1. Shoulder Instability Department of Orthopaedics, CKUH Sen-Jen Lee
Reference: Orthopaedic Knowledge Update 6

2. Natural History
The most common sequela of traumatic anterior shoulder instability is recurrence
90% for those 11 to 20 years of age
Averaging between 55% and 66%
87% recurrent instability after nonsurgical treatment
In the skeletally immature individual
Bankart lesion (labral detachment of the inferior glenohumeral ligament complex, IGHLC)
Length of immobilization, avoidance of overhead activity, and supervised physical therapy had no effect on outcome
Patients over 40 years of age
Neurologic injury and rotator cuff tears

4. Biomechanics Static Stabilizers
Articular curvature between the glenoid and humeral head
Superior glenohumeral ligament (SGHL) and coracohumeral ligament (CHL)
To resist inferior translation
Middle glenohumeral ligament (MGHL)
To limit anterior translation
IGHLC
Primary restraint to anterior and posterior translation
Secondary restraint to inferior translation

7. Biomechanics Dynamic Stabilizers
Rotator cuff muscles
Center the humeral head on the glenoid
Maintain joint stability
The capsuloligamentous structures (proprioception) provide afferent feedback for reflexive muscular control of the rotator cuff and biceps

8. Patient Evaluation History Physical examination Imaging
Specific provocative tests
Apprehension/relocation test and sulcus sign test
Imaging
Scapula (AP and lateral [y-view])
Axillary view
West point axillary view
CT arthrogram or MRI
Examination under anesthesia and arthroscopy

9. Apprehension test
Relocation test
Load shift test
Sulcus sign

10. True anteroposterior view
West Point view (axillary)

11. Computed tomography scan of glenohumeral joint with significant anterior bone loss and presence of Hill-Sachs lesion.
Magnetic resonance image with arthrogram of large Bankart lesion.

12. Arthroscopic Findings of Patients With Instability
Bankart lesions: 87%
Capsular insufficiency :79%
Hill-Sachs lesions: 68%
(posterosuperior humeral head impression fracture )
Glenohumeral ligament insufficiency: 55%

14. Clasification of Anterior Instability
Direction
Anterior
Posterior
Inferior
Multidirectional
Cause
Traumatic
Acute
Repetitive
Nontraumatic
Degree
Subluxation
Dislocation
Frequency
Acute
Recurrent
Patient control
Voluntary
Involuntary

15. Matsen’s Classification of Anterior Instability
AMBRI
Atraumatic
Multidirectional
Bilateral
Rehabilitation
Inferior capsular shift
TUBS
Traumatic
Unidirectional
Bankar lesion
Surgery

16. Redislocation Rates After Initial Dislocation (< 35 Y/O)
Investigators
Patients (%)
No. of patients
Age (years)
Rowe 94 53
< 20
Mclaughlin 95
181
Simonet 66 32
Henry 88
121
< 32
Hovelius 64
102
< 22
Wheeler 92 38
Marans
100 21

17. Causes of Anterior Shoulder Instability
Bankart lesion
Avulsion of the anteroinferior capsulolabral complex
Hill-Sachs lesion
Compression fracture of the posterosuperior humeral head
SLAP lesion
Superior labrum anterior posterior
HAGL lesion
Humeral avulsion of glenohumeral ligaments
ALPSA lesion
Ant. labroligamentous periosteal sleeve avulsion
Laxity of the joint capsule

18. Treatment of Anterior Glenohumeral Instability
Nonsurgical treatment:
Closed reduction
Immobilization (3 to 6 weeks) rehabilitation
Rate of recurrence : (less than 20 years old)
60% to 90%

19. Treatment of Anterior Glenohumeral Instability
Arthroscopic Bankart repair versus nonoperative treatment for acute, initial anterior shoulder dislocations.
14 % versus 80% recurrent instability
Arciero RA, wheeler JH, Ryan JB, et al: am J sports med 1994;22:

20. Treatment of Anterior Glenohumeral Instability
Inferior capsular shift procedure for anterior-inferior shoulder instability in athletes.
Satisfactory results: 94%
Returned to sports: 92% (75% at the same level).
The rate of recurrence: 3%.
Bigliani LU, Kurzweil PR, Schwartzbach CC, et al: am JSports med 1994;22:

21. Treatment of Anterior Glenohumeral Instability
Arthroscopic Bankart suture repair.
Recurrent instability: 44%
The authors recommend: caution in the use of arthroscopic stabilization for the competitive athlete.
Grana WA, Buckley PD, Yates CK: am J sports med 1993;21:

22. Treatment of Anterior Glenohumeral Instability
Reduction in
Surgical time
Blood loss
Postoperative narcotic use
Postoperative fevers
Duration of hospitalization
Work days missed
Arthroscopic versus open Bankart procedures: A comparison of early morbidity and complications.
Green MR, Christensen KP: arthroscopy1993;9:

23. Treatment of Anterior Glenohumeral Instability
Treatment of instability of the shoulder with an exercise program.
Response to treatment:
Atraumatic versus traumatic instability: 80% versus 15%
Burkhead WZ Jr, Rockwood CA Jr: J bone joint Surg 1992;74a:

25. Selective capsular tightening
Selective capsular tightening. A, The inferior capsule is tightened with the arm in 10° flexion, 60° abduction, and 45° to 60° external rotation. B, The superior capsule is tightened with the arm in 0° abduction and 45° external rotation.

26. Treatment of Posterior Instability
Nonsurgical treatment with exercise program. (First choice)
Surgical treatment
Provide bony stability:
Posterior bone block, opening wedge osteotomy of the posterior glenoid (glenoplasty), and rotational osteotomy of the humerus
Soft-tissue repairs:
Posterior labral repair, a posterior capsular plication, and posterior capsulorrhaphy.

27. Instability in Throwing Athletes
Anterior instability
During the late cocking phase
Posterior capsular tightness, pain, or impingement signs
Posterior instability
During the follow-through phase.
"Dead arm" syndrome
Transient neurological symptoms

29. Acromioclavicular Instability
Mechanism
Impact directly at the lateral edge of the acromion
Classification (Rockwood)
Type I: a sprain of the AC joint
Type II: partial rupture of the AC ligaments and the coracoclavicular ligaments with subluxation of the AC joint
Type III: dislocation of the AC joint with complete disruption of the coracoclavicular and AC ligaments
Type IV: dislocation of the AC joint with posterior displacement of the clavicle into or through the trapezius muscle
Type V: dislocation of the AC joint with marked superior displacement of the clavicle greater than twice the normal coracoclavicular distance
Type VI: inferior dislocation of the AC joint with subcoracoid displacement of the clavicle

30. Rockwood classification of ligamentous injuries to the acromioclavicular joint.

31. Treatment A-C Instability
Types I and II: nonsurgical
Sling for 2 weeks
Good results in over 90% of cases
Type III: controversial
Surgical treatment for acute injuries in laborers or high demand overhead athletes, and for chronic injuries in which initial nonsurgical treatment fails
Types IV, V, and VI : surgical management
AC fixation with pins or plates and coracoclavicular fixation with nonabsorbable suture or metallic screws

32. Chronic symptomatic A-C instability: The modified Weaver-Dunn procedure. (C-C fixation + transfer of the C-A ligament to the distal clavicle)

33. Thank you for your attention