Viscoelastic Joint Injections

Frequently Asked Questions

What are Viscoelastic Injections?
VE Injections are a type of treatment for patients with Osteoarthritis. Osteoarthritic joints may be stiff and painful due to a thinning of the articular cartilage (the gristle that covers the bone ends) and a change in the synovial fluid (the joint lubrication fluid) making it more watery.

Unlike cortisone (a drug used to treat inflammation), VE Injections work by improving the normal lubrication fluid within a joint. The injections are sometimes referred to as 'Visco-Supplementation' injections as they aim to improve the viscosity (thickness) of the joint lubrication fluid. 

There are a few different products on the market but they all contain hyaluronic acid (also called hyaluron or hyaluronate) which is a component of normal, healthy joint synovial fluid. 
The main products available are OSTENIL®, MONOVISC ® and SYNVISC®. Sometimes HA injections are combined with cortisone injections if the joint is inflamed (cortisone is an anti-inflammatory steroid). A product called CINGAL® combines HA with small dose of cortisone in a single injection product.

How does it work?  

The VE product is injected directly into the affected joint via a needle and syringe. It works by increasing the amount of hyaluronic acid in the synovial fluid of the joint which improves lubrication and joint movement.

Who might benefit from a VE injection?

Patients with mild to moderate Osteoarthritis are most likely to benefit from viscosupplementation. It can be especially helpful for those patients who have not responded to the usual treatment of exercise, weight loss, painkillers, anti-inflammatory tablets and gels or a Cortisone injection. VE injections are generally not helpful for severe osteoarthritis where bone-on-bone contact can be seen on X-Ray. Surgical treatments such as joint replacement may be considered in this case.

What joints can be treated?

VE injections are most commonly used for osteoarthritis of the knee but they can be used to treat osteoarthritis in any synovial joint and has been found to be particularly effective in the small joints of the hands and feet.

What are the differences between VE injections and Cortisone Injections?

VE products do not contain any medical drugs or other pharmaceutical agents. They can be likened to taking a cod liver oil tablet as opposed to taking an ibuprofen tablet. As such they do not have any of the drug related side effects associated with Cortisone.

Are there any risks associated with a VE injection?

As with any injection, there is a very small risk of infection. There is also a risk of an allergic reaction to the VE product. However, this is thought to be highly unlikely as VE injections contains no animal proteins.

How quickly does a VE injection take to work?

Following a VE injection the joint may feel more painful than usual for a few days. The benefits of the injection are usually apparent within 7-14 days.

How many injections will be needed and how long do they last?

A single VE injection will usually last for about 6-12 months. Most patients have them repeated at the 6-12 month point but they can be repeated earlier if needed. There is no limit to how many VE injections you can have.

How do I find out more?

Manufacturer’s information regarding OSTENIL® products is available here


This article provides general information related to various medical conditions and their treatment. It is intended for informational purposes only and  not a substitute for professional advice, diagnosis or treatment provided by a doctor or other qualified health care professional. The information provided does not constitute personal advice or guarantee of outcome and should not be used to diagnose yourself or others. You should never ignore advice provided by a health care professional because of something you have seen or read on this website. You should always consult a doctor or other qualified health care professional for personal medical advice.