Mr Justice Hickinbottom's seminal decision in Wilkes v DePuy (2016) EWHC 3096 (QB) marks a substantial departure from Burton J's controversial approach to "defect" under section 3 of the Consumer Protection Act 1987 in A v National Blood Authority (2001) 3 All E.R. 289.

The decision provides clarity on the circumstances which may be taken into account when assessing the level of safety that persons are generally entitled to expect. Crucially, it confirms that there is no requirement for absolute safety in all circumstances and will provide useful ammunition when defending many product liability claims.

Background

Mr Wilkes received a total hip replacement in January 2007. The prosthesis, manufactured by DePuy, comprised of a steel femoral stem connected to a metal femoral head. In January 2010, only three years after implantation, the prosthesis suffered a fatigue fracture at a grooved area on the neck of the stem requiring Mr Wilkes to undergo replacement surgery.

Mr Wilkes brought a claim against DePuy in negligence and under the 1987 Act. Whether Mr Wilkes could properly claim under the 1987 Act was determined by way of a preliminary issue:

  • Mr Wilkes contended that the product contained a "defect" as defined in s3 of the 1987 Act. He alleged that the design, in particular the presence of the groove, made it susceptible to failure which should have been eliminated by adopting a different design. He argued that the groove was unnecessary for connecting the metal femoral head, that it created an unsafe stress concentration and he was entitled to expect that there would be no risk of fatigue fracture in the prosthesis.
  • DePuy denied that the stem was defective as fatigue fracture of the femoral stem is a rare but recognised risk. An express warning was given in the instructions for use provided with the prosthesis to the surgeon. The groove provided a considerable benefit as it allowed the same stem to be used with both ceramic and metal femoral heads. The prosthesis had received UK and European regulatory approval, been tested to a level in excess of the relevant British Standards and been given a CE marking.

The Court held that there was no "defect" in the product and Mr Wilkes could not therefore bring a claim against DePuy under the 1987 Act.

Approach to the 1987 Act

Under s3 (1) of the 1987 Act there is a "defect" in the product if its safety is "not such as persons generally are entitled to expect". In a departure to the approach adopted in A v National Blood Authority, the Court held that the focus must first be on whether the product suffered from a "defect" and not on identifying "the harmful characteristic which caused the injury".

The latter circular approach was rejected by the Court as it prematurely considered the issue of causation before properly identifying the defect. The Court also confirmed that the test as to the level of safety is objective. The level of safety persons "generally are entitled to expect" is not what a person or persons actually expect or generally expect, but what, as a matter of law, they are entitled to expect.

The Court rejected the approach adopted A v National Blood Authority which considered the "legitimate expectation" of persons generally in dealing with this question. This was held to be an "unnecessary and unhelpful gloss on the Act".

Circumstances to be taken into account

Pursuant to s3 (2) the 1987 Act "all the circumstances shall be taken into account" in determining "what persons generally are entitled to expect in relation to a product". The Court confirmed there is no restriction on the considerations that may be taken into account and a flexible approach is required. The relevant circumstances and the weight to be given to each will vary from case to case depending on the particular facts.

Some of the key points arising in Wilkes v DePuy when considering the appropriate level of safety of a product are as follows:

1. The rigid categorisation of products into "standard" (when the product performs as the producer intended) or "non-standard" (when it does not perform in that manner) adopted in A v National Blood Authority is "unnecessary and undesirable" and "positively unhelpful and potentially dangerous". Following that approach is too rigid as it means that a risk-benefit analysis cannot be considered for "non-standard" products.

2. A product's risk-benefit balance, including the issue of cost in appropriate cases, is a circumstance that can be taken into account under the 1987 Act. The Court did however exercise some caution. On the one hand the 1987 Act, in imposing liability without fault on the part of the producer, focuses on the product rather than the acts or omissions of the producer.

On the other, conducting a risk-benefit analysis will inevitably involve consideration of the practicability of the producer adopting a different design. As such, the Court held that "detailed consideration" of whether a risk is avoidable "is unlikely to be fruitful", but "the ease and extent to which a risk can be eliminated or mitigated may be a circumstance that bears upon the issue of the level of safety that the public is generally entitled to expect".

This view again runs contrary to that which was expressed in A v National Blood Authority. At the same time, the Court also confirmed that the latter part of s3 (2) of the 1987 Act means that "the fact that a safer design can be envisaged does not mean that a current product is defective". Being able to eliminate one risk in a design does not necessarily make it defective as it may "result in disbenefits that would outweigh the benefits".

3. Compliance with appropriate mandatory standards and the grant of regulatory approval are relevant circumstances to be taken into account. Whilst compliance did not provide a complete defence to a claim, in an appropriate case it would be "powerful evidence" of meeting the required level of safety under the 1987 Act and "it may be challenging" for a claimant to prove that a higher level of safety is required. Conformance with a manufacturer's own specification and relevant standards could also be a relevant circumstance in an appropriate case.

4. Any warnings provided with the product will be a relevant circumstance under the 1987 Act.

Conclusions

Mr Justice Hickinbottom concluded that the loading to which the stem was exposed was clearly greater than it could withstand, and for which it had been tested in accordance with the relevant British Standard, but this was the result of "a constellation of factors, each variable, which came together in a manner such that the neck of the stem fractured". The decision provides welcome clarification as to the correct formulation of "defect" under the 1987 Act, following the much criticised decision in A v National Blood Authority.

It accepts that the risk a product may cause injury may be outweighed by its benefits, even if that risk could have been eliminated by adopting a different design. The decision should also deter speculative claims, particularly when the product has obtained regulatory approval or has met relevant standards.