Orthopaedic Surgeon

Consultations:

Randwick: 02 9399-5333

Concord: 02 9744-2666

Medications and Injections

- Systemic drugs

Paracetamol:

Paracetamol (Panadol, Tylenol, Herron, Panamax) is the oral pain killer of first choice. If it fixes your knee pain then it should be taken long term. Paracetamol should be taken in divided doses and at regular intervals. For most people the correct dose is 1000mg every 6 hours (1g, usually 2 tablets) with the total daily dose not exceeding 4g.

NSAIDs and cyclo-oxygenase-2-specific inhibitors (COX-2):

Anti-inflammatory tablets should only be used if paracetamol does not control your knee pain (or you are allergic to paracetamol). If you don’t have any risk factors then you should use conventional NSAIDs (COX-1), starting at a low dose and only increasing the dose as needed (not exceeding the maximum dose for that particular drug). Do not use two different NSAIDs at the same time. NSAIDs should only be used when pain is present and not as a preventative agent (although this often means continuous use). Different NSAIDs seem to work differently for different people. If one does not work then try another which may work for you. Since they all work for some people I suggest you start with those with the lowest risk profile for stomach bleeding such as ibuprofen and diclofenac. Orudis (ketoprofen) is often very effective for arthritis as well.

The newer, more expensive COX-2 NSAIDs, are supposed to have fewer side effects but can still cause problems. Some people find them less effective for pain relief than the older style drugs.

Opioids:

The combination of codeine and paracetamol provides better analgesia than paracetamol alone. Some people find that codeine makes them sick or constipated and are better off using Tramadol, Digesic or Endone.

All Opioid drugs are potentially addictive.

Always check with your GP or pharmacist before starting any drug, even those that you can buy over the counter



- Intra-articular injection

Injections are typically given into the knee when tablets are not controlling a flare up of the arthritis. They make last hours, weeks or months and are quite unpredictable as to who they will help. They are relatively cheap and easy to give and so are often used before progressing to an operation with an anaesthetic.

Cortisone Injections (Glucocorticoids):

If you are looking for relief from a severe flare up of knee pain then a cortisone shot might be a good idea. Most people get a modest and short-lived reduction in their pain. Some people have a dramatic and sustained response but there is no way of predicting which group you will fit into.

Complications are very rare but can happen.

These include: Death of nearby bone (osteonecrosis), Joint infection, Nerve damage, Skin and soft tissue thinning around injection site, Temporary flare of pain and inflammation in the joint, Tendon weakening or rupture, Thinning of nearby bone (osteoporosis), Whitening or lightening of the skin around injection site.

Is there a limit on the number of cortisone shots
 I can have in a year?

There is some concern that repeated use of cortisone shots may cause damage to the cartilage of the knee joint. This is not a real concern when treating an arthritic knee which is already damaged. Despite this, most doctors don’t like to inject the joint more than 3-4 times per year. Having an injection in one part of your body does not limit the number of injections to another part of the body (each knee can have 4 injections, as well as the shoulders, ankle etc).

I inject local anaesthetic into your knee with the cortisone and I use a water soluble cortisone (Celestone) so that if you do get a reaction to the drug it will be relatively short lived (compared to weeks of problems from a ‘depo’ style injection).

What should I feel after my Injection?

Your knee pain should be improved for a few hours after the injection just from the local. Some people feel a transient increase in discomfort in the joint which resolves in 24 hours.  You can treat this discomfort by applying ice to your knee and using paracetamol or Non-Steroidal Anti-Inflammatory Drugs.

What should I do after a Steroid (Cortisone) Injection?

If possible, it is best to rest the knee joint for 24-48 hours.  Studies have shown this may improve the effect of the injection.

Viscosupplementation:

Hyaluronan is a component of synovial fluid (the joint lining fluid), responsible for its viscoelasticity. In arthritis this fluid becomes thinner and less able to lubricate the joint. Viscosupplementation (adding synthetic material to the synovial fluid) works in some people to break the inflammatory cycle in the knee. It typically works as well as a cortisone injection but tends last much longer. It is not unusual for this injection to last 6 months.

Combinations of all these therapies may be require at different times since arthritis is a cyclical disease with flare ups and quieter times when the knee feels good.