular nerve exits Brachial Plexus trunk
VI. Diagnostics
- MRI Shoulder
- Evaluate for Rotator Cuff Tear, labral tear
- Obtain early in course (i.e. first month)
VII. Management
- Referral to orthopedic surgery if Rotator Cuff Injury or space occupying lesion
- Peripheral Nerve Block
- Physical Therapy
- Shoulder Range of Motion Exercises
- Strengthen compensatory Muscles
- Avoid reinjury
- Avoid heavy lifting
- Avoid repetitive overhead activity
VIII. Course
- Anticipate 6-12 month course with therapy
IX. References
- Mallon and Shoenberger in Herbert (2019) EM:Rap 19(2): 13-5
- Neal (2010) Am Fam Physician 81(2): 147-55 [PubMed]
- Safran (2004) Am Sports Med 32(4): 1063-76 [PubMed]
- Silver (2021) Am Fam Physician 103(5): 275-85 [PubMed]