Neurological shoulder disorders

Question 1

What are the types of scapular winging?

Answer 1

• 2 types
  
  • medial
    
    • serratus anterior- long thoracic nerve
  • lateral
    
    • Trapezius - CN XI- spinal accessory n

Question 2

Describe the normal anatomy and motion of the scapula?

Answer 2

• attachment of 17 muscles
• function
  
  • to stabilise the scapula to the thorax
  • provide power to the upper limb
  • synchronise glenohumeral motion
• ​Motion
  
  • ​Elevation and upwards rotation= Trapezius
  • scapular protraction (ant/lateral motion)= serratus ant/pect major & minor
  • Scapular retraction ( medial motion)= rhomboid majoir and minor

Question 3

Dsecribe the anatomy of serratus anterior?

Answer 3

• Origin
  
  • superolateral surfaces of upper 8-9 ribs at chest wal
• insertion- vertebral body of scapula
• action
  
  • draws scapula forward and upward
  • abducts scapula and rotates it
  • stabilises vertebral border of scapula
• innervation
  
  • long thoracic nerve C5,6,7
• Blood supply
  
  • circumflex scapular artery

Question 4

What is the aetiology of medial scapular winging?

Answer 4

• Deficit in Serratus anterior
• injury to long thoracic nerve C5,6,7
• by
  
  • Repetitive stretch injury
    
    • most common
    • head tilted away from overhead activity
    • e.g. weightlifters, volleyball
  • Compression injury
    
    • direct from lateral wall from contact sports/trauma
  • Iatrogenic injury
    
    • Axillary node clearance
  • Scapula fx

Question 5

What is the presentation of medial scapular winging?

Answer 5

• Shoulder pain and scapular pain
• weakness when lifting away from body or overhead activity
• discomfort when sitting against chair

O/E

• Inferior border of scapula goes medial
• shoulder girdle elevats

Question 6

What is the tx of medial scapular winging?

Answer 6

non operative

• Observation, bracing, serratus ant strengthening
  
  • obs for minimal of 6 months
  • wait for nerve to recover
  • bracing with modified thoracolumbar brace

Operative

• Pectoralis transfer
  
  • no spontaneous resolution after 1-2 years

Question 7

Describe the aetiology of lateral scapular winging?

Answer 7

• Deficit to trapezius due to spinal accessory nerve injury: CN XI
• often Iatrogenic injury - post neck surgery for nodes

Question 8

What is the presentation of lateral scapular winging?

Answer 8

• scapular moves lateral
• shoulder girdle appears depressed or dropped

Question 9

What is the tx of lateral scapular winging?

Answer 9

Nonoperative

• Observation and trapezius strengthening

Operative

• Nerve exploration
  
  • iatrogenic injury
• Eden-Lange transfer
  
  • lateralise levator scapulae and rhomboids ( transfer from medial border to lateral border)
• Scapulothoracic fusion

Question 10

What is the aetiology of suprascapular neuropathy?

Answer 10

• Suprascapular notch entrapment
  
  • weakness of supraspinatus and infraspinatus
• Spinoglenoid notch entrapment
  
  • weakness of infraspinatus only

Question 11

Describe the anatomy of the suprascapular nerve?

Answer 11

• C5/C5
• Emerges off superior trunk C5/6 of brachial plexus
• travels across post triangle to neck of scapula
• runs below suprascapular ligament/spinoglenoid ligament
• innervates
  
  • supraspinatus
  • infraspinatus

Question 12

What is the anatomy of the suprascapular ligament/spinoglenoid ligament?

Answer 12

• Suprascapular lig
  
  • arises from medial base of coracoid & overlies suprascapular notch
  • suprascapular artery runs above it
  • suprascapular n runs below
• Spinoglenoid ligament
  
  • ​arises near spinoglenoid notch
    
    • ​overlies distal suprascapular nerve

Question 13

What is suprascapular notch entrapment?

Answer 13

• Proximal compression of suprascapular n in the **suprascapular notch **
• leads to weakness of infraspinatus and supraspinatus
• compression from
  
  • ganglion cyst ( often w labral tears)
  • Transverse scapular ligament entrapment
  • fracture callus

Question 14

Describe the presentation of suprascapular notch entrapment?

Answer 14

• Deep , diffuse , posterolateral shoulder pain

O/E

• Pain on palpation of suprascapular notch
• weakness on supraspinatus- jobe test positive
• weakness on infraspinatus
• Atrophy of muscle

Question 15

How is suprascapular notch entrapment evaluated?

Answer 15

• MRI
  
  • to identify a compressive mass with assoc cyst
• EMG/NCV
  
  • diagnostic

Question 16

What is the tx of suprascapular notch entrapment?

Answer 16

Non operative

• activity modification. organised shoulder rehab
  
  • minimum 6 months
  • no abnormality on mri

Operative

• Surgical decompression at suprascapular notch
  
  • if structural lesion on mri or no response 1 yr consx
  • http://www.orthobullets.com/video/view?id=116

Question 17

What is spinoglenoid notch entrapment?

Answer 17

• Distal compression of the suprascapular nerve
• affects only infraspinatus
• compression due to
  
  • posterior labral tears -> cysts
  • spinoglenoid ligament
  • spinoglenoid notch ganglion
  • traction injury ( 45% vollet ball players)

Question 18

What is the presentation of spinoglenoid notch entrapment?

Answer 18

• Deep , diffuse, posterolateral shoulder pain

0/E

• Infraspinatus weakness
• infraspinatus atrophy along posterior scapula
• supraspinatus normal

Question 19

How is spinoglenoid notch entrapment evaluated?

Answer 19

• MRI
  
  • to identify any posterior labral lesions with assoc cysts
• EMG/NCV
  
  • diagnostic

Question 20

What is the tx of spinoglenoid notch entrapment?

Answer 20

Non operative

• Activity modifcation and organised shoulder rehab programme
  
  • if no structural lesion on MRI
  • posterior capsule stretching

Operative

• Arthroscopic cyst decompression & labral repair
  
  • labral lesion with assoc cyst seen on MRI
• Spinoglenoid ligament release with nerve decompression
  
  • ​if no lesion but failure consx tx 1 year
  • post approach to shoulder
  • decompress n in spenoglenoid notch

Question 21

What is thoracic outlet syndrome?

Answer 21

• A neurovascular compressive neuropathy with either a neurogenic or vascular etiology
• F>M

Question 22

What is the pathophysiology of thoracic outlet syndrome?

Answer 22

1. Neurogenic
   
   • compression of neurovascular bundle as it passes over 1st rib or thru scalene muscle by
     
     • scalene muscle abnormalities
     • scapular ptosis
     • clavicle/first rib malunion
     • cervical rib
     • vertebral transverse process
   • ​other causes in athletes
     
     • ​fibormuscular bands
     • abn pect major
     • reptitive shoulder use
     • extreme arm positions
     • weightlifting, swimming
2. ​Vascular
   
   • compression of subclavian vessel or aneursym
   • may lead to emboli at hands

Question 23

What is the assoc condition with thoracic outlet syndrome?

Answer 23

• Paget-Schroetter syndrome
  
  • thoracic outlet syndrome w compression of subclavian vein in the developed athlete due to scalene muscle hypertrophy

Question 24

What is the presentation of thoracic outlet syndrome?

Answer 24

• Arterial ischaemia
• Raynaud’s phenomenon
• venous congestion
• cold intolerance
• neurological
  
  • pain & swelling of upper extremities
  • ulnar nerve parathesias
    
    • differentiated form more distal compression due to sensory diff in medial brachial and antebrachial cutaneous nerves

O/E

• Wright
  
  • ​abduction, ER with neck rotated away from head to loss of pulse and reproduction of symptoms
  • http://www.orthobullets.com/video/view?id=903

Question 25

What is seen on imaging of thoracic oulet sydrome?

Answer 25

• C spine- rule out cervical rib
• cxr- rule out pancoast tumour
• Angiography
  
  • will subclavian vessel disease/aneurysm

Question 26

What is the tx of thoracic oulet sydrome?

Answer 26

non operative

• Physio, activity modifications
  
  • fist line
  • shoulder girdle strengthening, proper posture, relaxation techniques

Operative

• Neurologic decompression
  
  • adress site of compression
    
    • repair clavicle malunion
    • transaxillary 1st rib resection = 90% excellent results
    • sclene takedown
    • pectoralis minor tentomy
    • release of fibromuscular anomalous bands
• Vascular reconstruction ( open bs interventional)
  
  • for subclavian aneursym

Question 27

What is the complications of thoracic oulet sydrome?

Answer 27

• emboli to the hands
  
  • tx with heparinisation, embolectomy.
  • 7-10 days of heparin then 3/12 warfarin

Question 28

decribe what is brachial neuritis?

Answer 28

• AKA Pasonage- Turner syndrome
• 1-30 cases per 100,00
• any age affected
• typically middle aged individuals
• M>F
• risk factors
  
  • viral infection
  • immunisation
  • medications
  • extreme stress
  • autoimmune disease
• effects nerves of lower brachial plexus

Question 29

What is the pathophysiology of brachial neuritis?

Answer 29

• Autoimmune process, probably involving lymphocytes
• Hereditary form is extremely rare but autosomal dominant

Question 30

What is the presentation of brachial neuritis?

Answer 30

• Sudden onset of pain that subsides in 1-2 wks
  
  • typically awakens people from sleep
• Followed by Weakness period of up to 1 yr in muscles supplied by involved nerve

O/E

• Severe weakness of ER/ Abductors
• can have decreased sensation - up to 75% pts
  
  • esp in lateral antebrachial cutaneous n
• commonly affects >1 nerve

Question 31

What imaging is helpful in brachial neuritis?

Answer 31

• MRI
  
  • show signal abnormalities in affected muscle bellies
• EMG
  
  • abnormalities show acute degeneration w sharp waves and fibrillations

Question 32

What is the tx of brachial neuritis?

Answer 32

• Non operative
  
  • Observation for resolution and physio
  • follow pts monthly for improvement
  • outcomes
    
    • 90% pts recover at 3 years
    • only 35% of pt recover in 1 year

Question 33

What is quadrilateral space syndrome?

Answer 33

• Axillary nerve and posterior humeral artery compression in quadrilateral ( quardangular) space
• rare
• often misdx as subacromial impingement
• 20-40 years
• most commonly affects dominant shoulder
• risk factors
  
  • overhead athletes
  • contact throwing sports

Question 34

What is the pathophysiology of quadrilateral space syndrome?

Answer 34

• Compression & reduction of quadrangular space due to
  
  • Iatrogenic ( tight fibrous bands, muscle hypertrophy)
  • Paralabral cysts ( with inferior labral tears)
  • Trauma ( scap fx, shoulder dislocation)
  • Benign/Malignant masses
• ​Greatest amount of compression is when arm is in late cocking phase of throwing ( abduction/ER)

Question 35

what is the prognosis of quadrilateral space syndrome?

Answer 35

• Long-standing cases often causes atrophy/weakness of teres minor and deltoid

Question 36

Can you describe the anatomy of the quadrangular space?

Answer 36

• location
  
  • lateral to triangular space
  • medial to triangular interval
• Boundaries
  
  • superior- subscapularis & teres minor
  • inferior- teres major
  • medial - long head of triceps
  • lateral - surgcal neck of humerus
• contents
  
  • Axillary nerve (C5 n root, post cord)
  • Posterior circumflex humeral artery

Question 37

What is the presentation of quadrilateral space syndrome?

Answer 37

• Poorly localised pain of posteriolateral shoulder
  
  • often worse at night
  • worse with overhead activity or late cocking/acceraltion phase of throwing
• non dermatomal distribution of parathesia
• shoulder ER weakness

O/E

• Atrophy teres minor and deltoid
• point tendereness over quadrangular space
• ER weakness with arm abducted in throwing position
• pain exacerbated by active and resisted Abduction & ER of arm
• neurology - usually normal

Question 38

What is seen on imaging of quadrilateral space syndrome?

Answer 38

• Xray
  
  • usually normal
• MRI
  
  • rule out RC tears
  • may show…
  • atrophy teres minor( axillary innervation)
  • Compression of quadrilateral space
  • inferior paralbaral cyst asso w labral tear
• Arteriogram
  
  • lesion in post humeral circumflex artery
• EMG
  
  • used to confirm dx
  • show axillary n involvment

Question 39

What is the tx of quadrilateral space syndrome?

Answer 39

Non operative

• NSAIDS, activity restriction, physio
  
  • first line of tx
  • glenohumeral mobilisation & strengthening
  • posterior capsule stretching
  • massage
  • most pt improve in 3-6 months
• diagnostic lidnocaine block
  
  • inject lidnocaine into quadrilateral space
  • starting point is 2-3 cm inferior to standard post shoulder arthroscopy
  • positive if no point tenderness or pain on full rom

Operative

• nerve decompression
  
  • open release of quadrilateral space +/- arthroscopic repair of labral tear

Question 40

Describe the technique for quadrilateral space decompression?

Answer 40

• Approach
  
  • lateral decubitus position
  • 3-4cm incision over quadrilateral space
  • identify post border of deltoid and reflect superiolateral
  • expose fat in quadrilangulr space between teres minor and teres major
• Technique
  
  • identify axillary nerve by using the humeral neck as reference
  • avoid cutting the posterior circumflex artery
  • free any fibrous tissue aherence to the nerve
  • ensure n is completely free of compression by moving arm into abduction and ER
• Post op sling
  
  • immediate for comfort
  • early pendulum exercises to avoid new adhesions
  • progress to full active rom with supervsiedphysio

Question 41

What is scaphulothoracic dyskinesis?

Answer 41

• Abnormal scapula motion leading to shoulder impingement & dysfunction
• cause multifactoral
  
  • neurological injury
  • pathological thoracic spine kyphosis
  • periscapular muscle fatigue
  • poor throwing mechanics
  • secondary to pain
• seen in athletes

Question 42

Describe the pathoanatomy of scapular dyskinesis?

Answer 42

• Scapulothoracic power imbalance lead to protraction of scapula
• leads to alteration of mechanics of GH joint
  
  • excessive stress placed on anterior capsule of shoulder and posterosuperior labrum
• increase risk of injuring
  
  • labrum
  • RC
  • Capsule

Question 43

What is the presentation of scapular dyskinesis?

Answer 43

• shoulder pain and dysfunction worse with arm elevation
• loss of throwing velocity

O/E

• scapulothoracic crepitus
• affected scapula may be lower and protected
• symptom relieved with scapula stabilisation
• http://www.orthobullets.com/video/view?id=627

Question 44

What is the tx of shoulder dyskinesis?

Answer 44

• NSAIDS, PT local injections
• main tx
• physio emphasis on
  
  • core strengthening
  • scapular stabilisers , serratus ant , trapezius
  • RC muscles
  • core mechanics to throwers