1. Femoral Component Rotation
John R. Moreland, M.D.
Transforming Orthopedics: Advanced Outcomes and Techniques
January 30-February 2,2008
Vail, Colorado

2. Femoral Component Rotation
Measured resection using bony landmarks
Posterior femoral condyles
Femoral epicondyles
Whiteside’s line
Scratches on femoral condyles
Gap balancing using ligament tensing in flexion
John Insall

3. Chronology 1978-79 fellowship in London with Mr. Michael Freeman
Taught me equal posterior condyle resection
Did not look right to me
Insall TKR brochures said tense ligaments in flexion and cut parallel to the previously resected tibia
I was puzzled

4. Diagram from David Hungerford TKR Brochures
Early 1980’s

5. Radiographic Analysis of Lower Extremity Axial Alignment
Moreland and Hanker
JBJS 1987
25 volunteers

8. Angle B
Mean 92.8 degrees
S.D. 1.5 degrees
Range 90 to 96.5 degrees

10. Mechanisms of Failure in Total Knee Arthroplasty CORR 1988

12. External Femoral Rotation Relative to the Posterior Condyles
Less patellar dislocation/subluxation
Less patellar lateral release need
Better ligament balance in flexion
Now all authorities recommend unequal posterior condyle resection
Should the bony landmarks or the ligaments decide how much?

13. Gap Balancing Technique for Femoral Component Rotation
This is the Insall way of achieving external rotation of the femoral component relative to posterior condyles.
Insall told me he would never internally rotate the femoral component relative to the posterior condyles even if the ligaments told him to do so.
We know ligaments contract and give wrong information in extension and contracted ligaments can also give wrong information in flexion.
If contracted ligaments can be “balanced”, how does the surgeon judge when enough balancing is done other than if the ligaments after balancing give proper external rotation of the femoral component relative to bony landmarks?
Gap balancing is really using bony landmarks as the gold standard

14. Measured Resection Technique for Femoral Component Rotation
Uses bony landmarks
0 to 6 (mean 3) degrees of external rotation relative to the posterior femoral condyles
Parallel to the femoral epicondyles
Perpendicular to Whiteside’s line
Perpendicular to scratches on the femoral condyles
Use all four bony landmarks
Using bony landmarks for femoral component rotation is currently the distinct majority view
Informal poll at The Knee Society summer meeting.
Informal polls at other meetings I have attended.

15. Thank You