Introduction
Adhesive capsulitis, or frozen shoulder, is a painful
condition which results in a severe loss of motion in the shoulder.
It may follow an injury to the shoulder,
but may also arise gradually with no warning or injury.
Anatomy
The shoulder is made up of three bones: the scapula
(shoulder blade), the humerus (upper arm bone) and the clavicle (collarbone).
The shoulder joint capsule is a loose bag of tissue that completely surrounds
the shoulder joint. The joint capsule is made up of ligaments that form
this water tight bag. A ligament is a soft tissue
structure made up of connective tissue. Ligaments attach
bones to bones. Inside the bag there is a small
amount of joint fluid that lubricates the joint surfaces.
This bag that makes up the joint capsule has a considerable
amount of slack, loose tissue, so that the shoulder is
unrestricted as it moves through its rather large range of motion.
Causes
The cause of this condition is largely a mystery. One
theory is that the condition may may be due to an autoimmune reaction.
During an autoimmune reaction the body's defense system
that normally protects it from infection, mistakenly begins to
attack parts of the body itself. The body thinks that the tissue
it is attacking is foreign material. This
causes an intense inflammatory reaction to the tissue that is under attack.
The shoulder actually "freezes up" due to the severe
inflammation of the joint capsule. The loose tissue of the
joint capsule that usually allows a great deal of motion at the shoulder
sticks together, limiting the motion. Why this
should occur all of a sudden is a mystery.
Adhesive capsulitis may begin following other injuries
where the shoulder is not moved around normally because of the other injury. A common
example is after a wrist fracture, where the arm may
be kept in a sling for several weeks. For some reason, this seems to start the process in some
people. The condition has also been known to occur after surgical procedures for
something unrelated to the shoulder, and even after recovering
from a heart attack.
The condition can begin while other shoulder problems
are present. Sometimes, problems such as bursitis,
impingement syndrome, or a partial rotator cuff tear can lead to a frozen shoulder
as well. The pain from the first condition may cause
you to decrease the use of the shoulder, and the the underlying condition itself may lead to
chronic inflammation. These two things combine to make a dangerous situation
to develop adhesive capsulitis . Usually, the adhesive capsulitis must
be treated first to regain motion in the shoulder before the underlying problem can be
addressed.
Symptoms
The symptoms are primarily pain and a very reduced
range of motion in the joint. The range of motion is
the same whether your are trying to move the shoulder under your own power or if someone else
is trying to raise the arm for you. There comes a point in each direction of movement
where the motion simply stops as if there is something blocking
the movement. The shoulder usually hurts when movement reaches the limit
of the range of motion, and can be quite painful at night.
Diagnosis
The diagnosis of adhesive capsulitis is usually made
on the history and physical examination. One key finding that can help
differentiate adhesive capsulitis from a rotator cuff tear is how the
shoulder moves. In adhesive capsulitis the shoulder motion is the same, whether the patient
or the doctor tries to move the arm. In a rotator
cuff tear, the patient cannot move the arm, but when someone else lifts the arm it can be moved
in a nearly normal range of motion. X-rays are usually
not helpful. An arthrogram may show that the shoulder capsule is scarred and contracted.
This test is done by injecting dye into the shoulder joint and taking several X-rays.
When this is done in the shoulder with adhesive capsulitis
the first thing the radiologist will notice is that not much dye can be injected into the
shoulder joint - the capsule of the joint is contracted and, thus, smaller than normal.
The X-rays taken after injecting the dye will show very
little dye in the joint.
As the motion increases in the shoulder, your doctor
may suggest tests that look for an underlying condition, such as impingement,
or a rotator cuff tear, that may have initiated the
condition. Probably the most common test used is the MRI scan. An MRI scan is a
special radiological test where magnetic waves are used to create pictures that look
like slices of the shoulder. The MRI scan shows more than the bones
of the shoulder. It can show the tendons as well, and whether there has been a tear
in those tendons.
Treatment
Treatment of the frozen shoulder can be frustrating
and slow. Most cases will eventually improve, but it may be a process
that takes months. Initial treatment is directed at decreasing inflammation and
increasing the range of motion of the shoulder with a stretching program. Anti-inflammatory
medications may be prescribed. It is critical that a Physical Therapy program be started and
continued to regain the loss of motion.
An injection of cortisone and long-acting anesthetic,
similar to Novocain, may bring the inflammation under better control,
and allow the stretching program to be more effective. In some
cases, injecting a long acting anesthetic along with
the cortisone right before a stretching session with the Physical Therapist can allow the
therapist to break up the adhesions while the shoulder is numb from the anesthetic.
If progress is slow, your doctor may recommend a
manipulation of the shoulder while you are under anesthesia.
This procedure allows your doctor to stretch the shoulder joint capsule,
and break up the scar tissue while you are asleep.
In most cases, a manipulation of the shoulder
will increase the motion in the shoulder joint faster
than allowing nature to take its course. It may be
necessary to repeat this procedure several times.