Good morning, and intro
I am going to briefly discuss the potential value of POSSUM scoring patients with fractured neck of femurs; and its use in a small case series of 6 patients who died secondary to Bone Cement Implantation Syndrome
Arose as a means of classifying both those patinets that have a physiological (normallly anaesthetic) reaction to cement OR ‘on table’, intraoperative, or immediately post operative death. – ie. Death is not always to outcome of BCIS
Definition
Other physiological parameters - increased pulmonary vascular resistence
The five stages of hip arthroplasty are - femoral reaming; acetabular/femoral cement implantation; insertion of prosthesis; joint reduction
Pathophysiology
Older theories – release of monomers from cement + Anaphylaxis to cement
Most accepted theory – embolic theory
high intramedullary pressures from cement/ prosthesis insertion – exothermic reaction/ space expansion – formation of fat emboli – into the circulation
To lungs – right heart strain and subsequent cardiac effects
To brain via patent foramen ovale - ischaemia
Supported by TOE studies
Fractured neck of femur patients are highly at risk – normally elderly patients who have fallen as a result of poor medical comordities
Methods to reduce the risk – mention that these are standard in our department but practise does vary
RISKS of unecented prosthesis:
Say that uncemented prosthesis has a 10-15% periprosthetic fracture rate at our institution, thus we try to avoid unless the patinet is very immobile pre-op
Still have to ream/ broach the intramedullary canal, so still a risk of fat embulus
POSSUM has been validated for accuracy of prediction of mortality and morbidity in general surgery mainly by Copeland – not the role of this talk to discuss how good/ accurate a tool it is – generally accepted to be the best around
Copeland is a surgeon in the North of England
Scored as 1, 2, 4, 8 by predetermined criteria/ ranges
The intra-operative surgical parameters are standardised in Orthopaedics – by Copeland in another paper – as they are more easily predictable than in general surgery
Originated as a general surgical tool but due to its success has been adapted to be used in most other surgical specialities
Mohammed applied POSSUM to all Orthopaedic patients – elective and trauma
Mohamed paper did suggest that maybe POSSUM does slightly over predict mortality
Wright et al applied POSSUM to fractured NOF patients within Orthopaedics
Our question was, when these 6 deaths occurred within 12 months of each other – if we POSSUM scored them, could their adverse outcome have been ‘predicted’?
Can say that diagnosis of BCIS was made on the basis of anaesthetic chart reports (all patients) and post mortem examinations (3 patients)
POSSUM scored retrospectively to see if their deaths could have been PREDICTED
Unusual to have 6 deaths due to BCIS in 12 months – hence what propelled us to do this exercise
We were curious to initiate the possibility of us being able to use the POSSUM score to determine whether there was a ‘cut off’ predicted mortality or morbidity percentage above which we could say that a patient should most certainly NOT have a cemented hemiarthroplasty and the surgeon should opt for an undermented prosthesis.
Say that in our department we routinely use CEMENTED hemiarthroplasties (due to higher functional outcome).
Rarely do we use uncemented hemiarthroplasties unless patient is very unfit for anaesthetic/ bedbound prior to fall that led to fractured neck of femur
What we plan on doing in the future
Operative POSSUM score is fairly consistent, hence maybe physiological score may be used to predict mortality – unable to do in general surgery where the opeartive possum is not as predictable – ie in general surgery POSSUM is always a retrospective score, unlike in orthopaedics
Determine a ‘cut off’ POSSUM score value above which cement should not be used in patients requiring hemiarthroplasty – i.e. not just down to anecdotal evidence/ surgeon preference/ anaesthetic insistence
Incidence of fractured neck of femurs is set to increase with an ageing population – as are the comorbidities associated with patients – we need to come up with a standardised means to ensuring patients are being given the most appropriate surgical intervention.