summary Rotator cuff arthropathy is a specific pattern of shoulder degenerative joint disease that results from a rotator cuff tear leading to abnormal glenohumeral wear and subsequent superior migration of the humeral head. Diagnosis can be made primarily with shoulder radiographs showing glenohumeral arthritis with a decreased acromiohumeral interval. Treatment for minimally symptomatic patients involves activity modification, subacromial steroid injections, and physical therapy. Shoulder arthroplasty (most commonly reverse total shoulder arthroplasty) is indicated for patients with progressive pain and deterioration of shoulder function. Epidemiology Demographics females > males 7th decade most common Anatomic location more common in dominant shoulder Risk factors rotator cuff tear rheumatoid arthritis crystalline-induced arthropathy hemorrhagic shoulder (hemophiliacs and elderly on anticoagulants) Etiology Pathophysiology cuff tear arthropathy mechanical factors loss of the concavity due to compression effect decreased range of motion and shoulder function humeral head migration instability with possible recurrent dislocations nutritional factors loss of water tight joint space decreased joint fluid cartilage atrophy (decrease in water and glycosaminoglycan content) and subchondral collapse (disuse osteoporosis) crystalline-induced arthropathy degradation proteins in the synovium destroy the rotator cuff and cartilage end-stage disease leads to calcium phosphate crystal deposits Rotator cuff arthropathy is characterized by the combination of rotator cuff insufficiency glenohumeral cartilage destruction superior migration of the humeral head subchondral osteoporosis humeral head collapse Anatomy Glenohumeral joint Classification Seebauer Classification of Rotator Cuff Arthropathy Type IA Centered, stable Intact anterior restraints Minimal superior migration Dynamic joint stabilization Femoralization of the humeral head and acetabularization of coracoacromial arch Type IB Centered, medialized Intact or compensated anterior restraints Minimal superior migration Compromised joint stabilization Medial erosion of the glenoid Type IIA Decentered, limited stability Compromised anterior restraints Superior translation Minimum stabilization by coracoacromial arch Type IIB Decentered, unstable Incompetent anterior restraints Anterosuperior escape Nonexistent dynamic stabilization No coracoacromial arch stabilization Hamada Classification of Rotator Cuff Arthropathy Grade 1 Acromiohumeral interval ≥ 6mm Grade 2 Acromiohumeral interval≤ 5mm Grade 3 Acromiohumeral interval ≤ 5mm, with acetabularization of acromion Grade 4 4A: Glenohumeral arthritis without acetabularization, AHI < 7mm 4B: Glenohumeral arthritis with acetabularization, AHI ≤ 5mm Grade 5 Humeral head collapse Presentation Symptoms pain, including night-pain subjective weakness subjective stiffness Physical exam inspection & palpation supraspinatus/infraspinatus atrophy prominence of humeral head anteriorly (anterosuperior escape) with elevation of arm subcutaneous effusion from loss of fluid from capsule range of motion limitations in active and passive ROM crepitus in glenohumeral and/or subacromial joints with ROM pseudoparalysis inability to abduct shoulder provocative tests external rotation lag sign inability to maintain passively externally rotated shoulder with elbow at 90 degrees consistent with a massive infraspinatus tear Hornblower sign inability to externally rotate or maintain passive external rotation of a shoulder placed in 90 degrees of elbow flexion and 90 degrees of shoulder abduction consistent with teres minor dysfunction Imaging Radiographs recommended views complete shoulder series; AP, axillary, Grashey (true AP) findings acromial acetabularization (true AP) femoralization of humeral head (true AP) asymmetric superior glenoid wear lack of osteophytes osteopenia "snowcap sign" due to subchondral sclerosis anterosuperior escape MRI indications not necessary if humeral head is already showing anterosuperior escape on x-rays findings shows an irreparable rotator cuff tear with massive fatty infiltration severe retraction Treatment Nonoperative activity modification, subacromial steroid injection, physical therapy indications first line of treatment technique physical therapy with a scapular and rotator cuff strengthening program non-steroidal anti-inflammatories subacromial steroid injections Operative arthroscopic debridement indications controversial outcomes unpredictable results must maintain coracoacromial arch without acromioplasty or release of CA ligament hemiarthroplasty indications anterior deltoid is preserved coracoacromial arch intact deficiency of the coracoacromial arch will lead to subcutaneous humeral escape younger patients with active lifestyles outcomes will relieve pain but will not improve function (motion limited to 40-70 degrees of elevation) reverse shoulder arthroplasty indications pseudoparalytic cuff tear arthropathy preferred in elderly (>70) with low activity level anterosuperior escape requires functioning deltoid (axillary nerve) and good bone stock deltoid is used to assist glenohumeral joint to act like a fulcrum in elevation outcomes (short and intermediate at this point) has the potential to improve both function and pain risk of inferior scapular notching with poor technique latissimus dorsi transfer indications external rotation pseudoparalysis combination with reverse total shoulder arthroplasty pectoralis transfer indications internal rotation deficiency and subscapularis insufficiency techniques upper portion or whole pectoralis tendon transferred near subscapularis insertion on lesser tuberosity complications musculocutaneous nerve injury resection arthroplasty indications salvage only (chronic osteomyelitis, infections, poor soft tissue coverage) glenoid resurfacing contraindicated excess shear stress on superior glenoid leads to failure through loosening TSA contraindicated Complications Infection Neurovascular injury Deltoid dysfunction Instability (more common after hemiarthroplasty, rare after RTSA)