فیزیوتراپیست وحید صادقی هشجین

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.

Subacromial 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.

Rotator 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.

Subacromial 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 impingement pain.

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.

The diagnosis 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 cuff tear.

The treatment 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.

In 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.

In 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.

Regardless of 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.