Shoulder Osteoarthritis

Essentials

• In one patient in five, shoulder pain is due to glenohumeral osteoarthritis.
• Osteoarthritis may cause symptoms regardless of whether the rotator cuff tendon is intact or ruptured.
• The primary mode of treatment is conservative. The aim of treatment is to control and alleviate pain and maintain functional capacity.
• If there is pain and significant radiological evidence of osteoarthritis, and conservative treatment for 3-6 months has not helped, the patient can be referred to specialized care for arthroplasty assessment.

Prevalence

• In slightly less than one patient in five, shoulder pain is due to glenohumeral osteoarthritis 2.
• About 20% of people over 65 have radiological findings consistent with osteoarthritis. A radiological finding alone is not diagnostic.
• Patients with osteoarthritis are usually more than 60 years old, and most are female.
• Most patients have primary osteoarthritis with a multifactorial cause.
• Secondary osteoarthritis can develop with a history of fracture, instability or a joint disease, such as rheumatoid arthritis.

Symptoms and findings

• Symptoms of osteoarthritis fluctuate in cycles of several months or years. Patients usually see a doctor due to worsening symptoms, commonly pain 2.
• As no diagnostic criteria have been defined, the diagnosis is always clinical.
  • Shoulder osteoarthritis can be diagnosed based on the presence of a significant osteoarthritic finding and pain.
• Pain usually occurs with every movement of the shoulder, and pain at rest may disturb sleep.
• The joint may lock, crackle or squeak on movement, accompanied by pain.

Workup

Differential diagnosis

• The most typical conditions to be considered in differential diagnosis are rotator cuff disorders Non-Traumatic Tendon Problems of the Shoulder and incipient frozen shoulder Frozen Shoulder.
  • In such cases, the history is often shorter, a few weeks or months, while in osteoarthritis it is several months or years.
• A normal plain x-ray rules out a diagnosis of osteoarthritis.
  • If passive ranges of motion are significantly limited, the patient probably has a frozen shoulder Frozen Shoulder.
• Weakness against resistance with a full range of motion suggests rotator cuff rupture.
• Painful shoulder with a full or nearly full active range of motion in the absence of radiological findings indicating osteoarthritis usually suggests a tendon problem Non-Traumatic Tendon Problems of the Shoulder 1.

Treatment

• The primary mode of treatment is conservative.
• Conservative treatment involves analgesics (e.g. 1 g paracetamol 1-3 times daily and NSAIDs Safe Use of Non-Steroidal Anti-Inflammatory Drugs (Nsaids)) 4.
• Physiotherapy may help with the pain and, to some extent, with limited ranges of motion (control of the position and motion of the shoulder girdle, progressive strengthening of supportive muscles).
• Subacromial injection of a glucocorticoid + local anaesthetic can be tried a few times at intervals of 1-2 months. This may improve the condition significantly and facilitate optimal rehabilitation.

Criteria for referral to specialized care

• If there is significant radiological evidence of osteoarthritis and pain, and conservative treatment for 3-6 months has not helped, the patient can be referred to specialized care for arthroplasty assessment.
• Before referral, patients should be asked about their willingness for such a rather major operation with recovery taking about 3 months.
• Endoprosthetic options
  • In patients with intact rotator cuff, anatomic total shoulder arthroplasty (picture 4)
  • In patients with painful rotator cuff arthropathy, reverse total shoulder replacement (picture 5)
• If the patient is willing to have surgery, the following aspects need to be considered.
  • Shoulder surgery requires good cooperation and commitment to treatment after surgery.
    • Rehabilitation will proceed step by step, from wearing a collar and cuff sling first to assisted motion and after 2 weeks to active mobilization with no resistance.
  • As arthroplasty is hard on the patient, any underlying diseases should be investigated and documented. It is important to have any chronic diseases (diabetes, heart diseases, hypertension, etc.) under control.