Shoulder Osteoarthritis – exercise or joint replacement as a solution?

Published November 4, 2024

The shoulder is the most mobile joint in the human body. For this reason, shoulder problems often cause significant difficulties for patients in daily life and present challenges for orthopedic surgeons treating them. It is estimated that up to one in five people over the age of 45 with shoulder pain have underlying shoulder osteoarthritis. Shoulder osteoarthritis is the third most common large-joint osteoarthritis after hip and knee osteoarthritis.

What causes Shoulder Osteoarthritis?

The development of shoulder osteoarthritis is the result of multiple factors. Common risk factors include advanced age and a family history of osteoarthritis. Research shows that heavy physical work and certain sports that place stress on the shoulder, such as some strength-training disciplines practiced intensively – increase the risk of shoulder osteoarthritis. Shoulder injuries – such as dislocations and fractures of the upper humerus, also raise the risk of developing osteoarthritis later. Inflammatory joint diseases, including rheumatoid arthritis and psoriatic arthritis, can also lead to premature shoulder osteoarthritis.

How is Shoulder Osteoarthritis diagnosed?

About one in six people over 40 have radiographic signs of shoulder osteoarthritis, but many remain symptom-free. On X-ray, shoulder osteoarthritis appears as joint space narrowing and osteophytes (bone spurs) (Picture 1). If the patient experiences movement-related pain and/or night pain and/or joint stiffness, the condition is considered symptomatic shoulder osteoarthritis. Another type of degenerative shoulder disease is rotator cuff arthropathy. Symptoms are similar to osteoarthritis, but X-rays show the humeral head shifted upward relative to the glenoid cavity (Picture 2), caused by an underlying, usually extensive and chronic rotator cuff tear. Both shoulder osteoarthritis and rotator cuff arthropathy can be diagnosed with X-rays; other imaging (e.g., ultrasound or MRI) is generally unnecessary.

Conservative treatment options

First-line treatment for shoulder osteoarthritis and rotator cuff arthropathy is conservative. This includes pain management and cold therapy. Recommended pain medications are paracetamol and anti-inflammatory drugs. No activity or hobby is strictly prohibited, but shoulder pain often worsens with strain. In such cases, reducing painful strain is advisable. For working individuals, job modifications should be discussed with occupational health and the employer. Many patients benefit from physiotherapist-guided exercises for shoulder girdle posture and movement control. Long-standing symptoms can lead to abnormal movement patterns that further aggravate pain. Most patients manage well with these conservative measures alone. These initial treatments can be provided in primary care, occupational health, or by third-sector providers.

Shoulder joint replacement surgery

Joint replacement is not considered for early-stage osteoarthritis with mild changes on X-ray. In these cases, conservative treatment is usually sufficient. Even severe early pain often subsides over time, although osteoarthritis itself does not disappear. When X-rays show clear osteoarthritis or rotator cuff arthropathy changes and shoulder pain and/or restricted movement cause significant impairment and reduced quality of life, joint replacement may be considered. At this stage, the surgical unit reviews the patient’s symptoms and examines shoulder function. The decision for joint replacement is always individualized, weighing benefits and risks. Surgery is almost never mandatory – it is performed to improve quality of life by reducing pain and restoring function. Often, the final decision rests with the patient, provided the orthopedic surgeon deems surgery an appropriate option.

Major risks associated with the prosthesis after surgery include infection (0.5–2.9%) and instability (1–5%), influenced by many factors (e.g., type of degeneration and chosen prosthesis model, patient age and comorbidities, previous shoulder surgeries). Infection and instability often require revision surgery. With current prosthesis models, only about 5% of patients need revision within 10 years which is a good outcome. Risks and expected benefits should always be discussed in detail with the operating surgeon, as they vary individually.

In typical shoulder osteoarthritis (Picture 1), an anatomical prosthesis is used (Picture 3), where the humeral head is replaced with metal and the glenoid cavity with a plastic component. This prosthesis relies on an intact, functioning rotator cuff. If degeneration is atypical or rotator cuff arthropathy is present (Picture 2), a reverse prosthesis is used (Picture 4). As the name suggests, its components are reversed compared to the anatomical prosthesis. The reverse prosthesis functions mainly through the deltoid muscle, assisted by any remaining rotator cuff muscles.

Shoulder replacement can now often be performed as day surgery, though many patients stay overnight due to other health conditions. After surgery, a sling is worn for a few weeks. Gentle shoulder exercises begin after three weeks, and by six weeks, the arm can be used more actively, avoiding heavy strain for up to three months. Postoperative rehabilitation follows physiotherapist instructions during follow-up visits.

Life with a shoulder prosthesis

Outcomes of shoulder replacement surgery are excellent. For comparison, hip replacement is considered one of the most effective surgical procedures. According to recent research from our clinic, the benefit patients gain from shoulder replacement is at least as good as after hip replacement. After rehabilitation, the shoulder requires no special precautions in daily life. Previous restrictions on shoulder use have largely been abandoned. The shoulder can withstand normal daily activities and most work and hobby-related loads. However, very heavy repetitive strain (e.g., bench pressing) is not recommended.

Text: MD Anssi Ryösä, Specialist in Orthopedics and Traumatology
Images: Tyks
This article was previously published in Nivelposti magazine (issue 2/2024) by the Turku Region Joint Association. Read the full magazine here.