By: 12 December 2016
Being young is overestimated say National Joint Registry

The age of a patient has an important effect on how long a hip replacement will last, with younger patients, who are likely to be more active, likely to put more strain on their implants and increase the risk of revision, says a new report from the National Joint Registry

“Being young is greatly underestimated,” said Mary Quant, and she was almost certainly onto something. But when it comes to hip replacement surgery, and how long a hip replacement will last, younger patients could be seen to be at a disadvantage, according to the latest report from the National Joint Registry (NJR), which was published in September. The 13th Annual Report revealed that patient factors have a significant bearing on the lifespan of an implant, with younger patients having an increased risk of revision compared with their older counterparts. Moreover, the data reveals that a patient from a younger age group is more likely to be revised irrespective of gender, with the youngest group having the worst predicted outcomes in terms of the risk of subsequent revision.

Established in 2002 by the Department for Health, the NJR monitors the performance of hip, knee, ankle, elbow and shoulder joint replacements to improve clinical outcomes for the benefit of patients, clinicians and industry.

Commenting on the results of the report, NJR medical director Martyn Porter said: “Data emerging from this year’s report show that revision – or ‘re-do’ surgery – estimates following primary joint replacement procedures remain low. For example, primary total hip replacement revision estimates are less than 5 per cent for the majority of procedures at twelve years. Knee replacement data in numerous ways mirrors that of hip replacement.

Revision estimates are much higher in patients under 55 years compared with those over 75 years of age. (NJR 2014).

Revision estimates are much higher in patients under 55 years compared with those over 75 years of age. (NJR 2014).

“These outcomes are extremely impressive and underpin the enormous success and reliability of joint replacement surgery. These sorts of results should help drive greater confidence in the public and with commissioners of healthcare – that hip and knee replacement procedures are one of the most effective and cost-effective interventions that the NHS has to offer.

“Furthermore, as the dataset is now so large, it is possible for the most frequently used brands or types of replacement to be reported at a very granular level. In other words, data from the NJR offers patients and surgeons the ability to see what specific type of hip construct produces low revision rates. This is more relevant than just reporting on how the replacement is fixed to the bone. The good news is that many different types of replacement can produce good results at twelve years. There is not one specific implant that is out on its own at twelve years.

“However, there is an important trend emerging from the data which reinforces that the patient has an important effect on how long an implant will last. Revision estimates are much higher in younger patients under 55, compared with patients over 75 years of age. This presumably relates to patient activity: younger joint replacement patients, who are likely to be more active, may put more strain on their implants and increase the risk of revision.

“To be very clear, younger patients should not be denied life-changing surgery but they do need to be advised that revision may be two or three times more likely at ten years compared with less active patients.”

The results of the report were launched at the British Orthopaedic Association’s Annual Congress in Belfast to an international delegation of over 1000 joint replacement surgeons. Due to the registry’s rich dataset, important determinants that influence the outcome and longevity of joint replacement procedures can now be studied.

Porter, a practising orthopaedic surgeon at Wrightington Hospital, Lancashire, and a revision specialist, added: “The report’s analysis also includes further results on the relative success of revision surgery. The outcomes of the revised hip show that the ten-year further revision risk (re-revision) is nearly 15 per cent, which is three times greater than the risk for the primary procedure. The message from the data is that revision risk for most patients is low at ten years but if they do fail then further revision is substantially increased.

“Therefore, the findings in the report reinforce the principles of the Department of Health’s ‘Getting it Right First Time’ initiative. If patients under 55 years are most likely to need at least one revision surgery in their lifetime, then we must use the maturing dataset of the NJR to analyse long-term trends and get the first time surgery as right for the patient as possible.”

In September 2016, NHS England instructed one clinical commissioning group to rethink a move to see non-life threatening procedures, including hip replacement procedures, delayed by a year for those with a body mass index exceeding 30. Commenting on the rationing of services, Porter agrees with NHS England’s decision to intervene: “Joint replacement surgery offers significant benefits – getting patients back to their chosen lifestyle sooner, free from pain and with improved mobility. As a joint replacement patient myself, I particularly understand the importance of this.

“Financial pressures on the NHS have resulted in some providers recently suggesting a temporary suspension of joint replacement procedures or excluding certain patient groups based on lifestyle factors, such as weight. [The evidence] suggests that this is not rational,” argues Porter. The report highlights that the overall average BMI in 2015 was 28.74; the percentage of hip primary procedures submitted with BMI data in 2015 was 75 per cent which is an increase of 9 per cent since 2012.

“Joint replacement surgery is not a lifestyle operation, it is primarily an operation to relieve pain, keep people at work and free patients from community care. Registry data shows that, since 2003, osteoarthritis is the predominant diagnosis in 92 and 96 per cent of primary hip and knee replacement procedures respectively. The taxpayer will not save money by providers denying joint replacements to patients as these are highly effective and cost-effective procedures.”

For the period 1 April 2015 to 31 March 2016 there were just under 225,000 cases submitted to the NJR, bringing the total number of records in the registry to over 2.09 million since it was established in 2002.

On the collection of joint replacement data, NJR chairman Laurel Powers-Freeling said: “The NJR has continued to maintain its position as the world’s largest joint replacement registry and is proud to continue providing critical insights to all our stakeholders. We remain committed to improving the quality of our data to ensure the most robust evidence is available to monitor the performance of implants, the effectiveness of different types of surgery and to improve clinical standards – all with a sharp focus on patient outcomes.”

The full report is available at

Caption: Revision estimates are much higher in patients under 55 years compared with those over 75 years of age. © NJR 2014