Posterior Cruciate Ligament Tunnel Research Articles

Knee Multiligament Reconstruction: ACL / PCL / MCL

Background: Multiligament knee injury (MLKI) is a rare, complex injury that requires surgical intervention. However, there is a lack of consensus regarding optimal timing, staging, and graft choice for ligament reconstruction. Indications: Delayed, single-stage reconstruction offers the advantage of attaining improved preoperative range of motion and potential healing of extra-articular ligaments and may be necessary in the setting of multitrauma. Technique Description: A hamstring graft was harvested and diagnostic arthroscopy performed. Three posterior portals were made for posterior cruciate ligament (PCL) reconstruction. Femoral and tibial pins were placed for both PCL and anterior cruciate ligament (ACL) tunnels, positions confirmed with fluoroscopy, and tunnels drilled over the pins. The Achilles allograft was shuttled through the femoral and tibial PCL tunnels in anterograde fashion and fixed with a metal interference screw on the femoral side. The hamstring autograft was passed through the ACL tunnels and suspended on the femoral side. Tibial fixation of both grafts was achieved with biocomposite interference. Medial collateral ligament reconstruction was performed through the medial incision from hamstring harvesting. The semitendinosis allograft was passed and fixed with screws and spiked washers. Fluoroscopy confirmed that screw trajectory did not interfere with the ACL or PCL tunnels. Results: Bagherifard et al reported a study of 41 consecutive patients with MLKI who underwent single-stage reconstruction with autograft and/or allograft. Mean postoperative Lysholm and International Knee Documentation Committee (IKDC) scores were 86.9 and 70, respectively, and only 7 patients experienced restricted range of motion. Billieres et al reported a study of 23 patients with MLKIs who underwent single-stage reconstruction with allograft only. Mean postoperative Lysholm and IKDC scores were 77.3 and 67.2, respectively, and 19 patients returned to sport. Goyal et al reported a study of 27 patients with MLKI who underwent single-stage reconstruction greater than 6 weeks after injury. At 2 years, there were significant improvements in Visual Analog Scale, IKDC, and Lysholm scores, and no patients had residual laxity of the knee joint. Discussion/Conclusion: Single-stage reconstruction of MLKIs is an effective intervention that has been supported in literature; however, further studies are necessary to determine optimal surgical timing and graft type. 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.

Paper 17: Optimal Tibial Tunnel Placement for Medial and Lateral Meniscal Root Repair in the Setting of Multiligament Reconstructions of the Knee

Objectives:Although the risk of tibial tunnel convergence in the setting of multiligament reconstruction has been reported in the literature, the risk of tunnel convergence in the setting of posterior cruciate ligament (PCL), anterior cruciate ligament (ACL), and medial and lateral meniscal root repair has not been defined. The purpose of this study was to examine the risk of tunnel convergence and to determine optimal tunnel placement for ACL and PCL reconstruction performed in conjunction with posterior medial and lateral meniscal root repairs in the proximal tibia.Methods:Three-dimensional tibial models were created using computed tomography scans of twenty cadaveric specimens. After determining optimal tunnel entry and exit points for ACL and PCL reconstructions, and medial and lateral meniscal root repair on the models, Mimics software was used to create root tunnels. The meniscal root repair tunnels were then re-oriented to be parallel to the ACL tunnel. The initial and re-oriented configurations are illustrated in Figure 1. Tunnel convergence risk was analyzed with single and double tunnel techniques in both case scenarios.Results:There were no cases of convergence between the ACL and medial meniscal root tunnels in any of the configurations. The greatest distance between the tunnels was achieved with the single tunnel technique in parallel orientation (12.09 ± 2.78 mm). All specimens demonstrated convergence between the ACL and lateral meniscal root tunnels when the sagittal plane entry was not taken into consideration and only the anatomic root attachment was accounted for, for single and double tunnel techniques, but no convergence was seen between these tunnels with the parallel orientation in the sagittal plane. Figure 2 illustrates the reduction in the convergence risk when the meniscal root tunnels are reoriented as parallel to the ACL tunnel. There were no cases of convergence between the PCL and medial meniscal root tunnels in the original orientation, but 2/20 specimens demonstrated convergence in the parallel orientation with the double tunnel technique and no cases of convergence in the single tunnel technique. The PCL and lateral meniscal root tunnels did not demonstrate convergence in any configuration. Table 1 demonstrates the mean, minimum and maximum distances of each tunnel configuration as well as the number of cases where the distance between tunnels was <2mm. A summary of the preferred tunnel configurations for each setting, ranked by greatest tunnel distance conferred and cases of convergence, is reported in Table 2.Conclusions:There is a high risk of convergence between ACL and posterior meniscus root tunnels. Re-orienting meniscal root tunnels parallel to ACL tunnels may help reduce this risk. When PCL reconstruction is performed with ACL reconstruction and medial and lateral meniscal root repair, the single tunnel root repair technique may pose less risk over the double tunnel technique to prevent tunnel convergence between the meniscal root repair and PCL tunnels in the tibia.Figure 1. Illustration of the reconstruction of the tunnels. (A) Initial orientation where the meniscal root tunnels’ entry points on the anteromedial aspect of the tibia were created above the ACL tunnel. (B) The meniscal root tunnels re-orientated and were placed parallel to that of the ACL and aimed to exit at the anatomic attachment of the posterior roots of the meniscus. (Gold guide for the creation of the ACL tunnel and silver guide for the creation of the meniscal root tunnel)

Optimal Tibial Tunnel Placement for Medial and Lateral Meniscus Root Repair on the Anteromedial Tibia in the Setting of Anterior and Posterior Cruciate Ligament Reconstruction of the Knee

Background: Although the risk of tibial tunnel convergence in the setting of multiligamentous reconstruction has been reported in the literature, the risk of tunnel convergence in the setting of posterior cruciate ligament (PCL), anterior cruciate ligament (ACL) reconstruction and medial and lateral meniscus root repair has not been defined. Purpose: To examine the risk of tunnel convergence and to determine optimal tunnel placement for ACL and PCL reconstruction performed in conjunction with posterior medial and lateral meniscus root repairs on the anteromedial proximal tibia. Study Design: Descriptive laboratory study. Methods: Three-dimensional (3D) tibial models were created using computed tomography scans of 20 cadaveric specimens. After determining optimal tunnel entry and exit points for ACL and PCL reconstructions, and medial and lateral meniscus root reattachment to the anatomic footprints, we used image processing software to create root tunnels over the anteromedial tibia on the tibial models. ACL and PCL tunnels were kept constant. The meniscus root repair tunnels were then reoriented to match the angle of the ACL tunnel, making both tunnels parallel in the sagittal plane. Tunnel convergence risk was analyzed by identifying the shortest 3D distance between tunnel axes and subtracting the radius of each tunnel from this distance for single- and double-tunnel repair techniques in both case scenarios. Results: All specimens demonstrated convergence between the ACL and lateral meniscus root tunnels when the root tunnel’s entry was created proximal to the ACL tunnel’s entry for single- and double-tunnel techniques, but no convergence was seen between these tunnels using the parallel orientation in the sagittal plane. There were no cases of convergence between the ACL and medial meniscus root tunnels in any of the configurations. The greatest distance between the ACL and medial meniscus root tunnels was achieved using the single-tunnel technique in parallel orientation (12.1 ± 2.8 mm). There were no cases of convergence between the PCL and medial meniscus root tunnels in the original orientation; however, 2 of 20 specimens demonstrated convergence using the parallel orientation with the double-tunnel technique, and there were no cases of convergence using the single-tunnel technique. The PCL and lateral meniscus root tunnels did not demonstrate convergence in any configuration. Conclusion: There was a high risk of convergence between ACL and posterior meniscus root tunnels when all the tunnels were created on the anteromedial tibia. Reorienting meniscus root tunnels parallel to ACL tunnels may help reduce this risk. There is increased risk of tunnel convergence with root repairs in cases of bicruciate reconstructions, and therefore a double-tunnel root repair technique should be used with caution. Clinical Relevance: To avoid tibial tunnel convergence when performing ACL and PCL reconstruction with medial and lateral meniscus root repair, surgeons should reorient the meniscus root repair tunnels to be parallel on the sagittal plane to the ACL tunnel to decrease the risk of convergence. In cases of bicruciate ligament reconstruction, use of the double-tunnel technique requires caution to avoid convergence risk with the PCL tunnel.

Stay Ipsilateral: An Analysis of Tibial Tunnel Distance Between Cruciate Ligament Reconstruction and Posterior Meniscal Root Repair

PurposeTo establish mean distance or identify intersection between tibial tunnels for posterior meniscal root repair in the setting of anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) reconstruction.MethodsTwelve cadaver knees and 12 solid foam synthetic tibiae were used. ACL and PCL tunnels were drilled for single-bundle reconstruction, and both medial and lateral posterior root repair tunnels were drilled. Specimens underwent computed tomography scanning and shortest distances between tunnels in all planes were measured by 2 readers. Distances were compared between groups using a t-test.ResultsIn ACL reconstruction, the medial meniscal root tunnel was not significantly closer to the cruciate tunnel when drilled from either medial or lateral side (P = .333). The lateral meniscal root tunnel was significantly closer when drilled from medial compared to lateral side (P < .001). In PCL reconstruction, both medial (P = .037) and lateral (P = .028) meniscal root tunnels were significantly closer to the PCL tunnel when drilled from the contralateral side of the tibia.ConclusionThis study demonstrates that posterior meniscal root repair tunnels are often placed within a few millimeters and can even intersect cruciate ligament reconstruction tunnels in the proximal tibia.Clinical RelevanceThe information in this study may assist surgeons in planning for cruciate ligament reconstruction with concomitant posterior meniscal root repair.

Multiple Ligament Reconstruction Femoral Tunnels: Intertunnel Relationships and Guidelines to Avoid Convergence

Background: Knee dislocations often require multiple concurrent ligament reconstructions, which involve creating several tunnels in the distal femur. Therefore, the risk of tunnel convergence is increased because of the limited bone volume within the distal aspect of the femur. Purpose: To assess the risk of tunnel convergence and determine the optimal reconstruction tunnel orientations for multiple ligament reconstructions in the femur. Study Design: Descriptive laboratory study. Methods: Three-dimensional knee models were developed from computed tomography scans of 21 patients. Medical image processing software was used to create tunnels for each of the primary ligamentous structures, replicating a surgical approach that would be used in multiple ligament reconstructions. Thereafter, the tunnel orientation was varied in surgically relevant directions to determine orientations that minimized the risk of tunnel convergence. The orientation of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tunnels was held constant throughout the study, while the orientation of the fibular collateral ligament (FCL), popliteus tendon (PLT), superficial medial collateral ligament (sMCL), and posterior oblique ligament (POL) tunnels was varied to avoid convergence. Results: A high risk of tunnel convergence was observed between the FCL and ACL tunnels when the FCL tunnel was aimed at 0° in the axial and coronal planes. Aiming the FCL tunnel 35° anteriorly minimized convergence with the ACL tunnel. No tunnel convergence was observed for the PLT tunnel aimed 35° anteriorly and parallel to the FCL tunnel. To avoid convergence between the sMCL and PCL tunnels, the sMCL tunnels should be aimed 40° proximally in the coronal plane and 20° to 40° anteriorly. During concomitant POL reconstruction, the sMCL should be aimed 40° proximally and anteriorly and the POL 20° proximally and anteriorly. The PLT and POL tunnels aimed at 0° in both the coronal and axial planes had an increased risk of violating the intercondylar notch. Conclusion: Femoral tunnel orientations during multiple ligament reconstructions need to be adjusted to avoid tunnel convergence. On the lateral side, aiming the FCL and PLT tunnels 35° anteriorly eliminated convergence with the ACL tunnel. On the medial side, tunnel convergence was avoided by orienting the sMCL tunnel 40° proximally and anteriorly and the POL tunnel 20° proximally and anteriorly. The POL and PLT tunnels aimed at 0° in the axial plane had an increased risk of violating the intercondylar notch. Clinical Relevance: The risk of tunnel convergence with the ACL and PCL femoral tunnels can be reduced by adjusting the orientation of the FCL and PLT tunnels and the sMCL and POL tunnels, respectively.

MRI analysis of tibial PCL attachment in a large population of adult patients: reference data for anatomic PCL reconstruction.

BackgroundConsistent reference data used for anatomic posterior cruciate ligament (PCL) reconstruction is not well defined. Quantitative guidelines defining the location of PCL attachment would aid in performing anatomic PCL reconstruction. The purpose was to characterize anatomic parameters of the PCL tibial attachment based on magnetic resonance imaging (MRI) in a large population of adult knees.MethodsThe PCL tibial attachment site was examined in 736 adult knees with an intact PCL using 3.0-T proton density–weighted sagittal MRI. The outcomes measured were the anterior-posterior diameter (APD) of the tibial plateau; angle between the tibial plateau and the posterior tibial ‘shelf’ (the slope where the PCL tibial attachment site was) (PTS); length of the PTS; proximal, central, and distal PCL attachment positions as well as the width of the PCL attachment site; and vertical dimension of the PCL attachment site inferior from the tibial plateau.ResultsThe average APD of the tibia plateau was 33.6 ± 3.5 mm, yielding significant differences between males (35.5 ± 3.0 mm) and females (31.6 ± 2.7 mm), P <.05, and there was a significantly decreasing trend with increasing age in males (P <.05). Mean angle between the tibial plateau and the PTS was 122.4° ± 8.1°, and subgroup analysis showed that the young group had a differently smaller angle (120.9° ± 7.5°) than the middle-aged (123.7° ± 8.2°) and the old (123.4° ± 7.7°) in males population, while there were no significant differences between sexes (P >.05). The proximal, central positions and width of the PCL attachment site were 13.4 ± 3.0 mm, 17.8 ± 3.0 mm and 9.6 ± 2.4 mm along the PTS, with significant differences between males and females (P <.05), and accounted for 60.0 % ± 9.1 %, 80.0 % ± 4.6 % and 43.3 % ± 9.7 % of the PTS respectively, with no significant differences between sexes and among age groups (all P >.05).ConclusionsThis study provides reference data of the tibial PCL attachment based on MRI in the sagittal orientation. In analysis of retrospective data from a large population of adult patients, the quantitative values can be used as references to define the inserted angle and depth of the drill guide, and the exact position and size of the tibial PCL tunnel for performing arthroscopic anatomic PCL reconstruction.

Intertunnel Relationships in the Tibia During Reconstruction of Multiple Knee Ligaments

Background: Knee dislocations are rare but potentially devastating injuries, often involving tears of multiple knee ligaments. Several studies have reported improved clinical and functional outcomes with surgical management of torn knee ligaments compared with nonsurgical management. Most multiple ligament reconstruction techniques involve creating several tunnels for various reconstruction grafts, posing a risk of tunnel convergence in the proximal tibia. Purpose: To assess the risk of tunnel convergence and determine the optimal tunnel placement for the reconstruction of multiple ligaments in the tibia. Study Design: Descriptive laboratory study. Methods: Three-dimensional knee models were developed using customized software from computed tomography images of 21 patients. Mimics software was used to create tunnels for each of the 4 primary ligamentous structures, replicating a surgical approach that would be used in actual multiple ligament reconstruction surgery. The tunnel orientation was varied in anatomically relevant directions to find orientations that did not result in tunnel convergence. Results: There was a high risk of tunnel convergence (66.7%) between the posterior cruciate ligament (PCL) and posterior oblique ligament (POL) tunnels when the POL tunnel was aimed toward the Gerdy tubercle as suggested in the literature. No tunnel convergence was observed when the POL tunnel was aimed 15 mm medial to the Gerdy tubercle. No tunnel convergence was observed between the anterior cruciate ligament (ACL) and POL. Tunnel convergence was observed between the PCL and superficial medial collateral ligament (sMCL) in 19.0% of cases when the sMCL tunnel was aimed transversely across the tibia. Aiming the sMCL tunnel transversely and directing 30° distally significantly increased the mean distance between the sMCL and PCL to 6.9 mm (P < .001), and no tunnel convergence was observed. No tunnel convergence was observed between the PCL and posterolateral corner tunnels or between the ACL and PCL tunnels. Conclusion: There is a high risk of tunnel convergence in the proximal tibia during the reconstruction of multiple knee ligaments. Aiming the POL tunnel 15 mm medial to the Gerdy tubercle and the sMCL tunnel transversely across the tibia (anterior to the fibula) and 30° distal to the horizontal plane reduces the risk of tunnel convergence. Clinical Relevance: The tunnel orientation of the POL and sMCL on the tibia should be adjusted to avoid convergence with the PCL tunnel during multiple ligament knee reconstruction.

Femoral Tunnel Drilling Angles for Posteromedial Corner Reconstructions of the Knee

To determine the best angle to drill the femoral tunnels of the superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL) with concomitant posterior cruciate ligament (PCL) reconstruction to avoid either short tunnels or tunnel collisions. Eight cadaveric knees were studied. Double-bundle PCL femoral tunnels were arthroscopically drilled. Drilling of the sMCL and POL tunnels was performed in 4 different combinations of 0° and 30° axial (anteriorly directed) and coronal (proximally directed) angulations. Specimens were scanned with computed tomography to document the relations of the sMCL and POL tunnels to the intercondylar notch and PCL tunnels. A minimum tunnel length of 25 mm was required. When the sMCL femoral tunnel was drilled at 0° axial and 30° coronal (proximally directed) angulations or 30° axial (anteriorly directed) and 0° coronal angulations, the risk of tunnel collision with the PCL tunnels increased in comparison with the remaining evaluated angulations (P < .001). No POL tunnels collided with either PCL tunnel bundle with the exception of tunnels drilled at 0° axial and 30° coronal (proximally directed) angulations, which did so in 3 of 8 cases (P < .001). The minimum required tunnel length was obtained in all the sMCL and POL tunnels (P < .001 and P = .02, respectively). However, some of those angled at 0° on the axial plane violated the intercondylar notch. When one is performing posteromedial reconstructions with concomitant PCL procedures, the sMCL and POL femoral tunnels should be drilled anteriorly and proximally at both 30° axial and 30° coronal angulations. The POL femoral tunnel may also be angled 0° in the coronal plane. Tunnels at 0° axial angulations showed a shorter distance to the intercondylar notch and a higher risk of collision with the PCL tunnels. Specific drilling angles are necessary to avoid short tunnels or collisions between the drilled tunnels when sMCL and POL femoral tunnels are placed with concomitant PCL reconstruction.

Right angle to make posteromedial corner tunnels with concomitant posterior cruciate ligament reconstruction. CT evaluation in a cadaveric model

Introduction:The surface medial collateral ligament (LCMs) and the posterior oblique ligament (POL) are sometimes concomitantly reconstructed with the posterior cruciate ligament (PCL). The objective was to determine the most appropriate angle of the femoral tunnel.Material and Methods:8 cadaveric knees. Bifascicular LCP tunneling performed arthroscopically. Tunnels LCMs and LOP at 0 ° and 30 ° in axial / coronal planes (0A / 30A // 0C / 0C). Were studied by CT and valued intercondylar relationship, PCL ,and tunnels. A 25mm tunnel was the least considered sufficientResults:The LCMs tunnels 30A / 30C and 30A / 0C measured 31.8 ± 3.2 and 32.2 ± 2.8 mm, respectively, without encroaching on the LCP and 17.4 ± 4 and 17.67 ± 3.8mm intercondylar ceiling. The LCMs 0A / 0C and 0A / 30C tunnels were 5.8 ± 5.2 and 7.2 ± 4.7 of intercondilo respectively, without invasion of the PCL. The LCMs tunnels 0A / 30C in 4 cases ended intraarticulararmente. The LOP 30A / 0C and 30A / 30C measured 33 ± 2.7 and 32.3 ± 3mm, without invasion of the PCL and 16.2 ± 5.7 and 19.3 ± 4.6mm of intercondilo. The LOP 0A / 0C and 0A / 30C tunnels were 6.50 ± 3.9 and 2.9 ± 5.3mm of intercondilo. The LOP tunneled 0A / 30C invaded in 3 cases the PCL tunnels and ended intraarticularly on 7 occasions.Conclusions:The angulation of the femoral tunnels LCMs and POL have versatility although the LCP is rebuild concomitantly. LCMs tunnels and POL axially oriented at 0° and 30° in coronal planes have high risk of puncturing the joint and in the case of POL also invade LCP tunnels.

How to avoid collision between PCL and MCL femoral tunnels during a simultaneous reconstruction.

The purpose of the present study was to assess the risk of femoral tunnel collisions between the medial collateral ligament (MCL) and the posterior cruciate ligament (PCL) tunnels during a simultaneous PCL and MCL reconstruction. Fourth generation medium and large synthetic femur bones were used. On each femur, a MCL tunnel and a PCL tunnel were reamed. The MCL tunnel was drilled at 0°, 20° and 40° of axial and coronal angulations. The PCL femoral tunnel was reamed to simulate two different tunnel directions that could be obtained through an inside-out and outside-in technique. Tunnels were filledwith epoxy resin augmented with BaSO4, and a multidetector CT examination of each specimen was performed. High rate of tunnel collision (62.5%) was found when the MCL femoral tunnel was reamed with a coronal angulation of 0° and 20°. The rate of tunnel collision significantly decreased (0%) when the MCL tunnel was reamed proximally with a coronal angulation of 40°. No differences were found between the two PCL tunnel directions in terms of tunnel collision. The results of this study can help surgeons to better direct the femoral MCL tunnel in order to avoid a collision between femoral tunnels during a combined MCL and PCL reconstruction. In order to minimize such potential complications, the MCL tunnel should be created limiting the axial angulation and it should be drilled with a proximal angulation from 20° to 40°, depending on the medial condyle width.

Consequences of Tibial Tunnel Reaming on the Meniscal Roots During Cruciate Ligament Reconstruction in a Cadaveric Model, Part 2

Background: Recent emphasis has turned to reconstructing the posterior cruciate ligament (PCL) after injury. However, single-bundle PCL reconstruction of the anterolateral bundle may potentially injure the posterior meniscal roots. Purpose/Hypothesis: The purpose of this study was to determine if posterior meniscal root injuries occurred because of tunnel reaming for single-bundle PCL reconstruction. It was hypothesized that tibial tunnel reaming within the anterolateral bundle footprint during PCL reconstruction would result in clinically significant decreases in posteromedial (PM) root attachment areas and in ultimate failure strength for the PM root. Study Design: Controlled laboratory study. Methods: Testing was performed on 12 matched pairs of human cadaveric knees. For each pair of knees, one knee was left intact, while the contralateral knee was prepared with a tibial tunnel placed 5 mm anterior to the center of the tibial PCL attachment and within the previously described footprint of the anterolateral bundle of the PCL for single-bundle PCL reconstruction. The attachment areas of the posterior meniscal roots were measured with a coordinate measuring device before and after PCL tunnel reaming. The posterior meniscal roots were then pulled to failure with a dynamic tensile testing machine. Results: There was a significant mean decrease in the attachment area of the PM root (%Δ, 28%; 95% CI, 16-40) after PCL tunnel reaming compared with the intact state (P = .005). The mean ultimate failure strength of the native PM root (mean, 440 N; 95% CI, 347-534) was also significantly stronger (mean, 40%; 95% CI, 18-61; P = .005) than that of the PM root after PCL tunnel reaming (mean, 243 N; 95% CI, 176-309). No changes were found for the posterolateral (PL) root after PCL tunnel reaming. Conclusion: Tibial tunnel reaming for single-bundle PCL reconstruction in the anterolateral bundle footprint significantly reduced the ultimate failure strength and attachment area of the PM meniscal root. The attachment area and ultimate failure strength of the PL root were unaffected by tunnel reaming. Clinical Relevance: Tibial tunnels reamed in the footprint of the anterolateral bundle during single-bundle PCL reconstruction can cause iatrogenic damage to the PM meniscal root attachment. Thus, tibial tunnels should strive to be reamed in the center of the entire tibial PCL attachment site during PCL reconstruction.

Femoral Tunnel Drilling Angles for the Posterolateral Corner in Multiligamentary Knee Reconstructions: Computed Tomography Evaluation in a Cadaveric Model

The goal of this study was to determine the best angle at which to drill the femoral tunnels of the popliteus tendon (PT) and fibular collateral ligament (FCL) in combined reconstructive procedures so as to avoid either short tunnels or tunnel collisions with the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) femoral tunnels. Eight cadaveric knees were studied. ACL/PCL femoral tunnels were arthroscopically drilled. PT and FCL tunnels were drilled at 0° and 30° axial and coronal angulations. They were scanned by computed tomography todocument relations of the PT and FCL tunnels to the intercondylar notch and ACL/PCL tunnels. A minimum tunnel length of 25 mm was required. Drilling the PT tunnel at 0° axial angulation was associated with an increased risk of tunnel collision with the ACL (P < .001). Interference with the PCL tunnel can be avoided only if the K-wire guiding the PT tunnel is drilled with 30° coronal angulations (P < .001). The minimum tunnel length of the PT could be obtained only with both axial and coronal angulations of 30° (P= .003). Sufficient tunnel lengths of the FCL were obtained at all angulations evaluated (P= .036). However, only the tunnels drilled at 30° axial and 0° coronal angulations did not collapse with the ACL tunnels (P < .001). No intersections between FCL and PT tunnels were observed. When posterolateral reconstructions are performed in combination with concomitant anterior and posterior cruciate procedures, PT tunnels should be drilled at 30° axial and 30° coronal angulations. FCL tunnels should be drilled at 30° axial and 0° coronal angulations. These angulations should minimize such potential complications as short tunnels or collisions with the ACL/PCL tunnels. Specific drilling angles are necessary to avoid short tunnels or collisions between the drilled tunnels when FCL and PT femoral tunnels are performed in multiligament knee reconstructions.

Arthroscopically Pertinent Anatomy of the Anterolateral and Posteromedial Bundles of the Posterior Cruciate Ligament

The clock-face method to identify the femoral posterior cruciate ligament (PCL) attachment has poor accuracy and reproducibility. Measurements of clinically relevant anatomic structures would provide more useful surgical guidance. The purpose of the present study was to describe the attachments of the anterolateral and posteromedial bundles of the PCL relative to relevant landmarks to assist with arthroscopic anatomic PCL reconstructions. Dissections were performed on twenty nonpaired fresh-frozen cadaveric knees. The distal articular cartilage margin of the intercondylar notch had a consistent shape conforming to the attachments of the anterolateral and posteromedial bundles. The mean distance (and standard deviation) between the femoral centers of the anterolateral and posteromedial bundles was 12.1 ± 1.3 mm. The distal margins of the anterolateral and posteromedial bundles were a mean of 1.5 ± 0.8 mm and 5.8 ± 1.7 mm proximal to the notch articular cartilage, respectively. On the tibia, the lateral plateau articular cartilage, the medial meniscus attachment, and an osseous ridge ("bundle ridge") separating the anterolateral and posteromedial bundles were important arthroscopic landmarks. The mean distance between the tibial centers of the anterolateral and posteromedial bundles was 8.9 ± 1.2 mm. The pertinent landmarks identified during arthroscopic PCL reconstruction consistently marked the borders of the attachments of the anterolateral and posteromedial bundles. To guide femoral tunnel placement, the centers of both bundles should be triangulated relative to the reported landmarks. Furthermore, the distal edge of the femoral anterolateral bundle should be placed adjacent to the articular cartilage, whereas the posteromedial bundle should be centered, on average, 8.6 mm proximal to the cartilage margin, just distal to the medial intercondylar ridge. On the tibia, the PCL tunnel should be placed just anterosuperior to the bundle ridge, with use of the lateral articular cartilage and medial meniscus attachment to guide placement. The results of the present study can assist with more anatomic tunnel placement during single and double-bundle PCL reconstructions. The results also suggest that two reconstruction tunnels are needed to reconstruct the broad femoral attachment, whereas one reconstruction tunnel should be investigated further for the compact tibial attachment.

Tunnel position following posterior cruciate ligament reconstruction: An in vivo computed tomography analysis

The success of posterior cruciate ligament (PCL) reconstruction is dependent on appropriate tunnel placement. Computed tomography (CT) provides detailed images of intra-articular osseous anatomy. The objective of this study was to analyze by CT the position of femoral and tibial tunnels relative to intra-operative goals following arthroscopic-assisted PCL reconstruction. Nineteen patients who underwent single-bundle PCL reconstruction were evaluated 16months post-operatively. Each underwent a CT scan and tunnel locations were identified in the coronal, sagittal, and axial planes. The coronal plane tibial tunnel location was within 5mm of the intra-operative goal (48% of the total tibial plateau width from the medial border of the plateau) in 16 patients (84%). The sagittal plane tibial tunnel location was within 5mm of the intra-operative goal (the middle of the posterior half of the retrospinal surface) in 14 patients (74%). In the sagittal plane, the femoral tunnel location was within 5mm of the intra-operative goal (10mm from in the distal articular margin of the medial femoral condyle) in 15 patients (79%). In the notch, the femoral tunnel was between 10:30 and 11:30 for left knees or between 12:30 and 1:30 for right knees (the intra-operative goal was 11 o'clock for left knees and 1 o'clock for right knees) in 18 patients (95%). Arthroscopic PCL reconstruction results in tunnel positions near intra-operative goals. Further work is necessary to define CT-specific criteria for the assessment of PCL tunnel position.

Antegrade Tibial Tunnel Technique for Posterior Cruciate Ligament Reconstruction

Posterior cruciate ligament (PCL) reconstruction remains a difficult procedure even in experienced hands0 because there is a lack of consensus regarding the most reliable and least technically challenging technique. The commonly used retrograde anteromedial tibial tunnel leads to excessive angulation at the posterior tibia and risks catastrophic neurovascular complications. We present a technique of drilling the transtibial PCL tunnel in an antegrade fashion through a posteromedial portal. This technique offers the advantage of an anterolateral route to reduce graft angulation, as well as drilling away from the important posterior neurovascular structures.

Single–Achilles Allograft Posterior Cruciate Ligament and Medial Collateral Ligament Reconstruction: A Technique to Avoid Osseous Tunnel Intersection, Improve Construct Stiffness, and Save on Allograft Utilization

We present a method for single–Achilles allograft medial collateral ligament (MCL) and posterior cruciate ligament (PCL) reconstruction that eliminates the risk of tunnel intersection, stiffens the construct, and maximizes utilization of allograft tissue. An Achilles tendon allograft is prepared with an 11- to 12-mm bone plug with a gradual taper to 7 mm over approximately 15 cm. A transtibial PCL tunnel is created under fluoroscopic and arthroscopic guidance. The femoral tunnel is prepared in an “outside-in” fashion under direct arthroscopic visualization, originating at the anatomic origin of the MCL on the medial epicondyle and entering the joint at the anatomic origin of the anterolateral bundle of the PCL. The Achilles graft is pulled into the joint through the tibial tunnel and routed into the femoral tunnel so that the soft tissue exits at the medial epicondyle. The bone plug is fluoroscopically guided to the posterior aperture of the tibial tunnel and fixed with a bioabsorbable interference screw. The pretensioned graft is fixed in the femoral tunnel via interference screw fixation with the knee in 90° of flexion. The isometric position of the MCL insertion is identified with a K-wire isometer, and the graft is fixed in place at this point by use of an interference screw or screw and washer.

An accessory portal for posterior cruciate ligament tibial insertion visualization.

Posterior cruciate ligament (PCL) reconstruction is infrequently performed, technically challenging, and has less predictable results compared with its anterior cruciate ligament (ACL) counterpart. Creation of a transtibial tunnel has been associated with catastrophic neurovascular complications, as well as tunnel malpositioning. This technical note reports the use of the femoral PCL tunnel to visually access the posterior slope for tibial tunnel creation. This technique modification allows concurrent placement of instruments through an inferomedial and/or posteromedial portal to facilitate PCL insertional debridement, placement of the tibial aimer, and creation of the tunnel. We feel that this technical modification provides superior visualization of this anatomic area.

Radiographic analysis of femoral tunnel position in postoperative posterior cruciate ligament reconstruction

Purpose: The purpose of this study was to test the hypothesis that plain radiographs are accurate in assessing femoral tunnel positions in posterior cruciate ligament (PCL) reconstruction. Type of Study: Cadaveric study. Methods: Femoral tunnels were drilled in cadaveric distal femurs using standard techniques at the 12 o'clock, 1:30, and 3 o'clock positions in the left femora and at the 12 o'clock, 10:30, and 9 o'clock positions in the right femora. At each of the three positions, a 9-mm tunnel was drilled with its anterior edge 2 mm posterior to the articular surface of the medial femoral condyle (MFC). Posterior or “malpositioned” tunnels were drilled with the anterior edge 11 mm posterior to the articular surface of the MFC. Four radiographs; a true lateral, a 10° externally rotated lateral, a 10° internally rotated film in the sagittal plane, and an anteroposterior (AP) radiograph were then taken of each tunnel with a radiopaque dilator in the tunnel. All radiographs were analyzed with the 4-quadrant method (4 is the posterior quadrant) and the ratio method (0 is anterior and 1 is posterior). The AP radiograph was measured using a new technique, the intersection of the angle of a line through the center of the femoral tunnel and a line placed tangential to the femoral condyles. Results: Means were calculated for each of the 6 tunnel positions on the 4 radiographs (lateral, external rotation, internal rotation, and AP). Of the 15 comparisons among tunnel postions, 13 could be discriminated using the lateral and AP radiographs. The high-anterior (HA) (12 o'clock position) could not be differentiated on any radiograph from the high-posterior (HP) (12 o'clock position). The internally rotated lateral radiograph could discriminate the midanterior (MA) (1:30 and 10:30 positions) from the low-anterior (LA) (the 3 and 9 o'clock positions). Conclusions: Three radiographs; the AP, lateral, and internally rotated lateral, can be used to detect a significant difference in the majority of tunnel locations. The tunnel positions that could not be differentiated with these measurements were posterior and may not be clinically important. We concluded that a plain radiograph is an accurate indicator of PCL tunnel position.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 7 (September), 2002: pp 688–694