Invoking The ‘State Of The Art Defence'? Be Prepared To Back It Up Pre-Trial

Author:Ms Isabel Foley and Orla M. Clayton
Profession:Arthur Cox

Defendants to product liability claims seeking to rely on the 'state of the art' defence must be prepared to provide full particulars (or details) of the facts which they say support the defence prior to trial. The Court of Appeal made this clear in a recent decision arising from the DePuy hip implant litigation.


The 'state of the art' defence is one of the defences set out in the Product Liability Directive (Directive 85/37/EEC) and the Irish Liability for Defective Products Act 1991. The defence exempts a producer from liability where it can show that, in light of the state of scientific and technical knowledge at the time it put the product into circulation, it could not have discovered the particular defect.


The decision in Murphy v DePuy Orthopaedics & Ors relates to DePuy hip implant litigation. The plaintiff is claiming damages for personal injuries which he says he incurred when he was fitted with an allegedly defective artificial hip device. His claim includes a claim under the 1991 Act. The DePuy defendants have raised the state of the art defence.

The plaintiff recently applied to the High Court for an order compelling the DePuy defendants to provide further details on the state of the art defence.

Specifically, the plaintiff sought further particulars as to the scientific and technical knowledge that existed at the time the artificial hip device was put into circulation. The DePuy defendants said that this was a matter for evidence and they declined to provide the particulars sought. However, the High Court made an order directing them to do so.

The DePuy defendants appealed to the Court of Appeal. The Court noted that a defendant is obliged to give particulars of facts on which it proposes to rely in its defence. It said that what the DePuy defendants were being asked to do was to state the facts (i.e. the state of scientific and technical knowledge at the time the product was put into circulation) on which they intended to rely for the purpose of advancing the state of the art defence. The Court said that the plaintiff is entitled to know, in broad outline, the facts upon which the DePuy defendants propose relying in pursuing the state of the art defence.


The DePuy defendants argued that the expert reports already delivered in the case identified the scientific articles that would be referred to in evidence. However, the Court said that...

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