A number of different injections can be used when treating knee and hip problems. Some help to precisely diagnose your hip or knee pain and others are used to actually treat your pain.
So what types of injection are available?
Local anaesthetic injections (for diagnosis of difficult cases)
Sometimes pain felt in the hip or knee region can actually be coming from somewhere else completely and not from the hip or knee at all. A common site that mimics pain coming from the hip or knee is the spine. It is also common for knee pain to be mimicked by hip joint problems, a condition called referred pain. When there is a possibility of the pain being mimicked, it is vital to find the real site of pain so that the right area is treated.
In these cases Mr Sood performs an injection of long acting local anaesthetic into the joint that is painful, usually with ultrasound guidance. If the pain disappears, then the injected joint is definitely the site of pain. If not, the true source of pain being felt needs to be found.
These are used to treat inflammatory joint pain and swelling, caused by the lining of the joint becoming inflamed. This is called synovitis.
Although many doctors recommend and give these for wear and tear arthritis, we do not use steroid injections to treat hip or knee arthritis pain as, at best, these have a temporary suppressive effect and, at worst, no effect at all. We believe that other much better injections exist. Also, if a patient has severe arthritis and might need a joint replacement in the near future, such steroid injections can increase the risk of infection in the replaced joint which is a dreaded complication.
Hyaluronic acid (gel) viscosupplementation injections
Arthritic joints lack hyaluronic acid (HA), which is normally found in joints. HA is thought to be one cause of the pain that occurs in arthritis. In most patients, an injection of HA can ease the pain of knee arthritis for anything between a few weeks and a few months. Indeed some of our patients have one injection a year and have been maintained on this for a few years. This has been a wonderful option for their arthritis and is independent of the severity of arthritis. Mr Sood has used such injections for over 10 years and has a huge experience as a result.
Mr Sood also uses HA injections for hip arthritis and has had good success with most patients getting significant relief of pain. In hip arthritis the injections make pain more manageable and so can delay the need for surgery for some time. However, with severe arthritis, a hip replacement will usually be needed in due course.We have a few patients who cannot have a hip replacement because of severe medical problems and they are grateful for the pain relief provided by HA injections.
It is important to be aware that not all patients benefit from gel injections and that it is not possible to predict who will and who won't be helped.
Platelet-rich plasma (PRP) injections
These injections harness the healing effect of platelets that are found in blood. The process is quick and easy. A sample of blood is taken from the patient, the blood is spun down in a centrifuge and the platelet-rich fraction is injected into the knee or hip.
Mr Sood uses these injections in selected patients with knee arthritis. We have had good results in most patients and there is increasing evidence for the usefulness of this type of injection in easing pain and reducing the progression of arthritis.
These injections are also used to treat tendon pain where simpler non-invasive treatments haven't worked.
These are an exciting possibility in hip and knee arthritis, but the evidence for this type of injection has not yet reached the threshold for us to offer it to our patients routinely. We are continuing to monitor the latest research. Watch this space
Thus a variety of different injections can be used to treat hip and knee pain. Further research will identify more pain-relieving injections. One day we might even have injections available that do more than just relieve pain. They might even help to prevent or reverse the joint damage or wear in the joint. This is an incredibly exciting possibility but we are not there yet.