Three Australian women representing patients given vaginal mesh implants won a landmark class action today against international medical giants.

A Federal Court in Sydney found two Johnson & Johnson group manufacturers and its Australian supplier engaged in misleading or deceptive conduct and hid the risks associated with the implants from patients.

More than 90,000 devices were inserted into Australian patients wanting structural support to treat stress urinary incontinence and pelvic organ prolapse.

Studies show more than 10 per cent of cases have resulted in serious adverse side effects.

The court ruled that in instructions for use supplied with all the Ethicon devices, the company knowingly falsely represented that the mesh elicited a minimal to a slight inflammatory reaction that was “transient” or “transistory”.

Justice Anna Katzmann said an email from the Associate Medical Director of Ethicon’s Worldwide Customer Quality division to a colleague stated: “From what I see each day, these patient experiences are not 'transitory' at all”.

The admission, coming from the company’s international division, could have a significant impact on similar cases around the world - including in the UK and United States.

Justice Katzmann said one of the Ethicon devices satisfied the essential requirements to support their required certification, and some went to market without clinical trials.