Rotator cuff tear arthropathy

Rotator cuff tear arthropathy is a spectrum of degenerative disease that develops due in a rotator cuff deficient shoulder. The term encompasses both rotator cuff tendinopathic change as well as associated joint degenerative change. 

Epidemiology

Elderly women are affected more than men and it affects the dominant shoulder more than the non-dominant side ¹.

Clinical presentation

Most patients have shoulder pain (particularly at night), effusions and reduced range of motion. In moderately advanced cases, patients are unable to abduct the affected arm above 90 degrees, which is called pseudoparalysis. Weakness is usually that seen in cuff tears. In advanced cases, when the coracoacromial arch is also deficient, there can be humeral head anterosuperior escape ³.

Pathology

Rotator cuff tear arthropathy has three main components as described by Neer:

1. massive rotator cuff tear
2. degenerative changes primarily in the superior aspect of joint, i.e. glenoid and humeral erosions, articular chondral loss, disuse subchondral humeral osteoporosis, and finally humeral head collapse; noticeable lack of osteophytes 
3. superior migration of the humerus and rounding of the greater tuberosity resulting in “femoralization” of the humeral head and erosion and remodeling of the undersurface acromion, called “acetabularization” of the coracoacromial arch ³  

Several theories postulated regarding the cause and progression of this entity:

1. Mechanical: rotator cuff insufficiency causing loss of medial compressive and inferior force vectors hence uncoupled and unopposed deltoid superior force vector displacing the humeral head anterosuperiorly and micro instability of the joint which predisposed to recurrent micro-trauma, mainly affecting the superior aspect of the joint.
2. Nutritional: also disruption of the watertight joint and reduction in both amount and pressure of the joint fluid result in chondrolysis which along with multiple episodes of small haemarthroses resulting in damage to further cartilage damage by altering glycosaminoglycans GAG contents.

Radiographic features

Plain radiograph

• high riding humerus
  • superior migration of the humeral head with decreased acromiohumeral distance
  • "acetabularization" of the coracoacromial arch: pseudoarticulation of the humerus with the undersurface of the acromion causing concave acromial erosion and increased sclerosis ^1,3
  • this can lead to impingement
• decreased joint space in the superior aspect of the glenohumeral joint and associated osteoarthritic changes (compared with primary OA where the wear is inferomedial on the humeral head and posterior along the glenoid) ¹
• "femoralization" of the humerus: erosion and rounding of the greater tuberosity ³
• osteopenia of the proximal humerus and acromion

Treatment and prognosis

Conservative management includes NSAIDs and rehabilitation. Surgical management includes joint fusion or replacement by hemiarthroplasty or reverse total shoulder arthroplasty ³, depending on the severity of the disease. Anatomical total shoulder replacement is contraindicated due to rotator cuff insufficiency.

History and etymology

It was first reported by Neer et al. in 1983 ².

See also

• rotator cuff
• rotator cuff tear