Mt. Galloway et al., POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION - AN IN-VITRO STUDY OF FEMORAL AND TIBIAL GRAFT PLACEMENT, American journal of sports medicine, 24(4), 1996, pp. 437-445
We studied posterior cruciate ligament reconstruction in a cadaveric m
odel using two substitutes: a 1-mm diameter flexible cable and an 11-m
m diameter Achilles tendon autograft. The thin cable allowed us to stu
dy five femoral and five tibial attachments in each knee. A nearly iso
metric attachment was located after cutting the posterior cruciate lig
ament while the tibia was reduced with a 100 N anterior force. The fiv
e femoral locations studied were the isometric location and four locat
ions centered around this isometric point. The Achilles tendon reconst
ruction was used with both an isometric and a nonisometric femoral sit
e, allowing us to confirm the results with the wire cable. Posterior m
otion limits were measured under a 100 N posterior force in the intact
, posterior cruciate ligament-deficient, and posterior cruciate ligame
nt-reconstructed knees. We found that the restoration of knee stabilit
y in flexion depended strongly on the femoral attachment location. A f
emoral attachment that was nonisometric by intraoperative measurement,
but within the posterior cruciate ligament anatomic footprint, most c
losely reproduced the intact knee's posterior motion limits. Variation
s in the tibial attachment site produced only minor changes in the pos
terior motion limits. We concluded that the proximal-distal location s
elected for the femoral attachment of a posterior cruciate ligament su
bstitute was particularly important in the restoration of normal poste
rior motion limits.