2. INTRODUCTION 2-12% of all shoulder instability Isolation / MDI Symptoms are usually mild and can be overlooked Athletes
3. ETIOLOGY Congenital - Ligamentous laxity - Scapulohumeral anatomy Acquired - Athletes - Repetitive stress to the posterior capsule resulting in laxity Traumatic - Fall or blow to arm in “at risk” position (forward flexion, abduction and internal rotation)
4. ASSOCIATED ATHLETIC ACTIVITIES ACTIVITY MOTION Weightlifting Bench press, push-ups Pitching Follow-through phase Swimming Butterfly and freestyle Racquet sports Backhand stokes Golf Motions of lead arm Gymnastics Parallel bars, rings Boxing Axial load with punching
5. CLASSIFICATION Voluntary /Involuntary Habitual Instability Results from underlying neuromuscular imbalance Underlying psychiatric problems common Often refractory to surgery Positional Dislocator Demonstrate instability by placing the arm in a position of risk Usually do not have psychiatric illness or secondary gain Ordinary avoid provocative manoeuvres Physiotherapy still first-line treatment but surgery gives good results
6. CLINICAL PRESENTATION Pain rather than instability Usually mild Occur during or after activity Traumatic event may precede onset of symptoms Rarely is there a history of frank posterior dislocation Slip, pop or click out and in
7. EXAMINATION - 1 Posterior joint line tenderness ROM - Normal Rotator cuff strength - Normal Scapular winging secondary to scapula muscle dysfunction Ligamentous laxity? Examine unaffected shoulder
8. EXAMINATION - 2 Load and Shift Test (posterior drawer) Examiner grasps humeral head and pulls directly backward with the shoulder muscles relaxed. Humeral head subluxates posteriorly (<50% normal) Patients reaction to translation more important than amount Posterior Apprehension Uncommon Arm brought into forward flexion and internal rotation with posterior stress applied Sense of instability, pain or painful subluxation is suggestive of the diagnosis
9. INVESTIGATIONS Shoulder XR AP in ER/IR Lateral Axillary view Dynamic XR with shoulder subluxed CT Arthrogram MRI Labral changes Capsular Damage EUA +/- arthroscopy Doubt regarding direction or extent of instability
11. SURGERY - 1 INDICATIONS Recurrent, symptomatic, unidirectional subluxation that has failed to respond to a comprehensive non-operative program Posterior instability itself is not an indication for surgery 2/3 will respond to a proper exercise program No patient who has not had 6/12 of an exercise program should have surgery
12. SURGERY - 2 CONTRA-INDICATIONS Psychiatric disorder Significant degenerative gleno-humeral arthritis Failure to undergo or co-operate in physiotherapy program Ligamentous laxity Multidirectional instability
13. ARTHROSCOPY Capsular shift 25% recurrence at 2 year follow-up in one study on 20 patients Capsulo-labral augmentation 41 patients in study – 86% improved stability Thermal capsulorrhaphy Thin posterior capsule which is less responsive to shrinkage Complicated by necrosis
14. SURGICAL PROCEDURES OPEN SOFT TISSUE BONE Posterior capsulorrhaphy Glenoid osteotomy Inferior capsular shift Posterior bone block (anterior/posterior) Infraspinatus advancement Posterior Bankart repair Staple capsulorrphaphy Biceps tendon transfer Subscapularis transfer ARTHROSCOPIC Posterior Capsulolabral Augmentation Posteroinferior Capsular Shift Thermal Capsulorrhaphy
15. OPEN TECHNIQUES - 1 Soft tissue Soft tissue abnormalities are the predominant cause of posterior instability Posterior capsular shift Anterior/posterior approach Posterior capsule thin 1.5mm Staples fallen out of favour Recent report 13/14 patients were satisfied at 44/12 follow-up Recurrence rate 30% some studies 50% high level athletes return to sports
16. OPEN TECHNIQUES - 2 Bone Glenoplasty Glenoid retroversion/hypoplasia Opening wedge osteotomy Cadaveric studies confirm effective change in Glenoid shape and increased stability Recent study 17 patients atraumatic posterior instability at 5 year follow-up 81% rated good to excellent 12.5% had a recurrence Post-op degenerative changes were seen in 25% Recommended glenoplasty if glenoid retroversion 7-10° radiographically Humeral Osteotomy External rotation osteotomy Indicated if symptoms worsened on internal rotation Few reports in literature
17. POSTERIOR STABILISATION - 1 Lateral decubitus position +/- arthroscopic evaluation – rule out anterior labral injury A 10cm saber cut incision from posterior aspect AC joint to posterior axillary fold
18. POSTERIOR STABILISATION - 2 Deltoid split in line with its fibres from scapular spine 5cm distally +/- detachment deltoid
19. POSTERIOR STABILISATION - 3 Fascial layer covering teres minor and infraspinatus divided Two choices Develop interval between infraspinatus and teres minor Develop interval between two heads infraspinatus identified by fat stripe
20. POSTERIOR STABILISATION - 4 Divided from tendon insertion to just medial to glenoid beware branches suprascapular nerve 1.5cm from glenoid Infraspinatus dissected free from capsule
21. POSTERIOR STABILISATION - 5 Capsule divided lateral to medial in mid-portion +/- labral repair T-capsular incision based medially along edge of labrum Superior and inferior flaps tagged
22. POSTERIOR STABILISATION - 6 Inferior capsular flap advanced superiorly and medially and sutured to labrum
23. POSTERIOR STABILISATION - 7 Superior flap brought over inferior flap inferior and medially Sutures tied in neutral rotation
25. POST-OPERATIVE MANAGEMENT Abduction pillow for 3/52 in neutral rotation At 3/52 - Standard sling - ROM exercises - No forward flexion At 6/52 - Full ROM At 12/52 - Return to sport
26. COMPLICATIONS Loss internal rotation secondary to over-tight posterior capsular repair Suprascapular/axillary nerve injury Hardware problems Recurrence - 30%
