2017 Cook Children’s Sports Symposium

Multidirectional Shoulder Instability

Jason Kennedy, M.D.

Disclosures

• I have no financial/ industry disclosures.

Objectives

• Identify anatomy and risk factors related to multidirectional shoulder stability

• Differentiate the features of multidirectional shoulder instability

from traumatic instability • Summarize common patient characteristics and mechanisms

related to multi-directional instability • Apply knowledge of the pathoanatomy of MDI to better

formulate a treatment plan.

MDI

• 15 year female competitive swimmer • symptoms of increasing pain • occasional parasthesias • bilateral • no specific acute event • has had improvement with periods of rest

MDI Imaging

• Plain X-rays • AP, Scapular - Y, axillary lateral • Weighted AP can demonstrate sulcus (unnecessary)

• MRI • Usually not needed unless other pathology suspected

• Acute Dislocation • Exam suggesting labral or cuff patholgy • MR arthrogram most useful

MDI - Imaging

AP

Scapular-Y

Axillary Lateral

MDI

• Described in 1980 by Neer and Foster

• Many times in athletes with generalized laxity

• Commom sports • Swimming • Baseball (or other throwing events) • Raquet sports

MDI

• Microtrauma

• Patulous Inferior capsular pouch

• Widened Rotator Interval

• Decreased Quality and Quantity of collagen

MDI

AMBRI (Historical)

• Atraumatic

• Multi-directional

• Bilateral

• Rehabilitation

• Inferior capsular shift (surgery - unsually involves more)

Dynamic Shoulder Instability

Gerber and Nyffleler 2002

MDI - Static Stablilzers

Gaskill TR, et.al. 2011

MDI -Static Stabilizers

• Anterior Band of IGH ligament - with ABduction and ER

• Inferior Pouch/Posterior Band of IGH - posterior translation

• MGH ligament - resists ABduction/Inferior trans. @ mid range • max tension at 45 Degrees of ABduction

• Superior GH Ligament/Coracoacromial Lig.

• resists Inferior translation and ER • resists Posterior translation with Flexion/ADD/ER

MDI - Pathoanatomy

• Normal • Capsular ligaments

• Provide Proprioception • Cause the Rotator Cuff muscles to contract

• MDI - decreased

• decreased labral height • enlarged posterior capsule • findings are non-specific

Gaskill TR, et.al. 2011

MDI

MDI -Symptoms

• Pain • Internal impingement of cuff on coracoacromial arch • Subluxation episodes

• Instability • Decreased Proprioception • Decreased Rotator Cuff Strength • Sacpular Dyskinesis

Generalized Laxity

• Usually present • Can be familial laxity • Elbow,knee, or MCP hyperextension • Patellar instability • Thumb to ipsilateral forearm

• Can be sign of connective tissue disorder

• Marfan’s, Ehlers-Danlos, Loeys-Dietz • Important for cardiac and other potential problems

Shoulder Special Tests

Gaskill TR, et.al. 2011

MDI - Treatment

• Non-surgical • Rest • Immobilization (if acute event) • Activity modification • NSAIDS • Physical Therapy

• Rotator Cuff strengthening • Scapular Stabilization • Proprioception

MDI - Treatment

• Surgical • Capsular stabilization • Arthroscopic versus open

• Posterior • Anterior • +/- closure of rotator interval

• if sulcus sign does not resolve with External Rotation

• Contraindication - Voluntary Dislocators

Results - Arthroscopic Stabilization

• Treacy SH, et.al, Historical success at 12%recurrent instability after arthroscopic capsular plication

• McIntyre LF - 94% return to pre-surgery sports participation

• Baker et.al. - 86% return to sport with little or no limitation

Surgery Complications

• Subluxation/Dislocation events

• Subscapularis deficiency - failed repair

• Axillary nerve injury

• Stiffness - overtightening (loss of ER)

• Historical - thermal capsulorrhaphy - devastating Chondrolysis

References

• Ahmad CS. Pediatric and Adolescent Sports Injuries. AAOS Monograph Series. 2010.

• AAOS.org

• Gaskil TR, Taylor COL DC, and Millett PJ. Management of Multidirectional Instability of the Shoulder. JAAOS. 2011;19: 758-767.

• Neer CS II, Foster CR. Inferior capsular shift for involuntary inferior and multidirectional instability of the shoulder: A preliminary report. JBJS. 1980;62(6): 897-908.