Osteoarthritis affects around 15% of the Australian population, and is a leading cause of debilitating pain in the ageing population. (MJA) Approximately 65,000 total knee replacement operations are performed in Australia each year (AOANJRR 2019), putting it amongst the most commonly performed elective surgeries. There are a variety of non surgical treatment options for knee osteoarthritis, including anti inflammatory medications and physiotherapy. 

Imaging guided intra-articular injections have been used for many years including cortisone and local anaesthetic, Platelet Rich Plasma and Hyaluronic Acid injections such as Euflexxa and Synvisc.

Intra-articular injections of synthetic Hyaluronic Acid therapies such as Euflexxa replicate the synovial fluid found naturally in the joint space. The viscosity and shock-absorbing properties of normal synovial fluid may be temporarily replicated or restored, which can reduce knee joint pain and stiffness in osteoarthritis. It has been proposed that synthetic hyaluronan may interfere with inflammatory mediators such as cytokines and prostaglandins which promote joint pain and swelling in OA. 

Euflexxa injections may be of symptomatic benefit for patients who have not found improvement with other conservative treatment options. 

These are generally administered as a series of 3 fortnightly intra-articular injections under imaging guidance to ensure accurate intra-articular placement of the needle tip. 

A 2021 article published in Musculoskeletal Surgery reported that following intra articular Hyaluronic Acid injections, patient reported symptoms including pain, stiffness, functional limitation and total scores were significantly reduced at 1, 3 and 6 months, however not at 12 months. 

Medium term improvement in clinical symptoms following Hyaluronic Acid injections was also reported in a 2022 study in Journal of Orthopaedics for Physician Assistants, which found that overall hyaluronic acid injections were effective in reducing pain and improving physical function in patients with osteoarthritis of the knee, and may prolong time between diagnosis and arthroplasty. 

Adverse events after HA injection are rare, and radiologic severity of knee osteoarthritis changes may be predictive of successful treatment outcomes.

Panorama Radiology Specialists offers CT guided intra articular Euflexxa injection for symptomatic knee OA as a series of 3 fortnightly injections using our state of the art low dose CT scanner. 

MRI picture

I’m always happy to discuss individual cases with referring clinicians – if you’re a medical practitioner seeking an opinion on which imaging-guided pain management measures may be most appropriate and beneficial in an individual clinical situation, please feel free to contact me directly.

Dr Angus Watts


Diagnostic and Interventional Radiologist

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