Shoulder Impingement

Background

Shoulder impingement is a common condition of pain in the shoulder due to irritation of a fluid sac and the rotator cuff tendons underneath it. It frequently occurs with a ‘spur’ of bone under the point of the shoulder. The pain may restrict the ability to raise or rotate the arm. Treatment may include rest, injections, physiotherapy and surgery.

Anatomy

The shoulder joint consists of a ball and socket, held together with loose ligaments and surrounded by a cloak of tendons called the rotator cuff. There are four of these, and they work to keep the ball centred in the socket and help to move the arm in certain directions. Above the rotator cuff tendons is a fluid sac call the bursa which lies between these tendons and the arch of bone forming the point of the shoulder (the acromion). Making up part of this arch is a ligament called the CA ligament.

Structural Damage

Fig.1 Subacromial spur

The fluid sac becomes inflamed, as does the rotator cuff beneath it, and the CA ligament becomes thickened with time. As the process continues, a bony spur develops reducing the space for the fluid sac and the rotator cuff tendons further. A vicious cycle is thus set up.

Symptoms

Pain is usually felt over the top and front of the shoulder and may travel down the arm. It may be uncomfortable to lie on the shoulder at night. Pain is worse when elevating or rotating the arm and when loading the shoulder (pushing, pulling or lifting weights)

This process occurs most frequently in people who use their arms in overhead positions repeatedly and is more common with older age, but can occur in anyone. It may develop gradually, or more quickly after a minor injury or aggrevation. In young people, impingement may be due to excessive looseness of the shoulder joint itself.

Consequences

• Over time and with advancing age, persistent impingement can lead to tearing of the rotator cuff itself. This will lead to weakness, more pain and a greater likelihood of needing surgery.
• Shoulder movement particularly behind the back and above the head may become restricted.
• Neck and shoulder blade muscles may become sore

Treatment

Impingement will most often settle without surgery.
Initial treatment involves:

• Avoid persistent overhead work or any other specific aggravating activity.
• Physiotherapy – directed at and restoring full movement, strengthening the rotator cuff muscles and improving posture. Usually a combination of manual therapy plus exercises.
• Home exercise
• Injections of local anaesthetic with cortisone. This helps to settle the inflammation and break the pain cycle. The effect lasts for 6 to 8 weeks, but may be longer since it helps to eradicate the condition. It is safe to have approximately 3 per year; overuse may lead to rotator cuff tendon weakness and rupture.

If the condition does not resolve after 3 to 4 months of treatment, surgery may be required. This is called a ‘shoulder decompression’.

The surgery

Surgery for impingement (‘shoulder decompression’) is performed via a keyhole (arthroscopic) technique, and may be done as a day case or with a single night in hospital.

2 or 3 small incisions ( 1 cm each) are made around the shoulder through which the camera (arthroscope) and arthroscopic instruments are inserted.

Removal with a motorized burr

If a tear in the rotator cuff is discovered, it can be repaired at the same time and by the same keyhole technique. If this is necessary, the operation itself and the duration of rehabilitation afterwards are lengthened. Another 1 or 2 small instrument entry sites are usually required.

The keyhole technique has some advantages compared with traditional methods of ‘open’ surgery using larger incisions:

• Less pain
• Shorter hospital stay (day case or overnight only)
• Faster rehabilitation
• Less stiffness (restriction of movement) following the surgery
• Better ability to identify and treat other areas of damage

What to expect after the surgery

You will wake up in the recovery area of the operating suite with a bulky dressing over the shoulder and a sling applied.

Pain will be present; however, not extreme. By evening it should be well controlled with tablets given on the ward. Occasionally a small dose of a strong pain killer given via injection is needed.

The shoulder will be swollen for approximately 24 hours due to collection of sterile fluid used during the operation to enable vision inside the joint.

Discharge from hospital is usual the following morning but may be in the same evening following a morning operation. The bulky dressing is taken down and the small waterproof dressings replaced if soiled. Leave the dressings on until review - the date of this will be given to you at the time the surgery is booked. You may shower but try not to directly soak the dressings. The wounds should be kept dry until review and any stitches are removed (if present).

A physiotherapist will see you prior to discharge and instruct on simple exercises to do and how to manage the sling. In general, for the first 2 weeks, it should be used most of the time to keep the shoulder rested, comfortable and allow it to heal. It may be taken off when resting at home, or at night if desired. It should be taken off to do the exercises, and for showering.

You will receive a short (usually 5 day) supply of pain killing tablets to use at your discretion. Reaction to the tablets may occur and can include a rash, nausea, stomach pain, dizziness and light-headedness. Stop them and see your local doctor for alternatives if needed.

The small wounds usually heal well with only a faint scar ultimately visible.

In the short term, the size of the muscle surrounding the shoulder will decrease due to lack of use. This will return following rehabilitation and is expected to take many months.

Rehabilitation

If there was no rotator cuff tear, an early exercise programme will be encouraged to regain movement as soon as possible. Instructions for this will be given in hospital and exercises at home should commence from Day 1 following surgery.

The shoulder is often uncomfortable but with gradual improvement for the first 2 months after surgery, and full recovery requires at least 6 months.

There will be no restrictions imposed on what you can do with the arm during the recovery period, within the limits of pain. General advice; however, is not to ‘stress’ the shoulder with heavy lifting or repetitive overhead tasks within the first 2 to 3 months to allow the best chance for good recovery.

Referral to a physiotherapist is made to assist with regaining full movement and developing strength in the shoulder as well as for some pain control strategies. Full benefit from the surgery requires regular stretching and resistance exercise at the appropriate time. A physiotherapist has a key role in co-ordinating this aspect of your recovery.

Return to office work may commence from 2 weeks following surgery or earlier if comfortable and there is no requirement to drive. Physical work may recommence with light duties at 6 to 8 weeks, and heavier tasks from 3 months pending adequate return of strength.

Running and swimming may be started from 2 weeks if comfortable, avoiding freestyle for the first 2 months. Return to competitive sports is variable and the timing should be individualized.

Complications

Complications are rare from this type of surgery. The procedure generally takes less than an hour to perform and there is no blood loss.
Some of the more common or important potential complications or consequences are outlined below.

1. Some complications which are related more directly to the shoulder:

• Bleeding under the skin related to the arthroscopy entry holes leading to local bruising. This bruising may run down the arm and across to the chest area. It is common, goes away in a couple of weeks, and does not require treatment.
• Infection may occur and may be indicated by an increase in pain, fever, nausea and generally feeling unwell. The surgical wounds may be surrounded by reddening of the skin and may discharge fluid, blood or pus. There may be a foul odour. Infection around the small wounds only will settle without consequence after treatment to the area such as removing the stitch, local dressings and possibly antibiotic tablets. Infection deep within the shoulder is very rare however more serious when it occurs, and may require surgical washout of the shoulder along with prolonged courses of antibiotics. This type of infection may lead to permanent damage to the cartilage within the shoulder joint.
• Stiffness (restricted movement) may occur despite appropriate rehabilitation with exercise and physiotherapy. It is uncommon. On occasions a brief procedure under anaesthetic may be required to free up the shoulder.
• Ongoing pain can occur due to persistent inflammation or the development of a rotator cuff problem such as stretching or tearing of the tendons. Treatment of this will not always involve repeat surgery.
• Nerve injury resulting in weakness of the muscles around the shoulder or of the arm or hand, and / or loss of feeling in the skin in the same areas, has been reported following this type of surgery. It may result from stretching of the nerves during grasping and positioning of the arm during the surgery, or direct damage to the nerve from the arthroscope or arthroscopic instruments used. Nerve injury is usually temporary but rarely may be permanent. Permanent nerve injury may require grafting or other corrective surgery.
• Injury to the major blood vessels passing by the shoulder is possible however extremely rare. If this happens, surgery to reconstruct the artery or vein could be needed. Permanent loss of muscle function in the arm or hand may occur.

2. Some complications of a more general nature:

• The surgery is carried out under general anaesthetic which is extremely safe, however on very rare instances a problem relating to the airway, lungs or heart and circulation may occur.
• An intravenous line is always required, and often an additional line into a small artery near the wrist to monitor blood pressure. Its use may result in pain or bruising at the point of entry, and rarely an infection or thrombosis of the vein or artery.
• Blood clots in the veins of the calf and / or leg (Deep Venous Thrombosis) may occur despite the surgery not involving these areas. It is very rare but when large can pose the threat of movement of the clots within the veins to the lungs (Pulmonary Embolus) and this can be serious or even fatal.
• Your anaesthetist will discuss the use of an injection above the shoulder near the neck (Nerve Block) to help ‘deaden’ the shoulder and arm for approximately 24 hours to help control pain. There are complications reported relating to this including bruising and nerve damage. The anaesthetist will be happy to provide further details relating to nerve blocks or other issues regarding the anaesthetic on request. You will be given contact details for the anaesthetist at the time of surgery booking.
• Infection within the body at a place other than the shoulder can occur, e.g. pneumonia, urinary or blood infection. This is more likely in elderly people or those who smoke cigarettes.
• Allergy to the antibiotic which is routinely used immediately prior to the surgery can occur. This most often causes a rash. Very rarely when serious an allergy can cause obstruction to the airway or reduced blood pressure.

In case of problems:

1. Pain control – contact local GP initially if you have run out of the tablets given to you at discharge, or you are experiencing side-effects.
2. Signs of infection (persistent increase in pain, wound discharge beyond 2 days following surgery, foul odour, fevers) – contact Mr. Dallalana via the rooms or through the hospital where you had your surgery if out of business hours. A GP may be contacted for review at the same time.
3. Tingling in the arm or hand or calf pain – contact Mr. Dallalana via the rooms or GP. Contact the hospital where you had your operation if out of hours.
4. Numbness or persistent coolness in the hand or fingers – attend the nearest emergency department.
5. Shortness of breath, severe lack of energy or sudden high fevers with chills or shakes – attend nearest emergency department.

Non-urgent matters should be listed for discussion at the next review with Mr. Dallalana or alternatively queries can be directed via email or by calling the rooms.
Certificates can be obtained at review or by your GP at other times.

• Please contact Mr Dallalana's rooms if you require further information.