1. Three-Dimensional Mechanics, Kinematics, and Morphology of the Knee Viewed in Virtual Reality by Donald G. Eckhoff, Joel M. Bach, Victor M. Spitzer, Karl D. Reinig, Michelle M. Bagur, Todd H. Baldini, and Nicolas M.P. Flannery J Bone Joint Surg Am Volume 87(suppl 2):71-80 December 1, 2005 ©2005 by The Journal of Bone and Joint Surgery, Inc.

2. The sulcus (lowest point) is a nearly linear depression in the trochlear groove of the femur that lies lateral to the midplane, defined as the plane perpendicular to the posterior condylar axis. Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

3. The sulcus is oriented between the traditional mechanical axis (the line joining the center of the femoral head and the center of the knee) and the anatomic axis (the center of the femoral shaft). Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

4. The cross-sectional centers of the distal part of the femur and the proximal part of the tibia are not superimposed but are translated an average (and standard deviation) of 4 ± 6 mm anteroposteriorly and 5 ± 4 mm mediolaterally in both the normal knees and... Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

5. A cylinder has been fit into the osseous surface of the distal part of the femur to illustrate three features: (1) the circular profile of the condyles, (2) the small asymmetry in radius of curvature between the medial and lateral condyles (the medial is gr... Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

6. Three-dimensional knee model constructed from the Visible Human database (University of Colorado Center for Human Simulation), with epicondylar (yellow) and cylindrical (green) axes described in the text. Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

7. Coronal view with cylindrical axis. Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

8. Transverse view with cylindrical axis. Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

9. Computed tomographic scans were performed with the subject supine and the hip and knee in extension. Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

10. The mechanical axis was reconstructed, as described in the text, to allow the measures of angulation (left) and linear displacement (right) in this illustration. Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

11. Computer-assisted identification of the epicondyles was accomplished by extending the cylinder along its axis until only a point of bone remained on the lateral side or the dimple was apparent on the medial side as illustrated here. Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

12. Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

13. Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.

14. Histogram of the data illustrating the relative deviation of limb alignment from a straight line in the normal population of 180 limbs sampled in this study. Donald G. Eckhoff et al. J Bone Joint Surg Am 2005;87:71- 80 ©2005 by The Journal of Bone and Joint Surgery, Inc.