shoulder instability approach and management

1. Shoulder Instability
Akeel M. Almahdaly (R3)

2. Outlines
• Introduction
• Definitions
• Epidemiology
• Shoulder osteology and Planes of Motion
• Types of shoulder stability factors
• Classifications of shoulder instability
• History-taking and PE with special tests
• Differential diagnoses
• Management (Nonoperative, operative)

3. Introduction
• Shoulder stability is the result of a complex
interaction between static and dynamic
shoulder restraints.

4. Introduction
• The most frequent complication of shoulder
dislocation is recurrence.
• Instability is usually defined as a clinical
syndrome that occurs when shoulder laxity
produces symptoms.

5. Definition:
Instability:
• Inability to maintain the humeral head in the glenoid
fossa.
• Includes a spectrum ofdisorders
Dislocation
Complete loss of glenohumeralarticulation
Subluxation
Partial loss of glenohumeral articulation withsymptoms
Laxity
Incomplete loss of glenohumeralarticulation
unassociated with pain

6. Epidemiology

7. • Shoulder dislocation and subluxation occurs
frequently in athletes with peaks in the
second and sixth decades.
• The majority (98%) of traumatic dislocations
are in the anterior direction.
• 2%  Posterior direction

8. • Almost 95% of first-time shoulder dislocations
result from either a forceful collision, falling
on an outstretched arm, or a sudden
wrenching movement.
• About 5% of dislocations have an atraumatic
origin.

9. • Based on a study by Rowe, about 70% of those
who have already dislocated can expect to
dislocate again within 2 years of the initial
injury!

10. Planes of Motion
• Reference
– scapular plane is 30 degrees anterior to coronal
plane.
• Abduction
– abduction requires external rotation, why?
– 180° of abduction comes from motion in ? two
joints.

11. Osteology
 Glenoid fossa
 Pear shaped
 7 deg. of retroversion
 5 deg. of superiortilt
 Glenoid version
 30o anterior
 Humerus
 Neck-shaft – 130o to140o
 Retroversion – 30o

12. Stability
Static Factors
 Capsule andLigaments
 Glenoid Labrum
 Articular Congruence
 ArticularVersion
 Negative Pressure
Dynamic Factors
 Rotator Cuff
 Biceps Tendon
 Scapulothoracic Motion
 Propioception

13. Capsule And Ligaments
Capsule
 Attached medially
glenoid fossa
 laterally toanatomical neck
of humerus
 Anterior cap thicker thanpost.
 Little contribution tojoint
stability
 Strengthened by GHLsand
RC tendons
No Ligaments!

14. Glenohumeral Ligaments (GHL)
• SGHL
• MGHL
• IGHL
• CHL

15.  O = tubercle onglenoid just
post to long head biceps
 I = upper end oflesser
tubercle
Function:
 Resists inferior subluxation and
contributes to stability in
posterior and inferior directions
SGHL

16. MGHL
 O= sup glenoid andlabrum
 I= blends with subscapularis
tendon
Function:
 Limits anterior instability
especially in 45 degabduction
position
 Limits extrotation

17. IGHL
 O= ant. glenoid rim andlabrum
 I= inf. aspect of humeral articular
surface and anatomic neck
 3 bands: anterior, axillary and
posterior
 Acts like a sling ,the most
important single ligamentous
stabilizer .
 Primary restraint is at 45-90 deg
abduction.

18. CHL
 Contribute to restraining inferior subluxationwith
arm atside.
 And preventn posterior translation with shoulder
in flexion,adduction, and internal rotation
 So, same as SGHL!

20. Ligamentous Restraints in different
Arm Positions
Arm Position Anterior Res. Inferior Res. Posterior Res.
0° (side) and adduction SGHL/CHL
45° (ER) and 45° abducted MGHL MGHL
Adduction SGHL/CHL
90° (ER)
Anterior band
IGHL
Anterior band
IGHL
Posterior band
IGHL
90° (forward flexed, abduction,
and IR)
Anterior band
IGHL
Posterior band
IGHL
SGHL/CHL
Static

21. GLENOID LABRUM
 contributes 20% toGH stability
 Fibrocartilaginoustissue
 Deepens glenoid (50%)
 3 purposes:
 Inc. surface contactarea
 Buttress
 Attachment site forGH
ligaments
 Antomical variants?

22. Normal glenoid is about 7 degrees retroverted
If the retroversion is excessive, it leads to posterior
instability of shoulder
Articular Version

23. Glenohumeral Joint
 Humeral head 3x larger than glenoid
fossa
 Ball and socketwith translation
 3 degrees of freedom
 Flex/Ext
 Abd/Add
 Int/Ext rot
 Plus, Cricumduction

24. Negative Intra-articular Pressure
 -42 cm H2O incadaver
 Secondary to high osmoticpressure in interstitial
tissues
 Only clinically important in the arm at rest in
adduction
 Lost with lax capsuleor defect

25. Dynamic Factors
 Rotator Cuff
 Biceps Tendon
 Scapulothoracic motion
 Proprioception

26. Rotator Cuff
 Compression enhances conformity
 Greater than staticstabilizers
 Coordinated contractions/steering effect
 Supraspinatus most important
 Dynamization

27. Biceps long head, Deltoid
 secondary stabilizer headdepressor
Periscapular Muscles
 help position scapula and orient glenohumeral joint
contributes compressive force acrossjoint
 forms weak links that predisposes to SLAP tear

28. Classification:




Frequency
Cause
Direction
Degree

29. Classification of instability

30. Spectrum
Traumatic Microtrauma Atraumatic
Less laxity More laxity
Unidirectional Multidirectional

31. Thomas-Matsen classification
• TUBS (Traumatic Unilateral dislocations with a
Bankart lesion requiring Surgery)
• AMBRI
- Atraumatic
- Multidirectional
- Bilateral (frequently)
- Rehabilitation (often responds to)
- Inferior capsular shift (best alternative to nonop)

32. Evaluation Of Instability
History
 Age
 Trauma-Duration
 Associated Pain
 Sports, throwing or overheadactivities
 Voluntary subluxation
 “Clunk” or knock
 Fear-Limitation of Movements
 Hx dislocations and energyassociated
 Hx 1st dislocation orinjury
 Subsequent dislocations/subluxations

33. Physical Examination
 Inspection
 Palpation
 ROM
 Winging
 Neurovascular testing
 Generalized ligamentous laxity
 Instability tests

34.  Sulcus sign
 Drawer tests
 Load & Shifttest
Sulcus grading
1+ acromiohumeral interval < 1cm
2+ acromiohumeral interval 1-2 cm
3+ acromiohumeral interval > 2cm

35.  Apprehension test
 Jobe’s Relocation
 Jerk test

36. Diagnosis
 X-rays
 CT Scan
 MRI
 Arthroscopy

37. RADIOLOGY
 X-Rays
 Identify Bankart or Hill-Sachs Lesion

38. AP VIEW

39. Normal Shoulder AP view

40. Axillary View

41. Scapular Y-View

42. Stryker
view
Humeral Head
Defect

43. Apical Oblique view
Glenoid rim
lesion

44. West Point
Axillary view
Anteroinferior
glenoid rim

45. Anterior Dislocation
97% of recurrent dislocation
abduction, extension and
external rotation
Associated Injuries:
- Fractures
 Head & Neck
- Rotator Cuff Tears
 > 40 y/o = 30%
 > 60 y/o =80%

46. Neurologic Injury
 Axillary nerve
 10-25% incidence 1sttime.
 2-5% in recurrentdislocators
 Tx: “watchful expectancy”
 Poor prognosis if norecovery by
10 wks
Vascular Injury
 Axillary artery
 2nd part thoracoacromial
trunk

47. Posterior Dislocation
 Incidence: < 5% all shoulder
dislocations
 Axial load
 Flexed/Adduction
 Bench press-“lockout”
 Rowing
 Football Offensive Lineman
 Seizures or electrical
shocks

48. Pathoanatomy Of Shoulder Instability
Laberal Lesions
 – Bankart
 – Reverse Bankart
 – SLAP lesions
CapsularInjury
 – Intrasubstance Tear
 – HAGL
 – Capsular Laxity
Bone Loss
 – Glenoid
 – Humeral Head-Hill-Sachs Lesion

49. Bankart Lesion
 The traumaticdetachment
of the glenoid labrum has
been called the Bankart
lesion. 85%

50. BANKART LESION-labral tear at anterior
half of glenoid rim

51. Reverse Bankart lesion

53. Anchor used for repair

54. HILL-SACHS
LESION
This is a defect in the
posterolateral aspect of the
humeral head.

55. Hill Sach Lesion

56. Treatment
Non Operative
 Immobilization
 Protection
 Rehabilitation
 70-90% improve
 Functional disability
improved
 Instability noteliminated

57. Operative Management
 Overall 50-95 % success
 Higher recurrence vsant.
instability procedures
Soft Tissue Procedures
 Posterior Capsulorrhaphy
 Reverse Putti-Platt
(IS CapsularTenodesis)
 McLaughlin
Bone Procedures
 PosteriorGlenoid
Osteotomy
 Posterior BoneBlock

58. Operative Treatment:
Capsulolabral Repair
 Bankart
 Modified Bankart
Subscapularis Procedures
 Putti-Platt
 Magnuson-Stack
Coracoid Transfer
Procedures
 Bristow
 Latarjet

61. References
• Shoulder Instability: Management and Rehabilitation, Kimberley Hayes, PT, Mary
Callanan, MD, Judie Walton, PhD, Anastasios Paxinos, MD
• The anatomy and histology of the rotator interval capsule of the shoulder, Cole BJ
• Treatment of the athlete with multidirectional shoulder instability, Levine WN
• Multidirectional instability of the shoulder: pathophysiology, diagnosis, and
management, Schenk TJ
• Principles for the evaluation and management of shoulder instability, Matsen FA
3rd
• Pathomechanics of acquired shoulder instability: a basic science perspective, Wang
VM
• Miller’s Shoulder instability topic
• Orthobullets