Abstract
Background:
Multi-ligament knee injuries and knee dislocations are potentially devastating injuries that typically result in injury to both cruciate ligaments and variable injury to collateral ligament complexes.
Indications:
Surgical intervention typically leads to better patient outcomes than nonoperative management. We describe our preferred technique for bicruciate ligament reconstruction with a focus on double-bundle posterior cruciate ligament (PCL) reconstruction.
Technique Description:
A transtibial approach is used to drill the PCL tibial tunnel. A safety incision on the proximal medial tibia, which may incorporate the distal aspect of a medial-sided incision for medial collateral ligament (MCL) reconstruction, allows palpation of the PCL fovea for anatomic tunnel placement, protection of the posterior neurovascular structures, and egress of arthroscopic fluid during the case. This technique uses an inside-out approach for creation of the 2 femoral sockets to recreate the 2 PCL bundles. The grafts are passed in antegrade fashion, with passage and femoral fixation of the posteromedial (PM) bundle followed by the anterolateral (AL) bundle. After passage of the anterior cruciate ligament (ACL) graft and fixation on the femur in standard fashion, attention is turned to PCL tibia-sided fixation. We use a screw and spiked washer to fix the AL bundle at 90° of flexion with an anterior drawer maneuver. The PM bundle is then fixed with a polyetheretherketone (PEEK) interference screw in near full extension. Fixation of the ACL on the tibia in standard fashion completes the bicruciate ligament reconstruction.
Results:
In biomechanical cadaveric studies, double-bundle PCL reconstruction has been shown to more closely approximate native knee kinematics, with more restraint to posterior translation at all knee flexion angles and less internal rotation laxity at higher knee flexion angles. In clinical results, both single-bundle and double-bundle reconstructions improve knee stability and patient-reported outcomes. Double-bundle PCL reconstruction may provide improved objective posterior tibial stability and objective International Knee Documentation Committee (IKDC) scores.
Discussion:
Double-bundle PCL reconstruction can be performed efficiently with good outcomes and potentially less residual posterior translation or internal rotation laxity than single-bundle PCL reconstruction.
Patient Consent Disclosure Statement:
The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.
This is a visual representation of the abstract.
Video Transcript
This is a video from the University of New Mexico describing a surgical technique for bicruciate ligament reconstruction with a focus on the double-bundle posterior cruciate ligament (PCL), as described and performed by physicians Dustin Richter, Gehron Treme, and Kate Parker.
These are our disclosures.
In our discussion today, we will review the patient presentation, surgical treatment indications and contraindications, as well as preoperative planning for these difficult multi-ligamentous knee injury cases. We will then show a technique video on bicruciate reconstruction with a focus on the techniques used for double-bundle PCL reconstruction. In the video, we describe an inside-out technique for the femoral portion and transtibial drilling for the tibial. We will discuss pearls and pitfalls, postoperative protocol, and patient outcomes.
Patients presenting with a multi-ligament knee injury can be quite complex. They typically result in injury to both cruciate ligaments with variable injury to the collateral ligament complexes. Most often, they result from a high-energy mechanism, although Azar and colleagues 1 have discussed ultra-low-velocity knee dislocations. They may present either completely dislocated or in a reduced fashion. The clinician treating and evaluating these patients must have a high index of suspicion for this injury especially in the polytrauma patient, to ensure that knee dislocations are not missed. 5
The patient discussed in our video today is an 18-year-old man who was injured during a football game and sent to the Emergency Department for further evaluation. He presented with a large knee effusion, gross laxity with testing of his anterior cruciate ligament (ACL), PCL, and instability to valgus stress at both full extension and 30° of flexion. Varus stress and prone dial test were normal, as was common peroneal nerve function. He had symmetric pulses and his ankle-brachial indices (ABIs) obtained at the time of admission were equal bilaterally. Radiographs demonstrated a reduced knee with no fractures.
Magnetic resonance imaging (MRI) of the knee demonstrates a bicruciate ligament injury. On the coronal view, the medial collateral ligament (MCL) was noted to have an injury at the mid-substance level as well as distally, indicating a Schenck classification KD3M (ACL/PCL/MCL) injury.
Nonoperative treatment is rarely indicated in multi-ligamentous knee injuries; however, patients who have any concern for infection, an open injury with a severely damaged soft tissue envelope, or other co-morbidities may be appropriate nonoperative candidates. 4 Surgical intervention has been shown in several studies to lead to better outcomes than nonoperative management. Most patients with gross laxity and nonfunctional ligaments, with confirmed injury to at least 2 or more injured ligaments, are appropriate candidates for surgical intervention. 3 It is also important the patient can participate in rehabilitation post-operatively to avoid excess scar tissue formation or decreased motion.
In terms of single bundle (SB) versus double bundle (DB) PCL, both techniques have shown good outcomes in the literature. Biomechanical studies show more restraint and less internal rotational laxity with DB recon compared with SB reconstruction, and clinical studies show DB recon patients have significantly improved objective posterior tibial stability and objective International Knee Documentation Committee (IKDC) scores. 7 Ultimately, we believe this choice should be left to the discretion of the treating surgeon.
For preoperative planning, it is important to anatomically repair or reconstruct all injured structures. Whether you use a double-bundle PCL, single-bundle, or how you treat the corner, the surgeon should do what they are most comfortable with doing. An examination under anesthesia as well as an arthroscopic examination is critical to ensure that there are no missed injuries and ensure that all pathology is appropriately treated. On this slide are examples of a KD3M as well as a KD4 injury that we have treated.
It is important to place your preoperative plan on the whiteboard to ensure that no steps are missed. We prefer to take care of all injured ligaments in 1 setting with a single-stage procedure. We also prefer early versus delayed surgery as well as reconstruction as opposed to repair of the injured structures. Several controversies exist regarding single versus staged-reconstruction with collaterals before cruciates, in addition to timing of surgery. However, this discussion is outside the scope of this video.
An important point in this procedure addressing multi-ligamentous injuries is the order in which tunnels are created and grafts fixed. To avoid posterior translation of the tibia in extension, the PCL is tensioned first. Once this is complete, the ACL is fixed with the knee in full extension. Not fully shown in this presentation is how and when the posterolateral corner (PLC) and MCL are addressed when injured. After PCL and ACL fixation is complete, if a PLC injury is present, we then expose the PLC, perform peroneal nerve neurolysis, drill our tunnels but do not yet pass grafts. We then address the medial-sided injury and perform posteromedial corner (PMC) imbrication in full extension, then the superficial MCL graft is tensioned in 30° of flexion. Last, we return to the PLC to pass, tension, and fix the grafts. The PLC is addressed last to avoid excess tibial internal rotation.
Patient positioning involves a standard arthroscopic set-up and positioning with a side post.
Fluoroscopy is not routinely used during this procedure in our practice. Instead, we rely on palpation of bony landmarks. Fluoroscopy or plain radiographs are, however, recommended before leaving the operating room (OR).
In this video, we will demonstrate the reconstruction of a KD3M knee injury sustained after a knee dislocation event. Attention will be given to the double-bundle PCL reconstruction. An Achilles allograft and tibialis anterior allograft will be used. Representative MRI images are here. They show a bicruciate injury and an MCL injury. The grafts are prepared on the back table.
The Achilles allograft is seen here with an 11 mm diameter × 20 mm length bone plug. The anterior tibialis allograft above. Note the tapering of the tibial sides of the graft to ease graft passage. Full length is used. Excess will be removed. The tibial PCL footprint is prepared using a right angle rasp and a finger through a safety incision to protect neurovascular structures and palpate the PCL footprint as seen here. This can be incorporated into the MCL incision in this injury pattern. Care should be taken to expose the PCL footprint down to the bottom of the fovea. Medial and lateral soft tissues should be removed from the bone.
Attention is then turned to creation of the tunnel. The tibia guide is then placed, again with the finger in the safety incision. The guide pin is placed then once in good position and over-reamed with an 11-mm bit until the bit reaches the posterior cortex of the tibia. Once that occurs, the guide pin should be removed and reversed so that the blunt end is placed back into the reamer to further protect neurovascular structures. Power is placed back onto the reamer, the finger is placed back onto the PCL tibia fovea, and completion of reaming is performed. Once that is completed, attention is turned to the ACL.
The ACL femoral socket is created using standard technique through an anteromedial accessory portal and a passing stitch placed. Next, attention is turned to the PCL femoral socket creation. The anterolateral bundle is noted here between the trochlear notch point and medial arch point. The posteromedial bundle is on the wall noted there. An 11-mm bit is then placed at the anterolateral bundle site. Once placed free hand, a guide pin is placed into the center of the reamer. This is then over-reamed to create a 20 to 25 mm deep socket 11 mm in diameter.
Next, the posteromedial bundle is created using a 7-mm drill bit. Again, the bit is placed free hand on the wall of the notch. A guide pin is placed into its center, and the reamer is used to create a 25-mm deep socket. Two passing stitches are placed. A nitinol passer is then used to pass a suture up through the tibial tunnel. This is retrieved into the anteromedial portal and a chamfer passer is then used to chamfer the tibial tunnel. The chamfer passer is then used to pass 2 separately colored sutures. The suture, in this case the blue suture, for the anterolateral graft is then pulled into the anteromedial portal and secured there, so it is not lost during graft passage.
Next, the posteromedial bundle suture from the femur and tibia are grasped at the same time and pulled into the anterolateral portal. The graft is passed into the femur and then pulled down into the tibia. The graft is fixed on the femoral side with a 7 × 23 mm polyetheretherketone (PEEK) interference screw, securing the graft on the femoral side. Attention is then turned to the anterolateral graft. The suture is pulled back into the knee. Both the tibial-sided and femoral-sided sutures are grasped at the same time and pulled into the anterolateral portal. The Achilles graft is then passed through this portal and into the anterolateral socket.
Once the bone plug is in place, the tibial side of the graft is passed. This ensures that the graft will pass and give better visualization for screw placement. A guide wire is placed and then a 7 × 20 mm metal interference screw is used to secure the graft on the femoral side. This completes femoral-sided graft fixation for the PCL grafts. Attention is then turned to passage of the ACL graft. The tibial tunnel is created, and then the graft is passed using standard technique with a tensionable button shown here. The final femoral fixation with grafts in the knee is shown here. Attention is then turned to tibial-sided fixation. The anterolateral bundle will first be fixed on the tibial side. It is fixed with a 4.5-mm cortical screw with spiked washer. The graft is split with a knife, and the screw is placed within the split and into the tibia. The graft is tensioned and the knee placed at 90° of flexion. Next, the posteromedial bundle is fixed with a 12 × 28 mm PEEK interference screw with the knee in full extension.
X-rays here are of the completed reconstruction.
Some of the pearls to ensure optimal outcomes and efficient surgical technique include operating on patients once they have good range of motion as well as minimal knee effusion. We also suggest considering the use of tranexamic acid to limit bleeding, and judicious use of a tourniquet. At our institution for 3- and 4-ligament knees, we routinely use 2 surgeons, which can help with both graft preparation as well as more efficient arthroscopy and ligament reconstruction. Writing out the preoperative plan as demonstrated earlier, a safety incision on the medial aspect of the proximal tibia allows palpation of the mammillary bodies to ensure anatomic reconstruction while protecting the neurovascular structures during PCL tibia drilling. This also allows egress of arthroscopic fluid. Passing the PCL grafts into the femoral sockets then down through the tibial tunnel prior to fixation ensures smooth passage, and tapering the tibial ends of the graft also eases passage into the tibial tunnel.
In terms of avoiding tunnel convergence, the tunnels most at risk are the ACL femoral tunnel and the lateral collateral ligament (LCL) femoral tunnel for the PLC or the MCL femoral tunnel. To avoid convergence, we recommend aiming 30° anterior and 30° proximal when making the femoral PLC tunnel as well as the MCL tunnel. The DB PCL does not affect our reconstruction, as fixation occurs through sockets.
Postoperative rehabilitation includes touch-down weight bearing for 6 weeks. Bracing with a posterior Jack or standard range of motion (ROM) brace is typically done for up to 3 months. The first 2 weeks after surgery, the patient is locked in extension, and gradually the brace is advanced to full range of motion. If at 3 months the patient demonstrates good stability and range of motion, straight-line jogging is initiated. Return to sport occurs at least 9 to 12 months post operation.
Clinical outcomes reported in the literature describe similar results. This is a 2017 systematic review of 11 studies looking at single-bundle versus double-bundle PCL reconstruction. It involved 3 randomized control studies. Both single-bundle and double-bundle techniques showed improved patient-reported outcomes as well as knee stability. Double-bundle PCL reconstruction did provide significant improved objective posterior tibial stability and objective IKDC scores. 2
Double-bundle PCL reconstruction was shown to more closely approximate the native knee mechanics and kinematics as well. This is a biomechanical study comparing single-bundle versus double-bundle PCL reconstruction. In this study, there was more restraint to posterior translation at almost all knee flexion angles between 15° and 120°. Also, less internal rotation laxity was noted in the double-bundle PCL group at the higher flexion angles of 90° to 120°. 6
These are our references, and thank you for your attention.
Footnotes
Submitted February 1, 2023; accepted May 1, 2023.
The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
