Newsletter Feb 2021 – Medicolegal Corner

Alleged ‘metal allergy’ after joint replacement surgery catches out one OTSIS member…

“…The rise in patients concerned about the possibility of metal allergy affecting the outcomes of total knee arthroplasties may be due to an increasingly connected, neurotic few”.

These are strong and direct words from Bone & Joint³⁶⁰ [Bone & Joint³⁶⁰ 2016; Vol 5; Issue 5: Pg 14]. Is it enough to save us from the peculiarities and pitfalls of the modern medicolegal arena?

I am an OTSIS member and unfortunately I’m writing this account from first-hand experience in order to share my personal experiences as a way of hopefully helping protect other colleagues from suffering the same fate!

I first saw Mrs C in 2014, when she came to see me for a second opinion about her knee. Mrs C was 72 and she had advanced medial OA in her knee. She had already had 2 recent arthroscopies of her knee by 2 other consultants, neither of which had helped, plus she had had various i.a. injections as well. Mrs C had been listed for a total knee replacement with another surgeon, but she came to see me for a second opinion on this. Mrs C’s ongoing symptoms were easily bad enough to justify arthroplasty surgery, but her OA was isolated to her medial compartment, and so I listed her for a medical unicompartmental partial knee replacement.

In clinic, Mrs C stated that she was allergic to Penicillin and to ‘metals’.

Mrs C had her medial uni, and initially everything seemed to be going fine. However, at 6 months post-op Mrs C reported that she had a rash at the front of her knee and on the other leg and also on both arms. The knee itself, however, seemed to be fine. I therefore referred the patient across to a Dermatologist. The Dermatologist gave a diagnosis of probable psoriasis and recommended steroid cream.

Mrs C then ended up going to see a different Dermatologist, and they performed patch testing and advised her that she was allergic to Cobalt Chrome (but not Nickel or Titanium). The uni prosthesis that I had used was Cobalt Chrome.

The patient the went to another Orthopaedic Surgeon. He noted that the patient was actually doing very well with her knee and that the knee had an excellent range of motion with no effusion. He noted that the patient was, however, keen to have the knee revised to a titanium implant.

Mrs C went ahead with the revision surgery. The latest feedback following the revision surgery was that Mrs C still had the same ongoing rash.

Mrs C instructed a solicitor to pursue a claim of negligence against me on the basis that:

1. I had failed to perform patch-testing pre-operatively,
2. I had failed to adequately inform her of the risk of metal allergy to the prosthesis I was going to use, and that
3. had she known about the ‘Cobalt Chrome’ allergy she would not have gone ahead with the surgery that I had recommended (with that specific prosthesis), and that therefore
4. my actions were negligent and had caused her to end up needing the revision surgery.

Needless to say, I was extremely disappointed to receive this, and this was the first claim of negligence that I had ever received, in 14 years as a consultant. I felt that I had 100% followed contemporary professional scientific wisdom and advice, and that my actions had been entirely appropriate at all times. I took advice from the OTSIS medicolegal team and a solicitor was appointed to defend my case. Our intention was to defend my position on the basis that:

1. Patch testing is extremely unreliable, with very high false positive rates.
2. Skin allergy to metals does not seem to equate to people developing an ‘allergic’ response to internal metal prostheses.
3. Patch testing is not recommended as a pre-operative screening test prior to knee replacement surgery.
4. The latest, most up-to-date, specific professional advice, as published in the Bone and Joint Journal in 2016 is that standard metal knee prostheses should be used in all patients, even including those with a known pre-operative metal sensitivity, and that there was no evidence to support the use of so-called ‘hypoallergenic’ prostheses.

We also obtained a formal expert witness report from another orthopaedic surgeon who agreed that my actions had been appropriate in all aspects.

Following this, a case conference was held with myself, the expert witness, our appointed solicitor, and a barrister. The case was discussed at length. The barrister produced copies of two articles that he had found from non-UK-based journals that actually supported the use of pre-op patch-testing and the concept of potential metal allergy to implanted prostheses. Based on this evidence, the Barrister felt that there was a difference of scientific opinion, and that, based on the Montgomery Case, I would have had a duty to discuss this potential issue (with the potential differences of scientific opinion) with the patient pre-operatively, particularly given that the patient had flagged up an allergy to ‘metals’.

The barrister advised that he felt that there was a reasonable possibility that, based on the Montgomery ruling, a court might find in favour of the patient. It was therefore agreed that a no-liability out-of-court settlement offer should be made. The patient agreed to this and was paid £20,000 + costs.

What do I take from this?

This whole episode was extremely frustrating and deeply stressful, and the whole process, from start to finish, took well over 1 year: 1 year to dwell and stew on things and 1 year of worry… leaving me afterwards feeling pretty negative and down. What it showed me was that even if accepted contemporary orthopaedic scientific opinion says ‘X’, if someone can find a paper from somewhere (from anywhere!) that states ‘Y’, then because of the Montgomery ruling the legal profession now dictates that if the issue is of potential relevance or importance to the patient from their point of view, then we, as doctors, are obligated to discuss the potential issue with the patient ahead of any decision-making or treatment (and this discussion has to be clearly recorded in the patient’s records).

What has this meant for me and my practice, moving forwards?

I have now written an entire webpage of detailed information about the potential risks of knee replacement surgery on my website, and I e-mail a link to this to every potential knee replacement patient after I’ve seen them in clinic. I have also put together a 16-page Patient Advice Sheet that I e-mail to every patient pre-operatively, and this specifically includes a section dedicated to the issue of potential ‘metal allergy’.

I haven’t yet had another patient who’s stated pre-operatively that they have a ‘metal allergy’; however, when I eventually do, I’ll specifically have a discussion with them about ‘metal allergy’ in clinic and I’ll carefully document that discussion in my notes. I’ll also send the patient a copy of the BJJ article. However, if any patient still has ongoing concerns, then I think I’ll simply refer them across to a-n-other colleague for a separate second opinion… as personally, I’ll now see this as a ‘red flag’, and life’s just too difficult already for that kind of additional hassle!

The legal position – Emily Borhan

This is an interesting example of how a patient’s existing allergy could lead to a claim. What makes it more interesting is the fact that this has come from an OTSIS member, a colleague, which demonstrates just how easily these issues can arise.

As always, the starting point is that you have a duty of care to your patient when providing treatment. If you breach this duty of care, a claim of negligence could arise. For such a claim to be successful, the principle of ‘causation’ must be satisfied.  That means that the patient must establish that the loss they suffered was caused by the treatment that the doctor provided.

As part of the duty owed to your patients, it is important to be sure that the patient has been fully informed about the treatment they will receive, how this may affect them, and any risks involved with the treatment. As mentioned above, this is discussed heavily in the case of Montgomery (Appellant) v Lanarkshire Health Board (Respondent) [2015] UKSC 11, where it was stated that in order for a patient to consent, they must be aware of any potential issues. In the scenario above the patient is claiming that she was not aware of the risk of an allergy arising from the metal in the prosthesis.

The patient’s disclosure of her metal allergy gave rise to a risk of a reaction to the treatment. The difficulty with metal sensitivities and knee protheses is that the medical research is quite vague. Some published materials suggest that the risk of allergic symptoms arising from a prosthesis is low, even if there is a known metal allergy. It is also unclear which diagnostic or pre-operative tests (relating to allergies) are sufficiently reliable to be carried out prior to surgery. Routine pre-operative testing for allergies is not generally carried out, but if a patient mentions a pre-existing condition/sensitivity that may affect the treatment, then it may be worth doing further tests or referring for a second opinion.

There is still a lack of evidence regarding the correlation between metal hypersensitivity and implant-related complications. As we can see in the example above, the patient’s rash was still there, despite revision surgery, and there was no clear proof that the symptoms were caused by the metal prosthesis – therefore, it may not always be clear that the requirement of ‘causation’, mentioned above, is satisfied.

So, should diagnostic or pre-operative tests always be carried out, even where there is limited support for their effectiveness?  In short, it is unclear, and this will be a matter of judgment in each case. However, there are mitigating steps that should be taken as a matter of course. The key is following a robust process and ensuring that all appropriate steps are taken to make sure patients are fully informed of any potential issues as part of the consent process. If there are known pre-existing conditions, it is usually prudent to ensure that these have been discussed and addressed fully with the patient prior to surgery.  It is also important to make sure that everything is fully documented in the medical records to protect your position in the future.