This is the most common
painful condition of the shoulder. It frequently affects the age groups
40-60 years and in 30% of cases it may also be associated with a
rotator cuff tear.
Symptoms include pain and weakness on
activity, especially on elevating the arm sideways. The pain is usually
localised around the deltoid muscle and may interrupt sleep.
impingement syndrome results from abnormal contact between the greater
tuberosity and the under surface of the acromion during shoulder
abduction. Classically this contact occurs at 60°-120° of shoulder
abduction resulting in a painful arc in mid abduction as illustrated in
the opposite diagram.
The underlying causes of subacromial
impingement syndrome are multifactorial, but rotator cuff dysfunction
(weakness) is probably the most likely cause. In a normal shoulder, the
coordinated action of the rotator cuff muscles stops any abnormal
contact within the subacromial space between the opposing bony surfaces.
cuff dysfunction is often due to degenerative changes within the
rotator cuff muscles and is an age related phenomenon (>40 years).
In a minority of cases, rotator cuff dysfunction may follow a painful
injury or traumatic tear of the rotator cuff muscles.
impingement syndrome is a vicious cycle. The pain associated with this
condition increases the rotator cuff weakness (due to pain inhibition).
This then exacerbates the abnormal contact between the apposing bony
surfaces within the subacromial space, hence aggravating the
In the long-term subacromial impingement
syndrome would result in secondary changes within the subacromial space
such as formation of an acromial hook or an inflammatory bursitis, thus
further exacerbating the impingement syndrome.
could be confirmed by abolishing the pain using a local anaesthetic
injection into the bursa. MRI or shoulder ultrasound is frequently used
to confirm or rule out other associated conditions such as a rotator
for subacromial impingement syndrome is dependant on the severity of
the symptoms, age and occupation of the patient as well as whether
there is an associated rotator cuff tear.
If this condition is not
associated with a rotator cuff tear, the initial treatment consists of
a steroid injection into the subacromial bursa to decrease the pain
followed by physiotherapy to rehabilitate the weakened rotator cuff
muscles. Any residual stiffness in the shoulder should also be
addressed with regular stretching exercises. This method of treatment
could be successful in up to 70% of cases, although occasionally up to
3 separate injections are necessary to fully resolve the pain.
cases that fail to improve with injections and physiotherapy, surgical
intervention may be required. In these cases arthroscopic subacromial
decompression is the treatment of choice and carries a success rate of
around 90%. Please use the following link for more information on Arthroscopic Subacromial Decompression.
cases where the subacromial impingement syndrome is associated with
rotator cuff tear, rotator cuff repair may also be necessary as part of
the procedure. Depending on the size of the tear, the repair could be
achieved using arthroscopic or open techniques.
the method of treatment, physiotherapy to strengthen the rotator cuff
muscles remains an integral part of the treatment to avoid recurrence
of symptoms in the long-term.
Subacromial Impingement Syndrome
Abnormal contact between the greater tuberosity and under surface of acromion in mid abduction
Subacromial Steroid Injection
Arthroscopic Subacromial Decompression
نویسنده : مدیر سایت مدیر سایت در یکشنبه 10 خرداد 1388 و 05:40 ق.ظ