Subacromial Impingement

Shoulder Impingement

One of the problems that can impede proper shoulder movement is called subacromial impingement or bursitis.

The shoulder is one of the body’s most complex structural mechanisms. It gives us a range of motion greater than any other joint in our bodies.

Multiple elements within the shoulder socket, upper arm, and collarbone need to work together to allow full arm motion. If one contributor to the overall movement process becomes unable to do its job effectively, it can result in limited movement and shoulder pain.

What is subacromial impingement?

The terms impingement and bursitis refer to different parts of the same issue.

Shoulder impingement is a condition where the rotator cuff tendons are intermittently trapped and compressed during shoulder movements.

Between the bones at the tip of our shoulder lie a group of tendons that are part of our rotator cuff. Usually, tendons slide smoothly through the area.

But sometimes the space between our arm bone, and the tip of our shoulder (acromion), becomes too narrow for tendons to easily slip through. When this happens, raising the arm above shoulder height pinches the rotator cuff tendons between our arm and acromion bones. The more this pinching happens, the more inflamed and irritated the tendons become.

What is Shoulder Bursitis?

Likewise, this rubbing and compressing can also affect the subacromial bursa. Bursas are cushion-like sacs filled with lubricating fluid that sit between our tendons and bones. Their purpose is to ensure tendons glide smoothly next to our bones.

We have hundreds of bursas in our body. When shoulder bursae become inflamed, it’s called subacromial bursitis.

What causes subacromial bursitis?

Generally, subacromial bursitis is caused by impingement from repetitive or forceful use of the shoulder. It can also be caused by the shape of the shoulder bone.

Overhead lifting, forceful pulling, and a knock to the shoulder can all cause subacromial bursitis. Also, being very active in sport that involves repeated overhead movements, such as tennis, golf, swimming, or throwing a ball can cause the bursa to flare up.

Other factors that can contribute to bursitis are advancing age, poor posture, and not stretching properly before and after a workout.

Symptoms of subacromial impingement or bursitis

The main symptoms of shoulder impingement or bursitis is persistent pain bad enough to affect everyday activities.

More specifically, symptoms can include:

  • Shoulder pain that extends from the top of the shoulder to the elbow
  • Pain when lying on the sore shoulder
  • Shoulder pain even when the shoulder is resting
  • Muscle weakness and pain when attempting to reach or lift
  • Pain when putting your hand behind your back or head (such as when getting dressed)
  • Shoulder pain while sleeping

If you have subacromial bursitis, you may also notice redness and swelling in your shoulder. It may be sore to touch, and feel ‘hot’. In advanced cases of bursitis, you might not be able to move your shoulder at all (frozen shoulder).

Shoulder impingement /subacromial bursitis diagnosis

Diagnosis of the issue begins with a medical examination. The specialists at Adelaide Shoulder & Upper Limb Clinic will discuss your symptoms, and ask you some questions about your medical history before physically examining your shoulder.

During your physical examination, your surgeon will look for any unusual bone formations, and test for tenderness in any area of your shoulder. He may also examine your neck to make sure your pain isn’t caused by a pinched nerve, and also to rule out any other conditions such as arthritis.

Next, the specialists at Adelaide Shoulder & Upper Limb Clinic will measure your shoulder’s range of motion by moving your arm in several directions. He will also test your arm strength. Two clinical diagnostic tests that are commonly performed when dealing with shoulder subacromial impingement are the Neer test, and the Hawkins-Kennedy test.

Neer impingement test

When performing this test, the specialists at Adelaide Shoulder & Upper Limb Clinic will ask you to stand with your arms straight and hands turned outward. He will then place his hand on your shoulder blade (scapula), and the other on your arm near the elbow.

Then your surgeon will turn your arm outward, and gently lift it upward from sitting at your side to raised above your head. The test is positive if you feel some pain during this movement.

Hawkins-Kennedy impingement test

During this test, your surgeon will ask you to sit on the examination table, and raise your arm in front of you at a 90 degree angle. The specialist will then bend your arm inwards, while holding your elbow up at its initial 90 degree position. He will then gently push your hand down toward your lap.

If you feel shoulder pain during this test, it can be an indication of a subacromial impingement.

Imaging tests

If your surgeon suspects impingement or subacromial bursitis are causing your shoulder pain, he may order imaging tests to confirm his diagnosis.

These may include:

X-rays - These do not show soft tissues and tendons within your shoulder. However, they can indicate the presence of a bone spur that may be causing your pain.

MRI (magnetic resonance imaging) - These tests can create images of the soft tissues within the shoulder; outlining swelling, tearing, or inflammation in the rotator cuff tendons. An MRI can also show fluid or inflammation in the bursa, indicating bursitis.

Ultrasound - This test may be useful for visualising dynamic movement and detecting any associated problems as your tendons move within your shoulder.

Treatment for Shoulder Impingement or Subacromial Bursitis

Non-Surgical treatment for shoulder impingement and subacromial bursitis

Initial treatment is non-surgical. It focuses on avoiding the activities that caused the problem to occur, using anti-inflammatories to resolve any swelling, and following a set of shoulder exercises designed to stretch and strengthen the muscles affected.

If prescribed shoulder exercises aren’t helping improve bursitis, cortisone injections are sometimes used to deliver the powerful anti-inflammatory straight into the bursa. This procedure is usually done under ultrasound control to ensure the cortisol is delivered to its optimal place.

The cause and severity of a shoulder impingement or bursitis influences how well it responds to treatment. In some cases, the issue will respond positively to a single treatment session. In more complicated cases, the injury may take a few weeks or months to settle down. Other cases may require surgery to correct the issue.

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Shoulder surgery for impingement and bursitis

If your symptoms are persisting beyond three to six months, surgery may be recommended to resolve the problem.

Surgery aims to create more space for the tendons underneath the acromion, to prevent them from impinging against the bone. Surgery can also remove inflamed tissue from the bursa, or remove the bursa altogether if necessary (a new one will grow back). This process is referred to as subacromial decompression.

Subacromial decompression is an arthroscopic (key-hole) procedure in which tiny surgical instruments are inserted into the shoulder through small incisions. Among these instruments is a small camera that allows the orthopaedic surgeon to see the inside of the shoulder and perform repairs without opening the shoulder up.

During the procedure, the specialists at Adelaide Shoulder & Upper Limb Clinic will remove bone tissue to increase the amount of space under the acromion, allowing rotator cuff muscles and tendons to move more freely underneath it. The specialist may also remove any bone spurs that may have developed.

Because of the small-scale nature of an arthroscopy, pain is minimal and healing is fast. Patients often go home the same day, and are back to their regular activities within weeks. Arthroscopic procedures are also favourable because they minimise the risk of infection as opposed to a traditional open-surgical procedure.

Shoulder Arthroscopy Recovery

Rehabilitation plays an important role in getting you back to your normal routine. After your surgery, the specialist will create a shoulder exercise program that’s designed to help regain your shoulder’s strength and motion.

Shoulder exercises may include a range of light weights, stretching, and assisted rotation exercises. As your rehabilitation progresses, your surgeon will gradually adjust your exercise schedule and advise what level of activities you should be doing with your arm.

Typically it takes between 2 and 4 months to achieve complete relief from pain after a shoulder arthroscopy, but every case is different. The specialists at Adelaide Shoulder & Upper Limb Clinic will monitor your recovery, and work with you to ensure you are back to proper function with minimal delay.