Glenohumeral Joint
Glenohumeral (shoulder) arthritis is a common source of pain and disability that affects up to 20% of the older population. The shoulder can best be thought of as a golf ball sitting on a tee with the rotator cuff tendons keeping the ball in place. Glenohumeral osteoarthritis refers to wearing down of the articular surface of the glenoid (the tee) and the humeral head (the ball).
Causes
Glenohumeral joint arthritis is caused by the destruction of the cartilage layer covering the bones in the glenohumeral joint. This creates a bone-on-bone environment, which encourages the body to produce osteophytes (bone spurs). Friction between the humerus and the glenoid increases, so the shoulder no longer moves smoothly or comfortably. As osteophytes develop, motion is gradually lost. A number of conditions can lead to the breakdown of cartilage surfaces:
- Wear and tear over time which can manifest as rotator cuff tendinitis/tendinopathy
- Trauma (such as a fracture or dislocation)
- Infection
- A chronic (long-standing) inflammatory condition (such as rheumatoid arthritis)
- Osteonecrosis (bone death caused by loss of blood supply)
- Chronic rotator cuff tears in which the head of the humerus (the upper bone in the arm) loses its proper position in the middle of the glenoid (socket)
Symptoms
Pain from bone-on-bone rubbing within the joint is the most common symptom of glenohumeral arthritis. At first the pain may come and go, but it tends to increase with time, usually over several years and be exacerbated with motion and use. Overtime, pain may be present constantly. Loss of motion is another common symptom and sometimes crepitus (or grinding) as the shoulder moves is heard and felt.
Procedure
Procedural options include cortisone injections to help with pain relief. The relief may be temporary. It can provide longer lasting relief if the condition is treated in conjunction with physical therapy. The pain relief will allow for better participation in therapy. Regenerative-type injections (such as platelet-rich plasma [PRP]) can theoretically provide longer lasting pain relief and improved function. Some animal studies suggest a small amount of cartilage can be regenerated.
AC Joint
AC stands for acromioclavicular and the AC joint is located where the clavicle meets the tip of the shoulder blade (acromion). AC joint osteoarthritis can develop from wear and tear on the joint especially in weight lifters and populations/professions that are upper body intensive.
Causes
The AC joint is an atypical synovial joint in that it has covering fibrocartilage that essentially means it is less mobile for the tradeoff of better stability. Despite this, repetitive shoulder motion, overhead pressing, and wear and tear on the joint can lead to breakdown of the cartilage on either the end of the acromion or clavicle. There is an entity called distal clavicle osteolysis where the end of the clavicle closest to the acromion withers away and this can be another cause of AC joint pain.
Symptoms
Patients with AC joint arthritis will typically have well localized pain over the AC joint. The AC joint is anterior. This anterior pain may be exacerbated by reaching across body, to grab a seat belt for instance, where the AC joint is compressed.
Procedures
Procedural options include cortisone injections to help with pain relief. The relief may be temporary. It can provide longer lasting relief if the condition is treated in conjunction with physical therapy. The pain relief will allow for better participation in therapy. Regenerative-type injections (such as platelet-rich plasma [PRP]) can theoretically provide longer lasting pain relief and improved function. Some animal studies suggest a small amount of cartilage can be regenerated.