What is Shoulder Impingement?
Shoulder impingement refers to catching of the rotator cuff tendons and or sub-acromial bursa as these structures pass under the acromion process of the scapula (shoulder blade). These structures normally have quite a small space to pass through. This space can be smaller with the arm and shoulder in certain positions or when performing some activities. The acromion irritates the tendons and bursa. This results in inflammation and swelling of these structures. Thus a “vicious cycle” of irritation – swelling – impingement can be established. The terms Rotator Cuff Tendinitis and Sub-Acromial Bursitis are often used when describing Shoulder Impingement.
Causes of Shoulder Impingement
Most cases of Shoulder Impingement fall within two main categories:
The rotator cuff tendons and sub-acromial bursa may be thickened or swollen making it difficult for them to pass under the acromion. This scenario may result from and acute injury that pinches the rotator cuff such as a fall or wrenching injury. The tendons may be irritated in a more chronic fashion such as overhead sport activities, swimming, throwing sports or repetitive overhead workplace tasks. Sometimes shoulder ligament laxity, especially in younger patients, can cause subtle shoulder joint instability. That can result in “Secondary Impingement” of the rotator cuff. Some tendon thickening conditions such as rotator cuff calcification may occur with no obvious cause.
Too much tissue
- Inflammation of sub-acromial bursa (Bursitis)
- Inflammation of rotator cuff (Tendinitis)
- Thickening of rotator cuff due to Calcium Deposits
Alternatively the sub-acromial space may be narrowed which may then make it difficult for even a normal rotator cuff or bursa to negotiate the space without catching. Crowding of the tendons may occur due to the spectrum of different acromial shapes that are seen from person to person. Some people simply have a smaller space than others. Others may develop a smaller space for the tendons to pass due the acromion gradually changing shape over the years. This change is often referred to as the development of an “Acromial Spur”. Such a Spur can usually be identified on X-rays. Mal-Union of an upper Humerus Fracture may change rotator cuff mechanics.
Not Enough Space
- Natural curvature of the acromion
- Development of an Acromial Spur
- Displace fracture of Greater Tuberosity of Humerus
Symptoms of Shoulder Impingement
Common Shoulder Impingement Symptoms include:
- A sharp catching type pain with overhead and rotational type movements
- “Painful Arc” of motion where pain occurs in a specific sector of shoulder movement
- Aching in the front or back of the shoulder and upper arm even at rest
- Shoulder ache after excessive shoulder use
- Pain with the arm in a driving posture
- Shoulder pain when lying flat or on the shoulder
- Sleep Disturbance
Diagnosis of Shoulder Impingement
Diagnosis of shoulder impingement is a step-wise process. It involves:
- Analysis of the symptoms you have noticed
- Clinical Examination of your shoulder looking for “Impingement Signs”
- Evaluating response to Non-Surgical Treatments
- Special Investigations such as X-rays, Ultrasound, and MRI
Non-Surgical Treatment of Shoulder Impingement
Shoulder impingement symptoms may respond to non-surgical treatment especially if the onset of the symptoms is recent rather than long-standing. Also the less severe the inflammation, degeneration, or damage to rotator cuff tendons the more likely the condition may settle without a surgery. The presence of an acromial bone spur may crowd the sub-acromial space. This may reduce the chance of non-surgical treatment helping. Common non-surgical treatments include:
- Heat packs
- Sub-Acromial Cortisone Injections
Surgery for Shoulder Impingement
Surgery may be required in cases of severe acute shoulder pain or chronic pain which recurs, persists or worsens despite all appropriate non-surgical treatments.
The goal of surgery is to increase the space available for the rotator cuff tendons and sub-acromial bursa to pass under the acromion without catching or irritation. This is achieved by reshaping the acromion (tip of shoulder blade). The surgical term for this procedure is Acromioplasty. It literally means reshaping the acromion. The procedure is also referred to as rotator cuff or sub-acromial decompression. Mr Lyons achieves this in one of two ways:
- Arthroscopic Acromioplasty
- Open Acromioplasty
Arthroscopic Acromioplasty uses a “key-hole” technique via multiple small incisions. Miniature grinding or shaving instruments are used to make more space for the rotator cuff tendons.
Open Acromioplasty uses a slightly bigger “open” incision to achieve the same effect. Mr Lyons often prefers this method if there is not only impingement but also significant rotator cuff tendon tearing.
The ultimate goal of either technique is pain relief and restoration of the best possible function. The recovery process after each o the surgery methods can be quite similar. Mr Lyons will discuss the pros and cons of each technique. He will advise what he believes is the treatment best suited to your circumstances.