Patient Safety Notice follows recall of knee implants

[ON 15 FEBRUARY the Medicines & Healthcare products Regulatory Agency (MHRA) issued a Patient Alert notice regarding some of the NexGen knee replacement products.

The alert was issued after the National Joint Registry (NJR) identified that both of the NexGen Stemmed Option Tibial Components, when paired with either the Legacy Posterior Stabilized (LPS) Flex Option Femoral or the LPS Flex Gender Solutions Femoral (GSF) Option Femoral, had a higher overall revision rate and a higher revision rate for aseptic tibial loosening compared to the average revision rate of all other total knee replacements in the UK NJR.

The alert followed a voluntary product recall issued by supplier Zimmer Biomet, as reported in the last issue of Your Expert Witness

The MRHA said in its statement: “For patients implanted with the affected device combination there is an increased risk of needing an operation to replace their original implanted knee replacement. The UK NJR data suggests that tibial loosening is a key cause of the increased total knee replacement revisions for these specific combinations. Tibial loosening could typically present as new pain in the knee joint or limping. In rare cases tibial loosening may be asymptomatic.”

The NJR has provided all hospitals with a list of affected patients recorded in the registry with the affected combination. For Scotland this will be co-ordinated by health boards. q

• and the judge asked him to summarise it in a written document, in • plain English.

If a judge has to tell an expert to write his evidence in plain English, the expert has failed to help the court, which should be his overriding duty.

CPR says, at 35.3(1), that: ‘it is the duty of the expert to help the court on matters within their expertise’.

We doctors are good at writing letters to colleagues – doctors, members of multidisciplinary teams – who have some form of medical or allied training. So it is important that one attends courses and receives training to become an expert for the court, which is entirely different from being an expert in one’s field. Both are not synonymous and – as said by Barrister G. Eyres of Gough Chambers, London –‘requires one to develop a medicolegal mind’.

As I have previously said – and for fear of repeating myself – it is quintessential as an expert for the court to address one’s evidence and opinions at the level of an ‘informed layman’, whether judge or jury. Where it is essential to use medical terminology, make it bold and explain it in brackets in layman’s term, and reference in an appendix at end of report for cross referencing.

For example, an MRI scan report states: ‘Moderate degeneration of Tibio-Talar/Talo-Crural Joint and chondromalacia of SubTalar Joint’. Writing that in a letter to GP or medical records would be entirely reasonable, but it would be an alien language to judge and jury.

I would recommend that it should be written as below, so that the Judge and/or jury – normally in civil cases a jury is not involved – can understand easily.

‘Moderate degeneration [arthritis] of Tibio-Talar/Talo-Crural Joint [ankle joint] and chondromalacia [softening of cartilage – a sign of very early arthritis] of SubTalar Joint [the joint below the ankle joint which controls side to side movement and helps walking in rough or uneven surfaces]’.

One can use any format but I state in my expert reports that things in square brackets are my expert’s interpretation. q

• Mr Turab Syed MBBS MRCS DipSICOT DipSEM MFSEM FRCS (Tr & Orth) MSc (Sports Medicine) MFST (Ed) is consultant trauma and orthopaedics surgeon at Forth Valley Royal Hospital, Larbert, Stirlingshire, academic e-tutor in ChM Trauma & Orthopaedics at the University of Edinburgh, expert witness and treasurer of the Scottish MedicoLegal Society (SMLS).