Internal Impingement of the Shoulder

Jobe Classification (modified for internal impingement)

Most athletes present in Stage II with contact pathology but no complete structural failure.

This staging guides treatment decisions and prognosis for return to sport.

Ellman Classification (for partial-thickness tears)

Depth grading:

• Grade 1: Less than 3mm depth
• Grade 2: 3-6mm depth
• Grade 3: Greater than 6mm depth (greater than 50% thickness)

Internal impingement typically causes Grade A (articular-sided) tears affecting the posterosuperior cuff (supraspinatus-infraspinatus junction).

Tears greater than 50% thickness or progression to full-thickness require consideration of repair.

Posterosuperior labral tears in internal impingement:

Repair is indicated when labral detachment is extensive or associated with instability symptoms.

Measuring GIRD (critical for diagnosis):

Technique:

1. Patient supine
2. Shoulder abducted to 90 degrees
3. Elbow flexed 90 degrees
4. Stabilize scapula to isolate glenohumeral motion
5. Measure maximum passive internal rotation (compare to contralateral)

Normal values:

• Slight dominant-arm loss of IR (10-15 degrees) is normal adaptation
• Total arc should be preserved or increased

Pathologic GIRD:

• Greater than 20-25 degrees loss of IR compared to contralateral
• Loss of total arc of motion (ER + IR)
• Side-to-side total arc difference greater than 5 degrees

Measurement technique must be standardized and scapula stabilized to obtain accurate values.

Non-operative treatment is FIRST-LINE for all internal impingement.

Success rate: 70-80% return to sport with conservative management alone

Duration: Minimum 3-6 months trial before considering surgery

Core principles:

1. Relative rest from throwing (complete rest not required)
2. Posterior capsule stretching (primary intervention)
3. Scapular stabilization exercises
4. Maintain rotator cuff strength
5. Progressive return to throwing program

Posterior capsule stretching techniques:

• Sleeper stretch:

  • Lie on throwing shoulder
  • Arm forward at 90 degrees
  • Use opposite hand to push throwing arm into internal rotation
  • Hold 30 seconds, repeat 5 times, 3x daily

• Cross-body adduction stretch:

  • Bring throwing arm across body
  • Use opposite hand to assist stretch
  • Hold 30 seconds, repeat 5 times, 3x daily

• Horizontal adduction stretch:

  • Similar to cross-body but at 90 degrees flexion
  • Stretches posterior capsule effectively

Scapular stabilization program:

• Serratus anterior strengthening (wall slides, push-up plus)
• Lower trapezius strengthening (prone Y, T, W exercises)
• Middle trapezius strengthening (rows)
• Pectoralis minor stretching (doorway stretch)

Rotator cuff strengthening:

• External rotator focus (infraspinatus, teres minor)
• Maintain internal rotator strength
• Avoid excessive ER strengthening (can worsen GIRD)

Conservative management should address the entire kinetic chain including core, legs, and trunk.

Return to throwing protocol (after symptoms resolved and GIRD corrected):

Phase 1: Flat ground throwing (weeks 1-6)

• Start at 45 feet
• Progress distance gradually
• Light intensity only
• No breaking balls or max effort

Phase 2: Increased intensity (weeks 7-12)

• Progress to 120 feet
• Increase velocity gradually
• Introduce variety of pitches
• Monitor symptoms closely

Phase 3: Mound throwing (weeks 13-16)

• Start at 50% effort
• Progress to game intensity
• Pitch counts limited
• Biomechanics analysis

Phase 4: Return to competition (weeks 17-24)

• Gradual increase in pitch count
• In-game situations
• Maintain stretching program

Return to full competition typically takes 6-12 months from initial presentation.

Indications for surgery:

• Failed conservative management (3-6 months minimum)
• Persistent pain limiting performance
• Documented structural pathology (cuff tear, labral detachment)
• Progressive weakness
• Athlete's career timeline considerations

Contraindications to surgery:

• Inadequate conservative trial
• Poor biomechanics not addressed
• Unrealistic expectations
• GIRD not corrected preoperatively

Timing considerations:

• Off-season preferred
• Allow minimum 6 months before next competitive season
• Career-ending decisions require extensive counseling

Surgery should be viewed as a last resort after comprehensive non-operative management has failed.

Patient positioning:

• Beach chair or lateral decubitus position
• Lateral decubitus allows better access to posterior structures
• Arm in traction (10-15 lbs) for lateral decubitus

Portal placement:

• Posterior viewing portal: Standard posterior portal
• Anterior working portal: Mid-glenoid or low anterior
• Posterolateral accessory portal: For posterior labrum access
• Port of Wilmington: Anterosuperior portal for suture passage

Diagnostic arthroscopy sequence:

1. Glenohumeral joint evaluation (anterior, superior)
2. Posterosuperior inspection (key area)
3. Labral assessment (fraying, detachment)
4. Rotator cuff assessment (articular side from joint)
5. Subacromial space evaluation (rule out external impingement)

Systematic examination ensures all pathology is identified before proceeding with treatment.

Arthroscopic debridement (most common procedure):

Posterosuperior labrum:

• Debride frayed, degenerative labral tissue
• Remove unstable fragments
• Use shaver and radiofrequency device
• Preserve stable labral tissue (avoid excessive resection)
• Repair only if large detachment or instability

Partial-thickness rotator cuff tear:

• Debride to stable margins
• Remove unstable flaps of tissue
• Do NOT convert to full-thickness (leave intact bursal side)
• Repair if greater than 50% thickness or full-thickness

Loose bodies:

• Remove any loose bodies in posterior recess
• Common in advanced cases

Debridement alone has 60-70% success rate for return to throwing if GIRD has been corrected preoperatively.

Arthroscopic posterior capsular release (for persistent GIRD):

Indications:

• GIRD not corrected with conservative stretching
• Persistent posterior capsule contracture
• Combined with debridement

Technique:

• Viewing from anterior portal
• Working from posterior portal
• Identify posterior capsule at 7-9 o'clock position (right shoulder)
• Use radiofrequency device or arthroscopic knife
• Release posterior-inferior capsule from glenoid
• Extend release 1-2 cm
• Protect axillary nerve (stays inferior)
• Test ROM improvement intraoperatively

Extent of release:

• Adequate when internal rotation improves by 20-30 degrees
• Avoid excessive release (risk posterior instability)
• Some surgeons combine with rotator interval release

Posterior capsular release improves internal rotation immediately and allows more effective postoperative stretching.

Repair indications (less common):

Posterosuperior labral repair:

• Large detachment (greater than 1 cm)
• Unstable labrum contributing to symptoms
• Associated instability symptoms

Technique:

• Prepare glenoid bone edge (debride to bleeding surface)
• Place suture anchors at posterosuperior glenoid (1-2 anchors)
• Pass sutures through labral tissue
• Reduce labrum to glenoid rim
• Tie sutures arthroscopically

Rotator cuff repair:

• Full-thickness tear or high-grade partial (greater than 50%)
• Debride tear edges
• Place suture anchors at greater tuberosity
• Single or double-row repair depending on tear size
• Typically posterior (infraspinatus) or posterosuperior

Combined procedures:

• Debridement + posterior capsular release (most common)
• Labral repair + capsular release
• Cuff repair + debridement

Return to throwing after repair procedures requires 9-12 months and outcomes are less predictable than debridement alone.

Post-operative protocol (arthroscopic debridement ± posterior capsular release):

Athletes who undergo simple debridement can typically return to throwing by 4-6 months with good outcomes.

Post-operative protocol (labral repair or rotator cuff repair):

Return to full throwing after repair procedures requires 9-12 months and outcomes are less predictable.

Lifelong maintenance requirements:

Daily stretching:

• Posterior capsule stretching continues indefinitely
• Sleeper stretch: 5 reps x 30 seconds, 2x daily
• Cross-body adduction: 5 reps x 30 seconds, 2x daily

Ongoing strengthening:

• Scapular stabilization exercises 3x weekly
• Rotator cuff strengthening maintenance
• Core and kinetic chain strengthening

Monitoring:

• Periodic GIRD measurement (monthly during season)
• Early intervention if GIRD recurs
• Annual professional assessment

Biomechanics:

• Ongoing coaching on throwing mechanics
• Video analysis periodically
• Address any compensatory patterns

Compliance with maintenance program is the most important factor for long-term success.