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 (December 2023) there were 13 hospitals with higher than expected rates of revision for hip replacement over the past five years, while 20 hospitals had higher than expected rates over the past ten years.

Over the five-year period, six hospitals were identified with higher than expected overall knee revision rates, while six were identified for total knee replacement, one for unicondylar knee replacement and none for patellofemoral knee replacement. Over the past ten years, higher than expected overall knee revision rates were seen for 21 hospitals, while 23 hospitals had higher rates for total knee replacement, six for unicondylar knee replacement and two 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. No hospitals had higher than expected mortality rates for either hip or knee 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 (January 2019 to December 2023) and ten years of data (January 2014 to December 2023, 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 2019¹.
None identified

Table 5.6 Outliers for knee mortality rates since 2019¹.
None identified

Table 5.7 Outliers for hip revision rates, all linked primaries from 2019¹.
Broadgreen Hospital, Liverpool
Bassetlaw Hospital, Worksop
Hexham General Hospital
King Edward VII's Hospital Sister Agnes, London
Milton Keynes Hospital
Mount Vernon Treatment Centre, Middlesex
North Manchester General Hospital
North Tyneside General Hospital
Nuffield Orthopaedic Centre, Oxford
Practice Plus Group Hospital - Balborough
Spire Liverpool Hospital
St Mary's Hospital, Isle of Wight
Wansbeck Hospital, Northumbria

Table 5.8 Outliers for hip revision rates, all linked primaries from 2014².
Bassetlaw Hospital, Worksop
Broadgreen Hospital, Liverpool
Chorley and South Ribble Hospital
Fitzwilliam Hospital, Peterborough
Hexham General Hospital
Hull Royal Infirmary
King Edward VII's Hospital Sister Agnes, London
Meriden Hospital, Coventry
Milton Keynes Hospital
North Tyneside General Hospital
Nuffield Health Cheltenham Hospital
Nuffield Orthopaedic Centre, Oxford
Orthopaedics and Spine Specialist Hospital, Peterborough
Salisbury District Hospital
Southampton General Hospital
Spire Liverpool Hospital
St Mary's Hospital, Isle of Wight
St Richard's Hospital, Chichester
Wansbeck Hospital, Northumbria
Weston General Hospital

Table 5.9 Outliers for overall knee revision rates, all linked primaries from 2019¹.
Castle Hill Hospital, Humberside
Clementine Churchill Hospital, Middlesex
Guy's Hospital, London
King Edward VII's Hospital Sister Agnes, London
Nuffield Orthopaedic Centre, Oxford
Spire Southampton Hospital

Table 5.10 Outliers for overall knee revision rates, all linked primaries from 2014².
Bishops Wood Hospital, Middlesex
Bridlington and District Hospital
Guy's Hospital, London
Heatherwood Hospital, Ascot
Hillingdon Hospital, Uxbridge
Hospital of St John and St Elizabeth, London
King Edward VII's Hospital Sister Agnes, London
London Independent Hospital
Meriden Hospital, Coventry
Mount Vernon Treatment Centre, Middlesex
Nuffield Orthopaedic Centre, Oxford
Orthopaedics and Spine Specialist Hospital, Peterborough
Southmead Hospital, Bristol
Spire Hull and East Riding Hospital
Spire Southampton Hospital
Springfield Hospital, Chelmsford
St Mary's Hospital, Isle of Wight
Sussex Orthopaedic Centre, Haywards Heath
The London Clinic
The Royal National Orthopaedic Hospital (Stanmore), London
Winfield Hospital, Gloucester

Table 5.11 Outliers for total knee replacement revision rates, all linked primaries from 2019¹.
Guy's Hospital, London
King Edward VII's Hospital Sister Agnes, London
Nuffield Orthopaedic Centre, Oxford
Sussex Orthopaedic Centre, Haywards Heath
Torbay Hospital 
Wansbeck Hospital, Northumbria

Table 5.12 Outliers for total knee replacement revision rates, all linked primaries from 2014².
Bath Clinic
Bridlington and District Hospital
Guy's Hospital, London
Heatherwood Hospital, Ascot
Hillingdon Hospital, Uxbridge
Hospital of St John and St Elizabeth, London
London Independent Hospital
Mount Vernon Treatment Centre, Middlesex
Nottingham City Hospital
Nuffield Health Haywards Heath Hospital
Nuffield Orthopaedic Centre, Oxford
Ormskirk and District General Hospital
Orthopaedics and Spine Specialist Hospital, Peterborough
Southampton General Hospital
Southmead Hospital, Bristol
Spire Hull and East Riding Hospital
Spire Southampton Hospital
St Mary's Hospital, Isle of Wight
St Richard's Hospital, Chichester
Sussex Orthopaedic Centre, Haywards Heath
The Royal National Orthopaedic Hospital (Stanmore), London
Torbay Hospital
University Hospital Llandough

Table 5.13 Outliers for unicondylar knee replacement revision rates, all linked primaries from 2019¹.
King Edward VII's Hospital Sister Agnes, London

Table 5.14 Outliers for unicondylar knee replacement revision rates, all linked primaries from 2014².
Bishops Wood Hospital, Middlesex
King Edward VII's Hospital Sister Agnes, London
Meriden Hospital, Coventry
Springfield Hospital, Chelmsford
Sunderland Royal Hospital
The Cherwell Hospital, Banbury

Table 5.15 Outliers for patellofemoral knee replacement revision rates, all linked primaries from 2019¹.
None identified

Table 5.16 Outliers for patellofemoral knee replacement revision rates, all linked primaries from 2014².
Meriden Hospital, Coventry
Nuffield Health Tees Hospital

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 5.17 Better than expected hip revision rates, all linked primaries from 2019¹.
None identified

Table 5.18 Better than expected hip revision rates, all linked primaries from 2014².
Calderdale Royal Hospital, Halifax
Countess of Chester Hospital
Ipswich Hospital
Practice Plus Group Hospital - Emersons Green, Bristol
Royal Derby Hospital
Royal Devon and Exeter Hospital (Wonford)
Royal Surrey County Hospital

Table 5.19 Better than expected overall knee revision rates, all linked primaries from 2019¹.
None identified

Table 5.20 Better than expected overall knee revision rates, all linked primaries from 2014².
Burnley General Hospital
Hexham General Hospital
Ipswich Hospital
North Tyneside General Hospital
Nottingham Woodthorpe Hospital
Nuffield Health Cambridge Hospital
Nuffield Health Wolverhampton Hospital
Practice Plus Group Hospital - Emersons Green, Bristol
Rotherham District General Hospital
Spire Norwich Hospital
Stepping Hill Hospital, Stockport
The Horder Centre, Crowborough

Table 5.21 Better than expected total knee replacement revision rates, all linked primaries from 2019¹.
None identified

Table 5.22 Better than expected total knee replacement revision rates, all linked primaries from 2014².
Hexham General Hospital
Ipswich Hospital
Nottingham Woodthorpe Hospital
Nuffield Health Wolverhampton Hospital
Spire Norwich Hospital
Stepping Hill Hospital, Stockport
The Elective Orthopaedic Centre, London
The Horder Centre, Crowborough
Whiston Hospital, Prescot

Table 5.23 Better than expected unicondylar knee replacement revision rates, all linked primaries from 2019¹.
None identified

Table 5.24 Better than expected unicondylar knee replacement revision rates, all linked primaries from 2014².
Nuffield Health Derby Hospital
Practice Plus Group Hospital - Emersons Green, Bristol

Table 5.25 Better than expected patellofemoral knee replacement revision rates, all linked primaries from 2019¹.
None identified

Table 5.26 Better than expected patellofemoral knee replacement revision rates, all linked primaries from 2014².
None identified

_{¹Date range January 2019 to December 2023 inclusive.
²Date range January 2014 to December 2023 inclusive.}
 

Overall in 2023, 136 NHS trusts and local health boards (comprising 255 separate hospitals) and 176 independent hospitals were open and eligible to report patient procedures to the registry. Data were not submitted in 2023 by five NHS hospitals and four 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

58% of NHS hospitals achieved a consent rate greater than 95%
22% achieved a consent rate of 80% to 95%
20% recorded a consent rate of less than 80%

Independent hospitals

81% of independent hospitals achieved a consent rate greater than 95%
17% achieved a consent rate of 80% to 95%
2% 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 67%, from 54% in 2022 (47% in 2020). Consent rates are returning to pre-pandemic levels; this can be related to the ratio of elective to trauma cases, which changed significantly during 2020, having a higher proportion of trauma cases compared to previous years. There was a significant reduction in elective cases due to COVID and trauma cases have a higher rate where NJR consent is not obtained.

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

66% achieved a proportion of patients with a linkable NHS number greater than 95%
22% achieved a proportion of 80% to 95%
12% recorded a proportion of less than 80%

Independent hospitals

81% achieved a proportion of patients with a linkable NHS number greater than 95%
13% achieved a proportion of 80% to 95%
6% recorded a proportion of less than 80%

In 2023, 72% of all submitting hospitals achieved over 95% linkability, a decrease on the rate seen in 2022.

Note: Independent hospitals might be expected to have lower linkability rates than NHS hospitals, as a proportion of their patients may come from overseas and do not have an NHS number.
 

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 Guernsey for the 2023 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.