Injuries in the Throwing Shoulder David Conner MD OrthoNortheast 4/25/15

Patient Population Throwers Volleyball Swimmers Tennis Player

The Thrower Concept of kinetic chain –Legs and trunk-> generate power –Shoulder->funnel and force regulator –Arm-> force delivery system

The Throwing Shoulder Perfect balance of mobility & stability “Thrower’s Paradox” –Lax enough to allow excessive external rotation, but stable enough to prevent recurrent subluxation

The Set Point or Slot Excessive ER generates the velocity Throwers know ER “set point” to throw hard---known as “The Slot”

Phases of Throwing Late cocking- 165 degrees ER, 300 N anterior shear force Acceleration phase- 7,300 degrees/sec angular velocity Deceleration N distraction force

Potential for Disaster Significant motion Significant forces

Problem of the Throwing Shoulder “Dead Arm Syndrome” –Any pathologic shoulder condition where the thrower is unable to throw with preinjury velocity and control because of combination of pain and subjective unease SLAP lesion Internal Impingement Cuff tear

SLAP Lesions ( Superior Labrum Anterior to Posterior) Snyder Classification

Internal Impingement Contact of Supraspinatus/infraspinatus & posterior- superior labrum in ABER (abduction/ external rotation) ? Physiologic or pathologic Humeral Retroversion Crockett et al, AJSM, 2002 CT Scans bilateral shoulders Humeral retroversion –Dom = 40 deg –Non dom = 23 deg. Mean Diff between ER & IR Dom and Non dom, 7 & 9 deg

Dead Arm Syndrome: Theories Frank Jobe –Excessive ER causes micro stretch of anterior capsule –Anterior instability causes internal/external impingement –Internal Impingement causes SLAP lesion Burkhart & Morgan –Posterior capsule problem –SLAP lesion cause dead arm –No anterior instability present

Dead Arm Syndrome: Jobe Model Hyperangulation in ABER-Humerus left behind scapula Tensile overload of anterior capsule-subluxation

Dead Arm Syndrome: Jobe Model Muscles fatigue leading to pathologic internal impingement and subacromial impingement Secondary labral or cuff tears

Jobe Model Treatment-Eliminate anterior laxity –Surgical results Open capsular shift-> 50% return to play Halbrecht –Anterior instability DECREASES internal impingement

Burkhart-Morgan Model Posterior capsular tightness Posterior-superior instability “Peel-back” mechanism-SLAP Anterior pseudoinstability Internal impingement Result: SLAP & cuff pathology

Throwers Develop Increased ER in Abduction Humeral retroversion Soft tissue adaptation Gain in ER should equal loss of IR Need 180 degree total arc

G.I.R.D Glenohumeral Internal Rotation Deficit Loss of ER compared to nonthrowing side Posteroinferior capsular contracture –THE ESSENTIAL LESION

GIRD Posteroinferior capsular tightness –Posterior band of inferoglenohumeral lig. –Traction phenomenon

GIRD-Tethered shoulder Ant IGHL & Post IGHL act as sling

GIRD-Tethered Shoulder Tight post IGHL tethers contact point –Moves pivot posterosuperiorly –Allows GT to clear glenoid-> increases ER

Tight posteroinferior capsule –Hyper ER –Hyper horizontal ABD –Drop elbow –Premature trunk rotation

GIRD & Anterior Pseudolaxity Result: Able to increase ER by clearing GT and effective laxity of anterior capsule  Get to “The Slot”

GIRD & The Slot With GIRD, increase in ER puts major stress on structures –Biceps anchor –Labrum –Cuff

“Peel-Back” Mechanism ABER-> biceps vector moves vertical and posterior –Torsion to posterior superior labrum –Posterior Type II SLAP

Peel-Back

SLAP Repair Simple suture at root better than tacks Repair SLAP, eliminates anterior pseudo laxity  DO NOT NEED ANTERIOR STABILIZATION

SLAP Lesions Surgical debridement –Cordasco pts 2 yr 63% G/E 45% return to sport –Altcheck % moderate 2 years

SLAP Lesion Repair with Suture Anchor –Burkhart pts 2 yr 90% excellent 10% good 100% 2 yrs

Dead Arm & the Rotator Cuff Tension Compression—Internal Impingement Result: Partial Thickness Articular Sided RTC Tear

Dead Arm and RTC 31% of throwers with SLAP have RTC tear –38% were complete RTC –62% were PTRTC

The Problem Tight posterior capsule->posterosuperior shift-> Increased ER->Peel-back->Internal impingement/traction-> Cuff tear=Dead Arm Answer: Prevent Posterior capsular tightness

GIRD - Treatment Non-op

GIRD Non operative Treatment 90% throwers with symptomatic GIRD > 25 degrees respond to stretching in 2 weeks Best responders—young patients

GIRD - Treatment Operative Glenoid Capsule

Conclusion Dead arm- difficult clinical & radiographic diagnosis. Confirmed at arthroscopy Culprit- GIRD Best treatment- Prevention If symptomatic, SLAP usually present Look for cuff pathology Anterior laxity may exist, but don’t treat as initial problem

Young Throwing Shoulder Pain – not normal

Common Problems Little League shoulder Mild instability Rotator cuff tendonitis

Little League Shoulder Adams, Calif Med 1966 –“osteochondrosis of proximal humeral physis” Ages –Time of maximal prox humeral growth Rotational forces disrupt hypertrophic zone of physis –external rotation torque is estimated to be approximately 18 Nm 400% that physeal cartilage can take –distraction force estimated to be approximately Nm 5% of what physis can tolerate –bone is much stronger in tension than with rotational stresses

X-rays Widening of physis, metaphyseal demineralization and fragmentation, and periosteal reaction

Little League Shoulder Physeal widening can persist after symptoms resolve

MRI widening High intensity signal change adjacent to physis

Treatment Relative rest (sling?) No throwing 2-3 mos Anti-inflammatory meds Controlled return once asymptomatic Pitch Count Rehab -Strengthen Trunk

Pitch Count Guidelines Rest requirements –>61 pitches  3 days –41-60  2 days –21-40  1 day –0-20  0 days rest League Age – pitches per day – pitches per day – pitches per day – pitches per day – pitches per day

Carson & Gasser. Little leaguer’s shoulder. A report of 23 cases. Am J Sports Med 1998; 26:575–580. Excellent results protocol for return to play mentioned previous slide 21 of 23 patients (91%) were able to return to baseball at an average of 3 months (range: 1 month to 1 year) with asymptomatic shoulders Largest series to date

Prevention Information / education Fitness exercises = general basis for all sports participation Avoid specialization Begin training early (before season) No more than 10% increase each week