Cuff Tear Arthropathy

Definition

 

Chronic massive rotator cuff defect

- uncovered humeral articular cartilage

- high riding humeral head

- abrasion by undersurface of coracoacromial arch

 

History

 

Neer

- introduced term "cuff tear arthropathy"

- included significant rotator cuff diagnosis & arthritis in older patients

- especially women

- synovial fluid contained calcium phosphate crystals + proteases

 

Aetiology

 

Crystal induced arthropathy

- hydroxyapatite-mineral phase in altered capsule, synovium or degenerate articular cartilage

- induce synthesis of proteolytic enzymes

- destruction of cartilage via collagenase, stromeolysin

- origin of crystals unclear

- 1° or 2° to arthritis

- erosion of head begins superiorly rather than centrally

 

Cuff tear theory

- loss of cuff leads to mechanical and nutritional alterations in shoulder

- due to loss of closed joint space and altered range of motion

 

Incidence

 

4% of massive cuff tears go on to arthroplasty

 

Theory

- tears with unbalanced force couplet go on to arthropathy 

- massive tear that are balanced & / or above equator don't go onto to arthropathy

 

Epidemiology

 

Women > men

60% bilateral

 

Symptoms

 

Recurrent swelling

Loss of Motion

Night pain

 

Xray

 

1.  Superior migration of head 

- defined as AHI / acromiohumeral interval of 7mm or less

 

Humeral Head Superior Migration

 

2.  Collapse of proximal head articular surface 

 

3.  Proximal humerus becomes "Femoralized" 

- erosion of greater tuberosity

 

4.  Coracoacromial arch becomes "acetabularized"

- often articulates with acromion

- periarticular soft tissue calcification

 

Acromial Acetabularisation

 

CT

 

RC Arthropathy CT

 

DDx

 

GH OA 

- no superior migration

- beard osteophytes

 

Management

 

Non-Operative

 

Often appropriate 

- many patients only mild symptoms

- patients elderly

- accept limited ROM

- analgesia

 

Operative Management

 

1.  Acromioplasty & tendon debridement 

 

Not indicated with superior migration

- can consider biceps tenotomy if still intact

 

2.  Arthrodesis

 

Poorly tolerated in elderly 

- significant pseudoarthrosis & re-operation rate in osteoporotic bone

- reserve for those with non functioning deltoid

 

3.  TSR 

 

Increased loosening of glenoid component if TSR

- superior migration of head due to unopposed deltoid

-"rocking horse" phenomenon 

 

4.  Hemiarthroplasty

 

Indications

- < 70

- intact CA arch

- anterior deltoid muscle

 

Technique

- do not oversize head

- can cut in some valgus to allow articulation with acromion

- correct size allows arm to lie freely across abdomen

- head to translate 50% posterior / anterior / inferior

- subscapularis to be re-attached without bow stringing

- margin convergence of cuff as possible for force couplet

- reattach CA ligament to prevent superior escape

 

Results

 

Rockwood

- 18 of 21 satisfactory

- good pain relief

- ROM often not improved

 

Neer 

- concept of limited goals category

- 20° of ER and 90° of forward elevation

 

Poor prognosis

- previous acromioplasty

- previous division CA ligament

- deltoid insufficiency

 

5.  CTA Humeral Head

 

Depuy Cuff Tear Arthropathy

- arc of surface > 180o

- allows articulation of lateral head with acromion

- increased articulation in abduction and ER

 

CTA HemiarthroplastyCTA Head APCTA Head 2

 

6.  Reverse TSR

 

Indications

- > 70

- functioning deltoid

 

Concept

- medialises the centre of rotation

- increases lever arm for deltoid

- semiconstrained - prevents superior migration

- deltoid acts to stabilise shoulder