Title :
A simple radiographic measurement method for polyethylene wear in total knee arthroplasty
Author :
Fukuoka, Yutaka ; Hoshino, Akiho ; Ishida, Akimasa
Author_Institution :
Inst. for Med. & Dental Eng., Tokyo Med. & Dental Univ., Japan
fDate :
6/1/1999 12:00:00 AM
Abstract :
This study describes a new method for evaluating polyethylene wear in total knee arthroplasty. Since the amount of wear is dependent on a number of variables such as the weight and activity of the patient, it should be estimated based on in vivo measurements. We used a computer vision technique called three-dimensional/two-dimensional (3-D/2-D) matching to perform in vivo assessment using a single-plane radiograph. Using the 3-D/2D matching algorithm we estimated the 3-D position and orientation of each knee implant and then measured the femorotibial distance, which is defined as the shortest perpendicular distance from the tibial tray to the femoral component. The accuracy of the proposed 3-D/2-D matching method was determined by in vitro investigations. The worst errors in in-plane/out-of-plane translations and rotations were 0.20/1.95 mm and 0.17/0.29°, respectively. The root-mean-square error in femorotibial distance measurements using real polyethylene inserts was 0.04 mm. Results of in vivo femorotibial distance measurements are also described
Keywords :
biomedical materials; biomedical measurement; computer vision; diagnostic radiography; image matching; medical image processing; polymers; prosthetics; wear testing; 3D/2D matching; computer vision technique; femorotibial distance; in vitro investigations; in vivo assessment; in-plane/out-of-plane rotations; in-plane/out-of-plane translations; knee implant; orientation estimation; polyethylene wear; pose estimation; position estimation; radiographic measurement method; root-mean-square error; shortest perpendicular distance; single-plane radiography; total knee arthroplasty; Computer vision; Diagnostic radiography; Distance measurement; Implants; In vitro; In vivo; Knee; Polyethylene; Position measurement; Two dimensional displays;
Journal_Title :
Rehabilitation Engineering, IEEE Transactions on