The Posterior Cruciate Ligament: Anatomy, Biomechanics, and Double-Bundle Reconstruction

Abstract

The posterior cruciate ligament (PCL) is the largest intra-articular ligament in the knee and is the primary stabilizer to posterior tibial translation. Historically, the PCL’s functional dynamics and appropriate management after injury have been controversial. However, recent biomechanical and anatomic studies have elucidated a better understanding of PCL function, which has led to development of more anatomic reconstruction techniques. The larger anterolateral bundle and the smaller posteromedial bundle of the PCL exhibit a codominant relationship and have a wide femoral attachment footprint. For these reasons, the native kinematics of the knee is better restored with a double-bundle PCL reconstruction (DB-PCLR) technique than with a single-bundle PCL reconstruction (SB-PCLR). Likewise, clinical studies have demonstrated excellent outcomes for DB-PCLR compared to SB-PCLR, with decreased posterior knee laxity on stress radiography and improved International Knee Documentation Committee scores. This review will provide a detailed overview of the clinically relevant anatomy, biomechanics, injury evaluation, and treatment options, with an emphasis on arthroscopic DB-PCLR.

A Comprehensive Meta-analysis of Clinical and Biomechanical Outcomes Comparing Double-Bundle and Single-Bundle Posterior Cruciate Ligament Reconstruction Techniques

“…Kennedy et al 23 reported that the PMB provided the majority of rotational control at increased degrees of knee flexion, which supports the improved relative rotatory stability observed in the DB group when the knee was flexed for our study. 27 Last, there was no significant difference between the techniques when addressing varus laxity. The PCL's role in resisting varus laxity is less pronounced in the intact knee than its role in rotatory and translational stability.…”

“…The primary biomechanical function of the PCL is to stabilize the knee joint by resisting posterior tibial translation at all flexion angles and limit rotatory instability at higher degrees of knee flexion. 27 Multiple studies have shown that isolated PCL ruptures have the greatest effect at 90° of knee flexion, suggesting that it is most important to clinically assess PCL integrity at 90° of knee flexion. 13,14,32 This is consistent with the results in this investigation.…”

“…Several studies have reported that anatomic DB PCL reconstruction led to improved IKDC scores, reduced posterior tibial translation, and enhanced restoration of native knee kinematic function relative to the SB technique. 5,27 Furthermore, randomized controlled trials by Yoon et al 53 and Li et al 30 demonstrated superior clinical outcomes associated with DB reconstruction versus SB reconstruction. The present meta-analysis reflected the findings of these previous clinical investigations and revealed a statistically significant benefit in the majority of clinical outcomes.…”

Poor tibiofemoral congruity increases the risk of posterior cruciate ligament injury.

“…Injury to the posterior cruciate ligament, which acts as the ligament connecting the femur to the tibia, may be related not only to the anatomical morphological parameters of a single structure, but also to the combination of the distal femur and the proximal tibia [23,24] . A full understanding of the in uence of the morphology and correlation between the distal femur and the proximal tibia on PCL is of great signi cance for guiding the treatment and postoperative rehabilitation exercise of patients, but such studies are lacking in clinical practice.…”

Arthroscopic Remnant Preserving 3-Portal Posterior Cruciate Ligament Reconstruction With Reverse Passage of the Graft

“…However, up to 95% of cases of the PCL tears involve multiligamentous injuries, usually caused by vehicle or sports accidents. 3 , 4 The necessity of a multifactorial approach make the PCL tears challenging to treat and always require an individual approach. When the decision about surgery is made, one should remember that the PCL reconstruction itself is a technically demanding procedure.…”