Posterior subluxations of the medial and lateral tibiofemoral compartments

Abstract

We report for the first time the abnormal increases in posterior subluxation of the medial and lateral tibial plateaus after sectioning the posterolateral structures and posterior cruciate ligament. We applied specific forces and moments to the knees of seven cadaveric whole lower limbs and measured the position of the tibia at which the ligaments and the geometry of the joint limited motion. Removal of only the posterolateral structures resulted in an average increase in posterior translation of the lateral tibial plateau of 8.0 mm (range, 5.7 to 10.6) at 30 degrees of flexion over the intact state (P < 0.01), but no significant increase at 90 degrees of flexion (mean, 2.7 mm). Knees with underlying physiologic cruciate ligament laxity (high anterior/posterior displacement in the intact knee) had the greatest lateral tibial plateau subluxation (P < 0.01). There was no abnormal posterior translation of the medial tibial plateau. After sectioning the posterior cruciate ligament and the posterolateral structures, statistically significant increases in posterior translation of both the medial and lateral tibial plateaus occurred at 30 degrees and 90 degrees of flexion (P < 0.01). The increase in posterior translation of the lateral tibial plateau over the intact state averaged 17.8 and 23.5 mm at 30 degrees and 90 degrees of flexion, respectively; for the medial tibial plateau this increase averaged 7.6 and 12.3 mm at 30 degrees and 90 degrees of flexion, respectively. The diagnosis of abnormal tibiofemoral rotatory subluxations requires knowledge of the anteroposterior direction and magnitude of each tibial plateau under both low flexion and high flexion knee angle positions.

Management of combined anterior or posterior cruciate ligament and posterolateral corner injuries: A systematic review

“…The limitation related to the absence of objective tools for evaluating the various components of knee laxity, most notably in rotation, was also pointed out by Bonanzinga et al [26]. The potential severity of injuries that involve both the posterolateral corner and the ACL or PCL is well established [4,5,28,29]. Failure to take posterolateral corner lesions into account is also a known cause of failure of isolated cruciate ligament reconstruction in patients with combined injuries [21,26].…”

Effect of the posterior cruciate ligament on posterior stability of the knee in high flexion

“…The PCL has been identified as a major component constraining posterior tibial translation (Butler et al, 1980;Fanelli et al, 1994;Gollehon et al, 1987;Markolf et al, 1997a b;Noyes et al, 1993). However, these studies have focused on PCL function between 0 and 120 flexion.…”

“…The biomechanical function of the posterior cruciate ligament (PCL) has been investigated between 0 and 120 of knee flexion, with the PCL identified as the primary restraint to posterior tibial translation at flexion angles larger than 30 (Butler et al, 1980;Fanelli et al, 1994;Fox et al, 1998;Gollehon et al, 1987;Markolf et al, 1997a b;Noyes et al, 1993). The PCL has been shown to carry peak loads at about 90 under external loads (Hoher et al, 1999).…”

Posterolateral corner reconstruction for posterolateral rotatory instability combined with posterior cruciate ligament injuries: comparison between fibular tunnel and tibial tunnel techniques

“…Between January 1999 and October 2003, 96 patients with PLRI combined with chronic PCL injuries underwent a PLC reconstruction at the time of tensioning of the remnant PCL plus reconstruction of the anterolateral bundle of the PCL [9]. Among those patients, 28 were excluded from the study because they met one of the following exclusion criteria: (1) the PCL reconstruction had been performed using methods other than tensioning of the PCL remnant plus reconstruction of the anterolateral bundle, (2) there were additional reconstruction procedures performed on either the anterior cruciate or the medial collateral ligament, (3) a posterolateral corner reconstruction was performed for an acute injury, (4) an intraarticular fracture was involved, and (5) there was an associated knee injury of such magnitude that knee function could be affected.…”

“…When a reconstructed PCL appears to render sufficient stability, surgeons generally do not address posterolateral rotatory instability (PLRI) at the time of posterior cruciate ligament (PCL) reconstruction. Although grade 1 or 2 posterolateral instability is usually treated conservatively, Noyes et al [5] reported residual mild laxity following conservative treatment of grade 2 injuries. Thus far, several surgical techniques have been developed to treat posterolateral injuries [2,[6][7][8].…”