Rotator Cuff Tear Arthropathy

Epidemiology

• Mean age 69 years
• Female’s 3:1 males
• Associated with Rheumatoid

Aetiology

• Massive rotator cuff tear results in loss of fulcrum
  • Massive tear is generally 3-tendon involvement
• Usually SS, IS, TM with SSc sparing
• Humeral head migrates superiorly because of more vertical deltoid vector
• Coracoacromial arch forms a new more supero-anterior fulcrum
• CAL is generally last restraint to antero-superior escape
• Pain results from:
  • LHB inflammation and impingement
  • Acromial erosion
  • Superior glenoid erosion
• Not all patients with massive cuff tears develop symptomatic CTA
  • Estimated 5% with symptomatic massive cuff tear develop CTA
  • Therefore majority do not develop this problem

Clinical Diagnosis

History

• Pain
• Pseudoparalysis – pain & inability to elevate arm at all
• Swelling
  • Fluid formation and large effusion is a common feature

Examination

• Cuff weakness
• Hornblower sign (TM)
• External Rotation lag sign (IS)
• Must assess deltoid function
• Muscle wasting

Imaging

XR Features

• Reduced Acromio-humeral distance (<7mm usually pathologic)
• Acetabularisation of acromium
• Femoralisation of humeral head – rounding off of GT
• Sclerosis of acromium – snow cap sign
• Glenohumeral degeneration – especially posterior superior

MRI Scan

• Not usually necessary to make diagnosis

CT Scan

• If there is a doubt regarding glenoid bone stock
• Medial erosion to coracoid is not usually a feature of CTA

Management

Non-Operative

• Analgesia
• Activity limitation
• Physiotherapy
  • Concentrate on what cuff is intact
  • Subscapularis for rotational control of humeral head
  • Anterior deltoid strengthening
  • Anterior deltoid centres humeral head and helps with forward elevation
• Only has a role in the very low demand poor surgical candidate

Operative

Arthroscopic Debridement

• May provide some pain relief
• Use of electrocautery may denervate soft tissues in subacromial space
• LHB tenotomy
• Tuberoplasty of GT – rounding it off
• No acromioplasty should be performed
• Strictly avoid elevating or debriding CAL
  • Last restraint to anterior-Superior escape
• Will not improve function
• Improves but does not solves pain

Hemiarthroplasty

• Either stemmed or resurfacing with an extended head
• Principle is to remove pain generators by creating bone on metal articulation
• Using a large head creates some articulation with the glenoid
• A viable option if forward elevation is retained (>60 degrees)
  • i.e. no pseudoparalysis
• Problems
  • Pain
  • Acromial erosion continues
  • Glenoid erosion continues
  • Poor function
  • Continued superior migration
  • No fulcrum restored
  • Anterior-superior escape once CAL becomes deficient

Reverse Geometry Shoulder Arthroplasty (RSA)

• Indications
  • Pseudoparalysis (<60 degrees forward elevation)
  • Elderly Patient
  • Low demand patient
  • Failed cuff repair
  • Failed previous arthroplasty
  • Unreconstructable fracture with cuff deficit
• Design Principles
  • Moves centre of rotation medially and inferiorly
  • Restores fulcrum
  • Tensions deltoid
  • Better results with intact Subscapularis – rotational control
    • Can be combined with Lat Dorsi Transfer if SSc deficient
• Prerequisites
  • Functional Deltoid
  • Adequate glenoid bone stock for Glenosphere implantation
  • Older Patient
  • Lower demand patient
• Complications
  • In general are higher than other forms of shoulder arthroplasty
  • Likely due to learning curve
    • Infection
    • Inferior Scapula Notching
    • Glenoid Loosening – main cause of revision
    • Fracture – acromial or humeral
    • Nerve Injury – extensive inferior exposure required
• Outcomes
  • Better pain relief and function than any other operation for CTA
  • But,
  • Higher complication rate
  • Bigger surgery
  • No good bail out operation