Executive Summary

We now report on some 73,720 primary shoulder replacements with the growth in recent years coming from reverse polarity total shoulder replacements.

Overall activity is now above pre-COVID levels, bolstered by the independent sector (Figure 3.S2). Since 2020 we can see that the recovery of shoulder replacement is due to an expansion of provision within the independent sector (both NHS and independently-funded). Notably, there has been a substantial increase in the number of independently-funded procedures compared to pre-2020 data, but the NHS hospitals are still performing substantially fewer shoulder replacements than prior to the pandemic.

As detailed in Figure 3.S3, there has been a decrease in the use of stemmed humeral hemiarthroplasty and stemmed total shoulder replacements. Surgeons carrying out stemmed humeral hemiarthroplasties tend to not be doing many each year. The growth in stemless total shoulder replacements and stemmed reverse polarity total shoulder replacements appears to be occurring in higher-volume shoulder surgeons. The majority of procedures, by some margin, were stemmed reverse total shoulder replacements. 

Table 3.S3 demonstrates that the average number of primary replacements per unit (now 17) and per surgeon (now 12) is growing again since COVID and is the highest it has been. There has been relatively little growth in the number of surgeons performing these procedures over the last decade while the number of cases per surgeon per annum has grown by around 50%.

As always, the revision data in the shoulder section is very hard to interpret and the reader is referred to the main text and tables. The data needs to be interpreted in the context of revisability, cuff insufficiency, patient frailty, and PROMs scores. Revision rates at five years for patients under 55 however, do remain high in relation to hip and knee replacement at around 10%.

For PROMs, in Table 3.S15 we see that less than a quarter of patients complete the pre-operative Oxford shoulder PROMs at the appropriate time. Some 30% complete the questionnaire at six months but the utility of collecting post-op scores without pre-op is limited. Also, as overall compliance with the completion of pre-op PROMs is poor, those patients that have completed them cannot be seen as representative of the whole cohort. In 2022 less than 12% of elective patients had pre-op and the 6-month PROMs both recorded (Table 3.S17). 

Clearly having both pre-op and post-op scores for the same patients allows the calculation of health gain rather than simply a spot measure of the general pre-op or post-op status. Nonetheless, one of the main questions remaining to be answered from the data is whether the low revision rate in reverse shoulders reflects better overall performance or whether it reflects the relative difficulty in performing a revision procedure on a reverse shoulder prosthesis. It is possible that following post-op PROMs in large groups of patients may help us to resolve this issue even in the absence of individual pre-op scores and these post-op scores will therefore continue to be collected. That said valuable data is available. The vast majority of patients appear to improve with surgery and in the paired PROMs at six months only 5.1% of patients score worse outcomes than they had reported pre-operatively (Figure 3.S11).

The NJR collects pre-operative PROMs as part of the minimum data set to be entered by all hospitals carrying out shoulder surgery. These pre-operative measures are vital in assessing the benefits of shoulder surgery to the patient, and low compliance by hospitals continues to be of concern.
 

We have now been collecting data on elbow replacement for over ten years and data on first linked revision episodes and mortality are presented. There are over 10,000 elbow replacements in the registry available for analysis, with the majority in women (66%), and this is the largest dataset of elbow replacements globally. Almost half of the recorded primary elbow replacements are radial head replacements, and overall, some 56% of primary elbow replacements are performed for trauma. From Table 3.E2, we can see that in 2023 almost 70% of elbow replacements for trauma indications are radial head replacements, with the rest being equally split between distal humeral hemiarthroplasty and total elbow replacement. In elective primary elbow replacement, total elbow replacement dominates (73%). It is very important that the reader should appreciate this preponderance of trauma indications in the data when considering the analysis of outcomes.

Recovery from the pandemic has been slow. The increase in numbers of other joint replacements being performed recently in the independent sector has not been seen with elbow replacements. Overall, in the last three years, there have been more surgeons performing more than 13 cases per year but there is still a significant proportion of elbow replacements being performed by low volume surgeons performing one or two per year. The median number of elbow replacements per surgeon per year, over the last three years, has remained consistent at around three per annum. Networks are being set up and funded imminently in England, and this may improve the situation.

In terms of brands of total elbow replacement in the registry dataset, Coonrad Morrey and Discovery have had the highest numbers but there is an increase in the use of Latitude EV. In radial head replacement, the monopolar Anatomic dominates.

Within the registry we have 443 data-linked revisions within these elbow primaries. Single-stage is the most common type of revision procedure, although DAIR and one of two-stage procedures make up significant numbers. There is concern that radial head replacement revision may be underreported and excision joint replacement may be poorly recorded by units. This should be reported on NJR forms as with any other revision, and now relevant reoperation procedure.

Figure 3.E8 shows Kaplan-Meier estimates of the cumulative revision of total elbow replacements by implant brand within the elective cases. Broadly the market leaders have a revision rate at seven years of around 7 to 9%.

Mortality for acute trauma cases is 0.27% at 30 days, increasing to almost 24% at ten years. In elective cases 30-day mortality is 0.07%, rising to almost 30% at ten years.

Overall elective activity remains below that seen in 2013 but this may represent other factors such as alternative evolving non-surgical treatments.

It may therefore be necessary to carefully consider the implications of COVID as regards elbow replacement as the background trend may not be so clearly one of increasing numbers year-on-year because the proportion of cases performed for inflammatory arthritis is higher than for many other joints.
 

The NJR reports on ankle revision and mortality, with almost 10,000 primary ankle replacements available for analysis. Similar to hip and knee replacement, the average age of patients is 69.

Although designed as uncemented implants, some 4% of ankle replacements have been cemented; it is presumed that these operations were associated with poor bone stock or were in low demand patients. Although numbers of primaries performed increased after 2015, they dropped significantly during the COVID pandemic and have only just recovered. The recent recovery in numbers has been achieved in part by surgeons doing higher volumes of ankle replacement – more than 13 per year, but it seems unfortunate that a similar increase in numbers has been seen in those surgeons performing fewer than six cases per year. Similar trends are seen in both the NHS and the independently-funded sector but only in the latter has the number increased to above pre- COVID levels (Figure 3.A3). Expansion has been seen in the fixed bearing design, whereas the last three years have seen a partial recovery in the numbers of mobile bearing implants used against a background of steady decline of these implants over the last 12 years. Some 73.5% of all ankle replacements now have an Infinity tibial component, but 11.1% of these (8.2% of the total) use an Inbone talar component. This is reported separately by the NJR.

Over the years the mean number of primary procedures per surgeon has increased from 3.8 (2010) to 6.2 (2023) while the median has risen from 2 to 4. However, in 2023, 18% of surgeons performing the procedures were doing more than 10 per year, although over 45% of primary ankle replacement procedures were done by surgeons performing 13 or more per year. Figure 3.A4 shows there is still a high number of surgeons completing one to two procedures per year. The British Orthopaedic Foot and Ankle Society (BOFAS) has not given guidance on absolute minimum numbers but do encourage higher volumes per surgeon, and for surgeons to work in networks.

When it comes to revision, we have small numbers available for analysis, but it appears that younger people and particularly younger women have higher revision rates (Table 3.A3). The reason for this difference between males and females is not clear but merits further attention. Overall the revision rate is around 10% at 13 years. The device with Infinity talar and tibial components, now in common use, has a revision rate of <4% at seven years.
 

Coming soon.

Coming soon.

Professor Mike Reed - Chair, Editorial Committee
Mr Tim Wilton - NJR Medical Director

The year commenced 20 years after the first patient details were submitted to the NJR in 2003 and shortly after our 21st anniversary we have celebrated the submission of the four millionth case. As usual we attended the BHS, BASK and BESS specialist society events and in addition we have also celebrated at an event for our wide range of stakeholders recently in Westminster, at which many important development milestones were highlighted by a variety of members of the NJR team and our guests. The registry is the largest such database of joint replacement cases in the world, but more important is that the database is so complete, especially over the last 15 years. There have of course been some challenges along the way.

One such challenge has been the long-planned development of the new NJR Data Warehouse which has now been completed by NEC and which should afford a great deal of improvement in many of the NJR activities. This enhanced system puts many of the associated data streams in the same computer environment so that they can be analysed and integrated in a much more straight-forward way. It is difficult, though, to make an omelette without breaking a few eggs and there have been inevitable complexities and delays involved in overcoming some of the teething difficulties with the new system. We believe that the new system will now allow us to do things more quickly, more smoothly and to add new mechanisms to our repertoire, so the disruption should prove to have been worthwhile. The introduction of the new system has, however, contributed to the staggered appearance of parts of this year’s report because of the delays in the analysis of hip and knee data, while some of the database changes were ironed out. 

We have been developing an elaborate classification system with the German Arthroplasty Registry for some years and this year has not only seen this completed but the classification has also been accepted and adopted by the International Society of Arthroplasty Registries. This will now form the basis for specifying hip and knee implant characteristics for this whole international group. This is a major step forward which should enable all registries using the system to be very precise about exactly which variant of an implant they are describing. Hitherto this has been difficult because of the variety of types of implant available in different geographical areas and the fact that sometimes different names have been used for the same device.

We should now be able to be confident that an implant which has either much better (or much worse!) outcomes than another implant is clearly defined. Similarly, this system will allow the pooling of cases from different registries to enable more powerful analysis of outcomes in the knowledge that those pooled implants are all the same variant. This will be welcomed by the regulatory bodies, as well as clinical and patient organisations, as a significant step forward. 

Embedding this new classification system has also been the cause for some of the delay in our analysis of hip and knee data this year with the result that the production of our Annual Clinical Reports (ACRs) for hospitals, and Consultant Level Reports (CLRs) for surgeons have been delayed somewhat, as well as those respective joint sections of the Annual Report. On a more positive note, we look forward to seeing the wider variety of data in those and other reports as a result of this development.

Every few years we have a review of the Minimum Data Set (MDS), and this most recent review going on during 2023, has now been completed. The resulting version MDSv8 has now been implemented and allows us to collect more details about aspects of the patients, more complexity details for revision cases, and to collect data about complications and re-operations other than revision procedures. Although our primary outcome measure continues to be revision, with the same definition maintained, it is clearly important for patients when they have some other operation in relation to their replaced joint and we have greatly increased the scope of the data collected about these other re-operations.

An important development over the last year has also been to start collecting the same sort of data about hemiarthroplasty for hip fractures that we have previously collected for planned joint replacement. Previously we collected data about Total Hip Replacement for hip fractures but were not collecting hemiarthroplasty cases. These have a similar potential to have variation in the outcome depending upon the specific implant used and it is therefore a welcome development that we should now be able to perform suitable analysis to enable the improved treatment of these many thousands of frail and elderly patients.

A very significant problem over the last two years has been the breakdown in the provision of data feeds from the NHS data sources which has affected Hospital Episode Statistics (HES) data, civil registration data (death information) and national hip and knee Patient Reported Outcome Measures (PROMs) data. These are collected by the central NHS systems but are integral to the work of the NJR, as without these other data feeds the data collected specifically by the NJR can only be partially analysed. Some of these data have been supplied but have arrived very late so could not be included in some of the reports. 

The PROMs data have been an even greater problem as not only have they been greatly delayed but the data files have not been usable or complete when they have finally arrived. These matters have been completely outside the control of the NJR, but a solution is being actively pursued by the team at NEC Software Solutions and the NHS England Medical Directorate. In the meantime, the analysis of PROMs outcomes, which is so important to provide a comprehensive assessment of implants and hospital services alike, has not been possible for the last two years and we are therefore relying on primary outcomes such as revision rates and mortality.

There had been a delay to our development programme caused by the pandemic, as the funding of those projects was put on hold for two years. The programme has now been restarted and some of these developments will be specifically targeted at the data feeds and other issues outlined above.

Our continuing work in specific areas where the data were less complete have included: audits of elbow replacements to achieve full coverage particularly of trauma cases; audit of dual mobility hips to capture those with unusual combinations of components; and audit of shoulder replacements where historic missing cases are being picked up. These joint specific audits have greatly improved volumes on the registry and therefore our ability to analyse the relevant implant ranges and the accuracy of those analyses.

Acknowledgements 

The NJR continues to work collaboratively with our many stakeholders; the most important, of course, are the patients we serve, and whom we would like to thank for allowing us to use their data.

The NJR operational collaboration is a huge team effort. Elaine Young, NJR Director of Operations, has demonstrated the great versatility of her leadership and her team.

Many thanks also to the following without which the NJR could not function:

All members of the NJR Board and members of the NJR committees: 

Executive 
Data Quality 
Editorial 
Implant Scrutiny 
Medical Advisory 
Regional Clinical Coordinators 
Research 
Surgical Performance 

Members of the Data Access Review Group 

Members of the NJR Patient Network

Other organisations: 

Medicines and Healthcare products Regulatory Agency (MHRA) 
Care Quality Commission (CQC) 
NHS England (NHSE) 
Welsh Government 
Northern Ireland Executive 
Isle of Man Department of Health 
States of Guernsey 
Independent Healthcare Providers Network Services 
Getting It Right First Time (GIRFT) 
British Orthopaedic Association (BOA) 
British Hip Society (BHS) 
British Association for Surgery of the Knee (BASK) 
British Elbow and Shoulder Society (BESS) 
British Orthopaedic Foot and Ankle Society (BOFAS) 
European Orthopaedic Research Society (EORS) 
Healthcare Quality Improvement Partnership (HQIP) 
Confidentiality Advisory Group (CAG) 
Association of British HealthTech Industries (ABHI)

We are most grateful to our NJR delivery contractors for their very valuable input into the NJR Annual Report and their many other functions. NEC Software Solutions, University of Bristol and University of Oxford teams help us refine and improve each year.

We offer our personal thanks to Vicky McCormack, Report Project Manager, NEC; and Deirdra Taylor, Associate Director of Communication and Stakeholder Engagement, for getting the final report into shape.