The shoulder is a ball-and-socket joint: The ball, or head, of the upper arm bone fits into a shallow socket in the shoulder blade.
Your arm is kept in your shoulder socket by the rotator cuff. The rotator cuff is a group of four muscles that come together as tendons to form a covering around the head of the humerus. The rotator cuff attaches the humerus to the shoulder blade and helps to lift and rotate your arm.
There is a lubricating sac called a bursa between the rotator cuff and the bone on top of the shoulder (acromion). The bursa allows the rotator cuff tendons to glide freely when you move your arm. When the rotator cuff tendons are injured or damaged, this bursa can also become inflamed and painful.
There are different types of tears.
Partial tear. This type of tear does not completely detach the tendon from the bone. It is called partial because the tear goes only partially through the thickness of the tendon. The tendon is still attached to the bone, but it is thinned.
Full-thickness tear.With this type of tear, there is detachment of part of the tendon from the bone.
- When only a small part of the tendon is detached from the bone, it is referred to as afull-thickness incomplete tear.
- When a tendon is completely detached from the bone, it is referred to as afull-thickness complete tear. With a full-thickness complete tear, there is basically a hole in the tendon.
Cause
There are two main causes of rotator cuff tears: injury and wear (degeneration).
Acute Tear
If you fall down on your outstretched arm or lift something too heavy with a jerking motion, you can tear your rotator cuff. This type of tear can occur with other injuries, such as a broken collarbone, a dislocated shoulder, or a wrist fracture.
Degenerative (Wear-Related) Tear
Most tears are the result of a wearing down of the tendon that occurs slowly over time. This degeneration naturally occurs as we age and in most cases is relatively painless.
Rotator cuff tears are more common in the dominant arm — the arm you prefer to use for most tasks. If you have a degenerative tear in one shoulder, there is a greater likelihood of a rotator cuff tear in the opposite shoulder — even if you have no pain in that shoulder.
Several factors contribute to degenerative, or chronic, rotator cuff tears.
Repetitive stress. Repeating the same shoulder motions again and again can stress your rotator cuff muscles and tendons. Baseball, tennis, rowing, and weightlifting are examples of activities that can put you at risk for overuse tears. Many jobs and routine chores can cause overuse tears, as well.
Lack of blood supply. As we get older, the blood supply in our rotator cuff tendons lessens. Without a good blood supply, the body’s natural ability to repair tendon damage is impaired. This can ultimately lead to a tendon tear.
Symptoms
The most common symptoms of a rotator cuff tear include:
- Pain at rest and at night, particularly if lying on the affected shoulder.
- Pain when lifting and lowering your arm or with specific movements.
- Weakness when lifting or rotating your arm.
- Crepitus, or a crackling sensation, when moving your shoulder in certain positions.
Tears that happen suddenly, such as from a fall, usually cause intense pain. There may be a snapping sensation and immediate weakness in your upper arm.
Tears that develop slowly due to overuse may also cause pain and arm weakness. You may have pain in the shoulder when you lift your arm, or pain that moves down your arm.
- At first, the pain may be mild and present only when lifting your arm over your head, such as reaching into a cupboard. Over-the-counter medication, such as aspirin, ibuprofen, or naproxen, may relieve the pain.
- Over time, the pain may become more noticeable at rest and no longer goes away with medications. You may have pain when you lie on the painful side at night. The pain and weakness in the shoulder may make routine activities, such as combing your hair or reaching behind your back, more difficult.
It should be noted that some rotator cuff tears are not painful. These tears, however, may still result in arm weakness and other symptoms.
Diagnosis
After discussing your symptoms and medical history, your doctor will examine your shoulder.
- They will check to see whether it is tender in any area or whether there is a deformity.
- They will have you move your arm in several different directions to measure the range of motion of your shoulder.
- They will test your arm strength.
- They will check for other problems with your shoulder joint.
- They may also examine your neck to make sure that the pain is not coming from a pinched nerve, and to rule out other conditions, such as arthritis.
Tratamiento
El tratamiento de las lesiones del Manguito Rotador depende del tamaño de la lesión, cronicidad, edad del paciente y actividad pudiendo ser tratamiento conservador ( no quirúrgico) o quirúrgico.
Cuando el tratamiento conservador no es suficiente o el grado de lesión e incapacidad son intensos se opta por el tratamiento quirúrgico, siendo la artroscopia el más común para reparar los tendones afectados.
