Advanced G-H & A-C arthritis with complete cuff tear
Called Milwaukee Shoulder in 1981 (associated with HA deposition disease) then
Cuff Tear Arthropathy in 1983
Pathophysiology
Glenohumeral instability leads to advanced arthritis after cuff integrity lost
Rotator cuff prevents deltoid from elevating the head through compressive action
With Rotator Cuff loss, there is Progressive narrowing of the subacromial space with humeral head ascent
Coracoacromial arch is the secondary static stabiliser to humeral head migration
Pathogenesis
Initially loss of the cuff integrity through degeneration is tolerated
However as the superior forces exceed the medially directed forces the abrasive wear of cuff on acromion leads to buttonholing of head through the cuff
Articular surface of humerus abraded on undersurface of the acromion
The superiorly subluxed head has point contact on the superior glenoid
Particulate debris fills the joint with synovitis & effusion
subcutaneous fluid particularly superior to the AC joint
presence of cuff tear does not always indicate arthropathy if the force couples balanced across the humeral head
History
Unrelenting pain with referral to mid arm
Sharp pain with crepitus in overhead activities
Night pain significant
Examination
Effusion & SS / Deltoid atrophy common
Pain & crepitus with movement & loss of external rotation classical
Investigations
Xray
Osteopenia
Superior humeral head migration
Narrowing of AC interval
Severe erosions of the AC joint
Subchondral sclerosis
Cyst formation
Osteophytes
Loss of tuberosity prominence
“ Acetabularisation of glenoid “ & “ Femoralisation “ of the humeral head
Operative Treatment
Arthroplasty
Indications
Pain unresponsive to nonoperative care
Grade 4 deltoid power
The coracoacromial arch should be intact
Contraindications
Weakened or absent anterior deltoid
Active or suspected sepsis
Hemiarthroplasty with large head
Pollock compared TSR & Hemi in cuff arthropathy & found pain relief better with hemiarthroplasty
When the deltoid adequate & coacoacromial arch intact then procedure of choice
Use large head to limit migration & allow articulation with the coracoacromial arch
Total Shoulder Arthroplasty
Glenoid component loosening
high incidence of lucent lines
superior migration of head lead to eccentric forces at the glenoid margin & loosening
