In this post, Sophie Malley, a trainee solicitor at CMS, previews the decision awaited from the UK Supreme Court in Hastings v Finsbury Orthopaedics Limited and Anor.

The appeal was heard by the UK Supreme Court on 28 April 2022. In this case, Mr Hastings appeals against the findings of the lower courts in Scotland that the metal-on-metal prosthesis used for his total hip replacement was not defective within the terms of the Consumer Protection Act 1987 (the “CPA”).

Factual Background

Mr Hastings underwent a metal-on-metal total hip replacement (“MoM THR”) in March 2009 which was revised in October 2012. The prosthesis used comprised of compatible component parts manufactured by each of the defenders (the “Mitch/Accolade product”). Mr Hastings brought a claim under the CPA, s 2 which imposes strict liability on producers (meaning the pursuer does not need to prove the producer was at fault) if personal injury is caused by a defective product. In particular, he alleged that the Mitch/Accolade product was defective under the CPA, s 3 in that its safety was not such as persons generally are entitled to expect.

The Decision of the Outer House

The case was heard at first instance in the Outer House of the Court of Session. The question to be determined was whether the inherent propensity of MoM THR prostheses to shed metal debris once implanted and the risk that some patients may suffer an adverse reaction to such debris, rendered the Mitch/Accolade product less safe than persons generally were entitled to expect and therefore defective within the meaning of the CPA. To answer this, parties agreed that a two stage approach was required: (1) what was the entitled expectation of persons generally in respect of the Mitch/Accolade product; and (2) did the Mitch/Accolade product fail to meet this expectation.

Stage 1: Entitled Expectation

Lord Tyre considered the leading authorities on the issue of “defect” under the CPA, namely Wilkes v DePuy International Limited [2016] EWHC 3096 (QB) and Gee and Ors v DePuy International Limited [2018] EWHC 1208 (QB). Lord Tyre agreed with Hickinbottom J’s decision in Wilkes that the test for safety requires an objective approach to what persons generally are entitled to expect. He also agreed that a flexible approach should be taken to the circumstances that may be relevant when assessing the safety of a product as set out in Gee. However, this was where his agreement ended.

When determining which formulation “entitled expectation” should take, Lord Tyre rejected the position adopted in Gee that the product should not be materially worse than those it was intended to replace as this imposed an unnecessary burden on the claimant. Instead he set a lower bar for the entitled expectation test, that being “subject to de minimis considerations, its level of safety would not be worse, when measured by appropriate criteria, than existing non-MoM products that would otherwise have been used.”

There are two other notable distinctions in the way the Scottish court approached “entitled expectation” when compared to the English court in Wilkes and Gee. The first related to when defectiveness fell to be assessed. The CPA, s 3(2) states that “the time when the product was supplied by its producer to another” is a circumstance which shall be considered in determining what persons generally are entitled to expect as regards the safety of a product. The English cases proceeded on the basis that the level of safety expected had to be evaluated at the time the product was put on the market by the producer. Whereas, in this case, the date of supply was taken to be when Mr Hastings received the implant in 2009. Lord Tyre did, however, note that in Geeit was agreed that nothing turned on whether the time of supply was taken to be the date when the product was first put on the market or, alternatively, any of the various dates on which prostheses were supplied to the claimants.

The second distinction related to the weight Lord Tyre attached to the instructions for use (“IFU”) supplied with the Mitch/Accolade product. In accordance with the CPA, s 3 “any instructions for, or warnings with respect to, doing or refraining from doing anything with or in relation to the product” should be taken into account when considering what people are generally entitled to expect in relation to the safety of a product. The English cases confirmed, most notably in Wilkes, that IFUs are relevant to orthopaedic surgeons when selecting a prosthesis for a patient and so remain a valid consideration when assessing entitled expectation. However, Lord Tyre expressed skepticism “as to whether the instructions in this case had (or were expected to have) any real practical value”. He specifically pointed to the fact that the instructions were in very small font making them “virtually illegible” and “were in highly general and heavily qualified terms”. Lord Tyre accordingly concluded that “the IFU would have had no significant effect on entitled expectation” in relation to the Mitch/Accolade product.

Stage 2: Meeting the Entitled Expectation

The key issue for Mr Hastings was whether he could establish a causal link between MoM THR design and the generation of metal debris that is capable of causing damage to the body around the site of the prosthesis.

Lord Tyre found that Mr Hastings had established, on the balance of probabilities, that there may be a causal link. However, the evidence suggested that this was only present in a minority of cases and in limited circumstances. It could not therefore be concluded that the damage around the site of the prosthesis was solely related to MoM THRs. Lord Tyre was not satisfied that this was sufficient to “constitute a failure to meet entitled expectation” and so Mr Hastings’ claim failed.

The Decision of the Inner House

The Inner House of the Court of Session (Scotland’s highest civil court) refused Mr Hastings’ appeal. The Inner House was not convinced that Lord Tyre had erred in law, made a finding not based on the evidence or clearly misunderstood, or disregarded, relevant evidence. Rather, the Lord President noted that Lord Tyre’s reasoning “does explain and justify his ultimate decision that the inferences from the data did not demonstrate a defect” in the Mitch/Accolade product.

The Lord President acknowledged that this case was decided based on Mr Hastings’ failure to discharge the burden of proof upon him to demonstrate the existence of a defect. He noted that a determination of this nature can leave a first instance judge open to criticism. This is because once all the evidence has been heard, onus of proof ought not to matter unless the judge is unable to reach a view on the facts. Nevertheless, determining a case on this basis is an option open to the judge and it should not undermine a decision which is properly reasoned.

Within his judgment, Lord Tyre recognised the persuasiveness of the evidence which indicated a defect in MoM prostheses generally. The fundamental issue for the Inner House was whether Lord Tyre was entitled to reach a conclusion that, notwithstanding this evidence, Mr Hastings had failed to overcome the burden of proof. The Inner House found that he had been, as his decision was justified under reference to the material presented to him. Lord Tyre held, as a matter of fact, that an analysis of the current material available did not demonstrate that the evidence relied on by Mr Hastings was soundly based in science or statistics. Specifically, this evidence did not show that the revision rate of the Mitch/Accolade product was worse than alternative non-MoM prostheses or that it gave rise to an increased risk of unsatisfactory revision.

Referral to the Supreme Court

The issue for the Supreme Court to determine is whether the Inner House erred in law by not holding that the Mitch/Accolade product was defective within the terms of the CPA. Manufacturers will eagerly await this decision to obtain further clarity on the entitled expectation test and how it is to be applied in the United Kingdom.