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===Planning===Necessary projections are:*Frontal and axial image of the hip joint*Frontal image of the inferior parts of the hip bone (to include the [[ischium]] bones for measurements). ===Evaluation===Evaluate:*Prosthesis configuration*Cement coverage, where applicable*Any intraoperative fractures ====Configuration of total arthroplasty====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="330" heights="120150">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>

<gallery widths="330" heights="120150">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 widths="330" heights="120150">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&nbsp;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/>

====Configuration of hemiarthroplasty====[[File:Hip prosthesis zones by DeLee and Charnley system, and Gruen systemFemoral offset in hemiarthroplasty (crop).jpg|thumb|250px170px|Hip prosthesis zones according to DeLee and Charnley,Femoral offset in hemiarthroplasty.<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|pagename=958}}</ref> and Gruen.<ref"JonesBriffa2017">{{cite journal|last1=NeumannJones|first1=Daniel R.P.Carl|last2=ThalerBriffa|first2=ChristophNikolai|last3=HitzlJacob|first3=WolfgangJoshua|last4=HuberHargrove|first4=Monika|last5=Hofstädter|first5=Thomas|last6=Dorn|first6=UlrichRichard|title=Long-Term Results The Dislocated Hip Hemiarthroplasty: Current Concepts of a Contemporary Metal-on-Metal Total Hip ArthroplastyEtiological factors and Management|journal=The Open Orthopaedics Journal of Arthroplasty|volume=2511|issue=5Suppl-7, M4|year=20102017|pages=700–7081200–1212|issn=08831874-54033250|doi=10.10162174/j.arth.2009.05.0181874325001711011200}}</ref> These are used to describe the location of for example areas of loosening.]]

The main measures after hemiarthroplastyare:*'''Leg length discrepancy''Cement' as in total arthroplasty above.*'''Femoral (neck) offset''' , which is defined as the perpendicular distance between the intramedullary or longitudinal axis of the femur and the center of rotation of the native or prosthetic femoral head.<ref name="JonesBriffa2017"/> An offset of less than 33 mm is associated with hip dislocation.<ref name="NinhSethi2009">{{cite journal|last1=Ninh|first1=Christopher C.|last2=Sethi|first2=Anil|last3=Hatahet|first3=Mohammed|last4=Les|first4=Clifford|last5=Morandi|first5=Massimo|last6=Vaidya|first6=Rahul|title=Hip Dislocation After Modular Unipolar Hemiarthroplasty|journal=The Journal of Arthroplasty|volume=24|issue=5|year=2009|pages=768–774|issn=08835403|doi=10.1016/j.arth.2008.02.019}}</ref> ====Cement coverage====Cement coverage is regarded as acceptable when there are no translucent zones on an anteroposterior image in at least 6 of 7 Gruen-zones.<ref name=SOA/>  [[File:Hip prosthesis zones by DeLee and Charnley system, and Gruen system.jpg|thumb|250px|center|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.]] Absence of cement in zone 7 (medially-proximally) needs to be noted. On a lateral image, the distal tip of the prosthesis should be centered, and not be in contact with the cortex.<ref name=SOA/> The cup should not have translucent zones in zone 1 and 2. It is acceptable to have translucent zones in parts of zone 3.<ref name=SOA/> ====Fractures====Have at least a glance at bony contours around the prosthesis in order to detect intraoperative fractures.<gallery>File:Intraoperative acetabular fracture, annotated.jpg|Intraoperative acetabular fracture</gallery>

*Prosthesis configuration. If the report is likely to undergo double reading, the parameters need to may be given in numbers even if within normal limits.

==References=={{Reporting}} {{ReflistBottom}}