Download Total knee replacement

There is so much we don't know in medicine that could make a difference,
and often we focus on the big things, and the little things get forgotten. To
highlight some smaller but important issues, we've put together a series of
pearls that the Red Whale found at the bottom of the ocean of knowledge!
Total knee replacement
In an era of NHS rationing it often feels like patients and GPs have to jump through an inordinate number of hoops
to get to the point of having a total knee replacement. I think most of us who have been in practice for a while
have had the experience of patients who have fought hard for the surgery, only to be left with complications and
more pain! Knees just seem more fiddly than hips. So how do we help patients decide what is best?
Joint replacements were hailed as game changing in modern medicine when they were introduced in the 1970s and indeed did
mean for some patients that the days of becoming housebound and immobile with osteoarthritis were over. It was felt to be obvious
that they were a ‘good thing’ so randomised trials were not performed. However, audits and observational studies give us the
following data.
Total knee replacement statistics
80 000 total knee replacements are performed in the UK each year.
Peri-operative mortality is 0.5–1% in the first 90d.
Serious complications, e.g. DVT, infection and fracture occur in up to 3% of patients.
20% of patients are left with significant pain at 6m.
There are alternatives to knee replacement and the decision to proceed with surgery is always an individual choice, so having data
from randomised trials would be very useful to patients and clinicians.
NEJM has recently published the first small RCT of 100 patients with moderate to severe knee osteoarthritis randomised to total
knee replacement followed by 12w non-surgical treatment, or non-surgical treatment alone (NEJM 2015;373:1597). The primary
outcome measures were pain, function and quality of life, but complications were also considered.
Note that non-surgical treatment was not ‘usual care’ but rather an intensive package of physiotherapy, dietary advice, insoles (for
which evidence is pretty limited!) and pain medication.
Surgical group
Non-surgical group
Greater than 15% improvement in pain
at 12m follow-up
85%
68%
Serious adverse events
48%
12%
At the end of the trial, the patients in the non-surgical management group were offered the opportunity to have a total knee
replacement and 26% chose to do this. The authors expected that more would do so as time went on.
What does this mean in practice?
The key point here, as made by the accompanying editorial, is that this is not a no-brainer (NEJM 2015;373:1668)! Whilst total knee
replacement was significantly superior to non-surgical treatment in terms of pain and function, it was also associated with significant
complications.
There was also a substantial improvement in two-thirds of patients in the non-surgical group, to the extent that given free choice at
12m only one-quarter of those in this group elected to have surgery.
This supports patient choice, but is also good evidence for commissioners that well designed knee services offering non-operative
management can offer significant benefits for patients who might otherwise need surgery.
Total knee replacement
Total knee replacement is superior to non-surgical treatment for pain and function at
12m but is associated with a very significant complication rate.
12w of non-surgical treatment comprising physiotherapy, nutrition advice and pain
management offered good improvements in two-thirds of patients and seems a
worthwhile intervention.
Is there an organised non-surgical management service for patients with knee osteoarthritis in
your area? Talk to your CCG – this could be a good strategy to manage referrals.
We make every effort to ensure the information in these pages is accurate and correct at the date of
publication, but it is of necessity of a brief and general nature, and this should not replace your own good
clinical judgement, or be regarded as a substitute for taking professional advice in appropriate circumstances.
In particular check drug doses, side effects and interactions with the British National Formulary. Save insofar as
any such liability cannot be excluded at law, we do not accept any liability for loss of any type caused by
reliance on the information in these pages.
GP Update Limited
January 2017