Sub-Acromial Shoulder Pain Flashcards
What is subacromial impingement syndrome?
- Inflammation and irritation of rotator cuff tendons as they pass through subacromial spoace
- = pain, weakness and reduced ROM of shoulder
What does SAIS encompass?
Range of pathology eg:
* Rotator cuff tendinosis (swelling)
* Subacromial bursitis
* Calcific tendonitis
Typical patients with SAIS
- Active individuals eg manual professions
- Under 25
- MOST COMMON PATHOLOGY OF SHOULDER
What is the subacromial space?
- Below coracoacromial arch
- Above humeral head and greater tuberosity of humerus
- Arch consists of acromion (lateral), coracoacromial ligament and coracoid process (medial)
- Rotator cuff tendons, long head biceps tendon and coracoacomial ligament run through
- Subacromial bursa reduces friction
Two types pathologies that can lead to SAIS
- Intrinsic - pathologies of rotator cuff tendons due to tension
- Extrinsic - pathologies of rotator cuff tendons due to external compression
Intrinsic causes of SAIS
- Muscular weakness of rotator cuffs - imbalances = humerus shifts proximally
- Overuse - micrtrauma = inflammation and friction
- Degenerative tendinopathy - tearing due to degen changes = migration of humeral head
Extrinsic causes of SAIS
- Anatomical - variations of shape and gradient of acromion
- Scapular muscles - reduced function serratus anterior and trapezius - as usually allows humerus to move past acromion in overhead extension, may reduce size of subacromial space
- Glenohumeral instability - superior subluxation of humerus = increased contact
Video to see movement of shoulder and how scapula muscles effect
https://youtu.be/3VygGuBObVc
Clinical features of SAIS
- Progressive pain
- Exacerbated by shoulder abduction - 60 to 120 degrees painful arc
- Relieved by rest
- Associated with weakness and stiffness secondary to pain
Specific examination tests for SAIS
- Neers impingement test
- Hawkins test
Neers impingement test
- Arm placed by patients side
- Fully internally rotated
- THEN passively flexed
- If pain in anterolateral shoulder = positive
Hawkins test
- Shoulder and elbow flexed to 90 degrees
- Examiner stabilises humerus
- Passively internally rotates shoulder
- +ve if pain in anterolateral shoulder
Differentials for SAIS presentation
- Muscular tear of rotator cuffs/biceps long head
- Neurological pain eg brachial plexus injury - parasthesia also
- Frozen shoulder - relieve pain = still stiff
- Acromioclavicular pathology eg arthritis - general pain, weakness and stiffness from pain
Investigations for SAIS
- Clinical
- But can be confirmed with MRI
- X-ray may show osteophyte formation and sclerosis/irregularity of bones, sometimes cystic changes
- Can see bursitis on MRI
Conservative management SAIS
- NSAIDs
- Physiohterapy
- Corticosteroid injections into subacromial space
Surgery - when in SAIS?
If 6 months of conservative management tried and not improved
Surgery for SAIS
Commonly arthroscopic
Aim is to decompress and increase space within subacromial space
Options are:
* Muscle tear repairs
* Bursectomy - subacromial bursa
* Acromioplasty - removal of section of acromion
Complications of SAIS
- Rotator cuff degeneration and tear
- Adhesive capsulitis
- Complex regional pain syndrome
Why does overhead activity worsen SAIS pain?
- When arm moves above head rotator cuff tendons move through subacromial space
- Space also narrows
- Can then get caught/rub on acromion
- = pain
Recovery and rehab post SAIS surgery
- 3-6 months to fully recover
- Avoid lifting above head for 3 months
- Avoid heavy lifting for 3 weeks
- Easier to wash and dress after 3 weeks
