What is it?
Hyaluronic acid is a substance distributed widely throughout the body. It is an active component of connective tissue and contributes significantly to cell proliferation. Synvisc is a commercial product which is a hyaluronic acid supplement. Synvisc (the hyaluronic acid supplement) is injected directly into the joint. See Figure 1(A) which shows the deteriorated tissue and bone of a knee joint similar to what might be expected with those suffering with osteoarthritis and the 3 locations which would be injected with Snvisc. Figure 1(B) shows the Synvisc that has been injected into the joint to encourage the purported repair and improvement while providing lubrication of the moving parts within the knee.
Figure 1(a) and 1(b)
Why is it used?
It is purported to:
- supplement the fluid of a joint
- help lubricate it
- provide symptom relief
- delay progression of arthritic disease
What is the evidence?
There are conflicting results in clinical trials. Inconsistency in research design has resulted in a loss of validation
in regards to the clinical efficacy of Synvisc. Anecdotally athletes indicate a mixed response with its use. Some indicate positive outcomes while others indicate a poor response. Arguably it is probably most effective in people with more mild disease. It is quite expensive and is frequently delayed until the arthritis is quite severe. It could be argued that this may be one explanation for the problems with both the anecdotal and trial evidence i.e. it is most frequently used in the population segment least likely to benefit from it.
What are the risks?
There is a small risk of infection. With appropriate preparation the risk is probably one in several thousand. There is a moderate ~3% risk of having a severe reaction to the injection. This usually does settle down but can be very painful for an extended period of time.
Pre injection advice
No specific pre- injection preparation is required.
Post – injection advice
It may be worthwhile avoiding strenuous activity for the 48 hours following your injection. If you experience a severe flare of symptoms it is safe to take Panadol, Panadeine or Nurofen (provided that you have no other medical reason not to).