3. DEFINITION OF GLENOHUMERAL INSTABILITY
• GLENOHUMERAL INSTABILITY IS DEFINED AS THE SYMPTOMATIC AND PATHOLOGIC
CONDITION IN WHICH THE HUMERAL HEAD DOES NOT REMAIN CENTERED IN THE
GLENOID FOSSA
• LAXITY IS DEFINED AS THE DEGREE TO WHICH THE HUMERAL HEAD PASSIVELY
TRANSLATES, RELATIVE TO THE GLENOID, WITH THE APPLICATION OF A LOAD.
• IMPORTANTLY, INSTABILITY IS NOT THE SAME AS LAXITY, WHICH IS A PHYSICAL
EXAMINATION FINDING THAT IS A PROPERTY OF NORMAL JOINTS.
5. SEVERITY.
A DISLOCATION IS DEFINED AS A COMPLETE SYMPTOMATIC DISSOCIATION OF THE
ARTICULAR SURFACES OF THE HUMERAL HEAD AND GLENOID WITHOUT
SPONTANEOUS REDUCTION
A SUBLUXATION IS A SYMPTOMATIC DISSOCIATION OF THE ARTICULAR SURFACES
WITH SPONTANEOUS REDUCTION
6. ETIOLOGY.
TRAUMATIC, NEUROMUSCULAR, ATRAUMATIC, AND MICROTRAUMATIC
• NEUROMUSCULAR CAUSES LIKE SEIZURES AND STROKES IN WHICH THE IMBALANCE OF
THE GLENOHUMERAL MUSCULAR STABILIZERS LEADS TO INSTABILITY
• MICROTRAUMATIC INSTABILITY IS A CONTROVERSIAL THEORETICAL CATEGORY IN WHICH
REPETITIVE SYMPTOMATIC AND ASYMPTOMATIC MICROTRAUMA LEAD TO CHRONIC JOINT
CHANGES AND SUBSEQUENT INSTABILITY.
• ATRAUMATIC OR MICRO TRAUMATIC INSTABILITY IS OFTEN ASSOCIATED WITH
POSTERIOR, BIDIRECTIONAL, AND MULTIDIRECTIONAL INSTABILITY AND UNDERLYING
HYPERLAXITY
• CONGENITAL: RELATED TO GLENOID DYSPLASIA, OR SYSTEMIC SYNDROMES LIKE EHLERS–
DANLOS
7. FREQUENCY AND CHRONICITY
• INITIAL OR RECURRENT
• ACUTE IS BEST DEFINED AS A TIME FROM THE EPISODE TO PRESENTATION IN
WHICH A CLOSED REDUCTION IS LIKELY TO SUCCEED (3 TO 6 WEEKS)
• CHRONIC DISLOCATIONS ARE TYPICALLY LOCKED OR FIXED, MEANING THE
HUMERAL HEAD IS
IMPALED ON THE EDGE OF THE GLENOID MAKING REDUCTION DIFFICULT
8. VOLITION.
• ATRAUMATIC AND CAN BE ASSOCIATED WITH PSYCHIATRIC PROBLEMS OR
SECONDARY GAIN
• THEY CAN REPRODUCE THEIR INSTABILITY, BUT ARE SYMPTOMATIC AND TRY TO
AVOID THESE POSITIONS
9. DIRECTION
ANTERIOR UNIDIRECTIONAL INSTABILITY IS, BY FAR, THE MOST COMMON
THE TYPICAL ANTERIOR DISLOCATION, REPRESENTING ABOUT TWO-THIRDS OF
ANTERIOR
DISLOCATIONS, IS CALLED A SUBCORACOID DISLOCATION AS THE HUMERAL HEAD IS
LOCATED BELOW THE CORACOID PROCESS
10. SUBGLENOID DISLOCATIONS, IN WHICH THE HUMERAL HEAD IS INFERIOR TO THE
GLENOID, REPRESENTS ABOUT ONE-THIRD OF DISLOCATIONS
AP view of a subglenoid dislocation. Note the associated
greater tuberosity fracture.
11. • POSTERIOR INSTABILITY: 10% OF INSTABILITY
• A DIRECTLY INFERIOR DISLOCATION IS ALSO KNOWN AS LUXATIO ERECTA
THE HUMERAL HEAD IS DIRECTLY INFERIOR TO THE GLENOID AND THE
HUMERUS IS LOCKED IN 100 TO 160 DEGREES OF ABDUCTION
12. • SUPERIOR DISLOCATIONS ARE EXTREMELY HIGH-ENERGY INJURIES THAT HAVE
ONLY BEEN DESCRIBED IN CASE REPORTS
• MDI: INSTABILITY IN TWO OR MORE DIRECTIONS TYPICALLY ANTEROINFERIOR OR
POSTEROINFERIOR
13. Superior migration of the humeral head associated with a chronic massive rotator cuff tear. This superior
displacement
should be distinguished from a superior dislocation which is caused by a rare, acute, high-energy injury
mechanism
14. EPIDEMIOLOGY OF GLENOHUMERAL
INSTABILITY
• THE GLENOHUMERAL JOINT IS THE MOST COMMONLY DISLOCATED JOINT IN THE BODY
REPRESENTING 45% OF ALL DISLOCATIONS.
• THE DATA DOES NOT INCLUDE PATIENTS WITH SELF-REDUCED DISLOCATIONS OR
SUBLUXATIONS WHO DID NOT PRESENT TO EMERGENCY DEPARTMENTS.
• A TOTAL OF 8,940 DISLOCATIONS WERE SEEN OVER A 4-YEAR PERIOD BETWEEN 2002 AND
2006. MEN, COMPARED TO WOMEN, HAD AN INCIDENCE RATE RATIO OF 2.64, WITH 71.8%
OF DISLOCATIONS OCCURRING IN MEN.
15. • THE PEAK INCIDENCE OF DISLOCATION (47.8/100,000 PERSON-YEARS) OCCURRED
BETWEEN AGES 20 AND 29 YEARS WITH 46.8% OF ALL DISLOCATIONS OCCURRING IN
PATIENTS BETWEEN 15 AND 29 YEARS OF AGE.
• BIMODAL DISTRIBUTION, HOWEVER PEAK INCIDENCE BETWEEN 80 AND 89 YEARS OF
AGE
• THE RISK OF RECURRENT ANTERIOR INSTABILITY IS HIGHEST AMONG YOUNG MALE
PATIENTS
• ROBINSON ET AL IN THEIR PROSPECTIVE OBSERVATIONAL COHORT STUDY FOUND
PATIENTS BETWEEN 15 AND 35 YEARS OF AGE DEVELOPED RECURRENT INSTABILITY IN
55.7% OF SHOULDERS WITHIN THE FIRST 2 YEARS AFTER DISLOCATION
16. ORTHOPAEDIC TRAUMA
ASSOCIATION
IN THIS SYSTEM, THE SHOULDER REGION IS “10.” THE FIRST DIGIT (“1”) SPECIFIES THE
SHOULDER GIRDLE WHEREAS THE SECOND DIGIT (“0”) SPECIFIES DISLOCATION.
A LETTER IS USED TO IDENTIFY THE SPECIFIC JOINT
A, GLENOHUMERAL;
B, STERNOCLAVICULAR;
C, ACROMIO CLAVICULAR;
D, SCAPULOTHORACIC
FOLLOWED BY ANOTHER NUMBER TO DESCRIBE THE DIRECTION
(1, ANTERIOR; 2, POSTERIOR; 3, LATERAL (THEORETICAL); 4, MEDIAL (THEORETICAL); 5, OTHER
(INFERIOR-LUXATION ERECTA)).
17. ANATOMY AND PATHOANATOMY
ANATOMY OF GLENOHUMERAL STABILITY
• THE STATIC STABILIZERS INCLUDE THE BONY ANATOMY, THE GLENOID LABRUM,
NEGATIVE INTRA-ARTICULAR PRESSURE, ADHESION–COHESION,
CAPSULOLIGAMENTOUS STRUCTURES, AND THE ROTATOR CUFF.
• DYNAMIC STABILIZERS INCLUDE THE ROTATOR CUFF MUSCLES, THE BICEPS
TENDON,
THE DELTOID, SCAPULAR MOTION, AND PROPRIOCEPTION.
18.
19.
20. STATIC CONSTRAINTS
BONE.
GLENOID FACE IS PEAR-SHAPED, 24 AND 35 MM. THE GLENOID COVERS ONLY A
MAXIMUM OF 25% TO 30% OF THE HUMERAL HEAD315 AND THEREFORE THE
GLENOHUMERAL JOINT HAS LIMITED INTRINSIC BONY STABILITY. STABILITY IS
ENHANCED BY A SLIGHT CONCAVITY OF THE GLENOID
The glenoid face is pear shaped with the inferior
twothirds
roughly a circle. The diameter of the red circle is
exactly twothirds
the blue line, the height of the glenoid
21. RADIUS OF CURVATURE OF THE GLENOID SURFACE IS GREATER (LESS
CURVED) THAN THE HUMERAL HEAD BY 2.3 MM TO PREVENT IMPINGEMENT
OF THE HEAD AT THE PERIPHERY OF THE GLENOID
THE GLENOID ALSO HAS A SLIGHT (5 TO 10 DEGREES) SUPERIOR INCLINATION
RELATIVE TO THE VERTICAL AXIS OF THE SCAPULAR BODY.
THIS INCLINATION MAY PLAY A ROLE IN PREVENTING INFERIOR INSTABILITY
OF THE GLENOHUMERAL JOINT AS PATIENTS WITH MDI ARE MORE LIKELY TO
HAVE A DOWNWARD FACING GLENOID
22. • LABRUM
ITS PURPOSE IS TO DEEPEN THE GLENOID FOSSA AND TO CREATE MORE SURFACE
AREA
ANATOMICALLY, THE LABRUM AND CARTILAGE TOGETHER EFFECTIVELY DEEPEN
THE GLENOID BY 80% HELPING TO PREVENT THE HEAD FROM ROLLING OVER THE
GLENOID EDGE A: Cross-sectional
anatomy of a normal
shoulder. Note the
close relationship
between
the subscapularis
tendon and the
anterior capsule. B: A
magnified view of the
anterior joint is
essentially
devoid of
fibrocartilage and is
composed of tissues
from nearby hyaline
23. • INTRA-ARTICULAR PRESSURE: THE OSMOTIC ACTION OF THE SYNOVIUM TO REMOVE
FLUID CREATES A NEGATIVE INTRA-ARTICULAR PRESSURE IN THE JOINT
• ADHESION–COHESION: THE GLENOHUMERAL JOINT NORMALLY ONLY CONTAINS 1 CC
OF SYNOVIAL FLUID THAT NOURISHES THE ARTICULAR SURFACE. THIS FLUID ALSO
PROVIDES A MINOR STABILIZING MECHANISM THROUGH ADHESION–COHESION.
• CAPSULE AND LIGAMENT: THE LIGAMENTS AND CAPSULE IN THE SHOULDER ARE
GENERALLY LAX AND ONLY PROVIDE STABILITY AT THE EXTREMES OF MOTION UNDER
TENSION THE NORMAL GLENOHUMERAL JOINT CAPSULE IS LOOSE AND REDUNDANT TO
ALLOW FOR RANGE OF MOTION
24. DEPENDING ON THE POSITION OF THE SHOULDER, CERTAIN CAPSULOLIGAMENTOUS
STRUCTURES WILL TIGHTEN AND ACT AS A RESTRAINT AGAINST HUMERAL HEAD
TRANSLATION.
1. THE SUPERIOR GLENOHUMERAL LIGAMENT.
ORIGINS FROM THE ANTERIOR SUPERIOR ASPECT OF THE GLENOID (ANTERIOR AND INFERIOR TO
THE BICEPS ORIGIN) AND EXTENDS TO THE ANTERIOR ASPECT OF THE HUMERAL HEAD TO THE
SUPERIOR EDGE OF THE LESSER TUBEROSITY
IT IS THE MOST CONSISTENT OF ALL THE GLENOHUMERAL LIGAMENTS AND IS PRESENT IN OVER
90% OF SHOULDERS
THE SGHL, HOWEVER, CLEARLY LIMITS INFERIOR HUMERAL HEAD TRANSLATION AND EXTERNAL
ROTATION IN THE ADDUCTED ARM. IN ADDITION, IT LIMITS POSTERIOR HUMERAL HEAD
TRANSLATION WITH THE ARM IN FORWARD FLEXION ADDUCTION, AND INTERNAL ROTATION
25.
26. 2. THE MIDDLE GLENOHUMERAL LIGAMENT
• IT CAN ARISE FROM THE SUPRAGLENOID TUBERCLE, ANTEROSUPERIOR ASPECT OF
THE LABRUM, OR THE SCAPULAR NECK AND INSERT VARIABLY ON THE ANTERIOR
HUMERAL HEAD MEDIAL AND INFERIOR TO THE LESSER TUBEROSITY.
• ONE-THIRD OF SHOULDERS IT MAY BE ABSENT OR SIGNIFICANTLY ATTENUATED,
POTENTIALLY CONTRIBUTING TO ANTERIOR INSTABILITY
• THE MGHL IS MAXIMALLY TAUT IN EXTERNAL ROTATION AND ABOUT 45 DEGREES
OF ABDUCTION, FUNCTIONING AS A PRIMARY STABILIZER OF ANTERIOR
TRANSLATION AND A SECONDARY STABILIZER TO EXTERNAL ROTATION IN
ABDUCTION
27.
28. 3. THE INFERIOR GLENOHUMERAL LIGAMENT COMPLEX
• IGHL HAS 3 COMPONENTS: ANTERIOR BAND, AXILLARY POUCH AND POSTERIOR BAND
• THE LIGAMENT ORIGINATES FROM THE ANTEROINFERIOR–POSTEROINFERIOR LABRUM
AND EXTENDS TO THE INFERIOR ASPECT OF THE LESSER TUBEROSITY AND AROUND THE
ANATOMIC NECK OF THE HUMERUS.
• IGHLC IS TENSIONED IN FURTHER ABDUCTION AND EXTERNAL ROTATION AND IN THIS
POSITION HAS BEEN DEMONSTRATED TO BE THE PRIMARY STABILIZER AGAINST ANTERIOR
AND INFERIOR TRANSLATION OF THE HUMERAL HEAD.
• IN ADDUCTION, THE IGHLC IS A SECONDARY STABILIZER TO INFERIOR TRANSLATION THE
IGHLC IS THE MOST IMPORTANT LIGAMENT CLINICALLY
29. THE CORACOHUMERAL LIGAMENT AND THE ROTATOR INTERVAL
• ORIGINS FROM LATERAL ASPECT OF THE CORACOID PROCESS PASSES WITHIN THE
INTERVAL BETWEEN THE SUBSCAPULARIS AND THE SUPRASPINATUS TENDONS
BLENDING WITH THE CAPSULE, AND ATTACHING IN TWO BANDS TO THE LESSER AND
GREATER TUBEROSITIES, RESPECTIVELY
• CHL PLAYS THE SAME ROLE AS THE SGHL, LIMITING EXTERNAL ROTATION AND
INFERIOR TRANSLATION WHEN THE ARM IS ADDUCTED.
30. THE CORACOACROMIAL LIGAMENT
• ORIGINATING FROM THE LATERAL ASPECT OF THE CORACOID AND ATTACHING TO THE
ANTERIOR PORTION OF THE ACROMION
• THE LIGAMENT IS A CONSTRAINT TO SUPERIOR ESCAPE OF THE HUMERAL HEAD IN THE
SETTING OF MASSIVE ROTATOR CUFF TEARS
THE POSTERIOR CAPSULE
• CAPSULE EXTENDING FROM THE POSTERIOR BAND OF THE IGHLC TO THE BICEPS INSERTION
IS TERMED THE POSTERIOR CAPSULE
• IT HELPS TO LIMIT POSTERIOR TRANSLATION WHEN THE SHOULDER IS FLEXED, ADDUCTED,
AND INTERNALLY
ROTATED
31. DYNAMIC STABILIZERS
1. THE ROTATOR CUFF
• CONTRACTION OF THE ROTATOR CUFF COMPRESSES THE HUMERAL HEAD AGAINST THE
GLENOID, INCREASING THE ROLE OF THE LABRUM FOR STABILITY AND THE FORCE NEEDED
TO TRANSLATE THE HEAD
• LAST, IN THEIR FUNCTION TO ROTATE AND ELEVATE THE HUMERUS, THE CUFF MUSCLES
CAN DYNAMICALLY TIGHTEN THE CAPSULE AND LIGAMENTS.
2. THE BICEPS TENDON
SOME STUDIES INDICATE THAT BOTH PASSIVELY AND DYNAMICALLY THE LHB HELPS LIMIT
ANTERIOR, POSTERIOR,
AND INFERIOR TRANSLATION OF THE HUMERAL HEAD, ESPECIALLY IN ADDUCTION
32.
33. • OTHER DYNAMIC STABILIZERS
THE DELTOID AND THE SCAPULAR STABILIZERS ALL LIKELY PLAY SOME ROLE IN
THE NORMAL STABILIZATION OF THE GLENOHUMERAL JOINT, BUT THE EXTENT AND
THE EXACT MECHANISM OF EACH IS NOT WELL DEFINED IN OUR CURRENT SCIENCE.
• PROPRIOCEPTION
MECHANORECEPTORS HAVE BEEN FOUND IN THE CAPSULE AND LABRUM AND
LIKELY PROVIDE POSITIONAL FEEDBACK OF HUMERAL HEAD AND JOINT POSITIONING A
NUMBER OF STUDIES HAVE NOTED ALTERED PROPRIOCEPTION IN PATIENTS WITH MDI
AND IN PATIENTS AFTER A TRAUMATIC DISLOCATION
35. BANKART LESION
DISRUPTION BETWEEN THE ANTERIOR INFERIOR LABRUM AND THE GLENOID, AS SEEN
IN TRAUMATIC ANTERIOR INSTABILITY, WAS TERMED THE “ESSENTIAL LESION” BY
BANKART IN 1938.
36. THIS DISRUPTION IS CRITICAL IN THE DEVELOPMENT OF RECURRENT INSTABILITY BECAUSE
IT SERVES AS THE ANCHOR FOR THE IGHLC, WHICH IS THE PRIMARY STATIC STABILIZER
AGAINST ANTERIOR AND INFERIOR HUMERAL TRANSLATION IN ABDUCTION AND EXTERNAL
ROTATION.
37. SECOND, THE CONCAVITY–COMPRESSION EFFECT (DESCRIBED ABOVE) FORMED THROUGH THE
COMBINATION OF DYNAMIC HUMERAL HEAD COMPRESSION AND THE INCREASED GLENOID
CONCAVITY BY THE LABRUM IS DISRUPTED.
IMPORTANTLY, AN ISOLATED LABRAL LESION IS LIKELY NOT ENOUGH TO LEAD TO GROSS
INSTABILITY AND NEEDS TO INCLUDE DETACHMENT OF THE CAPSULOLIGAMENTOUS COMPLEX
IF THE IGHLC DETACHES WITH A SMALL PIECE OF AVULSED GLENOID, THE LESION IS CALLED A
BONY BANKART
38. ANTERIOR LABRAL LIGAMENTOUS PERIOSTEAL SLEEVE AVULSION.
ALPSA LESIONS ARE TECHNICALLY MORE DIFFICULT TO TREAT AND THE
OUTCOMES HAVE BEEN SHOWN TO BE INFERIOR TO TREATMENT OF MORE
ACUTE CAPSULE LIGAMENTOUS TEARS (I.E., BANKART LESIONS)
An axial cut of a T2-weighted MR
arthrogram with a
chronic ALPSA lesion (arrow) characterized
by medial displacement
of the labrum with surrounding fibrous scar
tissue
39. HUMERAL AVULSION OF GLENOHUMERAL LIGAMENTS.
• THIS INJURY IS A TRAUMATIC RUPTURE OF THE IGHLC AT ITS HUMERAL ATTACHMENT
• TYPICALLY IT OCCURS WITH THE ARM IN HYPERABDUCTION AND EXTERNAL ROTATION AND
OFTEN RESULTS IN INSTABILITY.
A coronal cut of a T2-weighted MRI showing a
humeral avulsion of the glenohumeral ligament from
the humeral
neck, or HAGL lesion.
40. ROTATOR CUFF
• ROTATOR CUFF TEARS ARE UNCOMMON IN PATIENTS UNDER 40 YEARS OF AGE
WITH GLENOHUMERAL INSTABILITY, BUT CAN BE SEEN IN HIGH-ENERGY
INJURIES.
• SUPRASPINATUS AND SUBSCAPULARIS TEARS ARE THE MOST COMMON IN
TRAUMATIC EVENTS
41. BONE
• GLENOID
SOME PATIENTS WITH SIGNIFICANTLY RETROVERTED, HYPOPLASTIC GLENOIDS
ARE PREDISPOSED TO RECURRENT POSTERIOR INSTABILITY
THE PATHOANATOMY IN TRAUMATIC ANTERIOR INSTABILITY IS MOST OFTEN
BONE LOSS OF THE ANTERIOR-INFERIOR GLENOID EITHER FROM AN ACUTE
FRACTURE/BONY BANKART OR CHRONIC BONY EROSION FROM MULTIPLE
DISLOCATIONS
42. • HUMERAL HEAD.
A COMPRESSION FRACTURE OF THE POSTEROSU PEROLATERAL HUMERAL HEAD,
ALSO KNOWN AS A HILL–SACHS LESION, IS A SEQUELA OF AN ANTERIOR
DISLOCATION.
LESION IS CREATED WITH THE ARM IN ABDUCTION AND EXTERNAL ROTATION
WITH THE POSTERIOR HUMERAL HEAD CRUSHED ON THE ANTERIOR GLENOID RIM
43. • REVERSE HILL SACHS
IT IS VISUALISED AS ANY LOSS OF NORMAL CONVEXITY IN THE ANTEROMEDIAL
ASPECT OF THE HUMERAL HEAD.
For posterior dislocations, the initial size of a “reverse”
Hill–Sachs on the anterior humeral head is an important
predictor of who may have recurrent instability
44. An axial cut of a CT scan showing chronic anterior
glenoid bone loss (black arrows)
and a large Hill–Sachs lesion (white arrow).
45. ASSESSMENT OF GLENOHUMERAL INSTABILITY
ANTERIOR INSTABILITY OCCURS THROUGH AN INDIRECT MECHANISM WITH ARM
ABDUCTION, EXTENSION, AND EXTERNAL ROTATION WITH THE HUMERAL HEAD
CHALLENGING THE ANTERIOR CAPSULE AND LIGAMENTS, GLENOID RIM, AND ROTATOR
CUFF.
POSTERIOR INSTABILITY OCCURS THROUGH THE INDIRECT MECHANISM OF FLEXION,
ADDUCTION, AND INTERNAL ROTATION WITH AN AXIAL LOAD (E.G., FALL ON AN
OUTSTRETCHED ARM). PATIENTS MAY SUFFER EITHER A POSTERIOR DISLOCATION FROM A
SINGLE TRAUMATIC EVENT OR MAY DEVELOP RECURRENT SUBLUXATIONS FROM REPETITIVE
MICROTRAUMA IN THIS POSITION.
46. NEUROMUSCULAR EVENTS (E.G., ALCOHOL WITHDRAWAL, SEIZURES OR ELECTRIC SHOCK)
ACCOUNT FOR 30% OF ALL POSTERIOR DISLOCATIONS AND LEAD TO INSTABILITY
THROUGH VIOLENT MUSCLE CONTRACTION
LUXATIO ERECTA
EXTREME HYPERABDUCTION IN WHICH THE PROXIMAL HUMERUS LEVERS AGAINST THE
ACROMION AND DISLOCATES INFERIORLY.
SUPERIOR DISLOCATIONS
ARE EXTREMELY RARE, BUT OCCUR WITH EXTREME UPWARD FORCE THROUGH AN
ADDUCTED ARM
47. SIGNS AND SYMPTOMS OF
GLENOHUMERAL INSTABILITY
• ACUTE INSTABILITY
HISTORY:
CLEARLY DESCRIBE THE MECHANISM OF INJURY AND SHOULDER POSITION DURING
DISLOCATION.
THOUGH ANTERIOR DISLOCATIONS REPRESENT THE VAST MAJORITY OF ACUTE TRAUMA,
SUSPICION OF A POSTERIOR DISLOCATION SHOULD BE RAISED WITH A HISTORY OF A
HIGH-ENERGY TRAUMA OR STRONG MUSCLE CONTRACTION AS SEEN WITH A SEIZURE OR
ELECTRIC SHOCK.
AS WITH ANY INJURY, PREVIOUS EPISODES, AND PRIOR TREATMENTS SHOULD ALL BE
NOTED.
49. HUMERAL HEAD MAY BE PALPABLE OR PROMINENT BENEATH THE SKIN AND THE
LATERAL EDGE AND POSTEROLATERAL CORNER OF THE ACROMION MAY APPEAR
PROMINENT
SOMETIMES A POSTERIOR FULLNESS CAN BE NOTED WITH ANTERIOR FLATTENING
AND A CORRESPONDING PROMINENCE OF THE CORACOID ANTERIORLY
A COMPLETE NEUROVASCULAR EXAMINATION OF THE UPPER EXTREMITY MUST BE
PERFORMED AND DOCUMENTED
50. DELTOID STRENGTH AND AXILLARY NERVE SENSATION SHOULD BE CAREFULLY EXAMINED.
THE MUSCULOCUTANEOUS NERVE IS THE NEXT MOST COMMONLY INJURED NERVE AND
CAREFUL ATTENTION TO CONTRACTION OF THE BICEPS OR BRACHIALIS IS IMPORTANT
ALONG WITH TESTING OF SENSATION IN THE LATERAL ANTEBRACHIAL CUTANEOUS
DISTRIBUTION ON THE LATERAL ASPECT OF THE FOREARM.
BRACHIAL, RADIAL, AND ULNAR PULSE SHOULD ALWAYS BE EXAMINED
51. • MOVEMENT RESTRICTION AT SHOULDER IN DISLOCATIONS
ANTERIOR: INTERNAL ROTATION AND ABDUCTION
POSTERIOR: EXTERNAL ROTATION AND ABDUCTION WITH LIMITED PASSIVE
ELEVATION TO 90 DEGREES
LUXATIO ERECTA: LOCKED IN A FULLY ABDUCTED POSITION
52. AFTER A REDUCTION IS PERFORMED AND VERIFIED RADIOGRAPHICALLY THE
EXAMINATION MAY BE LIMITED BY GUARDING.
TESTING POSTREDUCTION RANGE OF MOTION IS NOT ADVISED OR SHOULD BE VERY
LIMITED IF THE PATIENT IS AWAKE. IN ADDITION, TESTING MAY LEAD TO ANOTHER
DISLOCATION.
A THOROUGH NEUROVASCULAR EXAMINATION SHOULD BE REPERFORMED.
53. A patient with recurrent right shoulder instability with scapular dyskinesis and asymmetric motion. Note
right posterior incision from a failed capsulorrhaphy
54. GENERAL TESTS FOR LAXITY
• DRAWER TEST: MC TEST FOR LAXITY
PATIENT SITTING WITH THE EXAMINER BEHIND THE PATIENT
55. The Drawer Test. While stabilizing the scapula with
one hand,
the other hand grasps the humeral head. A gentle
pressure is then applied
toward the center of the glenoid. At the same time,
the humeral head is manually
translated in the anterior and in the posterior
direction. (A and B) Illustration
and clinical photo of the Drawer Test.
56. FOR NORMAL SHOULDERS, THIS TRANSLATION IS SMOOTH
IF THE TRANSLATION IS EXCESSIVE, THE PATIENT HAS INCREASED LAXITY, BUT NOT
NECESSARILY INSTABILITY.
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 FINDING
57. LOAD AND SHIFT TEST
• SUPINE AND ARM IN 60 DEGREE ABDUCTION
• AN AXIAL PRESSURE IS APPLIED TO THE HUMERAL HEAD TO PRESS THE HUMERAL HEAD
AGAINST THE GLENOID WITH THE FOREARM IN NEUTRAL POSITION
• SIMILAR TO THE DRAWER TEST, THE HUMERAL HEAD IS THEN GRASPED AND TRANSLATED IN
EITHER THE ANTERIOR OR POSTERIOR DIRECTION TO ASSESS FOR LAXITY AND PAIN
58.
59. SULCUS TEST
SEATED WITH THEIR ARM RELAXED AT THEIR SIDE AND THE ARM IS THEN PULLED
DOWNWARD
A POSITIVE TEST REVEALS A “SULCUS” OR HOLLOW AREA BELOW THE ACROMION
The sulcus test for inferior
instability of the shoulder.
With the patient in the
sitting
position, a downward
traction is placed on the
adducted arm (A). With a
positive test (B), excessive
inferior translation
produces a dimple (arrow)
on the lateral aspect of the
acromion. By performing
this test with the arm in
external rotation, the
maneuver can also be used
to test the integrity of the
60. GAGEY HYPERABDUCTION TEST
EXAMINER STANDS BEHIND THE PATIENT WITH THEIR FOREARM PUSHED DOWN
AGAINST THE SHOULDER GIRDLE
PATIENTS WHO CAN BE ABDUCTED OVER 105 DEGREES HAVE INCREASED LAXITY
WHEREAS THOSE WITH SYMPTOMS OF APPREHENSION SUGGEST A DIAGNOSIS OF
INFERIOR INSTABILITY.
NORMAL ABDUCTION SHOULD BE 85 TO 90 DEGREES.
61. The Gagey abduction test for
inferior laxity.
The examiner stands behind
the patient with their forearm
pushed down
against the shoulder girdle
using the other hand to
gently passively
abduct the patient’s arm.
Normal abduction is about 90
degrees as seen in this
patient.
Abduction over 105 degrees
reflects increased laxity,
whereas symptoms of
apprehension suggest a
62. SPECIFIC EXAMINATIONS FOR ANTERIOR INSTABILITY
APPREHENSION TESTS.
PATIENT SUPINE OR SITTING WITH THE EXAMINER BEHIND THE PATIENT.
FROM A POSITION OF 90 DEGREES OF ABDUCTION AND NEUTRAL ROTATION, THE
SHOULDER IS EXTERNALLY ROTATED UNTIL IT REACHES ITS MAXIMAL LIMIT OR UNTIL
THE FEELING OF APPREHENSION IS REPORTED BY THE PATIENT
IT MAY BE NECESSARY TO HOLD THE ARM IN THIS POSITION FOR 1 TO 2 MINUTES TO
FATIGUE THE SUBSCAPULARIS BEFORE APPREHENSION IS FELT FROM CAPSULAR
INSUFFICIENCY.
63. The apprehension test for anterior instability. In the apprehension test, the shoulder is abducted and
externally rotated such that it is in a position vulnerable to dislocation with the patient in supine
position. Symptomatic patients will report the sensation of apprehension or “getting ready to
dislocate.”
64. In the fulcrum test, this sensation of instability is accentuated by placing an anteriorly directed
force on the posterior humeral head
65. IN THE RELOCATION TEST AS DESCRIBED BY JOBE A POSTERIORLY DIRECTED FORCE IS
PLACED ON THE ANTERIOR ASPECT OF THE SHOULDER TO ELIMINATE THE FEELING OF
APPREHENSION
The relocation test for anterior
instability.
With the patient supine, the
shoulder is abducted and externally
rotated such
that it is in a position vulnerable to
dislocation.
With a positive relocation test, the
apprehension is reduced with a
posteriorly directed force on the
shoulder
66. A VARIATION OF THIS TEST IN WHICH AN ANTERIOR-DIRECTED PRESSURE IS ADDED TO
THE HUMERAL HEAD IS CALLED THE CRANK TEST
The crank test for anterior instability. The shoulder is abducted and externally rotated such that
it is in a position vulnerable to anterior dislocation with the patient in sitting position.
With an anteriorly directed force on the posterior humeral head, the instability is accentuated to
cause the sensation of apprehension or “getting ready to dislocate.”
67. JERK TEST
WITH THE ARM ELEVATED TO 90 DEGREES AND INTERNALLY ROTATED AN AXIAL LOAD IS
PLACED SUCH THAT THE HUMERAL HEAD IS COMPRESSED AGAINST THE GLENOID AND
THE SCAPULA IS STABILIZED BY THE EXAMINER’S OTHER HAND.
BY GRADUALLY ADDUCTING THE SHOULDER, THE HUMERAL HEAD MAY SUBLUXATE OR
EVEN DISLOCATE POSTERIORLY AND PRODUCE A SUDDEN JERK.
WHEN THE SHOULDER IS RETURNED TO ITS ORIGINAL POSITION, THE HUMERAL HEAD WILL
ABRUPTLY REDUCE BACK ONTO THE GLENOID AND PRODUCE ANOTHER JERK
68. The jerk test for posterior instability. With the patient in either sitting or supine position,
the arm is abducted and internally rotated. An axial load is then placed on the humerus
while the arm is moved horizontally across the body. With a positive test, a sudden jerk
occurs when the humeral head slides off of the back of the glenoid and when it is reduced
back onto the glenoid
69. IMAGING AND OTHER DIAGNOSTIC STUDIES
FOR GLENOHUMERAL INSTABILITY
Technique for obtaining anteroposterior (AP) thorax (A) and true AP (B) radiographs of
the shoulder. In an AP view, the radiograph actually represents an oblique view of the shoulder
joint.
In a true AP view, the x-ray beam is parallel to the joint so that there is minimal overlap
between the
75. CT IS NECESSARY TO DETERMINE THE SIZE AND DISPLACEMENT OF A SUSPECTED
GLENOID FRACTURE OR THE PRESENCE OF PROXIMAL HUMERUS FRACTURES AS
ROUTINE RADIOGRAPHS CAN BE DIFFICULT TO INTERPRET
IN THE SUBACUTE (FIRST OFFICE VISIT OF A FIRST TIME DISLOCATER) OR A NONACUTE
SETTING, IF CONSIDERATION IS GIVEN TO SURGICAL TREAMENT, MRI (IN COMPARISON
TO CT) IS CONSIDERED THE STANDARD OF REFERENCE FOR THE DETERMINATION OF
PATHOANATOMY BECAUSE THE MAJORITY OF INJURIES ARE CAPSULOLIGAMENTOUS
MRI IS ALSO NECESSARY TO EVALUATE FOR ROTATOR CUFF TEARS AND HUMERAL
AVULSIONS OF THE GLENOHUMERAL LIGAMENTS (HAGL)
76. CT SCAN WITH THREE-DIMENSIONAL RECONSTRUCTIONS IS THE IDEAL STUDY FOR
THE EVALUATION OF BONY PATHOLOGY:
• ACUTE FRACTURE,
• ANTERIOR-INFERIOR GLENOID HUMERAL BONE LOSS, AND
• HILL–SACHS DEFORMITIES
77. TREATMENT OPTIONS FOR GLENOHUMERAL INSTABILITY
• ANTERIOR INSTABILITY
FIRST-TIME DISLOCATION EVENTS CAN TYPICALLY BE MANAGED NONOPERATIVELY, WITH
CLOSED REDUCTION FOLLOWED BY SHOULDER REHABILITATION
ULTIMATELY, THE DECISION TO PROCEED WITH NONOPERATIVE VERSUS OPERATIVE
MANAGEMENT SHOULD BE MADE ON A CASE-BY-CASE BASIS, BASED ON THE PATIENT’S
AGE, ACTIVITY LEVEL, PRESENTING HISTORY, AND TYPE AND SEVERITY OF PATHOLOGY
81. STIMSON TECHNIQUE
Slow, steady traction provided by the attached
weights results in fatigue and relaxation of the
shoulder musculature that disengages the humeral
head reduces the shoulder after traction is released.
This method usually takes up to 15 to 20 minutes to
produce its effect; however, the patient should be
monitored closely to avoid a prolonged period of
time in this position that could result in traction
injury to a nerve.
82. MILCH METHOD
• EITHER A SUPINE OR PRONE POSITION
THE ARM IS SLOWLY ABDUCTED WHILE STABILIZING THE HUMERAL HEAD WITH
THE OPPOSITE HAND. THE SHOULDER IS THEN SLOWLY EXTERNALLY ROTATED,
CAUSING THE HUMERAL HEAD TO SPONTANEOUSLY REDUCE WHEN THE
SHOULDER HAS REACHED APPROXIMATELY 90 DEGREES OF ABDUCTION AND 90
DEGREES OF EXTERNAL ROTATION.
85. POSTOPERATIVE MANAGEMENT
• CONFIRMED WITH FLUOROSCOPY OR PLAIN RADIOGRAPHS
• POSTREDUCTION DOCUMENTATION OF THE NEUROVASCULAR STATUS OF THE ARM
SHOULD ALSO BE PERFORMED AND COMPARED TO THE PRE-REDUCTION EXAMINATION
FOR ANY CHANGES
• TO RESTORE FUNCTION AS PROMPTLY AS POSSIBLE, A BRIEF PERIOD OF IMMOBILIZATION
SHOULD BE FOLLOWED BY MOBILIZATION AND REHABILITATION OUTCOMES.
• THE MOST COMMON COMPLICATION AFTER A SUCCESS FUL CLOSED REDUCTION IS THE
DEVELOPMENT OF RECURRENT INSTABILITY.
86. OPEN REDUCTION OF AN ANTERIOR DISLOCATION
ACUTE SETTING, OPEN REDUCTION MAY BE ALL THAT IS NEEDED TO STABILIZE THE
JOINT; HOWEVER, OTHER SOFT TISSUE SURGERY MAY BE REQUIRED, SUCH AS
CAPSULOLABRAL REPAIR OR ROTATOR CUFF REPAIR
BONE LOSS IS MORE LIKELY TO BE PRESENT IN THE HUMERAL HEAD AND/OR GLENOID
AND ADDITIONAL SURGERY MAY BE NEEDED TO ADDRESS THE BONE DEFECTS
87. SURGICAL APPROACH AND TECHNIQUE
STANDARD DELTOPECTORAL APPROACH, WITH THE LONG HEAD OF THE BICEPS
TENDON AS A GUIDE TO FIND THE LESSER TUBEROSITY AND THE ROTATOR INTERVAL
IF A SIGNIFICANT HUMERAL HEAD DEFECT IS PRESENT FOLLOWING REDUCTION,
HUMERAL HEAD DISIMPACTION MAY BE CONSIDERED.
88. HILL–SACHS DEFECTS INVOLVING 25% OR MORE OF THE HUMERAL HEAD MAY BE
ADDRESSED WITH ALLOGRAFT RECONSTRUCTION OR PARTIAL RESURFACING.
SHOULDER ARTHROPLASTY MAY BE NECESSARY FOR EVEN LARGER DEFECTS,
ESPECIALLY IN OLDER PATIENTS WITH HILL–SACHS DEFECTS INVOLVING 40% TO 45%
OR MORE OF THE HUMERAL HEAD AN INDICATION FOR COMPLETE HUMERAL HEAD
REPLACEMENT
89. ARTHROPLASTY.
AS NOTED ABOVE, SHOULDER ARTHROPLASTY MAY BE NECESSARY FOR LARGER HUMERAL
HEAD DEFECTS, OR IF ADVANCED DEGENERATIVE CHANGES ARE PRESENT
HEMIARTHROPLASTY IS USUALLY PERFORMED IN YOUNGER PATIENTS BELOW THE AGE OF 50
AND PATIENTS WITH GOOD GLENOID CARTILAGE.
TOTAL SHOULDER ARTHROPLASTY IS INDICATED IN OLDER PATIENTS WITH SIGNIFICANT
GLENOID DEGENERATIVE CHANGES.
IN THE ELDERLY PATIENT, REVERSE TOTAL SHOULDER ARTHROPLASTY MAY BE NECESSARY IF
THE ROTATOR CUFF IS DEFICIENT
90. OPEN SOFT TISSUE PROCEDURES FOR RECURRENT ANTERIOR INSTABILITY
ANTERIOR INSTABILITY OPEN ANTERIOR SHOULDER STABILIZATION CONSISTING OF A
CAPSULOLABRAL (BANKART) REPAIR HAS TRADITIONALLY BEEN CONSIDERED THE “GOLD
STANDARD” FOR SURGICAL TREATMENT OF RECURRENT ANTERIOR INSTABILITY, WITH
MANY STUDIES REPORTING GOOD-TO-EXCELLENT OUTCOMES IN THE VAST MAJORITY OF
PATIENTS
91. ARTHROSCOPIC SOFT TISSUE PROCEDURES FOR
RECURRENT
ANTERIOR INSTABILITY
• EQUIVALENT OUTCOMES
• REMPLISSAGE IS THE TERM USED TO DESCRIBE ARTHROSCOPIC POSTERIOR
CAPSULODESIS AND INFRASPINATUS TENODESIS, IN WHICH THE POSTERIOR
CAPSULE AND INFRASPINATUS ARE ANCHORED INTO THE SURFACE OF A HILL–
SACHS DEFECT TO PREVENT ENGAGEMENT OF THE LESION
92. FIGURE 40-45 Intraoperative images of arthroscopic
Bankart repair.
A: Diagnostic arthroscopy demonstrates the torn
anteroinferior capsulolabral tissue (arrow).
B: The torn labrum is reattached to the glenoid rim using
suture anchors, with the initial anchors placed inferiorly.
C: Completed Bankart repair
93. BONY PROCEDURES FOR RECURRENT
ANTERIOR INSTABILITY
LARGE HILL–SACHS DEFECT, EITHER IN THE PRIMARY OR REVISION SETTING, IS AN INDICATION FOR A
BONY PROCEDURE FOR SURGICAL TREATMENT OF RECURRENT ANTERIOR INSTABILITY
GLENOID BONE LOSS MORE THAN 25% IS AN INDICATION
SEVERAL DIFFERENT BONE AUGMENTATION TECHNIQUES HAVE BEEN DESCRIBED;
INCLUDING THE LATARJET PROCEDURE, USE OF ILIAC CREST AUTOGRAFT, OR USE OF STRUCTURAL
ALLOGRAFT.
ALL FUNCTION TO FILL THE GLENOID DEFECT WITH A STRUCTURAL BONE GRAFT TAKEN FROM
ANOTHER SITE.
94. HOWEVER, THE LATARJET PROCEDURE, INVOLVING TRANSFER OF THE CORACOID
PROCESS TO THE ANTEROINFERIOR GLENOID, HAS BEEN THE MOST WELL STUDIED
AND POPULAR OF THESE TECHNIQUES
Coracoid exposure and osteotomy for Latarjet
procedure.
Coracoid osteotomy can be performed with an
osteotome or
angled, oscillating saw, with the cut made starting
along the superior
surface of the bone, just anterior to the
coracoclavicular ligaments
near the coracoid base, in a medial-to-lateral
direction. A 1-cm stump
of the coracoacromial ligament is left attached to the
coracoid
95. Anteroposterior (A) and (B) lateral views following fixation of the coracoid graft to the anterior
glenoid.
The stump of the coracoacromial ligament is repaired to the lateral capsular flap made during
capsular incision. Note the sling effect created by placement of the coracoid graft through the
split in the subscapularis. The inferior third of the subscapularis is maintained in an inferior
96. RECONSTRUCTION OF HILL–SACHS DEFECT. TO ACCESS THE HILL–SACHS DEFECT
THROUGH A STANDARD DELTOPECTORAL APPROACH, A SUBSCAPULARIS TENOTOMY
IS PERFORMED
HUMERAL HEAD IS THEN DISLOCATED FROM THE GLENOHUMERAL JOINT AND THE
HILL–SACHS DEFECT EXPOSED WITH SIMULTANEOUS ADDUCTION, EXTENSION, AND
MAXIMAL EXTERNAL ROTATION OF THE ARM, OSCILLATING SAW IS USED TO
CONTOUR THE BONE INTO A WEDGE-SHAPED DEFECT TO ACCEPT AN ALLOGRAFT
After appropriate contouring of the defect and graft,
the allograft bone is fitted into the Hill–Sachs defect
and provisionally
held in place with guidewires. Cannulated screws
can be placed
over the guidewires for definitive graft fixation
97. POSTERIOR INSTABILITY
MANAGEMENT SHOULD BE DISCUSSED BY THE TYPE OF INSTABILITY:
ACUTE DISLOCATION (<3 WEEKS) WHICH IS RARE, CHRONIC DISLOCATION WHICH
IS EVEN MORE UNCOMMON, AND RECURRENT INSTABILITY WHICH IS THE MOST
COMMON FORM.
THE USE OF 3 WEEKS IS ARBITRARY, BUT AS DISCUSSED BELOW, ATTEMPTED
CLOSED REDUCTION BECOMES LESS SUCCESSFUL AROUND THIS TIME.
98.
99. CLOSED REDUCTION. MANY POSTERIOR DISLOCATIONS ARE LOCKED AND INITIALLY
MISSED WITH THE EXACT TIMING OF THE INJURY SOMETIMES UNCLEAR. IN ADDITION, 30%
TO 40% OF DISLOCATIONS HAVE AN ASSOCIATED FRACTURE AND FOR THESE REASONS,
CLOSED REDUCTION REQUIRES COMPLETE MUSCLE RELAXATION AND FLUOROSCOPY
UNSUCCESSFUL, CONSIDERATION FOR OPEN OR ARTHROSCOPIC REDUCTION.
100. TECHNIQUE
• THE REDUCTION MANEUVER IS FORWARD FLEXION WITH THE ARM IN ADDUCTION AND
INTERNAL ROTATION
• ASSISTANT - GENTLE CROSS-BODY TRACTION, GENTLE DIGITAL PRESSURE IS PLACED ON
THE POSTERIOR HUMERAL HEAD
• ONCE THE HEAD IS DISIMPACTED, THE HEAD SHOULD BE BROUGHT ANTERIORLY AND
EXTERNALLY ROTATED
• POSTREDUCTION, THE ARM SHOULD BE PLACED IN NEUTRALROTATION WITH A BUMP
UNDER THE SLING OR A “GUN-SLINGER ORTHOSIS” SPLINT
101.
102.
103.
104. OPEN ANTERIOR PROCEDURES FOR CHRONIC
POSTERIOR
DISLOCATIONS
• SUBSCAPULARIS TRANSFER
• LESSER TUBEROSITY TRANSFER.
• ALLOGRAFT RECONSTRUCTION.
• ARTHROPLASTY.
POSTERIOR APPROACH: OPEN OR ARTHROSCOPIC
POSTERIOR CAPSULORRHAPHY
105. The McLaughlin operation. In the
presence of a large anterior humeral head
lesion, the subscapularis tendon can be
transferred into the defect.
A subsequent modification by Neer
transfers the lesser tuberosity with the
attached subscapularis tendon
106. MULTIDIRECTIONAL INSTABILITY
• NON OPERATIVE
FOCUSES ON IMPROVING THE COORDINATION OF THE DYNAMIC STABILIZERS TO
IMPROVE THE SCAPULOTHORACIC MOTION, TO STRENGTHEN THE ROTATOR CUFF,
AND TO IMPROVE THE GLENOHUMERAL PROPRIOCEPTION.
ALL PATIENTS DIAGNOSED WITH MDI SHOULD HAVE A PHYSICAL THERAPY
PROGRAM FOR A MINIMUM OF 6 MONTHS BEFORE SURGICAL INTERVENTION IS
CONSIDERED.
