Definition

Glenohumeral arthritis (more commonly known as shoulder arthritis) is defined as the loss of articular cartilage within the shoulder joint. The shoulder joint is made up of the humeral head and the shallow glenoid fossa of the scapula. Soft tissue contractures, rotator cuff dysfunction, and bone erosion often accompany arthritis of the shoulder and are important considerations when deciding on an appropriate treatment plan. When dealing with an arthritic shoulder it is vital to consider the integrity of the rotator cuff; the outcome of surgery is greatly dependent on the integrity or reparability of the rotator cuff. Conditions such as osteoarthritis, posttraumatic arthritis, and avascular necrosis are usually associated with an intact or reparable rotator cuff. However, rotator cuff arthropathy, a unique form of glenohumeral arthritis, only occurs in the context of a large, irreparable rotator cuff tear. Other conditions, including inflammatory arthritides, may also been associated with a non-functional cuff and is an important consideration for surgery.

XRay illustrating advanced, end-stage osteoarthritis of the glenohumeral (shoulder) joint.

Pathogenesis

In most cases, the specific cause of glenohumeral arthritis is unknown, termed primary or idiopathic osteoarthritis. However, the loss of articular cartilage may be associated with previous trauma or fractures of the joint (post-traumatic arthritis), avascular necrosis, or various autoimmune or inflammatory conditions affecting the shoulder (ex. rheumatoid arthritis). Primary osteoarthritis may be related to anatomic factors such as glenoid hypoplasia or increased retroversion, but for most patients no cause is evident. In avascular necrosis (AVN), arthritis results after collapse of the humeral head. Involvement of glenoid articular cartilage does not occur until the later stages of the disease when the irregular humeral head has been articulating with the previously normal glenoid surface. Rheumatoid arthritis (RA) is caused by the immune system activating and releasing excessive lymphocytes into the joint and synovial tissue. Cytokines, destructive enzymes, interleukins, and tumor necrosis factor are also released, which trigger the gradual destruction of the articular cartilage over time.

Natural History

Glenohumeral arthritis leads to progressive stiffness, pain, and loss of function of the shoulder. Full thickness rotator cuff tears only occur in 5% to 10% of the patients with primary arthritis. Rheumatoid arthritis results in progressive regional osteopenia, central glenoid bone erosion, and rotator cuff tears. Full thickness rotator cuff tears in RA occur in 25% to 40% of the patients, but rotator cuff dysfunction and tearing are very common.

Clinical Presentation

A patient with shoulder arthritis typically presents with severe, escalating shoulder pain, loss of range of motion (primarily external rotation of the shoulder), difficulty sleeping, and loss of shoulder function. Physical examination will focus on the integrity and function of the rotator cuff, which is important to consider when deciding on the appropriate treatment approach.

Differential Diagnosis

  • Frozen shoulder
  • Posttraumatic or post-surgical infection
  • Cervical stenosis
  • Cervical radiculopathy
  • Neoplasm

 Nonoperative Management

  • Avoid activities that exacerbate the pain such as weight lifting or overhead activities (activity modification).
  • NSAIDs (Non-steroidal anti-inflammatories)
  • Intra-articular injections:
    • Corticosteroid injections
    • Hyaluronic Acid (not yet approved by the FDA)
    • Platelet-rich plasma or BMAC injections
  • Physical therapy

Surgical Management

Surgical options for the management of advanced glenohumeral arthritis include:

  • Total shoulder arthroplasty/replacement (TSA)
  • Hemiarthroplasty
  • Reverse shoulder arthroplasty (RSA)
  • Arthroscopic debridement
  • Arthrodesis

The primary indications for a total shoulder arthroplasty (TSA) include the failure of an extensive course of non-operative management with an intact rotator cuff in the context of advanced osteoarthritis. In comparison, the primary indication for a reverse shoulder arthroplasty (RSA) is an irreparable rotator cuff tear in the context of advanced osteoarthritis.

If you are suffering from shoulder pain or arthritis, contact Dr. Dold for a consultation today!

Clinical Studies

Xray of the left shoulder following total shoulder arthroplasty (TSA).