posterior gleno-humeral-instability
TRANSCRIPT
POSTERIOR GLENO-HUMERAL INSTABILITY
INTRODUCTION
2-12% of all shoulder instability Isolation / MDI Symptoms are usually mild and can
be overlooked Athletes
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)
ASSOCIATED ATHLETIC ACTIVITIES
ACTIVITY MOTIONWeightlifting Bench press,
push-upsPitching Follow-through phaseSwimming Butterfly and
freestyleRacquet sports Backhand stokesGolf Motions of lead armGymnastics Parallel bars, ringsBoxing Axial load with punching
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
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
EXAMINATION - 1
Posterior joint line tenderness ROM - Normal Rotator cuff strength - Normal Scapular winging
secondary to scapula muscle dysfunction
Ligamentous laxity? Examine unaffected shoulder
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
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
MANAGEMENT
NON-SURGICAL TREATMENT
SURGICAL TREATMENT ARTHROSCOPIC OPEN
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
SURGERY - 2
CONTRA-INDICATIONS Psychiatric disorder Significant degenerative gleno-humeral
arthritis Failure to undergo or co-operate in
physiotherapy program
Ligamentous laxity Multidirectional instability
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
SURGICAL PROCEDURES OPEN
SOFT TISSUE BONEPosterior capsulorrhaphy Glenoid osteotomyInferior capsular shift Posterior bone block(anterior/posterior)Infraspinatus advancementPosterior Bankart repairStaple capsulorrphaphyBiceps tendon transferSubscapularis transfer ARTHROSCOPICPosterior Capsulolabral AugmentationPosteroinferior Capsular ShiftThermal Capsulorrhaphy
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
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
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
POSTERIOR STABILISATION - 2
Deltoid split in line with its fibres from scapular spine 5cm distally
+/- detachment deltoid
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
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
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
POSTERIOR STABILISATION - 6
Inferior capsular flap advanced superiorly and medially and sutured to labrum
POSTERIOR STABILISATION - 7
Superior flap brought over inferior flap inferior and medially
Sutures tied in neutral rotation
POSTERIOR STABILISATION - 8
Split in capsule repaired Wound closed
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
COMPLICATIONS
Loss internal rotation secondary to over-tight posterior capsular repair
Suprascapular/axillary nerve injury Hardware problems Recurrence - 30%