In the process of preoperative planning, two X-ray images (AP and LAT) of the knee joint are taken. In our novel method, they are taken with a 3D marker attached on the surface of the patient's lower leg. And the silhouette of the marker in the images are used to couple the two X-ray images three dimensionally(3D). With the aid of VR technology, the size selection and settlement of the implants can be performed in 3D way.

* Exploits the now pervasive Digital Medical Imaging environment.
How to matching marker.  
* Enhances the reliability of preoperative planning using the 3D VR spatial templating as opposed to the traditional 2D templating.
* VR technology created 3D framework for the planning from two original 2D X-ray Images.
* Spatial error for the orientation ,distance and the rotation of the patient's knee at the photographing are appropriately corrected.
* Optional CT data enables the precise determination of the rotaion and position in the axial plane.
* Predicts the thickness of the cutoff piece of the bone as a guiding information for the surgeon.


 Input data format    DICOM3.0 , BMP , JPEG
 Viewing    Surface rendering , Wireframe , Silhouette , Transparency ,   
 Volume rendering , Zoom in/out , Panning , Rotation , 
 Intensity and contrast
 Analyzing    Implant size selection , Positioning of the implant , 
 Orientation and position of the cutting plane , 
 Thickness of the cutoff
 Other features    Indicating the bone axes , 
 Separating the CT volume data into femur and tibia parts , 

Case example

The images are through the courtesy of
Shonan Kamakura Joint Reconstruction Center
Case I ) Case with bone defect on the medial side of the right knee, in which 3D template was effectively used.

  Preoperative planning by 3D templating of ATHENA
This case with bone defect on the medial side of the right knee was operated exactly as the planning.

Case II ) Osteoarthrosis of the Knee after High Tibial Osteotomy(HTO). 3D template Athena was very useful to determine the cut level of tibia and appropriate size of the implant.

  The surgery was performed using the same implant as the planning by Athena.
The coverage on the tibia and the osteophyte were operated exactly as the pre-operative planning, It was safely performed in MIS procedure for an hour and 45 minutes.
This patient also left hospital by herself with a single cane on the tenth day.

System requirements
 O S    Windows Vista / 7 / 8 / 8.1 (32bit/64bit)
 CPU    Core i5+
 Memory    2GB+
 Video environment    1280 x 1024+ , VRAM512MB+

 Supervised by Dr. I.Tatsumi
     Director of Knee Joint Reconstruction Center
     Shonan Kamakura General Hospital