Trust, Local Health Board and hospital-level activity and outcomes

The observed numbers of revisions of hip and knee replacements for each hospital were compared to the numbers expected, given the hospitals’ case mix in respect of age, sex and reason for primary surgery. Hospitals with a much higher than expected revision rate for hip and knee replacement have been identified. These hospitals had a revision rate that was above the upper of the 99.8% control limits (these limits approximate to +/-3 standard deviations). We would expect 0.2% (i.e. one in 500) to lie outside the control limits by chance, with approximately half of these (one in 1,000) to be above the upper limit.

Following discussions with the British Association for Surgery of the Knee (BASK) and British Orthopaedic Association (BOA), our alarm process has been amended to identify surgeons who appear as potential outliers for their total knee replacement (TKR) practice data and/or their unicondylar knee (UKR) practice and/or their patellofemoral joint replacement (PFJ) data alone rather than just based on their overall knee practice. Hospitals are now notified for these sub-strata, but also for their overall knee replacement outcomes.

In the latest analysed datacut (to February 2026) there were 11 hospitals with higher than expected rates of revision for hip replacement over the past five years, while 26 hospitals had higher than expected rates over the past ten years.

Over the five-year period, 12 hospitals were identified with higher than expected overall knee revision rates, while eight were identified for total knee replacement, two for unicondylar knee replacement and one for patellofemoral knee replacement. Over the past ten years, higher than expected overall knee revision rates were seen for 25 hospitals, while 26 hospitals had higher rates for total knee replacement, five for unicondylar knee replacement and one for patellofemoral knee replacement.

The 90-day mortality rate for primary hip and knee replacement was calculated using the last five years of data for all hospitals by plotting standardised mortality ratios for each hospital against the expected number of deaths. One hospital had a higher than expected mortality rate for hip replacement.

Note: The case mix for mortality includes age, sex and ASA grade. Trauma cases have been excluded from both the hip and knee mortality analyses together with hips implanted for failed hemiarthroplasty or for metastatic cancer (the latter only from November 2014 when recording of this reason began). Also, where both left and right side joints were implanted on the same day, only one side was included in the analysis.
Note: Any hospitals identified as potential outliers here have been notified. All hospitals are provided with an NJR Annual Clinical Report and additionally have access to the online NJR Management Feedback service.

Important note about the outlier hospitals listed
In earlier annual reports, we reported outlying hospitals based on all cases submitted to the registry since 1 April 2003. To reflect changes in hospital practices and component use, we now report outlying hospitals based on the last five years (February 2021 to February 2026) and ten years of data (February 2016 to February 2026, the latter date being when the dataset was cut). These cuts of data exclude the majority of withdrawn outlier implants and metal-on-metal total hip replacements from analysis, and thus better represent contemporary practice.

Table 5.5 Outliers for hip mortality rates since 2021¹.
Royal Gwent Hospital

Table 5.6 Outliers for knee mortality rates since 2021¹.
None identified

Table 5.7 Outliers for hip revision rates, all linked primaries from 2021¹.
Bassetlaw Hospital, Worksop
King Edward VII's Hospital Sister Agnes, London
King George Hospital
Nottingham City Hospital
Nuffield Health Plymouth Hospital
Practice Plus Group Hospital - Barlborough
Practice Plus Group Hospital - Southampton
Princess Royal Hospital, West Sussex 
Royal Hallamshire Hospital, Sheffield
Spire Little Aston Hospital
Spire Liverpool Hospital

Table 5.8 Outliers for hip revision rates, all linked primaries from 2016².
Bassetlaw Hospital, Worksop
Broadgreen Hospital, Liverpool
Chorley and South Ribble Hospital
Clifton Park Hospital, York
Colchester General Hospital
Fulwood Hall Hospital, Preston
Harrogate District Hospital
Hexham General Hospital
Hull Royal Infirmary
King Edward VII's Hospital Sister Agnes, London
King George Hospital, Ilford
Milton Keynes Hospital
North Tyneside General Hospital
Nuffield Health Plymouth Hospital
Nuffield Orthopaedic Centre, Oxford
Orthopaedics and Spine Specialist Hospital, Peterborough
Practice Plus Group Hospital - Barlborough
Practice Plus Group Hospital - Southampton
Southampton General Hospital
Spire Little Aston Hospital
Spire Liverpool Hospital
St Mary's Hospital, Isle of Wight
The Cambridge Movement Elective Surgical Hub
The Royal National Orthopaedic Hospital (Stanmore), London
Wansbeck Hospital, Northumberland
Weston General Hospital

Table 5.9 Outliers for total knee replacement revision rates, all linked primaries from 2021¹.
Bassetlaw Hospital, Worksop
Chesterfield Royal Hospital
Clementine Churchill Hospital, Middlesex
Freeman Hospital, Newcastle upon Tyne
King Edward VII's Hospital Sister Agnes, London
Nuffield Orthopaedic Centre, Oxford
Practice Plus Group Hospital - Barlborough
Spire Montefiore Hospital, Hove

Table 5.10 Outliers for total knee replacement revision rates, all linked primaries from 2016².
Abergele Hospital
Bath Clinic
Circle Reading
Guy's Hospital, London
Harrogate District Hospital
Hillingdon Hospital, Uxbridge
Hospital of St John and St Elizabeth, London
King Edward VII's Hospital Sister Agnes, London
Mount Vernon Treatment Centre, Middlesex
New Hall Hospital, Salisbury
Northern General Hospital, Sheffield
Nottingham City Hospital
Nuffield Orthopaedic Centre, Oxford
Ormskirk and District General Hospital
Practice Plus Group Hospital - Barlborough
Queen Elizabeth The Queen Mother Hospital, Margate
Southampton General Hospital
Spire Bushey Hospital
Spire Southampton Hospital
St Mary's Hospital, Isle of Wight
Sussex Orthopaedic Centre, Haywards Heath
The Berkshire Independent Hospital, Reading
The Great Western Hospital, Swindon
The James Cook University Hospital, Middlesbrough
The Royal National Orthopaedic Hospital (Stanmore), London
Torbay Hospital

Table 5.11 Outliers for unicondylar knee replacement revision rates, all linked primaries from 2021¹.
King Edward VII's Hospital Sister Agnes, London
Wansbeck Hospital, Northumberland

Table 5.12 Outliers for unicondylar knee replacement revision rates, all linked primaries from 2016².
Basingstoke and North Hampshire Hospital
King Edward VII's Hospital Sister Agnes, London
Sunderland Royal Hospital
Wansbeck Hospital, Northumberland
West Cumberland Hospital, Whitehaven

Table 5.13 Outliers for patellofemoral knee replacement revision rates, all linked primaries from 2021¹.
King Edward VII's Hospital Sister Agnes, London

Table 5.14 Outliers for patellofemoral knee replacement revision rates, all linked primaries from 2016².
King Edward VII's Hospital Sister Agnes, London

Better than expected performance

We also list hospitals where revision rates are statistically better than expected and the hospitals have complied with the NJR’s data quality audits. The lists here show hospitals that lie below the 99.8% control limit which also achieved greater than 90% compliance across all of the NJR data quality audits. Hospitals with lower data quality compliance are automatically excluded from these lists, but can revisit their automated audits to improve their compliance results.

Table 5.15 Better than expected hip revision rates, all linked primaries from 2021¹.
Spire Norwich Hospital

Table 5.16 Better than expected hip revision rates, all linked primaries from 2016².
Countess of Chester Hospital
Ipswich Hospital
Orpington Hospital
Royal Surrey County Hospital, Guilford
Sunderland Royal Hospital
King's Mill Hospital, Sutton-in-Ashfield
Nuffield Health Taunton Hospital
Spire Norwich Hospital

Table 5.17 Better than expected total knee replacement revision rates, all linked primaries from 2021¹.
None identified

Table 5.18 Better than expected total knee replacement revision rates, all linked primaries from 2016².
Rivers Hospital, Hertfordshire
Spire Norwich Hospital
The Elective Orthopaedic Centre (SWLEOC), Epsom

Table 5.19 Better than expected unicondylar knee replacement revision rates, all linked primaries from 2021¹.
Spire Norwich Hospital

Table 5.20 Better than expected unicondylar knee replacement revision rates, all linked primaries from 2016².
Nuffield Health Derby Hospital
Spire Norwich Hospital
West Suffolk Hospital, Bury St Edmunds

Table 5.21 Better than expected patellofemoral knee replacement revision rates, all linked primaries from 2021¹.
None identified

Table 5.22 Better than expected patellofemoral knee replacement revision rates, all linked primaries from 2016².
None identified

¹Date range February 2021 to February 2026 inclusive.
²Date range February 2016 to February 2026 inclusive.
 

Overall in 2025, 136 NHS trusts and local health boards (comprising 258 separate hospitals) and 177 independent hospitals were open and eligible to report patient procedures to the registry. Data were not submitted in 2025 by three NHS hospitals and two independent hospitals.

Of those hospitals submitting data, the proportion of patients who gave permission (consent) for their details to be entered into the registry were:

NHS hospitals

   63.2% of NHS hospitals achieved a consent rate greater than 95%
   15.9% achieved a consent rate of 80% to 95%
   20.9% recorded a consent rate of less than 80%

Independent hospitals

   91.5% of independent hospitals achieved a consent rate greater than 95%
   7.3% achieved a consent rate of 80% to 95%
   1.1% recorded a consent rate of less than 80%

There has been an increase in recorded consent for all submitting hospitals when compared to the previous year, with those achieving a higher than 95% rate rising to 75%, from 68% in 2024. While annual increases have often been small, the percentage of hospitals achieving 95% consent has increased by 25% since 2018.

Similarly, the proportion of entries in which there are significant data to enable the patient to be linked to an NHS number (linkability) is listed.

NHS hospitals

   82.6% achieved a proportion of patients with a linkable NHS number greater than 95%
   13.2% achieved a proportion of 80% to 95%
   4.2% recorded a proportion of less than 80%

Independent hospitals

   85.9% achieved a proportion of patients with a linkable NHS number greater than 95%
   11.3% achieved a proportion of 80% to 95%
   2.8% recorded a proportion of less than 80%

In 2025, 84% of all submitting hospitals achieved over 95% linkability, an 8% increase on the rate seen in 2024 and a return to the rates achieved before the pandemic.

Performance and data entry quality indicators are shown here for trusts and local health boards (many of whom comprise more than one hospital) and independent (private) providers in England, Wales, Northern Ireland, the Isle of Man and the Channel Islands for the 2025 calendar year. Outcomes analysis after hip and knee replacement surgery is also provided.

The full analysis for hospitals can be found in the document available in the downloads section.