Arthritis is inflammation of a joint. In the shoulder, it can occur at the glenohumeral (ball and socket), acromioclavicular (AC), or sternoclavicular joint (SC). Over time, the loss of the smooth covering on the ends of bones (aka - articular cartilage) causes pain and stiffness. This can lead to pain with motion or at rest, clicking or grinding and a loss of strength. When the cartilage is damaged or decreased, the bones rub together during joint motion, resulting in “bone-on-bone” arthritis. When arthritis becomes severe, inflammation occurs around the joint and extra bone is formed in an attempt to protect the joint, resulting in limited motion and strength.
The primary cause of arthritis is osteoarthritis (aka – “wear and tear” arthritis). Trauma and other illnesses like rheumatoid arthritis, systemic lupus, septic arthritis and psoriasis can result in degeneration of a joint, leading to symptoms of pain and lack of motion.
Glenohumeral Joint: Patients suffering from glenohumeral joint (GH) arthritis experience pain (sometimes at night), stiffness and loss of strength. A 'grinding', 'clicking' or 'locking' sensation may be felt in the shoulder. Loss of motion can become severe, and the patient may have trouble performing everyday tasks, such as placing object on shelves or combing their hair.
AC Joint: Patients suffering from AC joint arthritis will often notice a bump on top of the joint. This bump also extends downward on the inside of the shoulder and pushes into the top of the rotator cuff. For this reason, AC joint arthritis will often lead to rotator cuff symptoms, such as pain on the side of the shoulder, night pain and difficulty lifting objects overhead.
SC Joint: Patients suffering from SC joint arthritis notice a painful bump over the joint. This swelling can occur rapidly leading to a visible deformity.
Arthritis is diagnosed by your physician based on physical exam and X-rays. Your orthopedic surgeon will examine your shoulder, noting range of motion, strength and pain with motion. Your surgeon may order additional diagnostic tests to evaluate all shoulder structures (CT/”CAT” scan) to evaluate the bones and joints or MRI to evaluate the muscles, tendons and ligaments.
Shoulder arthritis can be treated with physical therapy, to strengthen the muscles that support the joint. Aggressive physical therapy is not suggested for advanced shoulder arthritis, as it may aggravate symptoms. Your surgeon may prescribe anti-inflammatory medication or offer an injection to reduce the inflammation. Certain nutritional supplements may be beneficial to decrease pain and inflammation.
When non-operative treatment does relieve symptoms, surgery may be indicated in certain situations.
Glenohumeral Joint – The definitive treatment for GH arthritis is shoulder replacement surgery. Your surgeon will resurface the ends of the bone where the cartilage has worn away, with metal and plastic implants. Reference the “Patient's Guide to Shoulder Replacement Surgery” for in-depth details about this surgery.
AC Joint: The definitive treatment for relieving the symptoms associated with AC joint arthritis is subacromial decompression and AC joint resection. These minimally-invasive arthroscopic procedures remove the bone spurs from in and around the joint, letting the bones move more freely and negating any pressure they may be placing on the rotator cuff muscles and tendons.
SC Joint: Surgery is rarely necessary for sternoclavicular arthritis as pain relief is usually accomplished with non-operative treatment. If surgery is required, your surgeon will remove bone spurs from both bones in the joint, preventing the collarbone from rubbing on the sternum. This eliminates pain and inflammation.
The rotator cuff is a group of 4 muscles that help move the shoulder. The muscles attach to the bones around the ball-and-socket joint by a thick, non-elastic tissue called a tendon. Tendons can tear by an acute injury or degenerate over time. Tears can occur in any of the 4 tendons. In order of commonality, the supraspinatus is most often injured, followed by the infraspinatus, subscapularis and teres minor. Rotator cuff arthropathy is defined as arthritis as the result of tearing of the rotator cuff tendons.
Rotator cuff tears have multiple causes. Acute trauma, longstanding impingement syndrome (caused by abrasion on the acromion or bone spurs at the AC joint), repetitive overhead activities and degeneration in the older population are all common. When the tendons are detached from the bone, the shoulder becomes dysfunctional. Pain is associated with motion of the arm and motion eventually decreases if the tendons are not repaired back to the bone.
Rotator cuff tears cause pain, particularly on the side of the shoulder and at night, leading the patient to believe they slept wrong on their shoulder. Subacromial bursitis typically accompanies rotator cuff tears. Depending on the severity and location of the tear, loss of motion and strength can occur in a specific plane. This may be lifting the arm to the side, overhead or behind their back. Activities of daily living like reaching up to a cupboard, reaching for a wallet in a back pocket, brushing your hair or fastening a bra may be severely impacted when a rotator cuff tear is present. A massive tear of more than one tendon may result in pseudoparalysis, an inability for the patient to move their arm away from their body. Pain may also radiate up the shoulder to the neck, as the patient attempts to move the shoulder using other muscles. If the tendons remain torn for an extended period of time, the ball does not stay centered in the joint, causing wear and tear to one or both sides of the ball-and-socket joint.
Your surgeon will perform a thorough history and physical exam including X-rays. Exam findings will consist of loss of active range of motion (you move your arm), preserved passive range of motion (the surgeon moves your arm), weakness and pain with muscle testing. X-rays may or may not demonstrate acromion abnormalities or AC joint bone spurs that may be causing impingement of the rotator cuff. Superior or anterior movement of the humerus (ball) on X-ray is a sign of a chronic rotator cuff tear that may not be amenable to repair (also known as superior or anterior escape). MRI is useful to quantify the size, severity and age of the tear. For patients who cannot have an MRI, CT/”CAT” scan with contrast dye may be helpful in assessing damage to the rotator cuff.
The extent of the arthritis, long term damage to the tendons and muscles, function of the shoulder, amount of pain and patient factors (age, health issues like diabetes or seizure disorder, tobacco use and activity level) all influence the treatment of rotator cuff arthropathy. Non-operative treatment can be attempted but once the diagnosis of rotator cuff arthropathy is made, is not usually helpful. Physical therapy, anti-inflammatory medication, cryotherapy, activity modification or injections into the space just above the rotator cuff may alleviate pain and inflammation. Patients whose pain does not resolve with non-operative treatment should discuss surgical treatment options with their surgeon.
Patients who have a chronic, irreparable tear in the rotator cuff but have minimal to no arthritis, several minimally invasive arthroscopic procedures can be performed for pain relief. An arthroscopic CAM procedure, also known as a debridement or "cleanout", can remove inflammatory tissue, remove bone spurs and treat biceps tendon injury/inflammation. An arthroscopic superior capsular reconstruction (SCR) uses donor tissue to realign the ball-and-socket joint and restore some of the mechanics that are affected by chronic rotator cuff tendon tears. Both of these procedures may decrease pain, but restoration of function is patient dependent. For more advanced rotator cuff arthropathy with moderate to severe arthritis, reverse total shoulder arthroplasty (rTSA) can be performed for pain relief and restoration of some function. In rTSA, your surgeon can remove the arthritic areas of the ball-and-socket joint and replace them with metal and plastic components. In this procedure, the ball-and-socket components are switched, so that the ball becomes a socket and the socket becomes a ball, allowing the shoulder to move pain-free and using other muscles in lieu of the rotator cuff. Your surgeon will discuss all of your options based on the severity of damage in your shoulder.