Two million plus records in the National Joint Registry provides a rich dataset for joint replacement surgery

16 September 2016

Martyn Porter, Medical Director and Vice-Chairman National Joint Registry 

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.

The National Joint Registry (NJR) plays a crucial role in this process. Established in 2002, the registry ensures that 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 an absolute focus on patient outcomes. For example, over the life of the registry several orthopaedic implants have been identified as having potentially worse than expected performance when compared to similar devices. These anomalies have been investigated in considerable detail and shared with industry and the regulator, the Medicines and Healthcare Products Regulatory Agency (MHRA).

The public should be assured that the NJR provides a high level of quality assurance which otherwise may not be possible. As we launch the results of our 13th Annual Report today, the registry now contains more than two million procedure records. This is an exciting juncture in the life of the registry. With the NJR’s rich dataset we can now start to see important determinants that influence the outcome and longevity of joint replacement procedures.

Data emerging from this year’s report show that revision (‘re-do’ surgery) estimates following primary (first-time) joint replacement procedures remain low. For example, primary total hip replacement revision estimates are fewer than five per cent for the majority of procedures at twelve years. Knee replacement data in numerous ways mirrors that of hip replacement.

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, the NJR offers patients and surgeons the ability to see what specific type of hip construct produce 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 to 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 to less active patients.

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.Copies of the NJR’s Annual Report and additional online content can be downloaded form the website: The website forms part of our commitment to share our annual dataset in a more accessible, responsive and timely manner. I hope you will visit the site to explore the data, which is continuing to ensure patient safety across the orthopaedic sector.

This blog originally appeared on NHS England's News site

Mr Martyn Porter is the National Joint Registry’s medical director and vice-chairman, appointed by the Department for Health from 1 February 2014.

Mr Porter is a practicing consultant orthopaedic surgeon based at Wrightington Hospital, Lancashire, a past-President of the British Orthopaedic Association (BOA) and immediate past-President of the International Society of Arthroplasty Registers (ISAR).

Martyn has published many papers on the outcomes of various different types of joint replacement and techniques. He is a keen teacher and has lectured on many courses and conference, both in the United Kingdom and abroad.