Acromio-clavicular joint arthritis
What is Acromio-clavicular joint arthritis?
Acromio-clavicular joint is the joint in the shoulder where clavicle (collar bone) meets the highest part of the scapula (shoulder blade). Acromio-clavicular joint arthritis refers to a progressive wear and tear or degenerative changes occurring in the AC joint. It is the most common joint in the shoulder girdle that develop arthritis. It commonly affects those over 40 years of age and is usually asymptomatic. In some, the joint becomes painful, swollen, with the gradual reduction in joint space and development of spur (osteophyte, bony projections) in the joint. The common cause of ACJ arthritis is the constant stress on the joint due to overuse (eg. Work related, repeated weight lifting, construction workers etc), previous injury to the joint and inflammatory arthritis (rheumatoid).
Injuries to the shoulder due to direct falls account 10-40% of the cases of ACJ arthritis. Rugby, hockey, alpine skiing, football, and cycling are the sports that have more incidences of ACJ arthritis due to repeated injuries. Weight lifters who perform excessive bench press can develop distal clavicular osteolysis and the distal clavicle gradually disintegrates due to repetitive damage.
What are the symptoms of Acromio-clavicular joint arthritis?
In the arthritis of the AC joint, you will feel pain, stiffness, and tenderness on the top of the shoulder joint that increases with activity. Pain is centred at the highest point of the shoulder which may extend to the neck. You will also feel swelling and limitation in the movement of the affected arm; you sometimes could struggle to lift your arm even to do simple activities like combing your hair. With the progress in the disease, night pain is also common with difficulty in sleep (especially on the affected side). Grinding, snapping or clicking sound is also heard with the movement of the shoulder, especially when reaching across the front of your body at shoulder height.
How is it diagnosed?
Your surgeon will diagnose ACJ arthritis by your detailed medical history which may include the history of injury, physical examination and X-ray. X-ray shows the narrowing of the joint space and spurs (bony projections) over the shoulder. Your surgeon may ask for more investigations like MRI and CT scan.
What happens if nothing is done?
If it is left untreated, the degenerative changes in the AC joint may progress affecting the function and mobility of the affected arm.
How is it treated?
ACJ arthritis can be treated conservatively or surgically. Conservative treatment or non-operative treatment includes rest, avoidance/reduction of provoking activities, physical therapy, medications, steroid injections and ice packs.
Surgery is indicated in
- Failure of conservative treatment
- Associated pathology of rotator cuff, subacromial bursa etc
- Persistence of pain and functional limitation
What are the non-operative treatments?
Initial treatment of the ACJ arthritis is started with non-surgical methods like other arthritis. The main aim of the conservative treatment is to reduce pain and swelling with the restoration of normal functioning of the joint.
- Remain active and rest when your joints start to ache, avoid repetitive overhead activity and maintain a healthy weight.
- Use of ice packs is helpful to reduce pain and inflammation. You can apply ice 20- 30 minutes twice or thrice a day.
- You can also opt for moist heat like a warming pad a few minutes before activity to release stiffness.
- Physical therapy is recommended to prevent the stiffness and disability of the joint. It helps to restore the normal range of motion and strengthen the muscles. Your physiotherapist will give you a set of exercises for this.
- Painkillers like paracetamol or codeine are given to relieve pain. Topical painkillers are given in the form of gel or cream that can stimulate nerve endings and reduce pain by blocking their supply to the brain.
- Anti-inflammatory medicines such as aspirin or ibuprofen are prescribed to control swelling and pain. It is advisable to take these medicines with food as they can damage your stomach and kidneys.
- Injections of corticosteroids are given to provide quick relief from pain and swelling. However, its effect may not last long.
- Dietary supplements like glucosamine and chondroitin sulfate could be used.
What does the operation involve?
After six months of non-operative treatment, if pain or disability persists, your surgeon will recommend you surgical options. The main aim of the surgery is to remove the inflamed end of the clavicle and to help restore the normal function of the shoulder joint.
- The operation generally occurs as a day case under general anesthesia. Though the surgery could be done in both open and arthroscopic (keyhole) technique, the author prefers Keyhole surgery.
- Few millimeters of bone is removed from the clavicle (collar bone), in order to increase the joint space. Your body will bridge the gap between collar bone and scapula (shoulder blade) by the formation of scar tissues. This helps to reduce pain by preventing rubbing of bones together and to restore full function back in the shoulder..
- The incised skin is sutured with absorbable sutures and a shoulder sling is applied. The surgical time is usually one to two hours and most of the patients are discharged on the same day.
What happens after surgery?
- General anesthesia wears off in one to two hours after the operation. Painkillers are given for minimum 48 hours as you may feel due to the operation. Most patients do not report pain due to pain medication.
- Before discharge, your physiotherapist will teach you gentle exercises of fingers, wrist, elbow and pendulum exercises for the shoulder. This is necessary to prevent stiffness and pain and to maintain the strength of the muscles.
- You are reviewed after two weeks of surgery to check the status of the wound and referred to physiotherapy.
- The wound should be massaged (typically after 2 weeks) using the moisturizing cream by the patient 3 times a day for 3 months once the wound is well healed. This reduces the scar sensitivity and scar-related complications (tenderness helps scar to mature).
- Physiotherapy is essential to facilitate rehabilitation. It usually begins with gentle exercises in the first two weeks and gradually increased to strengthening and resistant exercises around 6 weeks.
Are there any risks?
- Vascular (blood vessels) or nerve damage
- Frozen shoulder
- Tendon injury
- Persistence or recurrence of symptoms.
- Blood clots
- Anaesthetic complications
What are the results of the operation?
The results of operation depend on the severity of pain, progress, and type of arthritis and type of surgery performed. The outcome of the surgery is very good that can significantly reduce pain and restore normal movement.
When can I return to driving and work?
You can get back to work in 2-4 weeks if you have a desk job, however might take 2- 3 months if your job involves physical work. You should be able to resume driving in 4-6 weeks. The above time line could vary based on the severity of problem and the treatment modality. Your physician will be able to advise you.
Radiograph showing severe arthritis affecting the joint (Red arrow) and osteophyte (extra bone) formation.
ACJ arthritis (A) treated with arthroscopic excision of lateral end of clavicle (B)