A matched comparison of revision rates of cemented Oxford Unicompartmental Knee Replacements with Single and Twin Peg femoral components, based on data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

<p><strong>Background and purpose</strong> — Registries report high revision rates after unicompartmental knee replacement (UKR) due, in part, to aseptic loosing. In an attempt to improve Oxford UKR femoral component fixation a new design was introduced with a Twin rather than a Si...

Full description

Bibliographic Details
Main Authors: Mohammad, HR, Matharu, GS, Judge, A, Murray, DW
Format: Journal article
Language:English
Published: Taylor and Francis 2020
_version_ 1826270625080016896
author Mohammad, HR
Matharu, GS
Judge, A
Murray, DW
author_facet Mohammad, HR
Matharu, GS
Judge, A
Murray, DW
author_sort Mohammad, HR
collection OXFORD
description <p><strong>Background and purpose</strong> — Registries report high revision rates after unicompartmental knee replacement (UKR) due, in part, to aseptic loosing. In an attempt to improve Oxford UKR femoral component fixation a new design was introduced with a Twin rather than a Single peg. We used the National Joint Registry (NJR) to compare the 5-year outcomes of the Single and Twin Peg cemented Oxford UKRs.</p> <p><strong>Patients and methods</strong> — We performed a retrospective observational study using NJR data on propensity score matched Single and Twin Peg UKRs (matched for patient, implant and surgical factors). Data on 2,834 Single Peg and 2,834 Twin Peg were analyzed. Cumulative implant survival was calculated using the Kaplan–Meier method and comparisons between groups performed using Cox regression models.</p> <p><strong>Results</strong> — In the matched cohort, the mean follow up for both Single and Twin Peg UKRs was 3.3 (SD 2) and 3.4 years (SD 2) respectively. The 5-year cumulative implant survival rates for Single Peg and Twin Peg were 94.8% (95% CI 93.6–95.8) and 96.2% (CI 95.1–97.1) respectively. Implant revision rates were statistically significantly lower in the Twin Peg (hazard ratio [HR)] = 0.74; p = 0.04). The revision rate for femoral component aseptic loosening decreased significantly (p = 0.03) from 0.4% (n = 11) with the Single Peg to 0.1% (n = 3) with the Twin Peg. The revision rate for pain decreased significantly (p = 0.01) from 0.8% (n = 23) with the Single Peg to 0.3% (n = 9) with the Twin Peg. No other reasons for revision had significant differences in revision rates.</p> <p><strong>Interpretation</strong> — The revision rate for the cemented Twin Peg Oxford UKR was 26% less than the Single Peg Oxford UKR. This was mainly because the revision rates for femoral loosening and pain more than halved. This suggests that the Twin Peg component should be used in preference to the Single Peg design.</p>
first_indexed 2024-03-06T21:43:47Z
format Journal article
id oxford-uuid:48d779f8-ed35-4b69-94a9-f066760a6c71
institution University of Oxford
language English
last_indexed 2024-03-06T21:43:47Z
publishDate 2020
publisher Taylor and Francis
record_format dspace
spelling oxford-uuid:48d779f8-ed35-4b69-94a9-f066760a6c712022-03-26T15:28:09ZA matched comparison of revision rates of cemented Oxford Unicompartmental Knee Replacements with Single and Twin Peg femoral components, based on data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of ManJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:48d779f8-ed35-4b69-94a9-f066760a6c71EnglishSymplectic ElementsTaylor and Francis2020Mohammad, HRMatharu, GSJudge, AMurray, DW<p><strong>Background and purpose</strong> — Registries report high revision rates after unicompartmental knee replacement (UKR) due, in part, to aseptic loosing. In an attempt to improve Oxford UKR femoral component fixation a new design was introduced with a Twin rather than a Single peg. We used the National Joint Registry (NJR) to compare the 5-year outcomes of the Single and Twin Peg cemented Oxford UKRs.</p> <p><strong>Patients and methods</strong> — We performed a retrospective observational study using NJR data on propensity score matched Single and Twin Peg UKRs (matched for patient, implant and surgical factors). Data on 2,834 Single Peg and 2,834 Twin Peg were analyzed. Cumulative implant survival was calculated using the Kaplan–Meier method and comparisons between groups performed using Cox regression models.</p> <p><strong>Results</strong> — In the matched cohort, the mean follow up for both Single and Twin Peg UKRs was 3.3 (SD 2) and 3.4 years (SD 2) respectively. The 5-year cumulative implant survival rates for Single Peg and Twin Peg were 94.8% (95% CI 93.6–95.8) and 96.2% (CI 95.1–97.1) respectively. Implant revision rates were statistically significantly lower in the Twin Peg (hazard ratio [HR)] = 0.74; p = 0.04). The revision rate for femoral component aseptic loosening decreased significantly (p = 0.03) from 0.4% (n = 11) with the Single Peg to 0.1% (n = 3) with the Twin Peg. The revision rate for pain decreased significantly (p = 0.01) from 0.8% (n = 23) with the Single Peg to 0.3% (n = 9) with the Twin Peg. No other reasons for revision had significant differences in revision rates.</p> <p><strong>Interpretation</strong> — The revision rate for the cemented Twin Peg Oxford UKR was 26% less than the Single Peg Oxford UKR. This was mainly because the revision rates for femoral loosening and pain more than halved. This suggests that the Twin Peg component should be used in preference to the Single Peg design.</p>
spellingShingle Mohammad, HR
Matharu, GS
Judge, A
Murray, DW
A matched comparison of revision rates of cemented Oxford Unicompartmental Knee Replacements with Single and Twin Peg femoral components, based on data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man
title A matched comparison of revision rates of cemented Oxford Unicompartmental Knee Replacements with Single and Twin Peg femoral components, based on data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man
title_full A matched comparison of revision rates of cemented Oxford Unicompartmental Knee Replacements with Single and Twin Peg femoral components, based on data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man
title_fullStr A matched comparison of revision rates of cemented Oxford Unicompartmental Knee Replacements with Single and Twin Peg femoral components, based on data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man
title_full_unstemmed A matched comparison of revision rates of cemented Oxford Unicompartmental Knee Replacements with Single and Twin Peg femoral components, based on data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man
title_short A matched comparison of revision rates of cemented Oxford Unicompartmental Knee Replacements with Single and Twin Peg femoral components, based on data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man
title_sort matched comparison of revision rates of cemented oxford unicompartmental knee replacements with single and twin peg femoral components based on data from the national joint registry for england wales northern ireland and the isle of man
work_keys_str_mv AT mohammadhr amatchedcomparisonofrevisionratesofcementedoxfordunicompartmentalkneereplacementswithsingleandtwinpegfemoralcomponentsbasedondatafromthenationaljointregistryforenglandwalesnorthernirelandandtheisleofman
AT matharugs amatchedcomparisonofrevisionratesofcementedoxfordunicompartmentalkneereplacementswithsingleandtwinpegfemoralcomponentsbasedondatafromthenationaljointregistryforenglandwalesnorthernirelandandtheisleofman
AT judgea amatchedcomparisonofrevisionratesofcementedoxfordunicompartmentalkneereplacementswithsingleandtwinpegfemoralcomponentsbasedondatafromthenationaljointregistryforenglandwalesnorthernirelandandtheisleofman
AT murraydw amatchedcomparisonofrevisionratesofcementedoxfordunicompartmentalkneereplacementswithsingleandtwinpegfemoralcomponentsbasedondatafromthenationaljointregistryforenglandwalesnorthernirelandandtheisleofman
AT mohammadhr matchedcomparisonofrevisionratesofcementedoxfordunicompartmentalkneereplacementswithsingleandtwinpegfemoralcomponentsbasedondatafromthenationaljointregistryforenglandwalesnorthernirelandandtheisleofman
AT matharugs matchedcomparisonofrevisionratesofcementedoxfordunicompartmentalkneereplacementswithsingleandtwinpegfemoralcomponentsbasedondatafromthenationaljointregistryforenglandwalesnorthernirelandandtheisleofman
AT judgea matchedcomparisonofrevisionratesofcementedoxfordunicompartmentalkneereplacementswithsingleandtwinpegfemoralcomponentsbasedondatafromthenationaljointregistryforenglandwalesnorthernirelandandtheisleofman
AT murraydw matchedcomparisonofrevisionratesofcementedoxfordunicompartmentalkneereplacementswithsingleandtwinpegfemoralcomponentsbasedondatafromthenationaljointregistryforenglandwalesnorthernirelandandtheisleofman