Shoulder instabilities and dislocations
Typical picture of an anterior shoulder dislocation. The humeral head is in front of the glenoid.
What is it ?
If a shoulder dislocates, the humeral head is completely separated from the
glenoid. Most of the dislocations happen traumatically and in about 90% of
all cases the “ball” moves out of the joint in an anteroinferior
direction. Isolated inferior or posterior dislocations are rare and an upper
dislocation is a very rare event.
Instabilities are characterized by a loosening of the shoulder joint. The
humeral head is moving too much in the glenoid. It´s a kind of partial
dislocation. Quite a few instabilities are multidirectional, which means that
it is a very loose shoulder joint, where the “ball” can move out
of the joint to the back, bottom or anteriorly.
What do you feel ?
Dislocations are acute events. The patient is suffering from a
trauma and has acute, severe pain. He is nearly unable to move his arm. A
kind of numbness or tingling might occur. Those symptoms disappear when the
humeral head is placed back into the glenoid. Different reposition techniques
exsist for such maneuver.
An instability has a more chronic character. Some special movements of the
arm cause pain, some not. Some people describe a kind of snapping or clicking,
only. While others are suffering from complaints that are very similar to
an impingement syndrome.
Development
As mentioned above, most of the dislocations happen due to a trauma.
Depending on the age and traumatized structures in the shoulder joint, dislocations
happen again and again, after such an initial traumatic event. A grand mall
event in epilepsia might another and rare cause of a dislocation. Besides
those aspects, a few youngster can dislocate their shoulder joint voluntary.
Until today, we don´t know the exact mechanism of this kind of voluntary
dislocations.
Instabilities develop due to repetitive microtraumata, e.g. in sports. People
are swimming, playing handball or other sports and the shoulder capsule is
stretched year after year, until the joint will get loose and instability
complaints occur. Predominantly baseball and football are typical sports acitivities,
that lead to these problems in english speaking countries, like USA or United
Kingdom. In a lot of these ( or similar ) cases a genetic component ( very
elastic capsular tissue ) might be associated or the main reason for the problems.
Therapy:
After
a dislocation the arm will be put back by a reposition maneuver and placed
into a sling for a few days. Depending on the age of the patient it will be
operated. Younger people ( between 20 and 40 years ) have a chance about 90%
that the shoulder will dislocate again and again. Older patients ( 60 years
and older ) have a chance of about 90% that the arm will remain stable, which
means that an operation won´t be necessary in most of the patients in
this age group.
If only a few dislocations ( 2 to 5 ) had happened, the shoulder joint can
be stabilized in an arthroscopic operation. The more dislocations happened
in the past, the shoulder will be stabilized in an open operation.
Youngsters who can dislocate their shoulder voluntary, won´t be operated,
because of the bad operative results in these cases.
First, instabilities are treated by a special physiotherapy program. The physiotherapist uses special excersises to strengthen shoulder muscles, which will stabilize the joint. If a physiotherpeutic training has no success, the shoulder joint will be stabilized using different arthrocopic or open techniques.
Bony fragment in front and under the anterior glenoid
Why is it important to stabilize a shoulder joint ?
1. dislocations can harm the nerves
near the shoulder. Especially, the axillary nerve is at risk to be hurt during
a shoulder dislocation. If such a nerve is hurt it can result in permanent
numbness / tingling and / or palsy of the arm.
2. redislocations are very painful.
3. the more dislocations occur the more internal structures of the shoulder
joint are hurt and an arthrosis of the shoulder joint can develop.
You can find us here
Other themes & sites arround the shoulder:
Diseases of the shoulder ( german ): http://www.schulterinfo.de , http://www.schulter.info
Diseases of the shoulder ( english ): http://www.shoulderinformation.com
Shoulder arthroplasty: http://www.schulterprothesen.net , http://www.schulterprothesen.com , http://www.shoulderprosthesis.com , http://www.prothesenatlas.de
Frozen shoulder ( german ): http://www.schultersteife.de
Shoulder specialists ( german ): http://www.schulterspezialisten.de
Shoulder examination ( german ): http://www.schulteruntersuchung.de
Shoulder videos ( german ): http://www.schultervideo.de