The immediate post-operative radiograph is an unreliable measure of coronal plane alignment in total knee replacement.
Background - Restoration of a neutral mechanical axis is a primary goal of total knee replacement (TKR). A mechanical axis within three degrees of neutral has been correlated with improved implant longevity, function and patient satisfaction. We hypothesise that the immediate post-operative radiogr...
Main Authors: | , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Frontiers Media S.A.
2014-09-01
|
Series: | Frontiers in Surgery |
Subjects: | |
Online Access: | http://journal.frontiersin.org/Journal/10.3389/fsurg.2014.00035/full |
id |
doaj-e78188822616428da9b9c120fd92f213 |
---|---|
record_format |
Article |
spelling |
doaj-e78188822616428da9b9c120fd92f2132020-11-24T23:07:04ZengFrontiers Media S.A.Frontiers in Surgery2296-875X2014-09-01110.3389/fsurg.2014.00035111200The immediate post-operative radiograph is an unreliable measure of coronal plane alignment in total knee replacement.Joshua ePetterwood0Joshua ePetterwood1Michelle M Dowsey2Michelle M Dowsey3Daevyd eRodda4Daevyd eRodda5Peter F. Choong6Peter F. Choong7University of MelbourneSt. Vincent's Hospital (Melbourne)University of MelbourneSt. Vincent's Hospital (Melbourne)University of MelbourneSt. Vincent's Hospital (Melbourne)University of MelbourneSt. Vincent's Hospital (Melbourne)Background - Restoration of a neutral mechanical axis is a primary goal of total knee replacement (TKR). A mechanical axis within three degrees of neutral has been correlated with improved implant longevity, function and patient satisfaction. We hypothesise that the immediate post-operative radiograph is an unreliable method of measuring alignment following TKR surgery.Methods - 75 consecutive patients had supine x-rays performed on day two post-operatively followed by standing LLR six weeks post-operatively. Correlation was sought between the mechanical axis measured on the LLR and surrogate markers of alignment on the post-operative x-ray including component alignment and an estimation of anatomical alignment using the available length of femoral and tibial shafts. Inter and intra-observer reliability were assessed.Results - The mean mechanical axis was 180.5 (SD 3.0, range 175.1-187.1). Mean offset between anatomical axis and mechanical axis was 6.4 degrees. Inter- and intra-observer agreement were high on all measures. Using the Bland-Altman method demonstrated high levels of disagreement between measurements from short and LLR that included clinically important discrepancies of up to 7 degrees in multiple cases.Conclusion - The long leg weight bearing x-ray is an essential tool to accurately assess coronal plane alignment post TKR. Whilst the immediate post-operative x-ray taken supine provides useful information to the surgeon on any immediate complications our results indicate that it cannot be relied upon to determine correct restoration of the mechanical axis.http://journal.frontiersin.org/Journal/10.3389/fsurg.2014.00035/fullKneeAlignmentLong-Leg Radiographsknee replacementMechanical Axis |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Joshua ePetterwood Joshua ePetterwood Michelle M Dowsey Michelle M Dowsey Daevyd eRodda Daevyd eRodda Peter F. Choong Peter F. Choong |
spellingShingle |
Joshua ePetterwood Joshua ePetterwood Michelle M Dowsey Michelle M Dowsey Daevyd eRodda Daevyd eRodda Peter F. Choong Peter F. Choong The immediate post-operative radiograph is an unreliable measure of coronal plane alignment in total knee replacement. Frontiers in Surgery Knee Alignment Long-Leg Radiographs knee replacement Mechanical Axis |
author_facet |
Joshua ePetterwood Joshua ePetterwood Michelle M Dowsey Michelle M Dowsey Daevyd eRodda Daevyd eRodda Peter F. Choong Peter F. Choong |
author_sort |
Joshua ePetterwood |
title |
The immediate post-operative radiograph is an unreliable measure of coronal plane alignment in total knee replacement. |
title_short |
The immediate post-operative radiograph is an unreliable measure of coronal plane alignment in total knee replacement. |
title_full |
The immediate post-operative radiograph is an unreliable measure of coronal plane alignment in total knee replacement. |
title_fullStr |
The immediate post-operative radiograph is an unreliable measure of coronal plane alignment in total knee replacement. |
title_full_unstemmed |
The immediate post-operative radiograph is an unreliable measure of coronal plane alignment in total knee replacement. |
title_sort |
immediate post-operative radiograph is an unreliable measure of coronal plane alignment in total knee replacement. |
publisher |
Frontiers Media S.A. |
series |
Frontiers in Surgery |
issn |
2296-875X |
publishDate |
2014-09-01 |
description |
Background - Restoration of a neutral mechanical axis is a primary goal of total knee replacement (TKR). A mechanical axis within three degrees of neutral has been correlated with improved implant longevity, function and patient satisfaction. We hypothesise that the immediate post-operative radiograph is an unreliable method of measuring alignment following TKR surgery.Methods - 75 consecutive patients had supine x-rays performed on day two post-operatively followed by standing LLR six weeks post-operatively. Correlation was sought between the mechanical axis measured on the LLR and surrogate markers of alignment on the post-operative x-ray including component alignment and an estimation of anatomical alignment using the available length of femoral and tibial shafts. Inter and intra-observer reliability were assessed.Results - The mean mechanical axis was 180.5 (SD 3.0, range 175.1-187.1). Mean offset between anatomical axis and mechanical axis was 6.4 degrees. Inter- and intra-observer agreement were high on all measures. Using the Bland-Altman method demonstrated high levels of disagreement between measurements from short and LLR that included clinically important discrepancies of up to 7 degrees in multiple cases.Conclusion - The long leg weight bearing x-ray is an essential tool to accurately assess coronal plane alignment post TKR. Whilst the immediate post-operative x-ray taken supine provides useful information to the surgeon on any immediate complications our results indicate that it cannot be relied upon to determine correct restoration of the mechanical axis. |
topic |
Knee Alignment Long-Leg Radiographs knee replacement Mechanical Axis |
url |
http://journal.frontiersin.org/Journal/10.3389/fsurg.2014.00035/full |
work_keys_str_mv |
AT joshuaepetterwood theimmediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT joshuaepetterwood theimmediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT michellemdowsey theimmediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT michellemdowsey theimmediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT daevyderodda theimmediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT daevyderodda theimmediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT peterfchoong theimmediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT peterfchoong theimmediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT joshuaepetterwood immediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT joshuaepetterwood immediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT michellemdowsey immediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT michellemdowsey immediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT daevyderodda immediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT daevyderodda immediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT peterfchoong immediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement AT peterfchoong immediatepostoperativeradiographisanunreliablemeasureofcoronalplanealignmentintotalkneereplacement |
_version_ |
1725620273574576128 |