Impingement Syndrome: Diagnosis and Management

Introduction

Shoulder impingement syndromes are caused by external or internal impingement. External impingement includes subacromial and subcoracoid impingement, and is caused by the abnormalities of the anterolateral acromion and coracoacromial arch, leading to disorders of the outlet structures. Internal impingement is caused by pinching of the posterosuperior labrum on the glenoid rim and the undersurface of the rotator cuff with the arm in abduction and external rotation. This nonoutlet impingement usually occurs in overhead athletes.

Procedure

Subacromial or subcoracoid decompression can be used to treat the outlet impingement syndromes. Debridement or repair of the rotator cuff tear and posterosuperior labral lesion may be needed for symptomatic nonoutlet (internal) impingement.

Patient History

• Outlet impingement

• Middle age and older

• Obvious shoulder pain in certain positions during arm elevation

• Sleep disturbance due to night pain

• Nonoutlet impingement: internal impingement

• Young overhead athletes

• Night pain usually absent

• Decrease in throwing performance

• Posterosuperior shoulder pain initiated during the late cocking phase of throwing and intensified during the early acceleration phase

Patient Examination

• Outlet impingement

• Positive Neer impingement sign

• Positive Hawkins impingement sign

• Tenderness at the greater tuberosity

• Jobe test

• Positive bicep-provoking signs

• Internal impingement

• Relocation test with pain

• Speed test

• O’Brien test

• Crank test

• Compression-external rotation test

• Harbermyer test

Imaging

• Outlet impingement

• Anteroinferior acromial spur or ossification in the coracoacromial ligament noted on the radiographs of patients with subacromial impingement syndrome ( Fig. 7.1A )

  

• Hooked acromion on outlet view X-ray ( Fig. 7.1B )

• Decreased coracohumeral distance (CHD) (shortest distance between the humeral head and the coracoid process) on the axial sequences of computed tomography (CT) or magnetic resonance imaging (MRI) scans of patients with subcoracoid impingement syndrome ( Fig. 7.2 )

  

• Internal impingement

• Superior labral lesion on magnetic resonance arthrography (MRA) ( Fig. 7.3 )

  

• Posterosuperior labral lesions and articular-sided rotator cuff tears on MRI scans ( Fig. 7.4 )

  

Treatment Options: Nonoperative and Operative

• Outlet impingement

• Nonoperative treatment

• Rest

• Nonsteroidal antiinflammatory medications

• Corticosteroid injections

• Activity modifications with avoidance of provocative positions

• Physical therapy including rotator cuff and scapula-stabilizing musculature strengthening

• Operative treatment

• Arthroscopic subacromial (acromioplasty) or subcoracoid decompression (coracoplasty)

• Internal impingement

• Nonoperative treatment

• Rest

• Cryotherapy

• Nonsteroidal antiinflammatory medications

• Physical therapy including posterior capsular stretching and periscapular muscle strengthening for patients with decreased internal rotation capacity

• Operative treatment

• Debridement or repair of partial-thickness articular-sided rotator cuff tears

• Debridement or repair of posterosuperior labral lesions

Surgical Anatomy

• Inside the subacromial space

• Acromion

• Coracoid process ( Fig. 7.5A )

  

• Coracoacromial ligament ( Fig. 7.5A )

• Conjoined tendon ( Fig. 7.5A )

• Long head of biceps tendon

• Bursal side of the supraspinatus tendon

• Upper portion of subscapularis

• Inside the glenohumeral joint

• Posterosuperior labrum

• Articular side of the rotator cuff tendon ( Figs. 7.5A,B and 7.6A,B )

  

Surgical Indications

• Outlet impingement.

• Patients with persistent pain affecting the activities of daily living and symptoms irresponsive to conservative treatment (including subacromial cortisone injection and physiotherapy) for 3 to 6 months.

• Acromioplasty is indicated for patients with hooked acromion or huge acromial spur with a healthy cuff or reparable rotator cuff tear.

• Coracoplasty is indicated for the patients with both clinical and radiologic evidences of coracoid impingement (coracoid spur or close contact between coracoid and subscapularis).

• Internal impingement.

• Failure to respond to conservative treatment for 3 to 6 months (including intraarticular cortisone injection and physiotherapy).

• Inability to return to sports despite at least 3 months of structured rehabilitation.

• Simple debridement is needed for partial-thickness rotator cuff tears that involve less than 50% of the tendon thickness.

• Rotator cuff repair is indicated for tears that affect more than 50% of the tendon thickness.

• For young overhead athletes, debridement of posterosuperior labrum is indicated for type I and III superior labrum anterior and posterior (SLAP) lesions and SLAP repair in type II and IV SLAP lesions. Biceps tenodesis is recommended for older populations.

• Superior-posterior labral repair in overhead athletes should be cautiously indicated in high-demand overhead athletes, e.g., baseball pitchers. Return to preinjury sports level is unpredicted in this group of patients.

Surgical Technique Setup