In its recent ruling of 14 December 2022, the French Supreme Court (Cour de cassation) reiterated that, while trial judges are not bound by the conclusions of experts, they can only deviate from them if they give precise reasons, in fact and in law, for their decision.

In this case, following the fitting of a hip prosthesis, a patient suffered several dislocations, necessitating further operations involving the fitting of an anti-dislocation device and a change of prosthesis.

The patient therefore sued for liability and compensation:

• on the basis of liability for defective products: the manufacturer of the prosthesis, who called into question the manufacturer of the femoral head,
• on the basis of professional civil liability: the surgeon, who had acted in his professional capacity and as a public official.

Two expert reports – one judicial, the other administrative – concluded:

• that the patient’s state of health had necessitated the fitting of a prosthesis;
• that this prosthesis had been fitted by the surgeon in accordance with the rules of the art, no fault, error, clumsiness or negligence on the part of the surgeon having been noted;
• that the prosthesis fitted did not reveal any defect.

In its ruling of 1 June 2021, the Pau Court of Appeal dismissed the liability of the manufacturer of the prosthesis.

However, it did not follow the conclusions of the expert reports with regard to the surgeon and held him liable.

To justify its decision, the Court of Appeal noted that the surgeon should have drawn “the consequences of the morphological characteristics of his patient (overweight and propensity to physical activity) which required the implantation of an anti-luxation device ; [that] the rapid occurrence of a dislocation, followed by four others, all reduced under general anaesthetic in the months following the first operation, led to the decision to re-operate in order to implant a device, are proof of this initial poor assessment”, “this device had proved effective since the dislocations had not recurred”.

The Court of Cassation obviously did not criticise the Court of Appeal for not having followed the conclusions of the expert reports.

On the other hand, it censured it on the basis of article L. 1142-1 of the Public Health Code – according to which the liability of healthcare professionals for acts of care is only incurred in the event of fault – for failing to specify the medical evidence on which it based its conclusion, which was contrary to those of the judicial and administrative expert reports.

The obligation to give reasons for court rulings is an essential rule of civil procedure, controlled by the Cour de cassation.