The effect of femoral tunnel position on graft forces during inlay posterior cruciate ligament reconstruction.
BACKGROUND
The femoral tunnel may be positioned centrally or eccentrically within the posterior cruciate ligament footprint during a single-bundle posterior cruciate ligament reconstruction.


OBJECTIVE
After reconstruction, graft forces are significantly different from those of the native posterior cruciate ligament and are affected by the position of the femoral tunnel.


METHODS
Controlled laboratory study.


METHODS
The resultant force in the native posterior cruciate ligament was measured in nine cadaveric knees as the knee was flexed from -5 degrees to 120 degrees of flexion. Posterior cruciate ligament reconstruction was performed with the femoral side of the graft positioned centrally and then offset 5 mm eccentric to the central position.


RESULTS
Mean graft forces were not significantly different between eccentric and central tunnel positions during passive knee extension between 120 degrees and 0 degrees of flexion; at 5 degrees of hyperextension, the eccentric position generated significantly lower graft forces. For both reconstruction techniques, mean graft forces were significantly higher than those for the native posterior cruciate ligament beyond approximately 90 degrees of flexion, for 5 N.m internal and external tibial torque; 5 N.m varus and valgus moment.


CONCLUSIONS
Graft force reductions achieved with the eccentric femoral position appear to be relatively small compared with the forces expected during rehabilitation and activities of daily living.


CONCLUSIONS
After posterior cruciate ligament graft reconstruction, rehabilitation activities that load the knee at high degrees of flexion should be avoided to limit excessive forces on the maturing graft.
Oakes
Daniel A
DA
Department of Orthopaedic Surgery, University of California at Los Angeles, Los Angeles, California 90095-6902, USA.
Markolf
Keith L
KL
McWilliams
Justin
J
Young
Charles R
CR
McAllister
David R
DR
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D007718:Knee Injuries / Q000473:pathology / Q000534:rehabilitation* / Q000601:surgery*; D007719:Knee Joint / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods*; D016119:Posterior Cruciate Ligament / Q000293:injuries* / Q000601:surgery*; D019651:Plastic Surgery Procedures / Q000379:methods*; D013710:Tendons / Q000637:transplantation*; D016474:Weight-Bearing