Dr Ajay Shah IOM, Nepal shoulder instability bankarts lesion

1. Shoulder Instability-Pathology and Evaluation
(clinical and imaging)
Moderator : Dr Sunil Singh Thapa
Presenter: Dr Ajay Shah (Resident)
Department of Orthopedics and Trauma Surgery
IOM,TUTH

2. Contents
• Introduction
• Classification
• Pathoanatomy
• Clinical evaluation
• Radiological evaluation

3. Introduction
• Defined as the symptomatic and pathologic condition in which the humeral head
does not remain centered in the glenoid fossa
• Laxity: Degree to which the humeral head passively translates, relative to the
glenoid, with the application of a load.
Glenohumeral instability involves varying degrees of translation of the humeral
head beyond its physiologic limits that is associated with symptoms of pain and/or
subjective anxiety.
Current Concepts in the Diagnosis and Management of Traumatic, Anterior Glenohumeral Subluxations
Orthop J Sports Med. 2017

4. Incidence
Epidemiology of shoulder dislocations presenting to emergency departments in the United States. J Bone Joint
Surg Am. 2010;92(3):542–549).

5. Why dislocation more common in younger age
• Open physis
• Weaker epiphyseal growth plates in children tend to fracture
• Collagen fibers have fewer cross-links, making the joint capsule and
supporting tendons and ligaments weaker and dislocation more likely

6. Classification
Descriptive classification

7. Stanmore Classification
• Triangular relationship between these conditions allow for the fact there are intermediate types
that lies between poles
• Balance of abnormalities can shift and patient may move from one type to another over time

8. Pathological changes

9. Matsen’s classification
• TUBS (traumatic, unidirectional, Bankart lesion, Surgery)
• AMBRI ( Atraumatic , multidirectional, bilateral, rehabilitation, inferior capsule
shift, internal closure)
Microtraumatic or developmental lesions fall between the extremes of macrotraumatic and
atraumatic lesions and can overlap these extreme lesions

10. Evaluation and classification of shoulder instability. With special reference
to examination under anesthesia. Clin Orthop Relat Res 1987;223:32–44
FEDS Classification

11. Pathoanatomy

12. Circle concept of stability

13. Concavity-compression effect
• Deltoid produces primarily vertical shear forces, tending to displace the
humeral head superiorly
• Forces from the rotator cuff provide compressive or stabilizing forces.
• Loss of the labrum can reduce this stabilizing effect by 20%.

14. Hammock effect
• Hammock-type model consists of thickened anterior and
posterior bands and a thinner axillary pouch
• With external rotation, the hammock slides anteriorly and
superiorly, anterior band tightens, and posterior band fans
out.
• With internal rotation, the opposite occurs
• Provides restraint at extremes of motion and assists in the
rollback of the humeral head in the glenoid.

16. Labrum
Bankart lesion
• Disruption between anteroinferior
labrum and glenoid
• Seen in traumatic anterior instability
• Leads to recurrent instability
IGHLC serves as primary static
stabilizer against anterior and inferior
humeral translation
Disrupted concavity compression
effect

17. Bony Bankart lesion
• Fracture of the anterior inferior glenoid
• Present in up to 49% of patients with recurrent dislocations
• Higher risk of failure of arthroscopic treatment if not addressed
• Defect >20-25% is considered "critical bone loss" and is
biomechanically highly unstable

19. Variants of the Bankart lesion
1.Perthes lesion
2.Anterior Labral Ligamentous Periosteal Sleeve Avulsion
Perthes lesion
• Avulsion of capsulolabral complex from
the anterior-inferior aspect of the
glenoid
• But the medial scapular periosteum
remains intact.
• Non displaced Bankart lesion

20. Anterior Labral Ligamentous Periosteal Sleeve Avulsion
• Capsulolabral complex is avulsed and the medial scapular periosteum is stripped and
subsequently displaced down the denuded anterior glenoid neck
• In chronic situations, labrum and attached periosteum of anterior glenoid can heal in
a medialized position

21. Reverse Bankart Lesion
• Seen in recurrent posterior instability
• Posterior labral pathology ranges from
marginal crack without labral
detachment-KIM lesion to posterior
labral flap (reverse bankart lesion)
• Leads to laxity of posterior band of
the inferior glenohumeral ligament

22. Superior Labrum Anterior Posterior Tears
• Generally seen in higher energy trauma
• Compressive loading of shoulder in flexed
abducted position can damage superior
labrum anteriorly and posteriorly
• Injury begins posteriorly and extends
anteriorly upto mid-glenoid notch

23. Humeral Avulsion of Glenohumeral Ligaments
• Traumatic rupture of the inferior
glenohumeral ligament (IGHL)
complex at humeral attachment
• Typically occurs in
hyperabduction and external
rotation resulting in instability

24. Variations of instability in HAGL
• Anterior >90%
• Anterior bony avulsion
• Floating anterior HAGL
• Posterior
• Posterior bony avulsion
• Floating posterior HAGL
With studies reporting that the anterior band of the IGHL is affected in up to 93% of
HAGL cases
Bui-Mansfield LT, Taylor DC, Uhorchak JM, Tenuta JJ. Humeral avulsions of the glenohumeral ligament: Imaging
features and a review of the literature. AJR Am J Roentgenol 2002;179:649-655.

25. Glenoid
• Alterations of glenoid version can
lead to instability
• Posterior instability
Significant retroverted glenoid
Hypoplastic glenoid
Posterior glenoid rim fracture
• Anterior instability
Chronic anteroinferior bone loss

26. Traditionally , glenoid bone loss has been divided into
• Minimal (0% to20%) :soft tissue procedures
• Moderate (20% to 30%) :arthroscopic/open bony procedures
• Significant (over 30%) : open bony procedures

27. • In a cadaver model, glenoid defects of 25% width (21% of
length) were found to decrease stability
• Gerber and Nyffler found that if the length of the defect
was greater than the radius of a best-fit circle of the bottom
two-thirds of the glenoid, the force required for dislocation
was decreased by 70%

28. Safe Arc of Motion
• Effective Glenoid Arc: area of glenoid’s articular
surface available for humeral head compression
• Balance Stability Angle: angle between centre of
glenoid and the end of effective glenoid arc in
any direction

29. • The balance stability angle and the effective glenoid arc are reduced by a fracture
of the glenoid rim and hypoplastic glenoid.

30. Humeral Head
Hill-Sachs Lesions
• Compression fracture of the
posterosuperolateral humeral head caused
by anterior rim of glenoid
• Sequela of anterior dislocation
• Created with the arm in abduction and
external rotation

31. • Prevalence of HSL : 65% to 67% after initial dislocation
and 84% to 93% after recurrent dislocation
• Instability occurs :
when the defect engages the glenoid rim in functional
arc of motion(abduction/external rotation)
Humeral head defects of 35-40%

32. Engaging and Nonengaging Hill-Sachs Lesions
• Engaging Hill Sachs lesion: defined as
defects which are parallel to the long axis
of the glenoid rim in positions of function
(abduction and external rotation)
• Nonengaging Hill Sachs lesiom:(C) Hill
Sachs lesions vertically oriented on neutral
view become more diagonally oriented to
anterior labral rim in ABER position and
have lower tendency to engage (D).

33. Concept of Engaging and Nonengaging Hill-Sachs Lesions

34. Concept of On-Track and Off-Track Lesions
• When the arm is moved along the posterior end-range
of movement keeping in maximum external rotation
and maximum horizontal extension, the glenoid moves
along the posterior articular surface of the humeral
head. This contact zone is defined as the ‘glenoid
track’
Itoi E, Yamamoto N. Shoulder instability:
treating bone loss. Current Orthop Practice 2012;23:609-615.

35. • Width of the glenoid track, defined as the distance between the medial margin
of the glenoid track and the medial margin of the footprint of the rotator cuff
• 83% of the glenoid width with arm abducted to 90°

37. Reverse Hill-Sachs Lesions
• Also called a McLaughlin lesion
• Impaction fracture of anteromedial aspect
of the humeral head following posterior
dislocation
• Initial size of a “reverse” Hill–Sachs on the
anterior humeral head is an important
predictor for recurrent instability

38. Rotator Cuff Tear
• Seen in high-energy injuries or normal aging process
• Supraspinatus and subscapularis tears are the most common
• Subscapularis insufficiency plays a far greater role in instability
with loss of
Tenodesis
Compression–concavity effect
Direct barrier mechanism

39. Hyperlaxity of capsule
• Collagen related disorders
• Plastic deformation of capsulologamentous
complex from single macrotraumatic event
or repetitive microtraumatic events.

40. What are the factors for recurrent instability
Patient related:
• Male/young age/sports
Surgeon related:
• Misdiagnosis/failure to address pathology
Pathology related:
• Glenoid bone loss(>25%)
• IGHL laxity
• Large Hill-Sachs lesion

41. Evaluation of instability

42. Clinical Evaluation
History
• Demographic data( age, sex, occupation)
• Mode of onset
• Duration
• Frequency/episodeS
• Associated activities and energy related/Electric shock
• Fear/sensation of dislocation
• Mechanism of injury
• History of self reduction

43. Family History
• Connective tissue disorders
Medical History
• Seizure
• Psychiatric illness
• Previous surgery
Sports History
• Swimming, gymnastics

44. Examination
Inspection
• Scar marks
• Swelling
• Ecchymosis
• Asymmetry of
shoulders
• Muscular atrophy
• Scapular winging
• Position of limb

45. Palpation
• Tenderness
• Abnormal bony points
• Crepitus
• ROM
• Strength of dynamic stabilisers
• Any nerve injury?
• Generalized ligamentous laxity

46. General Tests for Laxity
• Drawer test
• Load and shift test
• Sulcus test
• Gagey hyperabduction test

47. Drawer test
If the maneuver reproduces the clinical
symptoms of apprehension or pain, a
presumed diagnosis of instability
(anterior or posterior) may be established if
consistent with the history and other
examination findings
• Translation of head to glenoid rim is graded
1+
• Translation over rim with spontaneous
reduction is grade 2+
• Dislocation is grade 3+

48. Load and shift test
• Easy subluxation of the humeral head
indicates loss of the glenoid concavity.

49. Sulcus Test
If distance between humeral head and
acromion
• <1cm :1+
• 1-2 cm:2+
• >2cm:3+
Subluxation at 0 deg is indicative of
laxity at rotator interval and that at 45
deg is indicative of IGHL complex

50. Gagey hyperabduction test
• Abduction over 105 deg reflects incraesed
laxity
• Symptoms of apprehension-inferior instability
• Typically positive with MDI
• Should be performed for all patients with
posterior instability as there is frequently a
bidirectional component

51. Specific Examinations for Anterior Instability
• Apprehension test
• Relocation test
• Crank test
• Fulcrum test
• Surprise test

52. Apprehension test
• Although pain may be used as an indicator for instability, it is typically not as
specific or as reliable as apprehension in documenting anterior instability.

53. Fulcrum test Crank test

54. Jobe’s relocation test
• Used for evaluating instability in athletes
involved in sports requiring overhead
motion
• A feeling of apprehension or subluxation
indicates anterior instability

55. Specific Examinations for Posterior Instability
Jerk test
• Provocative for posterior instability
• With a positive test, sudden jerk occurs
when the humeral head slides off the
glenoid and when it is reduced back
onto the glenoid

56. Kim Test
• Combination of positive Kim and
jerk tests has 97 % sensitivity for
posterior instability
• Indicates reverse bankart lesion

57. Examinations for Multidirectional Instability
No specific test for MDI, but inferior instability, by definition, is a major aspect of
the pathology. Therefore, specific tests of inferior laxity such as
• Sulcus test
• Gagey hyperabduction test
• Drawer test
• Load and shift test

58. X-rays
Anteroposterior View
• Due to oblique position of scapula, the
shadow of humeral head will overlap with
glenoid in AP view fossa.
• So this view is difficult to interpret with
respect to glenohumeral joint

59. True AP View
• Grashey view
• x-ray beam is angled 35 to 45 degrees
oblique to the sagittal plane of the
body
• x-ray beam is parallel to the joint so
that there is no overlap between
humeral head and glenoid surface
• If any overlap is seen dislocation
should be suspected

60. Axillary Views
• Accompanied with AP view to document the location of humeral head relative
to glenoid fossa
• Shows the direction and magnitude of humeral head displacement
• Associated fractures of both the humeral head and glenoid can be seen.
• Axillary views:
Standard axillary view
For patient who cannot abduct arm
Trauma axillary lateral view
Velpeau axillary lateral view

62. West Point View
• Provides tangential view of anterior glenoid
• Prone position
• Beam is angled approximately 25 degrees from midsagittal plane (A) to provide a tangential view of
glenoid.
• In addition, beam is angled 25 degrees downward (B) to highlight anterior and posterior aspects of
glenoid.

63. Apical Oblique View
• Sometimes referred to as the Garth view
• Clearly reveals the anterior inferior and
posterior superior glenoid rims
• X-ray beam angled approximately 45 degrees
(A) to provide a “true AP” view of the glenoid.
• In addition, the beam is angled 45 degrees
downward (B) to highlight the anterior
inferior aspect of the glenoid

64. Scapular Y view
• Cassette placed on the anterolateral aspect of the
shoulder
• X-ray beam is directed parallel to the plane of the
scapula(medial to lateral)
• Outline the scapula as the letter “Y”—hence the
name of this view.
• Two upper limbs of letter Y represent scapula spine
and coracoid process whereas inferior limb of the Y
represents scapular body

65. Stryker Notch View
• Best to characterize the Hill–Sachs defect and the posterior-superior humeral head
• Supine position
• Arm flexed to 120 degrees so that the hand can be placed on top of the head
• X-ray beam angled approximately 10 degrees.
• Radiograph shows presence of any osseous defects

66. CT scan
• Most sensitive for detecting and measuring bone deficiency, retroversion of
glenoid or bony pathology
• Indications:
Blunting of glenoid outline or obvious bony defect on plain x-rays
Evaluation of recurrent instability
Failed surgical procedures

67. CT Arthrography
• Useful in patients without clear-cut clinical signs of subluxation or dislocation, but
with pain, clicking, and vague discomfort suggestive of instability
• Helps in visualization of soft tissue pathology such as rotator cuff tears and
capsular lesions.
• Sensitivity of CT arthrography approaches conventional MRI in evaluating labral
tears (80% to 90%) with specificities in the 90% range

68. Estimation of bone loss

69. According to Lo et al., an anterior defect of 7.5
mm corresponds to approximately 25% of total
bone loss
Lo IK, Parten PM, Burkhart SS. The inverted pear glenoid: An indicator of significant
glenoid bone loss. Arthroscopy. 2004;20(2):169–174.

70. MRI
• Instability, if consideration is given to surgical treatment, MRI (in comparison to
CT) is considered the standard
• Best for: capsuloligamentous, labral and rotatorcuff lesions
• MR arthrography more sensitive than conventional MRI
• In MR arthrography, labral and rotator cuff tears all had sensitivities >95% and
specificities of nearly 100%
• Conventional 3-T MRI had similar specificities,but lower sensitivities in the 80% to
90% range

71. Diagnostic Arthroscopy
• Examination under anesthesia
• If any doubt of clinical diagnosis or pathological lesion
• More useful in multidirectional instability
• Reports have demonstrated sensitivity and specificity of 100% and
93% respectively

72. Advantages Disadvantages
•Reproducible technique
•Visualization of all pertinent structures
•Technique can be performed in beach
chair or lateral decubitus positions
•Thorough 360° glenohumeral evaluation
•Gold standard to diagnose shoulder
pathology
•Requires general anesthesia
•Risk of infection
•Risk of iatrogenic injury to anatomic
structures
•Risk of traction neuropathy in lateral
decubitus position
•Risk of cerebral hypoperfusion in beach
chair position
Diagnostic Shoulder Arthroscopy: Surgical Technique
Ian M. Crimmins, B.S.,a,∗ Mary K. Mulcahey, M.D.,b and Michael J. O'Brien, M.D.b

74. References
• Rockwood and Green fracture in adults,8th edn
• Campbells Operative Orthopaedics,13th edn
• Apleys system of Orthopedics,9th edn
• Related journals and articles