AC Joint Infection
Tips For General Practitioners – AC Joint Injection
Acromioclavicular (AC) Joint Arthritis
The principal causes of AC joint arthritis are overuse injuries or previous trauma to the AC joint. Any activity that can put pressure on the joint, either normal or excessive, may eventually cause this condition.
Constant overhead lifting, such as is engaged in by weightlifters or manual labourers who work overhead can increase the incidence of the disease. Other susceptible individuals are athletes participating in contact sports or engaging in any activity which may result in a fall on the end of the shoulder.
Typical symptoms of AC joint arthritis are pain and tenderness on the top of the shoulder around the AC joint. Sleeping on the side may cause pain and restlessness. There may be a decrease in shoulder motion. Compression of the joint, such as bringing the arm across the chest may result in increased pain.
First-line treatment consists of non-steroidal anti-inflammatory drugs (NSAIDs) and activity modification with physiotherapy. Steroid and local anaesthetic injections are quite useful in recalcitrant cases.
Steroid and Local anaesthetic injections are commonly used as part of the orthopaedic surgeon’s armamentarium when dealing with AC joint arthritis. They are useful both for diagnosis and treatment.
Injection with lignocaine is useful as a diagnostic tool to confirm the diagnosis of AC joint pain and can be used to exclude pain from subacromial impingement and rotator cuff tendonitis as well as referred pain from the neck.
- Use a 10 mL syringe and a 21-Gauge needle. A 23-Gauge needle is also acceptable.
- Lignocaine can be used safely in dosages of less than 2 mg/kg bodyweight. Generally, 50 mg (5 mL of a one percent preparation) provides adequate analgesia within safe limits.
- Triamcinolone or other steroid preparations are equally acceptable.
- Aseptic techniques should be strictly adhered to.
Post Op Advice For Patients
- Effects of the lignocaine usually wear off in a few hours. However, the steroid should slowly take effect over the next few weeks.
- Avoid strenuous activity for the following 24 hours.
- If symptoms worsen within the next 2 days, seek medical attention at the clinic. This may be due to a “steroid flare”, which can be managed with cold compresses, NSAIDs and adequate rest.
- Skin abrasions or infections.
- Known allergy to local anaesthetics.