“Leaders don’t step on the toes of dwarfs. They mount shoulders
of Giants.” ~Israelmore Ayivor
Although we sometimes feel as if we are carrying the world on our shoulders,
we are all lucky that, unlike Atlas, we are not. But our shoulders are
the point on our bodies we most consistently DO use to carry our loads
– parents tote their toddlers on them, women perch their purses
on them, students lug overflowing backpacks on theirs and we sometimes
even offer them to console a bereft friend. Luckily, the shoulder is designed
for exactly these functions: it is the most moveable joint, having multiple
planes of rotation and 360 degrees of freedom. Unlike most other joints
that are more constrained due to their bony anatomy, the shoulder gains
its stability through a balance of both bones and capsular attachments.
However, all of this movement comes at a cost—with great power comes
great responsibility, right? Unfortunately, the shoulder has the highest
risk for instability as a direct result of the very flexibility it is
so prized for. Not surprisingly, about half of all dislocations seen in
the Health System’s Emergency Care Center are of the shoulder.
The shoulder joint is made up of three bones: the upper arm bone (humerus),
the shoulder blade (scapula), and the collarbone (clavicle). The head,
or ball of the humerus, fits into a shallow socket of the shoulder blade,
called the glenoid. This is similar to the way a golf ball rests on a
tee. The strong shoulder capsule is made up of multiple ligaments that
surround the shoulder and keep it centered in the socket. This capsule
is surrounded by strong tendons in the rotator cuff that help with stability
and motion of the shoulder. This entire construct makes up the shoulder joint.
Mechanism of Injury
The primary cause of a shoulder dislocation is usually due to a trauma
from a direct blow with the arm up and away from the body, resulting in
the ball dislocating out the front of the shoulder joint. When the ball
of the humerus dislocates, the front of the glenoid and the attached ligaments
are often injured. A severe first dislocation will often tear away some
of the bone on the front of the shoulder along with its capsular attachments.
This is called a Bankart lesion and can result in continued dislocations,
giving out or a feeling of instability. The example of the golf tee is
important to remember here. If a golf tee is chipped, the ball will continue
to fall off. The same is true of a shoulder; when a piece of the glenoid
is chipped, your shoulder will continue to dislocate. In older patients,
not only does the capsular attachment tear, but there is also an increased
risk of rotator cuff tears that will cause persistent weakness and instability.
Some people have shoulder instability but have never had a traumatic dislocation.
These people will have looser ligaments in their shoulders as part of
their normal anatomy or secondary to repetitive overhead motion. Swimming,
tennis and volleyball are the most common sports that may cause shoulder
instability from repetitive strain on the ligaments. When the ligaments
become loose, it is hard to maintain shoulder stability resulting in a
painfully unstable shoulder.
During an exam, the physician will discuss symptoms and take a full medical
history. Common symptoms include chronic dislocations, repeated episodes
of the shoulder feeling unstable, giving out and pain with activity. The
physical exam consists of multiple maneuvers to assess the shoulder ligaments
for laxity. Patients will usually report apprehension with shoulder testing
as they feel the shoulder start to shift out of place. Imaging tests are
ordered to help confirm the diagnosis. X-rays are important to evaluate
for any bony deformity. If the bony anatomy looks normal, then an MRI
will be ordered to provide a detailed image of the capsular attachments
of the shoulder. This will help your doctor identify any injuries to the
ligaments and tendons surrounding the joint
Not all shoulder dislocations or chronic instabilities need surgery. Your
doctor may be able to develop a nonsurgical plan consisting of anti-inflammatory
medicines to decrease swelling, along with physical therapy to strengthen
the shoulder muscles in an attempt to increase the stability in the joint.
A nonsurgical program may take up to six months.
If these options do not relieve the pain and instability, then surgery
may be warranted. Surgery is often necessary when there is a bony avulsion
of the capsular ligaments and/or when the capsular attachments are so
stretched they cannot regain stability from nonsurgical means. Most capsular
repair techniques can be performed arthroscopically using a camera for
viewing inside the joint and small instruments. Arthroscopy is minimally
invasive surgery and is usually performed as an outpatient procedure.
Some patients may require a larger open procedure so the repair can be
performed under direct visualization.
The rehabilitation program after a shoulder dislocation is a step-wise
program where one step has to be accomplished before proceeding to the
next step. Initially the shoulder is placed in a sling for a short period
of time to decrease pain and allow the healing phase a head start before
jumping into physical therapy (PT). After a few weeks, therapy can be
initiated. The first goal of PT is to regain range of motion under safe
parameters so as not to injure the repair. This is then advanced to full
range of motion and a shoulder stabilization program. After full range
of motion has been achieved, the program is advanced to focus on exercises
to strengthen the shoulder. Finally after four to six months, sports specific
exercises can usually begin with the goal of return to play at around
six to nine months (sometime even longer depending on the activity).
While it sounds traumatic and certainly looks pretty bizarre, a shoulder
dislocation is pretty common and can usually be treated nonsurgically.
Only the most severe injuries or malfunctions of a shoulder joint end
up needing to go to the operating room, but having a history of dislocation
will increase your risk of a subsequent injury by 20 percent. By strengthening
the muscles and tendons around the joint, you can better the odds of not
having a repeat injury.
After spending eternity holding the weight of the world, I can only imagine
what Atlas’s medical bills might look like . . .