Skip to content
Blog

A new trend in elective hip surgery?

In archaeology there is a saying that one stone is a stone but three stones make a wall. When we looked at the trend for hip replacements in 2017 there was just one stone – one data point showing a decline in activity after more than a decade of steady growth. Two years later we have been back to see if it was the beginning of a wall.

Hip replacements are recognised as hugely successful, with most patients who undergo surgery reporting an improvement in their quality of life. In line with the ambitions first set out nearly 20 years ago in the NHS Plan, access to this type of surgery has increased over time, with the number of operations growing at a faster rate than the population. Between 2000/1 and 2014/15 the number of elective hip replacements carried out each year nationally almost doubled to 78,430, increasing on average by 4.8 per cent a year (see figure).

However, in 2015/16 the number fell and, after a small resurgence in 2016/17, it fell again in 2017/18, giving an average decrease of 0.5 per cent over these three years. Had the trend continued at the previous rate, an additional 13,200 hip replacements would have been undertaken in 2017/18. (Of course, this national data is likely to be masking some important regional variation too.)

Having seen a clear change in the trend, we expanded our research and looked at data on the average age of people receiving hip surgery, and the average health gain reported by patients (measured using patient-reported outcome measures (PROMs)) and found that both had increased. The increase in health gain is being driven primarily by a decline in patients’ health before the operation rather than an improvement in their health after. In short, those receiving hip surgery in 2017/18 tended to be older and to have reported being in worse health.

'This trend of growing demand and longer waits is not unique to hip replacements and should be viewed in the context of wider operational pressures on hospitals.'

So how should we interpret these trends? Viewed in isolation, the changing profile of those receiving surgery could be explained by clinical improvements, meaning that surgeons are able to operate safely on patients who are older, or have more severe conditions, than they could in the past. It could also be the result of a reduction in demand as those with less severe conditions increasingly opt to delay surgery or seek alternative treatments. This is certainly one objective of national programmes that support patients to manage their own conditions, or allow patients to refer themselves to physiotherapy services or see a ‘first contact practitioner’ based in general practice. There is also evidence that greater involvement of patients in decisions about their care (for example, through the use of decision aids) as called for in the long-term plan, can lead to fewer people opting for surgery.

However, as we found in 2017, other data tells us that a reduction in demand for hip surgery is unlikely to be the explanation for the reduction in procedures. The population of people over 65 – those most likely to receive hip replacement surgery – has continued to grow. At the same time, [waiting lists](waiting lists) for trauma and orthopaedic procedures, which include hip surgery, have been increasing, and the average (median) length of time people are waiting for treatment increased by more than 20 per cent between April 2012 and April 2018. Overall, this paints a picture of fewer people receiving treatment and longer waits to receive it (which may explain the decline in pre-operative health).

This trend of growing demand and longer waits is not unique to hip replacements and should be viewed in the context of wider operational pressures on hospitals. Rising emergency admissions, delayed transfers of care, high bed occupancy and staff shortages are all contributing to delays and cancellations in elective treatments.

'It’s difficult not to conclude that – for now at least – restrictions on patients’ access and longer waits are symptoms of a service under pressure.'

It also appears that – as we found in 2017 – financial pressures are playing a part, with commissioners responding to these by restricting access to some services, including hip replacement surgery. There are many examples of CCGs tightening the referral criteria for surgery on the basis of factors such as patients’ BMI or pain thresholds. Last year, for example, a group of Sussex CCGs attracted media attention over plans to restrict hip replacement surgery to those who had been in significant pain for at least six months. Commissioners can also choose not to fund certain treatments. There is evidence that exceptional funding requests (made by GPs to CCGs on a patient’s behalf), traditionally used to limit cosmetic procedures and fertility treatment, are increasingly being applied to a wider range of treatments, including hip surgery. This research also found that an increasing proportion of requests for hip (and knee) surgery are being rejected.

Thinking back to our archaeology metaphor, three stones may make a wall, but they don’t tell you what the wall is for or where it ends. In the long term we hope that the prevailing trend of fewer operations is a positive one, associated with improved population health and increasing access to non-surgical options. However, when we bring the data together with what we know about decisions by commissioners, it’s difficult not to conclude that – for now at least – restrictions on patients’ access and longer waits are symptoms of a service under pressure.