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Shoulder Instability

Leesa M. Galatz, MD

Mount Sinai Professor of Orthopedics

Leni and Peter May Department of

Orthopedic Surgery

Icahn School of Medicine

Mount Sinai Health System

New York, NY

COI Disclosure Information

Leesa M. Galatz, MD

Research Support- National Institute of Health

Medacta-Consultant, Royalties

Stability

• Osteochondral anatomy

• Capsular labral anatomy

• The rotator cuff

• Scapular mechanics

• Proprioception

• Negative intra-articular pressure

Stability

• Osteochondral anatomy

• Capsular labral anatomy

Stability

• Function of the rotator cuff

Shoulder Instability

• Anterior Instabilty– traumatic

– one direction

– high recurrence rate

– bankart lesion

– bankart repair

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Shoulder Instability

• Multidirectional Instability– more than one direction

– atraumatic

– bilateral

– voluntary

– rehab

– capsular shift

Shoulder Instability

• Modern Understanding

– spectrum of instability

– pure instability patterns rare

Multidirectional Instability

• Underlying, asymptomatic laxity who sustain traumatic event

• Progressive capsular stretching from repetitive microtrauma

• Purely atraumatic MDI

Pathoanatomy

• Essential Lesion

– Capsulabral avulsion - anterior inferior

Pathoanatomy

• Capsule

– stabilizing function shifts inferior as arm abducted

– IGHL most important in provocative

position

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Stability

• Scapula Thoracic Mechanics

• Voluntary Instability

History

• Voluntary posterior instability

– Positional

– Muscular

Generalized Ligamentous Laxity Instability

• Apprehension testing

• Relocation test

• Sulcus sign

• Load and shift

• Drawer test

• Posterior stress test

Clinical Evaluation

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Clinical Evaluation

• MRI

Clinical Evaluation

• MRI

Clinical Evaluation

• CT Scan

Clinical Evaluation

• Imaging Studies

Clinical Evaluation

• Correlation of the imaging studies

Non-Operative Treatment

• Indications

• Exercise Program

• Braces

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Indications For Surgery

• Recurrent Instability

–Age

–Pathology

–Activity level

–Level of disability

–Point in season

Glenoid Rim Morphology

• Critical Size?

– 20-25%?

– Inverted Pear Shape?

Itoi et al, JBJS ’00

Burkhart, De Beer Arthroscopy ’00

Gartsman JBJS ‘00

Arthroscopic Repair Arthroscopic Repair

Arthroscopic Repair Management of Anterior

Instability Associated with

Bone Deficiency

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Arthroscopic Bankart Repair

• Reliable surgery in selected patients

• Approaching results of gold standard open txment

• Recurrence risk ranging from 10-

25% contemporary techniques

Arthroscopic Bankart Repair

• Risk Factors for Recurrence:

– Age - females

– Ligamentous Laxity – inferior or general

– Contact/collision sports

– Chronicity of problem – time to surgery or # of dislocations

– Bone Loss!!

Results – Arthroscopic Bankart Repair(Traumatic onset, Sutures anchors and Primary surgery)

• Boileau, et al. Risk factors for recurrence of instability after

arthroscopic bankart repair. JBJS 2006, 1755-63.

– N=81, mean age 26 yrs. 87% athletic activities, 44% contact.

– 15% recur, RF – glenoid defects >25%, anterior (>90 ER neutral) or inferior hyperlaxity (>20 hyperabd), 3 or less suture anchors

• Porcellini, et al. Predisposing factors for recurrent shoulder dislocation after arthroscopic treatment. JBJS 2009, 2537-42.

– N=385, mean age 28.7 yrs, excluded bone loss, hyperlaxity (280 pts)

– 8.1% recur, RF – onset age 250 mm3 (3.9). Contact sports not a risk, did not examine sporting (10/38) vs gen pop (3/35). Virtually no discussion of glenoid bone loss.

Case 1 – 22 y/o male with failed Bankart repair

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• Options:

– Revision arthroscopic reconstruction

– Open soft tissue stabilization

– Glenoid bone graft stabilization

Glenoid Bone Loss

• Affects risk of recurrence

• More common than you think

• Critical degree of bone

loss?

– 20-30% loss of diameter

– may depend on

humeral bone loss

(bipolar lesions) and

type of bone loss

(erosion vs. boney

Bankart)

Sugaya, JBJS 2003. N=100, CT exam –

recurrent anterior shoulder instability.

90% glenoids had measurable bone loss.

50% had a boney frag (mean 7.7% diameter)

Of these, 28% (medium or large (5-20%).

An additional 40% shlds had anterior glenoid

erosion

Glenoid Bone Loss – Critical size?

• Itoi, 2000 JBJS

– Cadaveric study

– Sequential defects at 45

degrees from long axis

• 9, 21, 34 and 46% length of glenoid

• Measured translational forces

• Stability decreased with increasing size of defect

• 21% or greater (6.8 mm) was sig.

Glenoid Bone Loss – Critical size?

• Gerber, CORR 2002

– Cadaveric study

– Measured translational forces

– Decreased stability (by >40%)

when X > w/2

• Gries, JSES 2002

– Cadaveric study

– Increased GH contact pressures

with bone defects >30%

Critical Size – Clinical data

• Small glenoid defect -

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Critical Size – Clinical data

• Large glenoid defects ->25-30% diameter

– Burkhart, Arthroscopy 2000. N=194 scope repairs. 11% recur. 4% redislocation with no bone loss. 67% (14/21) with instability had bone loss (inverted pear glenoid). 89% instability in contact athletes with bone loss.

Glenoid Bone Loss

• How do you measure?

Inferior glenoid circular shape

Ave Diameter 24 mm

Locate the fovea (bare spot)

30%. 73% G/E results UCLA and ROWE score. 27% recurrent instability (1 dis, 2 sublux).

– Open soft tissue repair

– Soft tissue repair + address Hill-Sach lesion

– Latarjet/glenoid graft

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Case 3

• 26 yo s/p arthro.

Bankart repair

• Recurrent dislocations

Case 3

• Latarjet

• Advantages

– Vascular bone graft

– Subscapularis split

Case 4•56 yo female• arthroscopic procedure

•Open procedure

•Persistent pain and

instability

Case 4

•Surgical findings

•Arthrtitis (bipolar)

•Attenuated subscapularis

•Latarjet through subscap.

split

Hill Sachs Lesions

Humeral Sided Bone Loss

• Engaging Hill-Sachs

– Burkhart and DeBeer

• Rarely a problem in isolation in setting of normal glenoid

• Exponentially greater problem in setting of glenoid bone loss-decrease arc of motion

Hill Sachs Lesion

• Options

– Remplissage (Wolf)

– Attach infraspinatus into defect

– Decrease ROM, longevity?

– Bone graft

– Allograft- femoral or humeral head

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Hill Sachs

Reverse Hill-

Sachs

Conclusions

• Glenoid bone loss common

– Erosion vs fracture

• Clinically significant??

• Practical measurement techniques difficult

• High index of suspicion

• Look for it after failed instability surgery

Thank you