Anatomy of the Shoulder
The shoulder is a complex, ball-and-socket joint made up of three bones: the upper arm bone (humerus), shoulder blade (scapula), and collarbone (clavicle). The ball, or head, of the upper arm bone fits into a rounded socket (glenoid) in the shoulder blade. The shoulder socket (glenoid) is lined with a strong cartilage (labrum) that cushions the shoulder joint and adds stability.
The arm bone is kept centered in the shoulder socket by a combination of muscles and tendons (rotator cuff). The rotator cuff forms a cover around the head of the upper arm bone and attaches it to the shoulder blade. Between the rotator cuff and the bone on top of the shoulder (acromion) is a jelly-like, lubricating sac (bursa) filled with fluid. The bursa helps to reduce friction and allows the rotator cuff tendons to glide freely when the arm is moved.
What is Shoulder Impingement?
The shoulder is made up of many different structures that combine to allow a great range of motion in the arm. Because of this complexity, the shoulder is vulnerable to a wide variety of problems. The rotator cuff is a frequent source of shoulder pain, which can be the result of:
- Tendinitis—Rotator cuff tendons can be irritated or damaged.
- Bursitis—Bursa become inflamed and swell with more fluid, causing pain.
- Impingement—When raising the arm to shoulder height, space between the acromion and rotator cuff narrows and the acromion rubs against (or “impinges” on) the tendon and bursa, causing irritation and pain.
Symptoms
Rotator cuff pain commonly causes tenderness in the front and side of the shoulder. There may be pain and stiffness when lifting the arm, or when lowering the arm from an elevated position. Other symptoms may include:
- Minor pain, present with activity and at rest
- Pain radiating from the front of the shoulder to the side of the arm
- Sudden pain with lifting and reaching movements
- Athletes participating in overhead sports may experience pain when throwing or serving a tennis ball
Symptoms increase as the problem progresses, resulting in:
- Pain at night
- Loss of strength and motion
- Difficulty performing activities that place the arm behind the back, such as buttoning or zippering
What Causes Shoulder Impingement?
Rotator cuff pain is common in both middle-aged people and young athletes.
Most susceptible are those who:
- Do repetitive lifting
- Use arms overhead for sports such as swimming, baseball and tennis
- Perform overhead activities such as paper hanging, construction or painting
Shoulder pain may also develop as the result of a minor injury, or it may occur with no apparent cause.
Nonsurgical Treatment
In most cases, initial treatment for shoulder impingement is nonsurgical and may include one or more of the following:
- Rest—Your physician may recommend rest and activity modification, such as avoiding overhead activities.
- Nonsteroidal anti-inflammatory medication (NSAIDS)—Drugs such as ibuprofen or naproxen may help relieve pain and swelling. Most people are familiar with nonprescription NSAIDS such as aspirin and ibuprofen, however, whether using over-the-counter or prescription strength, they must be used carefully. Using these medications for more than one month should be reviewed with your primary care physician. If you develop acid reflux or stomach pains while taking an anti-inflammatory, be sure to talk to your doctor.
- Steroid injection—If rest, anti-inflammatory medications, and physical therapy do not relieve the pain, an injection of a cortisone preparation, along with a local anesthetic, may be helpful in relieving symptoms.
- Physical therapy—A physical therapist will initially focus on restoring normal motion to your shoulder. Specific stretching exercises or a shoulder conditioning program may be recommended to help you improve strength and flexibility, restore movement, and provide relief from uncomfortable symptoms. Physical therapy is often a key factor in successfully recovering from a wide range of conditions and disorders.
Surgery
If nonsurgical treatments fail to provide relief from symptoms, your orthopaedic surgeon may recommend surgery.With any surgery there are some risks, and these vary from person to person. Complications are typically minor, treatable and unlikely to affect your final outcome. Your orthopaedic surgeon will speak to you prior to surgery to explain any potential risks and complications that may be associated with your procedure.