Dislocation Rate After Conversion from Hip Hemiarthroplasty to Total Hip Arthroplasty by Alexander...

Dislocation Rate After Conversion from Hip Hemiarthroplasty to Total Hip Arthroplasty

by Alexander P. Sah, and Daniel M. Estok

J Bone Joint Surg AmVolume 90(3):506-516

March 1, 2008

©2008 by The Journal of Bone and Joint Surgery, Inc.

Abduction angle of the acetabular component (theta), defined by the angle between a horizontal line at the base of the ischia and a line parallel to the acetabular component on an

anteroposterior pelvic radiograph.

Alexander P. Sah, and Daniel M. Estok II J Bone Joint Surg Am 2008;90:506-516


Acetabular anteversion, defined as the angle (alpha) between a vertical line and a line parallel to the acetabular component on a shoot-through lateral radiograph of the hip.



Bar chart showing the percentage of dislocations associated with each femoral head size used in the conversions of the hemiarthroplasties and in the first-time revisions of the total hip

arthroplasties.



Figs. 3-A, 3-B, and 3-C Diagrams illustrating the effects of “femoral head downsizing” with conversion from a hemiarthroplasty to a total hip replacement.



The reduction in the femoral head size after conversion surgery results in increased relative laxity of the soft tissues, which have been previously compromised by the index procedure.



Dislocation is more likely to occur with smaller head sizes, since these represent the greatest amount of femoral head downsizing in the context of compromised soft tissues.



Dislocation Rate After Conversion from Hip Hemiarthroplasty to Total Hip Arthroplasty by Alexander...

Documents

Transcript of Dislocation Rate After Conversion from Hip Hemiarthroplasty to Total Hip Arthroplasty by Alexander...