acute rotator cuff tear

Introduction

acute shoulder rotator cuff tears can result in significant pain and disability
these should be managed more acutely than the more subacute/chronic rotator cuff syndrome conditions
3 main groups:
- 1: acute trauma without shoulder dislocation
  - ~2/3rds of those with red flags will have an acute tear, 1/3rd will have a complete tear
  - generally in those under 40yrs
  - accounts for 5% of tears
- 2: acute trauma with anterior shoulder dislocation:
  - ~50% of patients with dislocated shoulder aged over 40yrs will have an acute tear
  - extreme forces at any age with large cuff tear maybe associated nerve injury
- 3. impingement tears
  - no Hx of trauma, usually in those over 40yrs
  - impingement signs may be present - Neer's , Hawkin's

red flags which suggest a tear:
- trauma with acute painful shoulder, a normal Xray and inability to actively abduct greater than 90deg (this is particularly sensitive if pain is not the limiting factor)
generally cannot sleep on affected shoulder
may have pain down arm or chest wall
tenderness over anterolateral edge of acromion or biceps tendon (faces anteriorly at 5-10° of IR)
painful arc from 70-120°

Shoulder XRs to exclude fractures and dislocations
- should include 3 views:
  - True AP Glenohumeral Joint (Grashey View)
  - Scapula Lateral (Neer View)
    - Axillary Lateral
simple analgesia, sling, physiotherapy
if suspected, and pain not settling within 1-2 weeks:
- arrange USS or MRI scan (sensitivity of 100% and specificity of 95%) within 1-2wks of injury and if present, early surgery within 1 month of injury appears to be preferable and thus referral to an orthopaedic surgeon at the 2 week mark is optimal, once imaging has been obtained and confirmed the tear
  - partial thickness tears generally can be managed without surgery but many will progress in size and rpt USS in 6-12 months is advisable in those with ongoing symptoms
  - full thickness acute tears generally should be considered for surgery within 1 month
    - 60-80% have a satisfactory outcome and improvement continues over 2 yrs
    - poorer outcomes are more likely in those over 60yrs, large tears, and neglected tears