The rotator cuff is made up of four muscles that help move and stabilize the shoulder joint. Damage to any one of the four muscles or their ligaments that attach the muscle to bone can occur because of acute injury, chronic overuse, or gradual aging. This can cause significant pain and disability with range of motion or use of the shoulder joint.
The shoulder is a ball-socket joint that allows the arm to move in many directions. It is made up of the humeral head (the upper end of the bone of the upper arm) fitting into the glenoid fossa of the scapula (shoulder blade).
The humeral head is kept in place by the joint capsule and labrum, thick bands of cartilage that form an elongated cone where the humeral head fits. The rotator cuff muscles are the dynamic stabilizers and movers of the shoulder joint and adjust the position of the humeral head and scapula during shoulder movement.
When the rotator cuff is damaged, a variety of issues arise:
- Pain and spasm limit the range of motion of the shoulder.
- The muscles do not make the small adjustments within the joint to allow the humeral head to move smoothly.
- Fluid accumulation within the joint due to inflammation limits movement.
- Arthritis and calcium deposits that form over time limit range of motion.
The severity of injury may range from a mild strain and inflammation of the muscle or tendon, that will lead to no permanent damage, to a partial or complete tear of the muscle that might require surgery for repair.
Symptoms of a rotator cuff injury are due to the inflammation that accompanies the strain. This inflammation causes swelling, leading to the clinical picture of pain and decreased range of motion.
Because the muscles and tendons of the rotator cuff are hidden well below skin level, it may be hard to feel the swelling that accompanies the injury, but that swelling within the small space that makes up the shoulder joint prevents the normal range of motion of the shoulder joint.
- Acute rotator cuff tear.
- Symptoms can be a sudden tearing sensation followed by severe pain shooting from the upper shoulder area (both in front and in back) down the arm toward the elbow. There is decreased range of motion of the shoulder because of pain and muscle spasm.
- Acute pain from bleeding and muscle spasm: This may resolve in a few days.
- Large tears may cause the inability abduct the arm (raise it out to the side) due to significant pain and loss of muscle power.
- Chronic rotator cuff tear.
- Pain usually is worse at night and may interfere with sleep.
- Gradual weakness and decreased shoulder motion develop as the pain worsens.
- Decrease in the ability to abduct the arm or move it out to the side. This allows the arm to be used for most activities but the affected person is unable to use the injured arm for activities that entail lifting the arm as high as or higher than the shoulder to the front or side.
- Rotator cuff tendinitis.
- More common in women 35-50 years of age.
- Deep ache in the shoulder also felt on the outside upper arm over the deltoid muscle.
- Point tenderness may be appreciated over the area that is injured.
- Pain comes on gradually and becomes worse with lifting the arm to the side (abduction) or turning it inward (internal rotation).
- May lead to a chronic tear: When a rotator cuff tendon becomes inflamed (tend=tendon +itis=inflammation), it runs the risk of losing its blood supply, causing some tendon fibers to die. This increases the risk that the tendon can fray and partially or completely tear.
Injuries to muscle-tendon units are called strains and are classified by the amount of damage to the muscle or tendon fibers. Grade I strains involve stretching of the fibers without any tears. Grade II injuries involve partial muscle or tendon tearing, and grade III injuries are defined as a complete tear of a muscle or tendon.
The muscles and tendons in the rotator cuff group may be damaged in a variety of ways. Damage can occur from an acute injury (for example from a fall or accident), from chronic overuse (like throwing a ball or lifting), or from gradual degeneration of the muscle and tendon that can occur with aging.
- Acute rotator cuff tear.
- This injury can develop from sudden powerful raising of the arm against resistance or in an attempt to cushion a fall (for example, heavy lifting or a fall on the shoulder).
- The injury requires a significant amount of force if person is younger than 30 years of age.
- Chronic tear.
- Found among people in occupations or sports requiring excessive overhead activity (examples, painters, baseball pitchers).
- The chronic injuries may be a result of a previous acute injury that has caused a structural problem within the shoulder and affected the rotator cuff anatomy or function (for example, bone spurs that impinge upon a muscle or tendon causing inflammation).
- Repetitive trauma to the muscle by everyday movement of the shoulder.
- Degeneration (wearing out) of the muscles with age.
- This usually occurs where the tendon attaches to bone. The area has poor blood supply and a mild injury may take a long time to heal and potentially lead to a secondary tear.
The treatment of rotator cuff disease depends on the severity of the injury to the tendons of the rotator cuff and the underlying condition of the patient.
Mild rotator cuff disease is treated with ice, rest, and antiinflammatory medications (such as ibuprofen and others). Generally, a gradual exercise rehabilitation is instituted. Exercises are used that are specifically designed for rotator-cuff strengthening.
Patients with persistent pain and motion limitation can often benefit by a cortisone injection in the rotator cuff. Sometimes, repeat injections are necessary.
More severe rotator cuff disease can require surgical repair.
Subacromial decompression is the removal of a small portion of the bone (acromion) that overlies the rotator cuff. This removal can relieve pressure on the rotator cuff in certain conditions and promote healing and recovery. This procedure can be done by arthroscopic or open surgical techniques. Both methods have been reported to be equally successful.
The most severe rotator cuff disease, complete full-thickness rotator cuff tears, usually requires surgical procedures for the best results. These procedures, which can also be done by either arthroscopy or open surgery, involve mending the torn rotator cuff by suturing the tissues back together.
Self-Care at Home
- Rest and ice are the first-line home treatment of any sprain or strain.
- Apply ice for 15-20 minute periods at least three times a day.
- A sling may be helpful to rest the shoulder but care must be taken not to wear the sling for too long, otherwise the shoulder joint will become stiff and may require significant effort in regaining the lost range of motion.
- Anti-inflammatory medication such as ibuprofen or naproxen may help decrease the pain and swelling of the injury. These over-the-counter medications should be taken with care if there are underlying stomach or kidney problems or if the patient is taking a blood thinner likewarfarin (Coumadin). It is appropriate to check with your family physician or pharmacist if concerns exist.