Midland Knee Protect Clinic, Barn House, Barston Lane, Solihull, B92 0JJ   Book Appointment

Hyaluronic Acid

Ostenil Plus or Durolane

This treatment is performed in an out-patient setting.

Hyaluronic acid occurs naturally in synovial joints. It aids lubrication and shock absorption. It also has an effect on cartilage metabolism.

In the UNHEALTHY, ARTHRITIC joint, the concentration of hyaluronic acid is reduced. This appears to contribute to joint pain and stiffness

Hyaluronic acid is manufactured from biological sources and non-biological sources in the laboratory.

It works by:

  • Playing a significant role in the body during repair process, mediating cell adhesion, differentiation, motility and blood vessel growth;
  • Retaining large quantities of water and therefore controlling tissue hydration; 
  • Protecting tissue against overuse and shocks by its viscoelastic properties.

But does it really work? Click here

What is the process for having the treatment?

The treatment is provided in a pre-prepared syringe. The knee is cleaned and the injection is inserted through a small needle. A dressing is applied. This should be kept dry for 24 hours.

After the injection you should have a relatively low activity level for 72 hours – NO SPORT for this time period.

How effective is it at treating knee arthritis?

This is not a cure for arthritis. It is intended to improve the symptoms of arthritis by reducing pain and improving function.

A study in 2006, (the most comprehensive review to date), reviewed 76 randomized placebo-controlled trials. The authors concluded that hyaluronic acid is an effective treatment for osteoarthritis of the knee with favourable effects on pain, function, and quality of life, especially in months 1 to 3 after injection.

Five meta-analyses have been published on the same treatment in knee arthritis with the primary outcome being pain relief. The studies support the efficacy of the treatment for reducing pain.

A study by Wang and colleagues looked at 20 randomized controlled trials that compared both cross-linked (hylan G-F 20) and noncross-linked hyaluronates with placebo. All trials
used validated outcome measures and safety was assessed by the relative risk of an adverse event.

The authors reported that both cross-linked and noncross-linked hyaluronates do indeed have a therapeutic effect in patients with osteoarthritis of the knee when compared with placebo

They found significant improvements in pain on activity, pain at rest, and function.

The science behind it

Hyaluronic acid is a high-molecular-weight glycosaminoglycan made up of repeating disaccharide units of N-acetylglucosamine and glucoronic acid. It is a large molecule that becomes bulkier when hydrated. The amount of hyaluronic acid in the knee and its hydration have a big influence on joint fluid lubrication.

It acts as a lubricant during slow movements and as a shock absorber during rapid movements.

The normal adult knee contains approximately 2 mL of synovial fluid, with a hyaluronic acid concentration of 2.5 to 4.0mg/mL.

…when the joint becomes arthritic…

In the arthritic joint, the concentration and molecular weight of HA are decreased by about 45%. This is because the synthesis of hyaluronic acid in the arthritic knee is disrupted by increased levels of pro-inflammatory cytokines, free radicals and proteinases.

This makes the synovial fluid lubricant in the knee more runny and the elastic properties deteriorate.

Decreased lubrication leads to increased stress on the damaged cartilage which causes more damage to the cartilage surface.

How does injecting hyaluronic acid into the arthritic knee work?

Normally hyaluronic acid is produced in the healthy knee by synoviocytes in the joint lining.

The goals of injecting hyaluronic acid are to improve function, reduce pain and possibly modify disease activity.

Hyaluronic acid exerts its effect within the joint space by influencing a variety of inflammatory processes and mediators including prostaglandins, fibronectin and cyclic AMP. It also stimulates cartilage cells (chondrocytes) and joint lining cells (synoviocytes) to promote healing and cartilage repair.


Wang CT, Lin J, Chang CJ, Lin YT, Hou SM. Therapeutic effects

of hyaluronic acid on osteoarthritis of the knee. A meta-analysis

of randomized controlled trials. J Bone Joint Surg Am


Bellamy N, Campbell J, Robinson V, et al. Viscosupplementation

for the treatment of osteoarthritis of the knee. Cochrane

Database Syst Rev.2-CD005321, 2006.

Arrich J, Piribauer F, Mad P, Schmid D, Klaushofer K, Mullner

M. Intra-articular hyaluronic acid for the treatment of osteoarthritis

of the knee: systematic review and meta-analysis.

CMAJ 2005;172(8):1039–1043.

Lo GH, LaValley M, McAlindon T, Felson DT. Intra-articular

hyaluronic acid in treatment of knee osteoarthritis: a meta-analysis.

JAMA 2003;290(23):3115–3121.

Modawal A, Ferrer M, Choi HK, Castle JA. Hyaluronic acid injections

relieve knee pain. J Fam Pract 2005;54(9):758–767.