Development of a method to characterise tibial shape: Implications for the success of the Oxford Unicompartmental Knee arthroplasty

Antonia Trent, Alexander D Liddle, Stephen J Mellon, David Murray, Hemant Pandit, Elise Pegg

Research output: Contribution to conferencePoster

Abstract

Introduction
The Oxford Unicompartmental knee arthroplasty (UKA) is indicated in patients with anteromedial osteoarthritis. Although the Oxford UKA preserves knee kinematics and function more than total knee replacement designs, outcome is variable with comparatively high revision rates reported. Proximal tibial (PT) shape shows considerable natural variation; however, it is unknown whether PT morphology has any impact on the functional outcome of the Oxford UKA.

Method
AP radiographs from 78 patients with 81 medial Oxford UKA were analysed to characterise PT shape according to 7 parameters, 4 dimensional and 3 angular. These were: Total Tibial Area (TTA); Tibial Area Beneath Tibial Tray (TABT); Tibial Width (TW); Tibial Canal Flare Index (TCFI); Lateral Tibial Angle (LTA); Medial Shaft Angle (MSA); Lateral Shaft Angle (LSA). The aims of the study were threefold: (1) to assess the feasibility of using a semi-automated measurement process by comparing Active Shape Modelling (ASM) results to manual measurements, (2) to assess the validity of the characterisation by comparing the resulting distributions to known variation in PT shape, (3) to assess the impact of established variation in PT morphology on functional outcome using the Oxford Knee Score (OKS).

Results
Results showed a high degree of correlation between ASM and manual measurements, particularly for the area measurements (TTA: 0.908, TABT: 0.922). Angular measurements were more reliably achieved using ASM (Inter-observer ICC LTA: 0.050). Bland-Altman plots demonstrated a consistent deviation in ASM dimensional results suggesting modification of the process is required (TTA MD: 330.37, TABT MD: 99.28). The validity of the characterisation was supported by trends in parameter variation according to gender, height, weight and age.

Conclusions
No association was found between PT shape and functional Oxford UKA outcome. However, this preliminary work was limited by cohort size and should be extended to allow for more high-powered analysis.

Conference

Conference4th Joint Meeting of the Bone Research Society & the British Orthopaedic Research Society
CountryUK United Kingdom
CityOxford
Period4/09/135/09/13

Fingerprint

Knee Replacement Arthroplasties
Knee
Biomechanical Phenomena
Osteoarthritis
Weights and Measures

Cite this

Trent, A., Liddle, A. D., Mellon, S. J., Murray, D., Pandit, H., & Pegg, E. (2013). Development of a method to characterise tibial shape: Implications for the success of the Oxford Unicompartmental Knee arthroplasty. Poster session presented at 4th Joint Meeting of the Bone Research Society & the British Orthopaedic Research Society, Oxford, UK United Kingdom.

Development of a method to characterise tibial shape: Implications for the success of the Oxford Unicompartmental Knee arthroplasty. / Trent, Antonia; Liddle, Alexander D; Mellon, Stephen J; Murray, David; Pandit, Hemant; Pegg, Elise.

2013. Poster session presented at 4th Joint Meeting of the Bone Research Society & the British Orthopaedic Research Society, Oxford, UK United Kingdom.

Research output: Contribution to conferencePoster

Trent, A, Liddle, AD, Mellon, SJ, Murray, D, Pandit, H & Pegg, E 2013, 'Development of a method to characterise tibial shape: Implications for the success of the Oxford Unicompartmental Knee arthroplasty' 4th Joint Meeting of the Bone Research Society & the British Orthopaedic Research Society, Oxford, UK United Kingdom, 4/09/13 - 5/09/13, .
Trent A, Liddle AD, Mellon SJ, Murray D, Pandit H, Pegg E. Development of a method to characterise tibial shape: Implications for the success of the Oxford Unicompartmental Knee arthroplasty. 2013. Poster session presented at 4th Joint Meeting of the Bone Research Society & the British Orthopaedic Research Society, Oxford, UK United Kingdom.
Trent, Antonia ; Liddle, Alexander D ; Mellon, Stephen J ; Murray, David ; Pandit, Hemant ; Pegg, Elise. / Development of a method to characterise tibial shape: Implications for the success of the Oxford Unicompartmental Knee arthroplasty. Poster session presented at 4th Joint Meeting of the Bone Research Society & the British Orthopaedic Research Society, Oxford, UK United Kingdom.
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title = "Development of a method to characterise tibial shape: Implications for the success of the Oxford Unicompartmental Knee arthroplasty",
abstract = "IntroductionThe Oxford Unicompartmental knee arthroplasty (UKA) is indicated in patients with anteromedial osteoarthritis. Although the Oxford UKA preserves knee kinematics and function more than total knee replacement designs, outcome is variable with comparatively high revision rates reported. Proximal tibial (PT) shape shows considerable natural variation; however, it is unknown whether PT morphology has any impact on the functional outcome of the Oxford UKA. MethodAP radiographs from 78 patients with 81 medial Oxford UKA were analysed to characterise PT shape according to 7 parameters, 4 dimensional and 3 angular. These were: Total Tibial Area (TTA); Tibial Area Beneath Tibial Tray (TABT); Tibial Width (TW); Tibial Canal Flare Index (TCFI); Lateral Tibial Angle (LTA); Medial Shaft Angle (MSA); Lateral Shaft Angle (LSA). The aims of the study were threefold: (1) to assess the feasibility of using a semi-automated measurement process by comparing Active Shape Modelling (ASM) results to manual measurements, (2) to assess the validity of the characterisation by comparing the resulting distributions to known variation in PT shape, (3) to assess the impact of established variation in PT morphology on functional outcome using the Oxford Knee Score (OKS). ResultsResults showed a high degree of correlation between ASM and manual measurements, particularly for the area measurements (TTA: 0.908, TABT: 0.922). Angular measurements were more reliably achieved using ASM (Inter-observer ICC LTA: 0.050). Bland-Altman plots demonstrated a consistent deviation in ASM dimensional results suggesting modification of the process is required (TTA MD: 330.37, TABT MD: 99.28). The validity of the characterisation was supported by trends in parameter variation according to gender, height, weight and age. ConclusionsNo association was found between PT shape and functional Oxford UKA outcome. However, this preliminary work was limited by cohort size and should be extended to allow for more high-powered analysis.",
author = "Antonia Trent and Liddle, {Alexander D} and Mellon, {Stephen J} and David Murray and Hemant Pandit and Elise Pegg",
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note = "4th Joint Meeting of the Bone Research Society & the British Orthopaedic Research Society ; Conference date: 04-09-2013 Through 05-09-2013",

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T1 - Development of a method to characterise tibial shape: Implications for the success of the Oxford Unicompartmental Knee arthroplasty

AU - Trent, Antonia

AU - Liddle, Alexander D

AU - Mellon, Stephen J

AU - Murray, David

AU - Pandit, Hemant

AU - Pegg, Elise

PY - 2013/8

Y1 - 2013/8

N2 - IntroductionThe Oxford Unicompartmental knee arthroplasty (UKA) is indicated in patients with anteromedial osteoarthritis. Although the Oxford UKA preserves knee kinematics and function more than total knee replacement designs, outcome is variable with comparatively high revision rates reported. Proximal tibial (PT) shape shows considerable natural variation; however, it is unknown whether PT morphology has any impact on the functional outcome of the Oxford UKA. MethodAP radiographs from 78 patients with 81 medial Oxford UKA were analysed to characterise PT shape according to 7 parameters, 4 dimensional and 3 angular. These were: Total Tibial Area (TTA); Tibial Area Beneath Tibial Tray (TABT); Tibial Width (TW); Tibial Canal Flare Index (TCFI); Lateral Tibial Angle (LTA); Medial Shaft Angle (MSA); Lateral Shaft Angle (LSA). The aims of the study were threefold: (1) to assess the feasibility of using a semi-automated measurement process by comparing Active Shape Modelling (ASM) results to manual measurements, (2) to assess the validity of the characterisation by comparing the resulting distributions to known variation in PT shape, (3) to assess the impact of established variation in PT morphology on functional outcome using the Oxford Knee Score (OKS). ResultsResults showed a high degree of correlation between ASM and manual measurements, particularly for the area measurements (TTA: 0.908, TABT: 0.922). Angular measurements were more reliably achieved using ASM (Inter-observer ICC LTA: 0.050). Bland-Altman plots demonstrated a consistent deviation in ASM dimensional results suggesting modification of the process is required (TTA MD: 330.37, TABT MD: 99.28). The validity of the characterisation was supported by trends in parameter variation according to gender, height, weight and age. ConclusionsNo association was found between PT shape and functional Oxford UKA outcome. However, this preliminary work was limited by cohort size and should be extended to allow for more high-powered analysis.

AB - IntroductionThe Oxford Unicompartmental knee arthroplasty (UKA) is indicated in patients with anteromedial osteoarthritis. Although the Oxford UKA preserves knee kinematics and function more than total knee replacement designs, outcome is variable with comparatively high revision rates reported. Proximal tibial (PT) shape shows considerable natural variation; however, it is unknown whether PT morphology has any impact on the functional outcome of the Oxford UKA. MethodAP radiographs from 78 patients with 81 medial Oxford UKA were analysed to characterise PT shape according to 7 parameters, 4 dimensional and 3 angular. These were: Total Tibial Area (TTA); Tibial Area Beneath Tibial Tray (TABT); Tibial Width (TW); Tibial Canal Flare Index (TCFI); Lateral Tibial Angle (LTA); Medial Shaft Angle (MSA); Lateral Shaft Angle (LSA). The aims of the study were threefold: (1) to assess the feasibility of using a semi-automated measurement process by comparing Active Shape Modelling (ASM) results to manual measurements, (2) to assess the validity of the characterisation by comparing the resulting distributions to known variation in PT shape, (3) to assess the impact of established variation in PT morphology on functional outcome using the Oxford Knee Score (OKS). ResultsResults showed a high degree of correlation between ASM and manual measurements, particularly for the area measurements (TTA: 0.908, TABT: 0.922). Angular measurements were more reliably achieved using ASM (Inter-observer ICC LTA: 0.050). Bland-Altman plots demonstrated a consistent deviation in ASM dimensional results suggesting modification of the process is required (TTA MD: 330.37, TABT MD: 99.28). The validity of the characterisation was supported by trends in parameter variation according to gender, height, weight and age. ConclusionsNo association was found between PT shape and functional Oxford UKA outcome. However, this preliminary work was limited by cohort size and should be extended to allow for more high-powered analysis.

M3 - Poster

ER -