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Suprascapular Nerve Injury
From WikiSM
Contents
Other Names
- Suprascapular Neuropathy
- Suprascapular Neuropraxia
- SSN
Background
- This page refers to all injury patterns associated with the Suprascapular Nerve
Epidemiology
- Prevalence, incidence large unknown
- Zehetgruber et al: 88 cases in the literature from 1959 to 2001[1]
- Prevalence estimated to be between 12-33% in athletes, 8-100% in patients with rotator cuff tears[2]
Pathophysiology
- Challenging diagnostic entity due to vague symptoms, co-existence of other conditions[3]
Compressive
- Paralabral Cyst associated with Glenoid Labrum Lesions
- Most commonly at spinoglenoid notch
- Rotator Cuff Tear
- Fracture of the body of the scapula
- Vascular
- Compression by the transverse scapular ligament, spinoglenoid ligament
- History of rotator cuff surgery or failed rotator cuff surgery
Noncompressive
- Generally considered idiopathic
- Sports with repetitive overhead activities (volleyball)
- Up to 30% of volleyball players have asymptomatic infraspinatus atrophy, weakness[4]
- Typically affects infraspinatous
- Good prognosis
Pathoanatomy
- SupraScapular Nerve
- Ventral rami of C4-C6 originating from Brachial Plexus
- Courses through Suprascapular Notch and Spinoglenoid Notch
- Motor innervation: Supraspinatus, Infraspinatus
Associated Conditions
Risk Factors
- Sports
- Volleyball
- Baseball
- Tennis
- Basketball
- Swimming
Differential Diagnosis
- Fractures
- Proximal Humerus Fracture
- Humeral Shaft Fracture
- Clavicle Fracture
- Scapula Fracture
- First Rib Fracture (traumatic or atraumatic)
- Dislocations & Separations
- Arthropathies
- Muscle & Tendon Injuries
- Rotator Cuff
- Bursopathies
- Ligament Injuries
- Neuropathies
- Other
- Pediatrics
- Coracoid Avulsion Fracture
- Humeral Head Epiphysiolysis (Little League Shoulder)
Clinical Features
- General: Physical Exam Shoulder
- History
- Deep, dull and aching chronic pain in the superior-posterior-lateral aspect of the shoulder
- Pain is worse with adduction, internal rotation
- Subjective weakness, fatigue
- Physical
- Observe for atrophy of the supraspinatus, infraspinatus muscles
- Compression at suprascapular notch: weakness in abduction, external rotation[5]
- Compression at spinoglenoid notch: weakness in external rotation can be compensated by Deltoid, Teres Minor
- Atrophy
- Special Tests
- Jobe Test: Shoulder abducted to 90°, forward flexion to 30°, internal rotation against resistance
- Drop Arm Test: Abduct arm to 90° and lower slowly
Evaluation
Radiographs
- Standard Radiographs Shoulder
- Typically normal
- Useful to screen for other causes of symptoms
CT Scan
- Useful to evaluate for anatomic variants of either notch
- Can add arthrography
MRI
- Best overall diagnostic imaging study
- Ideally with arthrogram to evaluate labrum, paralabral cysts
Ultrasound
- Can be useful to evaluate rotator cuff
- Role in suprascapular nerve injury not clearly defined
- Can be used to guide diagnostic nerve block to suprascapular nerve notch[6]
- Ultrasound reduced risk of neurovascular injuries as well
EMG/NCS
- Gold standard for diagnosis
- Sensitivity 74-91%[7]
Classification
- Compressive
- Non-compressive
Management
- Most management and treatment guidelines driven by case series and retrospective reviews
Nonoperative
- Generally first line therapy
- Indications
- Non-compressive or dynamic causes
- Absence of space occupying lesion
- Approach
- Physical Therapy
- Activity Modification
- Medical therapy including NSAIDS
Operative
- Indications
- Failure of conservative management
- Presence of space occupying lesion
- Technique
- Percutaneus drainage (high failure rate)
- Surgical decompression
- Repair of underlying injuries (i.e. labral tear, rotator cuff tear, etc)
Rehab and Return to Play
Rehabilitation
- Emphasis
- Rotator Cuff
- Deltoid
- Periscapular muscles
- Scapular stabilization
Return to Play
- Needs to be updated
Complications
- Weakness
- Inability to return to sport
See Also
- Internal
- External
- Sports Medicine Review Shoulder Pain: https://www.sportsmedreview.com/by-joint/shoulder/
References
- ↑ Zehetgruber H, Noske H, Lang T, Wurnig C. Suprascapular nerve entrapment. A meta-analysis. Int Orthop 2002;26:339-43.
- ↑ Shah, Anup A., et al. "Clinical outcomes of suprascapular nerve decompression." Journal of shoulder and elbow surgery 20.6 (2011): 975-982.
- ↑ Moen, Todd C., et al. "Suprascapular neuropathy: what does the literature show?." Journal of shoulder and elbow surgery 21.6 (2012): 835-846.
- ↑ Lajtai G, Pfirrmann CW, Aitzetmuller G, Pirkl C, Gerber C, Jost B. The shoulders of professional beach volleyball players: high prevalence of infraspinatus muscle atrophy. Am J Sports Med 2009;37: 1375-83
- ↑ Gerber C, Blumenthal S, Curt A, Werner CML. Effect of selective experimental suprascapular nerve block on abduction and external rotation strength of the shoulder. J Shoulder Elbow Surg 2007;16: 815-20
- ↑ Gorthi, Venkat, Young Lae Moon, and Jeong Hoon Kang. "The effectiveness of ultrasonography-guided suprascapular nerve block for perishoulder pain." Orthopedics 33.4 (2010).
- ↑ Atroshi I, Johnsson R. Evaluation of portable nerve conduction testing in the diagnosis of carpal tunnel syndrome. J Hand Surg Am 1996;21:651-4
Created by:
John Kiel on 14 June 2019 08:35:03
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Last edited:
1 October 2022 19:12:39
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