subacromial impingement syndrome

Question 1

what is subacromial impingement syndrome?

Answer 1

inflammation and irritation of the rotator cuff tendons as they pass through the subacromial space

Question 2

what group of people is subacromial impingement syndrome most commonly seen in?

Answer 2

under 25yrs, active individuals or in manual professions

Question 3

what are the boarders of the subacromial space?

Answer 3

superior = coracoacromial arch (Lateral to M= coracoacromial ligament, acromial and coracoid process)

inferior = head of humerus

Question 4

what runs in the subacromial space?

Answer 4

rotator cuff tendons

long head of biceps tendon

coracoacromial ligament

surrounded by subacromial bursa which helps reduce friction in these structures

Question 5

what are the intrinsic mechanisms for pathophysiology of SAIS?

Answer 5

intrinsic mechanisms

• muscular weakness in rotator cuff = humerus shift towards body
• overuse of shoulder = repeated micro trauma = inflammation of rotator cuff tendons and bursa
• degenerative tendinopathy = tearing of rotator cuff

Question 6

what are the extrinsic mechanisms for pathophysiology of SAIS?

Answer 6

• anatomical factors e.g congenital or acquired variations
• scapular musculature = a reduction in function of the scapular muscles especially serious anterior and trapezium that help humerus in overhead extension. may result in reduction in size of subacromial space
• glenohumeral instability - can lead to superior subluxation of humerus causing increased contract between acromion and subacromial tissues

Question 7

what are the clinical features of SAIS?

Answer 7

• progressive pain in superior anterior shoulder, exacerbated by abduction

Question 8

what are the differential diagnoses for SAIS?

Answer 8

• muscular tear
• neurological pain
• frozen shoulder syndrome
• acromioclavicular pathology

Question 9

what investigations can be does for SAIS?

Answer 9

usually clinical

MRI can be done

Question 10

how is SAIS managed conservatively?

Answer 10

usually conservative mamangement

analgesia
NSAIDS
physiotherapy

may need corticosteroid injections in subacromial space if all else fails

Question 11

when will surgical intervention be required for SAIS and what is done?

Answer 11

if it persists beyond 6 months without response to conservative management

useful in patients with reduced range of movement

techniques include

• repair of muscular tears e.g long head of biceps tendon or supraspinatus
• bursectomy to increase space and reduce pain
• removal of section of acromion

Question 12

what are the complications of SAIS?

Answer 12

rotator cuff degeneration and adhesive capsulitis