Oxfordshire patient left with ‘two left knees’ as NHS Trust reports implant or prosthesis errors

The patient was sent home with ‘two left knees’ in one of four errors in the past three years involving an implant or prosthesis, according to newly-gathered data.

Medical Negligence Assist sent Freedom of Information requests to Trusts around England, and Health Boards in Wales and Scotland.

The Oxford University Hospitals NHS Foundation Trust (OUH) said all of the incidents were between August 2022 and May 2024. Prior to that, the Trust faced at least one medical negligence compensation claim related to a previous alleged implant error.

The Trust received a report in March 2023 that a patient suffered ‘minor’ harm during elective revision surgery. Instead of receiving a new right knee, the patient was given a prosthesis labelled as a left knee. It was added in the report that ‘further surgery is not currently required’.

In reviewing the incident, the Trust acknowledged the need for training and ensuring that the ‘pause/check’ procedure was followed in future. It also resolved to report to the Medicines and Healthcare products Regulatory Agency (MHRA) ‘the lack of uniformity of labelling of laterality in prostheses (position, font and colour) and request a single system to be used across all manufacturers of knee prostheses’.

In August 2022 a patient with a left-sided, distal radius fracture was meant to receive a plate designed for use on that side, but they had a right-sided plate implanted instead. The Trust noted the ‘standard process for trauma prosthesis was not followed’ but that poor labelling allowed for misinterpretation.

In June 2023, a patient undergoing cataract surgery suffered ‘moderate’ harm because the intra-ocular lens that was implanted was ‘at a different power from that intended’.

The fourth incident was in May last year, when an error was recorded during a neurosurgical procedure. The patient required a ventriculoperitoneal shunt, a device like a catheter for the brain that drains cerebrospinal fluid. The shunt used had an incorrect valve, an error which led to moderate harm for the patient.

OUH is still investigating the latest incident.

The Trust said it could not comment on individual cases but it is understood it completes some 146,500 surgical procedures every year.

Dr Rustam Rea, Deputy Chief Medical Officer and Director of Patient Safety, said: “We sincerely apologise for the distress caused to our patients by these incidents.

“We take patient safety extremely seriously and have carried out a thorough and detailed investigation for each incident. This has involved the patients who have been affected.

“These investigations have enabled us to identify how we can continuously improve patient care and reduce the risk of similar incidents happening in the future.”

NHS England says that a wrong implant or prosthesis error is ‘Placement of an implant/prosthesis different from that specified in the procedural plan, either before or during the procedure’.

The OUH Trust uses a continuous improvement approach in the implementation of the new patient safety framework (Patient Safety Incident Response Framework) to drive and sustain high quality care for all patients.

Such errors can be considered a ‘Never Event’ by the NHS, which recorded 41 cases across England between April 2024 and the end of January 2025.