What is moderate narrowing of the glenohumeral joint in an older adult, likely due to osteoarthritis?

Moderate Narrowing of the Glenohumeral Joint

Moderate narrowing of the glenohumeral joint represents a radiographic finding of osteoarthritis where the cartilage space between the humeral head and glenoid cavity has decreased to an intermediate degree, indicating progressive degenerative disease that typically occurs in older adults and is more common in women. 1

Radiographic Definition and Significance

Joint space narrowing is the primary radiographic hallmark of glenohumeral osteoarthritis, appearing on true anteroposterior shoulder views as decreased distance between the humeral head and glenoid surface. 2, 3 The normal glenohumeral joint space measures approximately 4.28 mm centrally on anteroposterior views and 6.12 mm on axillary views in young adults, but this progressively decreases with age even before osteoarthritis develops. 4

• Moderate narrowing falls between early disease (minimal narrowing) and severe disease (marked narrowing with bone-on-bone contact), representing an intermediate stage where cartilage loss is substantial but not complete. 5
• The joint space naturally decreases with age beginning in early adulthood, declining from approximately 4.28 mm to 3.12 mm by middle age, independent of osteoarthritis development. 4
• When osteoarthritis supervenes, this narrowing accelerates dramatically to mean values of 1.47 mm in advanced disease. 4

Associated Radiographic Features

Beyond joint space narrowing, moderate glenohumeral osteoarthritis typically demonstrates additional radiographic characteristics:

• Osteophyte formation and hypertrophic spurring develop at joint margins as the disease progresses. 5, 2
• Subchondral bone sclerosis and cyst formation may be present, representing bone remodeling in response to altered mechanical forces. 6
• Posterior subluxation of the humeral head occurs in 45% of cases, which can create asymmetric posterior glenoid wear and biconcave glenoid morphology. 3
• Glenoid retroversion averages 15.4 degrees but can be more pronounced, contributing to abnormal joint mechanics. 3

Clinical Presentation

Patients with moderate glenohumeral joint narrowing typically present with characteristic symptoms:

• Activity-related pain is the hallmark, particularly with overhead activities and throwing motions, located in the anterior or anterolateral shoulder. 2
• Painful limitations with abduction affect daily activities and functional capacity. 2
• Progressive stiffness and loss of range of motion develop as the disease advances. 7
• The condition is more common in women and increases with age, affecting 16-20% of adults over 65 years with radiographic evidence. 1, 8

Clinical Implications and Management Pathway

Treatment should be dictated by patient age, severity of symptoms, radiographic findings, and medical comorbidities. 5

Conservative Management (Initial Approach)

• Physical therapy, pharmacotherapy (extrapolated from hip/knee literature), and activity modification form the foundation of initial treatment. 5
• Injectable corticosteroids have insufficient evidence for recommendation (Grade I), though commonly used in practice. 5
• Viscosupplementation represents a treatment option with weak supporting evidence (Grade C recommendation). 5

Surgical Considerations

• Total shoulder arthroplasty (TSA) is preferred over hemiarthroplasty when conservative measures fail, with moderate-strength evidence showing superior pain relief and functional outcomes. 1, 5
• Surgery should be considered when conservative treatment fails and symptoms significantly impair quality of life. 7
• Pre-operative imaging is essential to evaluate glenoid morphology, bone loss, retroversion, biconcavity, and bone quality before arthroplasty planning. 9

Critical Pitfalls to Avoid

• Rotator cuff integrity must be assessed, as irreparable tears contraindicate standard TSA and require alternative approaches like reverse total shoulder arthroplasty. 5, 2
• True anteroposterior views are mandatory for accurate diagnosis; standard AP views may miss glenohumeral joint narrowing. 3
• Posterior subluxation and glenoid retroversion must be identified pre-operatively, as they affect surgical planning and component positioning to prevent post-operative instability and glenoid loosening. 3
• The glenohumeral joint is the third most common large joint requiring surgical reconstruction after knee and hip, emphasizing the clinical significance of this condition. 1, 7