shoulder pain and scapulothoracic dyskinesia

1. Tip & tricks:
nerve entrapment
around SHOULDER
AHMAD DASHT BOZORG MD
AHVAZ JOUNDISHAPUR UNIVERSITY OF MEDICAL SCAIENCES

2. Three Common Entrapments
Cervical radiculopathy
Brachial plexopathies
peripheral nerve entrapments

3. Peripheral nerve injuries about the
shoulder are a cause of pain and
dysfunction

4.  These neuropathies are thought to occur in
actively working young/ middle-aged
individuals (between the ages of 25 and 40)

5.  The mechanisms of nerve injury include:
1. direct pressure
2. repetitive microtrauma
3. compression- or stretch-induced ischemia

6.  In order to diagnose entrapment neuropathy,
the patient’s clinical history and
examination are very important

7. Diagnostic Evaluation
 Electromyography and Nerve Conduction Studies
 Ultrasound
 Magnetic Resonance Imaging (MRI)
 emphasis on increased structural resolution and
optimized nerve T2 contrast may be termed magnetic
resonance neurography (MRN)
 Peripheral nerve blocks (PNBs) can offer both diagnosis
and treatment of peripheral nerve entrapments

8. Common Nerves Affected Around The
Shoulder
1. Axillary nerve
2. Suprascapular nerve
3. Long thoracic nerve
4. Spinal accessory nerve
5. Dorsal scapular nerve

9. Axillary Nerve Entrapment
 Axillary nerve originates from the posterior
cord of the brachial plexus (C5-C6)
 Mixed sensory and motor nerve

10. Axillary Nerve Entrapment
Young adults presenting with diffuse,
poorly localized shoulder and upper arm
pain
Athletes involved in over head sport

11. Causes
Trauma(shoulder Dx – proximal humerus Fx)
Iatrogenic(shoulder surgery)
Entrapment(quadrilateral space syndrome)

12. Quadrilateral Space Syndrome (QSS)
primary area for
potential
entrapment is in
the quadrilateral
space

13. Fibrous bands are the most common cause
of compression in the QS.
 space-occupying lesions in the QS
(paralabral cyts, bony fracture fragments,
being tumors)

14. The AN usually
divides into
anterior and
posterior branches
in the
space

15. Quadrilateral Space Syndrome
Because the anterior branch of the nerve
(supplying the deltoid) is spared.
There is selective denervation of the
teres minor muscle

16. Clinical Presentation
 Poorly localized lateral
and posterior
shoulder pain and
weakness,
 Exacerbated by
abduction and
external rotation of
the arm.

17. Point tenderness
in the quadrilateral
space

18. The deltoid extension lag sign
 the deltoid extension lag sign reveals a discrepancy between
passive and active ROM of the shoulder

19. The abduction in internal rotation test

20. Identification and Treatment of
Contributing Factors
 AN entrapment is often seen after trauma or
injury to the axilla. (overaggressive stretching,
falling on the shoulder, pressure from casts or
splints, and improper use of crutches)
 Relative rest, stretching, and evaluation of an
athlete’s biomechanics may provide relief

21. Axillary nerve injection in the
quadrilateral space
 A teres minor
 B short head of the
biceps
 C long head of the
biceps
 D teres major

22. Surgery
 When symptoms persist for more than 6 months +
clear local tenderness in the quadrilateral space
(and perhaps a positive arteriogram)
 surgical intervention is targeted at releasing the AN
and the PHCA

23. Suprascapular Nerve Entrapment
 The C5-C6 nerve roots
and leaves the upper
trunk
 Mixed motor &sensory
nerve
 Subacromial bursa
,acromioclavicular joint,
GH joint

24. Entrapment
Three sites of entrapment of SSN
1. cervical origin
2. suprascapular notch
3. spinoglenoid notch
 The most common site of its entrapment is at
the suprascapular notch.

25. Suprascapular notch
 Microtruma from repetitive movement
 Small & calcific notch
Spinoglenoid notch
 forced addution & internal rotation
 Labral or mocoid cysts and tumors

26. Clinical Presentation
Signs and symptoms of SN
entrapment depend on the location
of nerve compression.

27. Entrapment at the suprascapular
notch
 Sudden onset of shoulder pain due to
compression of the deep sensory fibers
 limitations in abduction and external rotation
 Can also develop a “ frozen shoulder ”

28. Entrapment at the spinoglenoid notch
 Pain is largely absent because the deep sensory
fibers to the shoulder joint exit proximal to this
entrapment site
 Isolated atrophy and weakness of the infraspinatus
muscle.

29.  Suprascapular notch entrapment: as much
as 75% loss of abduction & external rotation
 Spinoglenoid notch entrapment: posterior
deltoid & terse minor may be able to
compensate

30. Palpation of the
suprascapular
notch region to
elicit pain

31.  Atrophy is most
easily visualized in
the infraspinatus
muscle, because the
trapezius muscle can
obscure the
supraspinatus

32. Suprascapular stretch test Cross-arm adduction test

33. Identification and Treatment of
Contributing Factors
 SN entrapment arises from overuse of the
muscles of the rotator cuff
 Range of motion and stretching exercises

34. Injection Techniques
Vertical approach Horizontal approach

35. Surgical Decompression
 Significant muscle wasting, weakness
 Intractable pain
 Failed non-operative therapy
 Arthroscopic surgical approaches have been
described for SN decompression

36. Long Thoracic Nerve Entrapment
 The LTN ( Charles Bell
nerve) arises from C5,C6
and C7
 Innervate the
serratus anterior

37. Long Thoracic Nerve Entrapment
 Repeated microtrauma as a result of a
stretching
 Athletic activities
 Breast surgery(specially mastectomy)
 Carrying a heavy bag over the shoulder

38. Entrapment
There are multiple sites of entrapment of LTN
1. Between the middle & posterior scalene
2. At the fist rib
3. Between the clavicle & second rib
4. Between the second rib & coracoid
5. The inferior angle of scapula

39. Long thoracic nerve
 A deep non-specific
ache in shoulder
 Radiating through the
neck to scapula and
lateral chest wall
 Burning pain at lower
pole of scapula

40.  Pain is not a major complaint with LTN
entrapment.
 Severe pain should raise suspicion of brachial
neuritis

41. Clinical Presentation
 Weakness with forward elevation & over head
activity
winging, particularly when the patient extends
his or her arms and pushes against a wall
 Medial scapular winging (prominence of the
scapula) is the hallmark of LTN injury.

42. Medial scapular winging
 The scapula is slightly
higher and closer to the
midline when
compared to the
unaffected side
 It can be amplified by a
“wall push-up”

43. Identification and Treatment of
Contributing Factors
Three stages of LTN injury
 In the acute stage, the LTN injury causes SAM
pain(pain reduction, range of motion exercises, and
activity modification)

44.  Once the nerve begins to heal (passive stretching of
the rhomboids, levator scapulae, and pectoralis
is used to prevent contracture)
 In the third stage, the SAM becomes progressively
stronger (strengthening exercises of all shoulder
girdle muscles)

45. Injection Technique
 At the apex of the
posterior triangle of the
neck, between the SCM
and the trapezius, and
the needle is advanced
into the body of the
middle scalene muscle

46. Surgical Treatment
 When entrapment was deemed to be within or near
the middle scalene muscle, a supraclavicular
approach has been used
 More distal neurolysis has been described in a larger
number of patients.

47. Surgical Treatment
 If symptoms persist beyond a year or 2 despite
nonoperative management, and there are no signs
reinnervation on EMG, the patient may be a
candidate for reconstructive surgery
 Traditional surgical options include muscle
transfers, scapulopexy, and scapulothoracic
fusion

48. Spinal Accessory Nerve Entrapment
The spinal
accessory nerve
(SAN), the 11th
cranial nerve
(CNXI)

49. Spinal Accessory Nerve Entrapment
 Vulnerable to blunt trauma, traction, and
penetrating wounds
 surgical procedures(radical neck dissection for
neoplasm, carotid endarterectomy, and cervical
lymph node biopsy)

50. The SAN
innervates the
trapezius and
SCM muscles

51. Clinical Presentation
 Ipsilateral neck,
shoulder and occipital
pain and headache
 Contralateral spasm of
the SCM and trapezius
 Winged scapula

53. Entrapment
 If the site is proximal, both the SCM and trapezius
muscles will be involved
 If it is at the more usual site in the posterior
triangle, the trapezius alone is affected

54.  A sudden acceleration-deceleration incident
(whiplash)
 Iatrogenically (radical neck dissections, lymph node
biopsies)

55. The winging is usually most
obvious when the patient actively
externally rotates the shoulder
against resistance.

56. Lateral winging

57. The most consistent physical finding
is weakness of arm abduction

58. Identification and Treatment of
Contributing Factors
 Forward head posture and posterior cervical
ligamentous laxity, because of the already
compromised ergonomics
 Early physical therapy for postoperative shoulder
dysfunction is “mandatory”

59. Injection techniques
 The landmark-guided
technique should only
be attempted in
patients with a neck
thin enough to palpate
the styloid process

60. Surgical Techniques
 If SAN injury is diagnosed within 1 year, microsurgical
reconstruction should be considered

61. Surgery
If diagnosed later, surgically
repositioning the functioning
shoulder muscles, known as the
Eden-Lange procedure