http://upload.orthobullets.com/topic/3054/images/bennet lesion.jpg
http://upload.orthobullets.com/topic/3054/images/internalvsexternal.jpg
http://upload.orthobullets.com/topic/3054/images/Illustration_moved.jpg
http://upload.orthobullets.com/topic/3054/images/arthroscopy question 3_moved.jpg
http://upload.orthobullets.com/topic/3054/images/pasta.jpg
Introduction
  • Internal impingement refers to pathology on undersurface of rotator cuff 
    • in contrast to subacromial or "external" impingement which occurs on bursal side of rotator cuff) 
    • internal impingement covers a spectrum of injuries including
      • fraying of posterior rotator cuff
      • posterior and superior labral lesions
      • hypertrophy and scarring of posterior capsule glenoid (Bennett lesion)
      • cartilage damage at posterior glenoid
  • Epidemiology
    • major cause of shoulder pain in throwing athletes
  • Pathoanatomy
    • caused by impingement of posterior under-surface of supraspinatus tendon on greater tuberosity insertion on the posterosuperior glenoid rim 
      • impingement occurs during maximum arm abduction and external rotation during late cocking and early acceleration phases of throwing  
      • causes"peel-back" phenomenon of posterosuperior labrum
    • thought to be due to combination of
      • tightness of posterior band of IGHL 
      • anterior micro instability
  • Associated conditions
    • associated with GIRD 
Anatomy
  • Glenohumeral joint anatomy 
  • Glenohumeral stability
    • static restraints
      • glenohumeral ligaments
      • glenoid labrum 
      • articular congruity and version
      • negative intraarticular pressure
    • dynamic restraints
      • rotator cuff muscles
      • biceps
      • periscapular muscles
  • Glenohumeral ligaments
    • Superior GHL  
      • restraint to inferior translation at 0° degrees of abduction (neutral rotation) 
    • Middle GHL  
      • resist anterior and posterior translation in the midrange of abduction (~45°) in ER 
    • Inferior GHL  
      • posterior band
        • most important restraint to posterior subluxation at 90° flexion and IR
      • anterior band
        • primary restraint to anterior/inferior translation 90° abduction and maximum ER (late cocking phase of throwing) 
      • superior band
        • most important static stabilizer about the joint
Presentation
  • Symptoms
    • diffuse pain in posterior shoulder along the posterior deltoid
      • shoulder pain worse with throwing
        • especially during late cocking and early acceleration
  • Physical exam
    • increased external rotation
    • decreased internal rotation 
      • loss of > 20° of IR at 90°
        • must stabilize the scapula to get true measure of glenohumeral rotation
    • often can demonstrate rotator cuff weakness
Imaging
  • Radiographs
    • recommended views
      • complete shoulder series
    • findings
      • usually unremarkable
      • AP may show a Bennett lesion (glenoid exostosis) 
  • MRI
    • can show associated rotator cuff and/or labral pathology
      • such as partial articular sided supraspinatus tendon avulsion (PASTA) or tear 
      • signal at greater tuberosity and/or posterosuperior labrum 
Treatment
  • Nonoperative
    • posterior capsule stretching PT for 6 months
      • indications
        • most internal impingement can be treated non-operatively
      • technique 
        • posterior capsule stretching with sleeper stretches
        • rotator cuff stretching and strengthening
  • Operative
    • arthroscopic debridement and/or repair of rotator cuff tear and labrum 
      • indications
        • failed nonoperative treatment
        • partial thickness rotator cuff tear (PASTA) compromises the integrity of the rotator cuff
          • partial rotator cuff tears >50%  
        • Bennett lesions
    • posterior capsule release vs anterior stabilization
      • indications
        • failed nonoperative treatment
        • shoulder instability
      • technique 
        • surgical techniques are controversial
          • some perform a posterior capsule release
          • some perform anterior stabilization
      • complications
        • inferior suprascapular nerve (infraspinatus) is at greatest risk during posterior capsule release
 

Please rate topic.

Average 4.2 of 30 Ratings

Questions (5)

(OBQ11.140) Internal impingement commonly occurs in overhead athletes and is very common amongst elite baseball pitchers. In which phase of throwing does this pathologic process occur? Review Topic

QID:3563
1

Wind-up

1%

(17/1765)

2

Early cocking

6%

(104/1765)

3

Late cocking

79%

(1393/1765)

4

Deceleration

9%

(154/1765)

5

Follow-through

5%

(91/1765)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

Internal impingement refers to the impingement within the glenohumeral joint which occurs as the posterosuperior glenoid labrum makes contact with the greater tuberosity, causing impingement on the posterior rotator cuff. This occurs commonly among baseball pitchers during late cocking and early acceleration as the shoulder joint reaches it's maximum external rotation.

Drakos et al studied internal impingement in overhead athletes. In their review, they describe how adaptations to throwing including increased external rotation, increased humeral and glenoid retroversion, and anterior laxity, all predispose these individuals to internal impingement. They recommend initial nonoperative treatment, with a focus on increasing the range of motion and improving scapular function. If this fails, surgical treatment should address microinstability to ensure good outcomes.

Illustration A shows an example of internal impingement as the shoulder reaches its maximal external rotation. The posterior rotator cuff is "pinched" between the greater tuberosity and the posterosuperior labrum.

ILLUSTRATIONS:

Please rate question.

Average 3.0 of 17 Ratings

Question COMMENTS (1)

(OBQ10.174) A 19-year-old left-hand dominant collegiate baseball pitcher has left shoulder pain with late cocking and early acceleration of the ball. His velocity has decreased over the past 2 months. Rotator cuff strength is normal, he denies symptoms of instability, and Hawkins impingement testing is unremarkable. MRI with contrast reveals no intra-articular lesions. What is the most likely physical exam finding in this patient? Review Topic

QID:3267
1

Positive sulcus sign

1%

(21/1578)

2

Decreased external rotation of the affected shoulder

9%

(141/1578)

3

Positive Speed's test

4%

(68/1578)

4

Decreased abduction of the affected shoulder

1%

(13/1578)

5

Decreased internal rotation of the affected shoulder

84%

(1327/1578)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

Internal rotation contracture (GIRD - glenohumeral internal rotation deficit) occurs most commonly in throwing athletes and is thought to be due to a tight posteroinferior capsule. It typically presents with pain while throwing and decreased velocity. Physical exam will often reveal increased external rotation, and an isolated internal rotation deficit without further positive provocative tests. Sulcus sign testing is performed by pulling downward on elbow or wrist with the shoulder in an adducted position and is usually indicative of inferior glenohumeral instability, due to superior glenohumeral laxity. The Speed's test, which is commonly used to evaluate for biceps tendinitis, involves positioning the arm in 90 deg of forward flexion (FF) and the forearm in supination. The patient then resists attempts at pushing the arm downward, with pain/weakness being a positive test.

Burkhart et al, in Part 1 of 3, present a thorough summary of the disabled throwing shoulder that encompasses biomechanics, pathoanatomy, kinetic chain considerations, surgical treatment, and rehabilitation.


Please rate question.

Average 3.0 of 13 Ratings

Question COMMENTS (10)

(OBQ09.142) Mineralization of the posterior-inferior glenoid has been implicated as a possible source of pain in which athletic population? Review Topic

QID:2955
1

football players

13%

(46/360)

2

swimmers

11%

(40/360)

3

basketball players

1%

(3/360)

4

rowers

17%

(60/360)

5

baseball pitchers

59%

(211/360)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

The Bennett's lesion is mineralization of the posterior-inferior glenoid observed in overhead athletes. it is felt to be a traction spur of the posterior inferior glenohumeral capsule which is repetitively stressed during the deceleration and follow-through phases of the throwing cycle.

Wright and Paletta documented 22% of major league pitchers in their series had radiographic evidence of a Bennett's lesion, although none required surgical treatment.

Illustration A is an axillary radiograph showing a posterior glenoid radiodensity consistent with a Bennett's lesion.

ILLUSTRATIONS:

Please rate question.

Average 2.0 of 30 Ratings

Question COMMENTS (5)

(OBQ08.4) The term internal impingement is used in throwers to describe a condition where the posterior-superior glenoid labrum impinges on which structure? Review Topic

QID:390
1

The anterior rotator cuff

9%

(70/797)

2

The posterior rotator cuff

68%

(544/797)

3

The anterior glenohumeral ligaments

4%

(29/797)

4

The posterior glenohumeral ligaments

16%

(124/797)

5

The biceps tendon

4%

(30/797)

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

(OBQ07.38) A baseball pitcher has aching pain in the posterior shoulder after throwing. On exam, he has a 30 degree internal rotation deficit and is diagnosed with internal impingement. Stretching should focus on which aspect of the joint capsule? Review Topic

QID:699
1

Superior

4%

(8/210)

2

Anterior

4%

(9/210)

3

Antero-inferior

8%

(16/210)

4

Inferior

1%

(2/210)

5

Postero-inferior

83%

(175/210)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

Internal impingement is when the posterior rotator cuff pinches against the poster-superior labrum. It is implicated in the development of articular sided rotator cuffs and SLAP tears. This patient has a glenohumeral internal rotation deficit (GIRD) which is felt to contribute to this pathology. Treatment is directed at posterior capsule and rotator cuff stretching. This if often performed with the sleeper stretch, which is shown in the illustration below. The paper by Burkhart et al reviews the pathoanatomy of the throwing shoulder and notes that the use of a prophylactic posterior-inferior stretching program has been shown to decrease both GIRD and subsequent throwing injuries. The reference by Tehranzadeh reported the MRI finding of thickening of the posterior band of the inferior glenohumeral ligament on a small series of throwers with GIRD.

ILLUSTRATIONS:

Please rate question.

Average 4.0 of 14 Ratings

Question COMMENTS (3)
Sorry, this question is available to Virtual Curriculum members only.

Click HERE to learn more and purchase the Virtual Curriculum today!


VIDEOS (1)
GROUPS (1)
EVIDENCE & REFERENCES (15)
Topic COMMENTS (9)