Glenohumeral Arthritis

The glenohumeral joint is one of three joints in the shoulder that allow for mobility of the arm. This shoulder joint is a ball-and-socket joint situated between the head of the humerus (upper arm bone) and the glenoid fossa of the scapula (shoulder blade). The surfaces of the bones that meet in the joint are covered with articular cartilage, a smooth surface that allows the bones to freely slide over one another so the joint moves smoothly. The joint is comprised of a ball (the head of the humerus) that is large and a socket that is small, resulting in a joint that, although mobile, is relatively unstable. It is surrounded by muscles, ligaments, the glenoid labrum and the joint capsule, which all provide stability to the shoulder joint.

There are a number of different causes of glenohumeral arthritis, and specific causes may depend on the type of arthritis that is experienced in the shoulder. Some common causes of the condition include:

• Repetitive strain and overuse of the shoulder, whether due to recreational or work-related activities, can accelerate wearing of the joint surfaces and cause damage to joint cartilage, resulting in arthritis.
• Traumatic injury to the shoulder in the past (including a fall, fracture or dislocation) can later result in the development of arthritis in the glenohumeral joint.
• Anything that diminishes the stability of the shoulder joint causes increased stress on the areas within the joint, which can lead to arthritis. Ligament damage or damage to the glenoid labrum are examples.
• Excessive use of steroid medications can cause accelerated degeneration of cartilage in the joint, leading to arthritis.
• Genetics can make individuals pre-disposed to developing degeneration of cartilage in their joints (arthritis), including glenohumeral arthritis.
• Diseases that affect the joint, such as rheumatoid arthritis, can result in damage to cartilage in the shoulder.

Symptoms of glenohumeral arthritis can vary in severity, but generally include:

• Pain and swelling around the shoulder joint.
• Diminished range of motion, mobility and functioning of the shoulder.
• An aching feeling, or the sensation of “crunching” or “cracking” within the joint.
• Weakness of the shoulder that can make some movements difficult to perform. This especially affects overhead movements, reaching behind the back, or activities that require lifting.
• Deformity of the joint can be visible or the joint may appear to be increased in size (due to inflammation and swelling).

Most patients with mild glenohumeral arthritis experience diminished pain and improved functioning within 4 – 6 weeks following conservative treatment, such as rest, NSAIDs and therapeutic exercises.

Moderate forms of the condition, in which patients experience more extensive pain, weakness and loss of mobility or function, may require more aggressive treatment, including possible arthroscopic surgery to debride the joint surfaces, followed by physical therapy. If this occurs, recovery can expect to take 6 – 12 weeks following surgery before stability, strength and functioning is restored.

Severe glenohumeral arthritis may necessitate joint replacement surgery due to significant pain, stiffness and loss of functionality brought on by bone-on-bone contact. If this occurs, recovery can require 3 – 6 months of intensive physical therapy following surgery, although additional functional gains can continue for up to a year. Quality of life is typically significantly improved following joint replacement surgery, although there will still be some limitations to mobility and function.