Presentation on theme: "Femoral Component Rotation"— Presentation transcript:
1 Femoral Component Rotation John R. Moreland, M.D.Transforming Orthopedics: Advanced Outcomes and TechniquesJanuary 30-February 2,2008Vail, Colorado
2 Femoral Component Rotation Measured resection using bony landmarksPosterior femoral condylesFemoral epicondylesWhiteside’s lineScratches on femoral condylesGap balancing using ligament tensing in flexionJohn Insall
3 Chronology 1978-79 fellowship in London with Mr. Michael Freeman Taught me equal posterior condyle resectionDid not look right to meInsall TKR brochures said tense ligaments in flexion and cut parallel to the previously resected tibiaI was puzzled
4 Diagram from David Hungerford TKR Brochures Early 1980’s
5 Radiographic Analysis of Lower Extremity Axial Alignment Moreland and HankerJBJS 198725 volunteers
12 External Femoral Rotation Relative to the Posterior Condyles Less patellar dislocation/subluxationLess patellar lateral release needBetter ligament balance in flexionNow all authorities recommend unequal posterior condyle resectionShould 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 landmarks0 to 6 (mean 3) degrees of external rotation relative to the posterior femoral condylesParallel to the femoral epicondylesPerpendicular to Whiteside’s linePerpendicular to scratches on the femoral condylesUse all four bony landmarksUsing bony landmarks for femoral component rotation is currently the distinct majority viewInformal poll at The Knee Society summer meeting.Informal polls at other meetings I have attended.