Administrators, Editors, Administrators
3,484
edits
Changes
Jump to navigation
Jump to search
Created from content I previously added to Wikipedia
[[File:Hip prosthesis components.jpg|thumb|160px|Main components of a hip prosthesis<ref>{{cite web|url=http://illumin.usc.edu/61/total-hip-replacement/|title=Total Hip Replacement|website=[[University of Southern California]]|author=Andrew Still|date=2002-11-02|accessdate=2017-01-05}}</ref>]]
{{Authors
|author1=[[User:Mikael Häggström|Mikael Häggström]]
|author2=
}}
==Configuration==
Post-operative projectional radiography ("X-ray") is routinely performed to ensure proper configuration of hip prostheses.
The direction of the acetabular cup influences the range of motion of the leg, and also affects the risk of dislocation.<ref name=Watt/> For this purpose, the ''acetabular inclination'' and the ''acetabular anteversion'' are measurements of cup angulation in the [[coronal plane]] and the [[sagittal plane]], respectively.
<gallery widths="230">
File:Acetabular inclination of hip prosthesis.jpg|Acetabular inclination.<ref name=Vanrusselt2015/> This parameter is calculated on an anteroposterior radiograph as the angle between a line through the lateral and medial margins of the acetabular cup and the ''transischial line'' which is tangential to the inferior margins of the [[ischium]] bones.<ref name=Vanrusselt2015>{{cite journal|last1=Vanrusselt|first1=Jan|last2=Vansevenant|first2=Milan|last3=Vanderschueren|first3=Geert|last4=Vanhoenacker|first4=Filip|title=Postoperative radiograph of the hip arthroplasty: what the radiologist should know|journal=Insights into Imaging|volume=6|issue=6|year=2015|pages=591–600|issn=1869-4101|doi=10.1007/s13244-015-0438-5|pmid=26487647}}</ref>
File:Range of acetabular inclination.png|Acetabular inclination is normally between 30 and 50°.<ref name=Vanrusselt2015/> A larger angle increases the risk of dislocation.<ref name=Watt>{{cite web|url=http://www.radiologyassistant.nl/en/p431c8258e7ac3/hip-arthroplasty.html|title=Hip - Arthroplasty -Normal and abnormal imaging findings|author=Iain Watt, Susanne Boldrik, Evert van Langelaan and Robin Smithuis|website=Radiology Assistant|accessdate=2017-05-21}}</ref>
</gallery>
<gallery widths="230">
File:Acetabular anteversion of hip prosthesis.jpg|Acetabular anteversion.<ref name="ShinLee2015"/> This parameter is calculated on a lateral radiograph as the angle between the [[transverse plane]] and a line going through the (anterior and posterior) margins of the acetabular cup.<ref name="ShinLee2015">{{cite journal|last1=Shin|first1=W. C.|last2=Lee|first2=S. M.|last3=Lee|first3=K. W.|last4=Cho|first4=H. J.|last5=Lee|first5=J. S.|last6=Suh|first6=K. T.|title=The reliability and accuracy of measuring anteversion of the acetabular component on plain anteroposterior and lateral radiographs after total hip arthroplasty|journal=The Bone & Joint Journal|volume=97-B|issue=5|year=2015|pages=611–616|issn=2049-4394|doi=10.1302/0301-620X.97B5.34735}}</ref>
File:Range of acetabular anteversion.png|Acetabular anteversion is normally between 5 and 25°.<ref name=Watt/> An anteversion below or above this range increases the risk of dislocation.<ref name=Watt/> There is an [[intra-individual variability]] in this method because the pelvis may be tilted in various degrees in relation to the transverse plane.<ref name=Watt/>
</gallery>
<gallery widths="230">
File:Leg length discrepancy after hip replacement.jpg|''Leg length discrepancy'' after hip replacement is calculated as the vertical distance between the middle of the minor trochanters, using the acetabular tear drops<ref name=Vanrusselt2015/> or the transischial line<ref name=Watt/> as references for the horizontal plane. A discrepancy of up to 1 cm is generally tolerated.<ref name=Vanrusselt2015/><ref name=Watt/>
File:Center of rotation of hip prosthesis.jpg|''Center of rotation'': The horizontal center of rotation is calculated as the distance between the acetabular teardrop and the center of the head (or caput) of the prosthesis and/or the native femoral head on the contralateral side.<ref name=Vanrusselt2015/> The vertical center of rotation instead uses the transischial line for reference.<ref name=Vanrusselt2015/> The parameter should be equal on both sides.<ref name=Vanrusselt2015/>
</gallery>
==Complications==
===Dislocation===
<gallery>
File:Dislocated hip replacement.jpg|Dislocated artificial hip
File:Hip prosthesis liner creep and wear.png|Liner wear, particularly when over 2 mm, increases the risk of dislocation.<ref name=berry2012>{{cite book|title=Surgery of the Hip|url=https://books.google.se/books?id=Kc-AhYLnIF4C&pg=PA1035|author=Daniel J. Berry, Jay Lieberman|publisher=Elsevier Health Sciences|year=2012|isbn=9781455727056|page=1035}}</ref> Liner creep, on the other hand, is normal remoulding.<ref name=Watt/>
</gallery>
===Fracture===
Post-operative femoral fractures are graded by the Vancouver classification:
{| class="wikitable"
|-
! Type
! Description
|-
| A
| Fracture in the [[human trochanter|trochanteric]] region
|-
| B1
| Fracture around stem or just below, with well fixed stem
|-
| B2
| Fracture around stem or just below, with loose stem but good proximal bone
|-
| B3
| Fracture around stem or just below, with poor quality or severely comminuted proximal bone
|-
| C
| Fracture below theprosthesis
|}
===Loosening===
[[File:Hip joint aseptic loosening ar1938-1.png|thumb|upright|Hip prosthesis displaying aseptic loosening (arrows)]]
[[File:Hip prosthesis zones by DeLee and Charnley system, and Gruen system.jpg|thumb|210px|[[Hip prosthesis zones]] according to DeLee and Charnley,<ref>{{cite book|title=The Adult Hip, Volume 1|url=https://books.google.com/books?id=-fwULYB1gJIC&pg=PA958|author=John J. Callaghan, Aaron G. Rosenberg, Harry E. Rubash|publisher=Lippincott Williams & Wilkins|year=2007|isbn=978-0-7817-5092-9|page=958}}</ref> and Gruen.<ref>{{cite journal|last1=Neumann|first1=Daniel R.P.|last2=Thaler|first2=Christoph|last3=Hitzl|first3=Wolfgang|last4=Huber|first4=Monika|last5=Hofstädter|first5=Thomas|last6=Dorn|first6=Ulrich|title=Long-Term Results of a Contemporary Metal-on-Metal Total Hip Arthroplasty|journal=The Journal of Arthroplasty|volume=25|issue=5|year=2010|pages=700–708|issn=0883-5403|doi=10.1016/j.arth.2009.05.018}}</ref> These are used to describe the location of for example areas of loosening.]]
On radiography, it is normal to see thin radiolucent areas of less than 2 mm around hip prosthesis components, or between a cement mantle and bone. However, these may still indicate loosening of the prosthesis if they are new or changing, and areas greater than 2 mm may be harmless if they are stable.<ref name="RothMaertz2012"/> The most important prognostic factors of cemented cups are absence of radiolucent lines in DeLee and Charnley zone I, as well as adequate cement mantle thickness.<ref>{{cite book|title=The Well-Cemented Total Hip Arthroplasty: Theory and Practice|url=https://books.google.se/books?id=PQ6NZAeJUXcC&pg=PA337&lpg=PA336|author=Steffen Breusch, Henrik Malchau|publisher=Springer Science & Business Media|year=2005|isbn=978-3-540-24197-3|page=336}}</ref> In the first year after insertion of uncemented femoral stems, it is normal to have mild subsidence (less than 10 mm).<ref name="RothMaertz2012">{{cite journal|last1=Roth|first1=Trenton D.|last2=Maertz|first2=Nathan A.|last3=Parr|first3=J. Andrew|last4=Buckwalter|first4=Kenneth A.|last5=Choplin|first5=Robert H.|title=CT of the Hip Prosthesis: Appearance of Components, Fixation, and Complications|journal=RadioGraphics|volume=32|issue=4|year=2012|pages=1089–1107|issn=0271-5333|doi=10.1148/rg.324115183}}</ref>
==References==
{{Reflist}}
{{Authors
|author1=[[User:Mikael Häggström|Mikael Häggström]]
|author2=
}}
==Configuration==
Post-operative projectional radiography ("X-ray") is routinely performed to ensure proper configuration of hip prostheses.
The direction of the acetabular cup influences the range of motion of the leg, and also affects the risk of dislocation.<ref name=Watt/> For this purpose, the ''acetabular inclination'' and the ''acetabular anteversion'' are measurements of cup angulation in the [[coronal plane]] and the [[sagittal plane]], respectively.
<gallery widths="230">
File:Acetabular inclination of hip prosthesis.jpg|Acetabular inclination.<ref name=Vanrusselt2015/> This parameter is calculated on an anteroposterior radiograph as the angle between a line through the lateral and medial margins of the acetabular cup and the ''transischial line'' which is tangential to the inferior margins of the [[ischium]] bones.<ref name=Vanrusselt2015>{{cite journal|last1=Vanrusselt|first1=Jan|last2=Vansevenant|first2=Milan|last3=Vanderschueren|first3=Geert|last4=Vanhoenacker|first4=Filip|title=Postoperative radiograph of the hip arthroplasty: what the radiologist should know|journal=Insights into Imaging|volume=6|issue=6|year=2015|pages=591–600|issn=1869-4101|doi=10.1007/s13244-015-0438-5|pmid=26487647}}</ref>
File:Range of acetabular inclination.png|Acetabular inclination is normally between 30 and 50°.<ref name=Vanrusselt2015/> A larger angle increases the risk of dislocation.<ref name=Watt>{{cite web|url=http://www.radiologyassistant.nl/en/p431c8258e7ac3/hip-arthroplasty.html|title=Hip - Arthroplasty -Normal and abnormal imaging findings|author=Iain Watt, Susanne Boldrik, Evert van Langelaan and Robin Smithuis|website=Radiology Assistant|accessdate=2017-05-21}}</ref>
</gallery>
<gallery widths="230">
File:Acetabular anteversion of hip prosthesis.jpg|Acetabular anteversion.<ref name="ShinLee2015"/> This parameter is calculated on a lateral radiograph as the angle between the [[transverse plane]] and a line going through the (anterior and posterior) margins of the acetabular cup.<ref name="ShinLee2015">{{cite journal|last1=Shin|first1=W. C.|last2=Lee|first2=S. M.|last3=Lee|first3=K. W.|last4=Cho|first4=H. J.|last5=Lee|first5=J. S.|last6=Suh|first6=K. T.|title=The reliability and accuracy of measuring anteversion of the acetabular component on plain anteroposterior and lateral radiographs after total hip arthroplasty|journal=The Bone & Joint Journal|volume=97-B|issue=5|year=2015|pages=611–616|issn=2049-4394|doi=10.1302/0301-620X.97B5.34735}}</ref>
File:Range of acetabular anteversion.png|Acetabular anteversion is normally between 5 and 25°.<ref name=Watt/> An anteversion below or above this range increases the risk of dislocation.<ref name=Watt/> There is an [[intra-individual variability]] in this method because the pelvis may be tilted in various degrees in relation to the transverse plane.<ref name=Watt/>
</gallery>
<gallery widths="230">
File:Leg length discrepancy after hip replacement.jpg|''Leg length discrepancy'' after hip replacement is calculated as the vertical distance between the middle of the minor trochanters, using the acetabular tear drops<ref name=Vanrusselt2015/> or the transischial line<ref name=Watt/> as references for the horizontal plane. A discrepancy of up to 1 cm is generally tolerated.<ref name=Vanrusselt2015/><ref name=Watt/>
File:Center of rotation of hip prosthesis.jpg|''Center of rotation'': The horizontal center of rotation is calculated as the distance between the acetabular teardrop and the center of the head (or caput) of the prosthesis and/or the native femoral head on the contralateral side.<ref name=Vanrusselt2015/> The vertical center of rotation instead uses the transischial line for reference.<ref name=Vanrusselt2015/> The parameter should be equal on both sides.<ref name=Vanrusselt2015/>
</gallery>
==Complications==
===Dislocation===
<gallery>
File:Dislocated hip replacement.jpg|Dislocated artificial hip
File:Hip prosthesis liner creep and wear.png|Liner wear, particularly when over 2 mm, increases the risk of dislocation.<ref name=berry2012>{{cite book|title=Surgery of the Hip|url=https://books.google.se/books?id=Kc-AhYLnIF4C&pg=PA1035|author=Daniel J. Berry, Jay Lieberman|publisher=Elsevier Health Sciences|year=2012|isbn=9781455727056|page=1035}}</ref> Liner creep, on the other hand, is normal remoulding.<ref name=Watt/>
</gallery>
===Fracture===
Post-operative femoral fractures are graded by the Vancouver classification:
{| class="wikitable"
|-
! Type
! Description
|-
| A
| Fracture in the [[human trochanter|trochanteric]] region
|-
| B1
| Fracture around stem or just below, with well fixed stem
|-
| B2
| Fracture around stem or just below, with loose stem but good proximal bone
|-
| B3
| Fracture around stem or just below, with poor quality or severely comminuted proximal bone
|-
| C
| Fracture below theprosthesis
|}
===Loosening===
[[File:Hip joint aseptic loosening ar1938-1.png|thumb|upright|Hip prosthesis displaying aseptic loosening (arrows)]]
[[File:Hip prosthesis zones by DeLee and Charnley system, and Gruen system.jpg|thumb|210px|[[Hip prosthesis zones]] according to DeLee and Charnley,<ref>{{cite book|title=The Adult Hip, Volume 1|url=https://books.google.com/books?id=-fwULYB1gJIC&pg=PA958|author=John J. Callaghan, Aaron G. Rosenberg, Harry E. Rubash|publisher=Lippincott Williams & Wilkins|year=2007|isbn=978-0-7817-5092-9|page=958}}</ref> and Gruen.<ref>{{cite journal|last1=Neumann|first1=Daniel R.P.|last2=Thaler|first2=Christoph|last3=Hitzl|first3=Wolfgang|last4=Huber|first4=Monika|last5=Hofstädter|first5=Thomas|last6=Dorn|first6=Ulrich|title=Long-Term Results of a Contemporary Metal-on-Metal Total Hip Arthroplasty|journal=The Journal of Arthroplasty|volume=25|issue=5|year=2010|pages=700–708|issn=0883-5403|doi=10.1016/j.arth.2009.05.018}}</ref> These are used to describe the location of for example areas of loosening.]]
On radiography, it is normal to see thin radiolucent areas of less than 2 mm around hip prosthesis components, or between a cement mantle and bone. However, these may still indicate loosening of the prosthesis if they are new or changing, and areas greater than 2 mm may be harmless if they are stable.<ref name="RothMaertz2012"/> The most important prognostic factors of cemented cups are absence of radiolucent lines in DeLee and Charnley zone I, as well as adequate cement mantle thickness.<ref>{{cite book|title=The Well-Cemented Total Hip Arthroplasty: Theory and Practice|url=https://books.google.se/books?id=PQ6NZAeJUXcC&pg=PA337&lpg=PA336|author=Steffen Breusch, Henrik Malchau|publisher=Springer Science & Business Media|year=2005|isbn=978-3-540-24197-3|page=336}}</ref> In the first year after insertion of uncemented femoral stems, it is normal to have mild subsidence (less than 10 mm).<ref name="RothMaertz2012">{{cite journal|last1=Roth|first1=Trenton D.|last2=Maertz|first2=Nathan A.|last3=Parr|first3=J. Andrew|last4=Buckwalter|first4=Kenneth A.|last5=Choplin|first5=Robert H.|title=CT of the Hip Prosthesis: Appearance of Components, Fixation, and Complications|journal=RadioGraphics|volume=32|issue=4|year=2012|pages=1089–1107|issn=0271-5333|doi=10.1148/rg.324115183}}</ref>
==References==
{{Reflist}}
