Glenohumeral Internal Rotation Deficit (GIRD) - Shoulder & Elbow

Introduction

Definition
- a condition resulting in the loss of internal rotation of the glenohumeral joint as compared to the contralateral side
Epidemiology
- occurs primarily in overhead athletes
  - often seen in baseball pitchers
Pathophysiology
- mechanism
  - caused by repetitive throwing
    - thought to occur during the late cocking and early acceleration phase
- pathoanatomy
  - tightening of posterior capsule or posteroinferior capsule leads to translation of humeral head (capsular constraint mechanism)
  - translation of humeral head is in the OPPOSITE direction from area of capsular tightening
  - posterior capsular tightness leads to anterosuperior translation of humeral head in flexion
  - posterorinferior capsular tightness leads to posterosuperior translation of humeral head in ABER
  - anterior capsule is stretched
Associated conditions
- glenohumeral instability
- internal impingement
  - abutment of the greater tuberosity against the posterosuperior glenoid during abduction and external rotation leads to pinching of posterosuperior rotator cuff
- articular-sided partial rotator cuff tears
  - tensile failure in excessive rotation
  - internal impingement
- SLAP lesion
  - throwers with GIRD are 25% more likely to have a SLAP lesion
  - peel-back mechanism (biceps anchor and postero superior labrum peels back) during late cocking
    - because of posterosuperior translation of humeral head and change in biceps vector force posteriorly

Anatomy

Presentation

Symptoms
- vague shoulder pain
- sometimes painless
- may report a decrease in throwing performance
Physical exam
- stabilize the scapula to obtain true measure of glenohumeral rotation
- increased sulcus sign
  - due to stretching of anterior structures that resist external rotation (coracohumeral ligament, rotator interval)
- characterized by altered glenohumeral range of motion
  - decrease in internal rotation and increase in external rotation
    - if the GIRD (loss of internal rotation) is less than external rotation gain (ERG), the shoulder maintains normal kinematics
    - if the GIRD exceeds external rotation gain (ERG), this leads to deranged kinematics
      - decrease in internal rotation is usually greater than a 25° difference as compared to non-throwing shoulder

Imaging

Radiographs
- recommended views
  - AP and lateral of glenohumeral joint
- findings
  - usually normal
CT
- may show increased glenoid retroversion
MRI
- ABER view on MRI can show associated lesions

Treatment

Nonoperative
- rest from throwing and physical therapy for 6 months
  - indications
    - first line of treatment
  - physical therapy
    - posteroinferior capsule stretching
      - sleeper stretch
        
        performed with internal rotation stretch at 90 degrees abduction with scapular stabilization
      - roll-over sleeper stretch
        
        arm flexed 60° and body rolled forward 30°
      - doorway stretch
      - cross-body adduction stretch
    - pectoralis minor stretching
    - rotator cuff and periscapular strengthening
  - outcomes
    - 90% of young throwers respond to sleeper stretches/PT
    - 10% of older throwers do not respond, and will need arthroscopic release eventually
Operative
- posteroinferior capsule release vs. anterior stabilization
  - indications
    - only indicated if extensive PT fails

Techniques

Posterior capsule release vs. anterior stabilization
- some advocate posterior capsule release while others advocate anterior stabilization
- repair thinned rotator cuff if significantly thinned (transcuff or takedown and repair)
- technique controversial
  - for throwing athlete with posteroinferior capsular contracture, release posterior inferior capsule and posterior band of IGHL
  - electrocautery inserted through posterior portal, camera from anterior portal
  - from 9 to 6 o'clock position
  - at level of glenoid rim
  - until rotator cuff fibers (behind the capsule) can be seen from within joint
  - insert arthroscopic shaver to widen gap in capsule (prevents recurrence)
  - gentle manipulation at the end completes release of any remaining fibers, maximizes IR and flexion
- results
  - will immediately gain 65° of internal rotation postop

Complications