Product liability litigation in relation to various prosthetic hips is currently active with two sets of test cases due to be heard in October 2017. These relate to the early failure and removal of metal-on-metal prosthetic hips.

A number of group litigations are ongoing but the court has determined that two specifically - those concerning the Pinnacle Ultamet THR and the Corin Cormet THR and resurfacing devices - should progress to trial first. The remainder of the metal-on-metal litigation cases, involving other devices, have been stayed pending this trial.

Penningtons Manches’ product liability team is acting for a number of claimants with different implants involved in the group litigation and has advised on the process of taking the initial test cases to trial. In the meantime, the Queen's Bench Division in the High Court has heard and given judgment in another case involving a hip implant which was alleged to be defective. This claim was brought against DePuy International Limited, a defendant in some of the group action cases.

In the case of Wilkes, the claimant underwent a surgical procedure in 2007 to insert an artificial left hip made up of metal components manufactured by DePuy. One of the components was a steel femoral shaft called a 'C-Stem'. In January 2010, that stem fractured and, when the artificial components were replaced, there was some evidence of metal debris having been shed around the joint.

The claimant brought a claim against DePuy, alleging that the fracture and metallosis were caused by its negligence, and also brought a claim under the Consumer Protection Act 1987, alleging that the C-Stem component had a 'defect' in it. The case went to trial on the issue of whether the component had a defect as defined by the Act and also whether the claimant had a claim against DePuy under this legislation.

The court provided judgment in the following terms: ‘For the purposes of the Act, there was a defect in a medicinal product if the safety of the product was not such as persons generally were entitled to expect, taking into account all the circumstances. Whilst, in relation to a product, negligence focused upon the acts and omissions of those involved in the production etc, the Directive and the Act focused rather upon the condition or state of the product itself… The condition of the product required by the Directive and the Act was not put in terms of fitness for purpose or efficacy, but rather in terms of safety and only in terms of safety; the required hallmark of defect being a lack of safety. Safety was inherently and necessarily a relative concept. Although a claimant had to prove causation in the sense of showing a causal link between the defect and damage… a claimant was not required to prove the cause of that lack of safety or why the product failed. The court had to consider the level of safety at the time the product had been put out onto the market by the relevant producer… The Act, reflecting the Directive, simply required consideration of whether, at the time the producer first put the product into circulation, that product did or did not have the level of safety that persons generally were entitled to expect, taking into account all relevant circumstances, including those set out in section 3 of the Act.’

The court went on to find that there was no evidence of any manufacturing or design defect. The C-Stem had fractured because of the load it was exposed to, which had been excessive and unpredictable, and in conflict with the advice given to the claimant. There was no indication that it would have failed under ‘normal’ loading. On that basis, the C-Stem had not fallen below the safety standards people had generally been entitled to expect at the time it was put into circulation and had not been defective for the purposes of the Act. The court dismissed the claimant’s case accordingly.

Philippa Luscombe, a partner in the clinical negligence team at Penningtons Manches LLP, comments: “This is an interesting case because most of the claims relating to metal-on-metal hip implants are now covered within the various group litigation processes that are ongoing. Very few claims are proceeding on an individual basis and in fact most of the cases we are dealing with are stayed pending the outcome of the trial in October. These cases are generally similar – the hip replacements failed far earlier than they should have and there is evidence of metal reactions in the hips when revision surgery was carried out. While the extent of problems suffered by individuals varies, the basic principles as to the nature, timing and cause of the failures are consistent.

However, Wilkes was something of a standalone case. The court found that this was not a hip implant which had been subject to normal use and had failed earlier than expected. There were very specific factors in play here – all of which related to the loading and use of the hip, not the structure or design of the implant. On that basis, the claimant failed. The particular circumstances of his claim may explain why it was not brought within any group litigation but the court used it as a good opportunity to remind people what the applicable tests are to establish that a product is defective and that liability rests under the Consumer Protection Act.”