The National Joint Registry and Hip Replacements – what does it tell us?

The National Joint Registry (http://www.njrsurgeonhospitalprofile.org.uk) is a registry of all the hip and knee replacements taking place in hospitals in England and Wales. It relies on hospitals to submit accurate data about the joint replacements that are done in their units. The reason this was initiated was to flag up concerns with particular implants that were not performing well and had high re-do rates. This was because historically there have been some hip or knee replacement designs that have not worked well and because there was no central collection of data, it took too long for the problems to be recognised. This resulted in more patients ending up with revision surgery than would otherwise have been the case. Overtime the Registry has been used to provide more and more information about joint replacement and the surgeons performing them. It is now possible to look at the NJR website and look at what individual surgeons are doing. It gives information about mortality rates and revision rates, the number of cases being done and the types of patients.

What does the NJR say about my surgical workload?

It indicates that my revision rate and mortality rate for hip replacement is not an outlier. It also shows that 62% of patients are under age 60 which is a much higher proportion than the national average. There are many things that the Registry cannot tell you in particular the data related to the complexity of cases is poorly documented  and such cases may of course have a higher complication rate. This information being available to the public is a good thing, but a concern is that surgeons taking on difficult cases may become reluctant to do so if they feel that this could prejudice their profile on the NJR.

The NJR has been collecting data since 2003 and the primary purpose to raise concern about failing implants has been effective, in particular the high revision rate of certain types of metal-on-metal hip replacements and resurfacings. The temptation is often to extrapolate data from registries such as this for political purposes or to produce information from it that can’t really be substantiated by the quality of the data that goes into it. Having said that, the NJR is here to stay and will provide significant longterm information about how joint replacements function and provides an important role in improving safety for patients.