Anterior Cruciate Ligament Tunnel Research Articles

Combined ACL and Anterolateral Ligament Reconstruction Using an Adjustable-Loop Fixation Device: Surgical Technique

Background: There are several techniques for the combined reconstruction of the anterior cruciate ligament (ACL) and the anterolateral ligament (ALL), but none have shown superiority. This study aims to present a surgical technique that theoretically reduces some of the risks reported in these procedures. Indications: The main indications for the ALL reconstruction include chronic ACL injuries, revision ACL reconstruction, acute ACL injuries in patients with high-grade pivot-shift (grades 2 or 3), patients involved in pivoting sports, and generalized ligament hyperlaxity or knee hyperextension. Technique Description: Hamstring tendon autografts are used for the ACL and ALL reconstruction; a common femoral ACL and ALL tunnel is made outside-in, making a short socket. A continuous looped hamstring tendon autograft attached to one button is used. The ACL is fixed with an adjustable-loop button. Through small incisions, the tibial fixation of both grafts is performed with bioabsorbable screws. Results: We present a 19-year-old professional soccer player with an acute ACL tear, with no associated meniscal or chondral lesions. Owing to his young age and high-risk sports practice, a combined ACL and ALL reconstruction was performed. The combined ACL and ALL reconstruction with a single femoral tunnel using the hamstrings tendons graft is a well-established procedure for ACL augmentation, reducing failure rates for certain risk groups, with excellent outcomes reported. The use of an adjustable-loop button on the femur is a viable option for this kind of reconstruction with postoperative stability comparable to the interference screw, classically used for this kind of reconstruction. Discussion/Conclusion: This technique has some advantages, such as the use of a short outside-in femoral socket, thus theoretically improving healing. In addition, this lowers the risk of lateral collateral ligament injury, and since the ileotibial band graft is not used, the risk of injuring the lateral inferior genicular vessels and the peroneal nerve is theoretically reduced. Besides, using an adjustable-loop cortical button in the femur can theoretically reduce potential complications such as screw migration, soft-tissue impingement, femoral-site pain, and implant removal. Finally, the reconstruction is done with small incisions, improving the aesthetic result and postoperative pain. Considering all the aforementioned factors, this technique theoretically offers some benefits. 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.

Incidence of Convergence Between Distally and Anteriorly Oriented ALL Femoral Tunnels and ACL Femoral Tunnels in Combined ACL and ALL Reconstruction: 3-Dimensional Computed Tomography Analysis of 227 Patients

Background: Adjusting the direction of the anterolateral ligament (ALL) femoral tunnel is suggested to avoid tunnel convergence during anterior cruciate ligament (ACL) reconstruction. Yet, there has been no in vivo clinical study reporting the effect of changing the direction of the ALL tunnel on the incidence of convergence with the ACL tunnel. Purpose: To report the incidence of convergence between the ACL femoral tunnel and a distally and anteriorly directed ALL femoral tunnel and to determine a safe distal angle and anterior angle. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 227 patients undergoing concomitant ALL and anatomic single-bundle ACL reconstruction between January 2020 and December 2022 were retrospectively reviewed. The tunnel convergence rate, angular orientation of the tunnels, and distance between tunnels were obtained using postoperative computed tomography. The patients were grouped based on the direction of the ALL tunnel (transverse vs distal anterior) and the presence of tunnel convergence (convergence vs no convergence). Results: The overall tunnel convergence rate was 53.3% (121/227 patients). Tunnel convergence was observed less frequently in the distal anterior group (33.7%) than in the transverse group (65.2%) (P < .001). The no convergence group showed an ALL tunnel oriented more distally (20.2°± 11.1°) and anteriorly (19.5°± 10.2°) compared with the convergence group (8.7°± 6.5° and 6.9°± 5.3°, respectively) (P = .005 and P = .008, respectively). There were no cases of tunnel convergence for ALL tunnels >24.3° distally and >25.5° anteriorly. There was no difference in the angle of the ACL femoral tunnel between all groups. Conclusion: A distally and anteriorly directed ALL femoral tunnel reduced the incidence of convergence with the ACL femoral tunnel. A distal angle >24.3° and an anterior angle >25.5° of an ALL tunnel are suggested to safely avoid convergence with the ACL tunnel.

Femoral Tunnel Length in Anatomical Double-Bundle Anterior Cruciate Ligament Reconstruction Is Correlated with Body Size and Knee Morphology.

The purpose of this study was to reveal the correlation between anteromedial (AM) and posterolateral (PL) femoral tunnel lengths in anatomical double-bundle anterior cruciate ligament (ACL) reconstruction and body size and knee morphology. Thirty-four subjects undergoing anatomical double-bundle ACL reconstruction were included in this study. Preoperative body size (height, body weight, and body mass index) was measured. Using preoperative magnetic resonance imaging (MRI), quadriceps tendon thickness and the whole anterior-posterior length of the knee were measured. Using postoperative computed tomography (CT), axial and sagittal views of the femoral condyle were evaluated. The correlation between measured intraoperative AM and PL femoral tunnel lengths, and body size and knee morphology using preoperative MRI and postoperative CT parameters was statistically analyzed. Both AM and PL femoral tunnel lengths were significantly correlated with height, body weight, posterior condylar length, and Blumensaat's line length. These results suggest that the femoral ACL tunnel length created using a transportal technique can be estimated preoperatively by measuring the subject's body size and/or the knee morphology using MRI or CT. For clinical relevance, surgeons should be careful to create femoral tunnel of sufficient length when using a transportal technique, especially in knees of subjects with smaller body size and knee morphology. Level of evidence is III.

Revision ACL-R With Contralateral BTB Autograft and Iliotibial Band Lateral Extra-Articular Tenodesis With Interference Screw Fixation: A Technique Video

Background: Lateral extra-articular tenodesis (LET) is a reproducible and reliable technique to assist in control of rotational stability of the knee and decrease forces across an anterior cruciate ligament (ACL) graft in the setting of ACL reconstruction. Bone-tendon-bone (BTB) autograft is a common graft choice in revision ACL reconstruction. We present a technique for combining contralateral BTB autograft with LET in revision ACL reconstruction. Indications: This technique is indicated in patients undergoing ACL reconstruction who are at increased risk of graft failure, including revision cases, high-grade rotational instability, return to pivoting/cutting sports, ligamentous laxity, young age, meniscal deficiency, and hyperextension/recurvatum. Technique Description: The contralateral BTB autograft is harvested through standard fashion. We begin with the LET dissection prior to fluid infiltration in the soft tissues. A 1-cm strip of iliotibial (IT) band is harvested and whipstitched. The IT band strip is passed from anterior to posterior deep to the lateral collateral ligament (LCL). The LET socket is aimed 10° proximal and 10° anterior to limit tunnel convergence with the ACL. The LET is fixed with a tenodesis screw with the knee in neutral rotation and 30° of flexion. The ACL femoral socket is then placed, and care is taken to avoid convergence. A 10-mm tibial tunnel is drilled near the level of the posterior margin of the anterior horn of the lateral meniscus. The ACL is subsequently fixed with standard techniques. Results: The addition of LET to revision ACL has been shown to improve failure rate and outcomes. The use of contralateral patella tendon graft reduces morbidity on the operated leg. Notably, the position of the femoral LET tunnel is less important than the ACL tunnel position on the femur. If the LET is passed under the LCL, then the fixation point on femur becomes less relevant. The technique presented is a time-efficient way for combining tenodesis with revision ACL. Discussion/Conclusion: Performing a revision ACL reconstruction utilizing contralateral donor tissue with the addition of LET is a viable and reliable option for competitive athletes. 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.

Lateral Extra-articular Tenodesis: The Onlay Technique

Tibial anterolateral rotary instability associated with anterior cruciate ligament (ACL) tears is a well-documented and difficult problem with a long history of solutions. The lateral extra-articular tenodesis (LET) has undergone multiple refinements in technique, largely focusing on the femoral site insertion using either an interference screw versus a staple for adequate fixation. In this article, we present an improved technique using a suture anchor as an alternative to a staple or an interference screw with secure fixation to insert the LET graft onto the femur. This technique diminishes the chance of ACL tunnel–LET drilling convergence, minimizes the footprint required for adequate graft fixation, and allows the surgeon to dial in the correct tension necessary for adequate augmentation of an ACL reconstruction.

Poster 351: Relation Between Femoral Anterior Cruciate Ligament Tunnel Orientation and Anterolateral Ligament Tunnel Collision in a 3D-CT Model

Poster 351: Relation Between Femoral Anterior Cruciate Ligament Tunnel Orientation and Anterolateral Ligament Tunnel Collision in a 3D-CT Model

Anatomical Landmark Technique for Femoral Tunnel Placement of Lateral Extra-Articular Tenodesis

The anterolateral ligament is a crucial part of the anterolateral complex of the knee, providing rotator stability to the knee and being a primary restraint to tibial internal rotation. Lateral extra-articular tenodesis added to anterior cruciate ligament reconstruction can reduce pivot shift without sacrificing the range of motion or increasing the risk of osteoarthritis. A 7- to 8-cm longitudinal skin incision is made and a 9.5- to 10-cm × 1- cm wide iliotibial band graft is dissected, leaving the distal attachment intact. The free end is whip stitched. One of the most important steps during the procedure is the identification of the site of attachment of the iliotibial band graft. The leash of vessels, fat pad, lateral supracondylar ridge, and fibular collateral ligament serve as important landmarks. The tunnel is drilled from the lateral femoral cortex with a guide pin and reamer pointing 20 to 30° anteriorly and proximally while the arthroscope visualizes the femoral anterior cruciate ligament tunnel. The graft is routed under the fibular collateral ligament. The graft is fixed with a bioscrew while the knee is kept in 30° flexion and the tibia is kept in neutral rotation. We believe that lateral extra-articular tenodesis gives the anterior cruciate ligament graft a good chance for faster healing along with addressing anterolateral rotatory instability. Choosing a correct fixation point is very important to restore normal knee biomechanics.

Anterior Cruciate Ligament Reconstruction With Transtibial Medial Meniscus Root Repair

Background: The incidence of anterior cruciate ligament (ACL) injuries has rapidly increased. Patients with ACL injuries frequently present with concomitant meniscal pathologies. Posterior medial meniscal root tears (PMMR) are less commonly seen with acute ACL injuries as compared with lateral tears and are often degenerative in nature or more rarely in an acute setting. Clinical studies have demonstrated medial meniscal deficiency to be a significant risk factor for graft failure and poor postoperative clinical outcomes. As such, given its demonstrated efficacy, there has been growing interest in transtibial meniscal repair mechanisms in combination with an ACL reconstruction as a potential solution to this challenging pathology. Indication: Patients are indicated for surgery when presenting with symptomatic ACL deficiency verified on provocative testing and advanced imaging and objective insufficiency of the medial meniscal root. Contraindications for this procedure include advanced osteoarthritis (Kellgren–Lawrence grade ≥3) on weight-bearing x-rays, age &lt;50 years, and body mass index (BMI) &gt; 30 as well as poor-quality meniscal tissue and unrepairable chondral defects. Technique Description: The ACL stump is debrided and a burr hole is created. A femoral aiming guide is used to drill the femoral tunnel. Following medial collateral ligament (MCL) release, a healing bony bed is prepared with a curette and shaver at the anatomic tibial footprint. An aiming device is then used through the anterior medial portal to create 2 transosseous tibial tunnels. A vertical mattress suture and simple suture are placed through the meniscal root, shuttled through the posterior and anterior transosseous tunnels, respectively. The tibial ACL tunnel is placed using a standard guide to avoid tunnel convergence with the root tunnels and prevent graft tunnel mismatch. After graft passage, interference screws are inserted while maintaining graft tension. The sutures are then tied over a cortical button over the tibia. Results: Within 2 years postoperatively, patients are expected to have improved overall knee-specific quality of life, reduced pain, and a successful return to activities with low rates of graft failure. Discussion/Conclusion: Recent advancements in our understanding of the relationship between the medial meniscus and the ACL should prompt surgeons to continue considering such combined treatments in indicated patients. 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.

Grid and Image Intensifier Improve Arthroscopic ACL Tunnel Position and Patient-Reported Outcomes

To evaluate the accuracy in the femoral and tibial tunnel placement after the use of fluoroscopy along with an indigenously designed grid method to assist in arthroscopic anterior cruciate ligament reconstruction as compared with the tunnel placement without using them and to validate the findings with computed tomography scan performed postoperatively along with assessing the functional outcome at a minimum of 3 years of follow-up. This was a prospective study conducted on patients who underwent primary anterior cruciate ligament reconstruction. Patients were included and segregated into a nonfluoroscopy (group B) and a fluoroscopy group (group A), and both had postoperative computed tomography scans so that femoral and tibial tunnel position could be evaluated. Scheduled follow-up occurred 3, 6, 12, 24, and 36 months' postoperatively. Patients were evaluated objectively with the Lachman test, measurement of range of motion, and functional outcome using patient-reported outcome measures, i.e., Tegner Lysholm Knee score, Knee injury and Osteoarthritis Outcome Score, and International Knee Documentation Committee subjective knee score. A total of 113 subjects were included. There were 53 in group A and 60 in group B. The average location of femoral tunnel showed significant differences between the 2 groups. However, the variability in femoral tunnel location was significantly lower in group A as compared with group B for proximal-distal planes only. The average location of the tibial tunnel as per the grid of Bernard etal. showed significant differences in both the planes. The variability in tibial tunnel was greater in the medial-lateral plane as compared with the anterior-posterior plane. There was a statistically significant difference in mean value of the 3 scores among the 2 groups. The variability of the scores was greater in group B as compared with group A. None of the patient was reported as a failure. The results of our study suggests that fluoroscopy-guided positioning using a grid technique increases the accuracy of anterior cruciate ligament tunnel positioning with decreased variability and is associated with better patient-reported outcomes 3 years after surgery compared with tunnel positioning using landmarks. Level II, prospective, comparative therapeutic trial.

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.

The effects of initial graft tension on femorotibial relationship following anatomical rectangular tunnel anterior cruciate ligament reconstruction using bone–patellar tendon–bone graft

BackgroundThe purpose of this study was to elucidate the effects of the difference of initial graft tension on the femorotibial relationship on an axial plane and its chronological change following anatomical anterior cruciate ligament (ACL) reconstruction. MethodsA total of 63 patients who underwent anatomical ACL reconstruction were included in this study. The graft was fixed at full knee extension with manual maximum (higher graft tension; group H) and 80 N (lower graft tension; group L) pulls in 31 and 32 patients, respectively. The femorotibial positional relationship in axial computed tomography at 1 week and 1 year postoperatively were retrospectively evaluated. The side-to-side differences (SSDs) and the amount of changes of SSDs over 1 year were compared between groups. ResultsThe SSDs of the external rotational angle of the tibia in group H were significantly larger than those in group L at postoperative 1 week (2.7 ± 3.9° vs. 0.3 ± 3.3°; P < 0.01). The amount of internal rotational changes of SSDs of the internal–external rotational angles over 1 year in group H was significantly larger than that in group L (−3.6 ± 3.9° vs. − 0.3 ± 2.7°; P < 0.01). No significant differences were observed on the anterior–posterior translation distance and medial–lateral shift distance. ConclusionThe application of higher initial graft tension resulted in excessive external rotation of the tibia to the femur at 1 week postoperatively in anatomical ACL reconstruction, and the excessive early external tibial rotation had resolved over 1 year.

The orientation of the ALL femoral tunnel to minimize collision with the ACL tunnel depends on the need or not of far-cortex drilling.

To (1) evaluate the optimal drill orientation of the anterolateral ligament (ALL) femoral tunnel to minimize collision with the anterior cruciate ligament (ACL) femoral tunnel during anatomical ACL reconstruction according to the need for far-cortex drilling and (2) investigate the geometric factors that affect tunnel collision secondary to drill orientation of the ALL femoral tunnel. A three-dimensional femoral model of patients who underwent anatomical single-bundle ACL reconstruction between 2015 and 2016 was constructed, and the geometric factors were evaluated. Virtual ALL femoral tunnels were created to simulate 45 drilling conditions. For each condition, whether the virtual ALL femoral tunnel and its trajectory violated the femoral cortex and the minimum distance between tunnels was investigated. Thirty-nine subjects were included. Overall violation rates of the femoral cortex by the ALL tunnels and its trajectories were 11.1% (195 of 1755 conditions) and 40.7% (714 of 1755 conditions), respectively. A drilling angle of axial 0° and coronal -40° showed the longest minimum distance between tunnels without femoral cortex violation by the ALL tunnel (6.3 ± 4.0mm; collision rate 2.6% [1 of 39 subjects]). With simultaneous consideration of the ALL tunnel's trajectory representing far-cortex drilling, a drill angle of axial 40° and coronal 10° showed the longest minimum distance between tunnels without femoral cortex violation (0.6 ± 3.9mm; collision rate 38.5% [15 of 39 subjects]). For surgical techniques requiring far-cortex drilling, regression analyses were performed on geometric factors that could affect tunnel collision, which revealed that the sagittal inclination angle of the ACL and the distance between the ACL femoral tunnel's outlet and ALL's femoral attachment were associated with tunnel collision. The optimal drill orientations of the ALL femoral tunnel to minimize collision with the ACL femoral tunnel were axial 0° and coronal -40° for surgical techniques not requiring far-cortex drilling and axial 40° and coronal 10° for techniques requiring far-cortex drilling. For techniques requiring far-cortex drilling, additional adjustment for orientation of the ACL femoral tunnel is required to reduce the risk of tunnel collision. Therefore, an individualized surgical strategy should be applied according to the graft fixation method of the ALL femoral tunnel.

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.

Lower anatomical femoral ACL tunnel can be created in the large volume of femoral intercondylar notch.

The purpose of this study was to investigate the correlation between femoral intercondylar notch volume and the characteristics of femoral tunnels in anatomical single bundle anterior cruciate ligament (ACL) reconstruction. Fifty-one subjects (24 male and 27 female: median age 27: range 15-49), were included in this study. Anatomical single bundle ACL reconstruction was performed in all subjects using a trans-portal technique. Femoral tunnel length was measured intra-operatively. Three-dimensional computed tomography (3D-CT) was taken at pre and post-surgery. The intercondylar notch volume was calculated with a truncated-pyramid shape simulation using the pre-operative 3D-CT image. In the post-operative 3D-CT, the modified quadrant method was used to measure femoral ACL tunnel placement. Femoral tunnel placement was 47.6 ± 10.5% in the high-low (proximal-distal) direction, and 22.6 ± 5.4% in the shallow-deep (anterior-posterior) direction. Femoral tunnel length was 35.3 ± 4.4cm. Femoral intercondylar notch volume was 8.6 ± 2.1cm3. A significant correlation was found between femoral intercondylar notch volume and high-low (proximal-distal) femoral tunnel placement (Pearson's coefficient correlation: 0.469, p = 0.003). Femoral ACL tunnel placement at a significantly lower level was found in knees with large femoral intercondylar notch volume in the trans-portal technique. For the clinical relevance, although the sample size of this study was limited, surgeons can create femoral ACL tunnel low (distal) in the notch where close to the anatomical ACL footprint in the knees with large femoral intercondylar notch volume. III.

The Modified Ellison Technique: A Distally Fixed Iliotibial Band Transfer for Lateral Extra-articular Augmentation of the Knee

Lateral extra-articular augmentation (LEA) of anterior cruciate ligament reconstructions significantly reduces graft failure rates. Currently, proximally fixed LEA procedures are popular techniques. However, there are concerns about these techniques regarding anterior cruciate ligament tunnel collision, kinematic overconstraint, and increasing lateral-compartment contact forces. These issues are potentially avoided by the modified Ellison procedure, which is a distally fixed LEA technique. This article describes the surgical details of this easily reproducible technique.

A Higher Initial Tensioning Force of an ACL Graft Results in a Higher Graft Force After Screw Fixation Irrespective of the Screw Diameter: A Biomechanical Study

Background: The intra-articular graft force (IAGF) in anterior cruciate ligament reconstruction decreases quickly over the first hours after surgery. Nevertheless, little is known about whether the initial extra-articular tensioning force (EATF) and screw diameter affect the graft force after fixation. Purpose: To investigate the effects of different EATFs on the IAGF of a soft tissue graft fixated via a bioabsorbable interference screw over 100 minutes after fixation and to evaluate the effects of different screw diameters within 1 mm of the tunnel width during this process. Study Design: Controlled laboratory study. Methods: In this biomechanical study, a porcine quadruple-strand soft tissue graft was inserted into the tibial anterior cruciate ligament tunnel. On the extra-articular side, 3 loads were applied during retrograde insertion of the bioabsorbable interference screw (6, 7, and 8 mm): 20 N, 80 N, and maximum manual EATF (Nmax). Nine study groups consisting of 10 tibiae each were created to test the effects of different EATFs and screw sizes. The IAGF was measured up to 100 minutes after the EATF was released. Results: An EATF ≥80 N resulted in a larger IAGF for all screw sizes at 100 minutes. There were no significant associations between the IAGF at 100 minutes and different screw diameters. Inserting the tibial screw significantly increased the IAGF in all groups, with the exception of Nmax applied in groups with 7- or 8-mm screws. When compared with the end of screw insertion, after the release of the EATF, the IAGF dropped by 55% to 77 % at 100 minutes. Conclusion: An initial EATF ≥80 N is associated with a significantly larger IAGF at 100 minutes in this cadaveric simulation. The IAGF in soft tissue grafts decreased substantially after the retrograde placement of an interference screw. A recommendation regarding screw diameter with respect to the IAGF cannot be given. Clinical Relevance: To obtain a higher residual graft force after bioabsorbable interference screw fixation, an initial EATF ≥80 N should be applied according to this model. The significant decrease in graft force after the release of the EATF indicates that the reconstructed knee cannot be mechanically stabilized after the surgery.

An Analysis of the Femoral Drilling Angle to Avoid Tunnel Collision during Double-Bundle Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction on the Knee.

Concomitant anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction has been reported as an effective technique for providing rotational control of the knee. However, the intraoperative risk of collision with an ACL tunnel during the drilling for the femoral ALL tunnel has been described. The purpose of this study was to investigate the various femoral drilling procedures to avoid tunnel collisions during combined double-bundle ACL and ALL reconstruction. Nine cadaveric knees were used in this study. ACL drilling was performed through the anteromedial portal to footprints of the posterolateral bundle at 120° (PL120) and 135° (PL135) knee flexion and the anteromedial bundle at 120° (AM120) and 135° (AM135) knee flexion. ALL drilling was performed at 0° (Cor0-ALL) and 30° (Cor30-ALL) coronal angles using a Kirschner wire (K-wire). The distance between the ALL footprint and ACL K-wire outlets, axial angles of ALL K-wires colliding with ACL K-wires, and distances from the ALL footprint to the collision point were measured. From these values, the safe zone, defined as the range of axial angles in which no collisions or penetrations occurred, was identified by simulation of tunnels utilized for reconstruction grafts in each drilling procedure. The point-to-point distance from the ALL footprint to the K-wire outlet was significantly greater in the AM120 than the AM135 (13.5 ± 3.1, 10.8 ± 3.2 mm; p = 0.048) and in the PL135 than the PL120 (18.3 ± 5.5, 16.1 ± 6.5 mm; p = 0.005) conditions, respectively. During an ACL drilling combination of PL135/AM120, a safe zone of > 45° in Cor30-ALL was identified. With a narrow safe zone during the PL135/AM120 combination only, the risk of femoral tunnel collisions in combined double-bundle ACL and ALL reconstruction is high. AM drilling at 120° and PL drilling at > 135° knee flexion, combined with ALL drilling at 30° coronal angle and > 45° axial angle, may reduce this risk.

Transepicondylar Distance Can Predict Graft and Tunnel Length for Different Pediatric Anterior Cruciate Ligament Reconstruction Techniques: A Magnetic Resonance Imaging Study

To find a correlation and mathematical formulas between a linear 2-dimensional (2D) magnetic resonance imaging (MRI) measurement around the knee and the length of the grafts and tunnels required for both all-inside-all-epiphyseal and Kocher-Micheli pediatric anterior cruciate ligament (ACL) reconstruction techniques. At time 0 and 30 days after, 2 observers measured: (1) on standard 2D knee MRI, 7 linear distances, representing morphologic measurements, such as transepicondylar distance (TD), and (2) on 3-dimensional (3D) MRI, 5 curved distances, corresponding to Kocher-Micheli and all-epiphyseal ACL reconstruction techniques. Intra- and interobserver reliability was tested for all measurements. The correlation between 2D and 3D measurements was tested. The 2D measurement with highest repeatability and reproducibility and with strongest correlation with 3D measurements was used to extract formulas to calculate the tunnel and graft length for the 2 techniques. Seventy-six MRIs were used. The intra- and interobserver reliability of 2D measurement was high, with TD showing the highest reproducibility and repeatability. 3D measurements also showed good intra and inter-observer reliability. A linear correlation was found between 2D and 3D measurements, with TD showing the strongest correlation. TD was used to extract formulas to calculate graft or tunnel length for Kocher-Micheli and all-epiphyseal ACL reconstruction. All formulas were proven to be accurate. A reference chart was also created to be used in the surgical setting. With specific formulas, TD can be used to calculate the length of the tunnels, intra-articular portion and graft length for an all-inside all-epiphyseal pediatric ACL reconstruction and the length of the iliotibial band required for the Kocher-Micheli technique. The surgeon can use these formulas in pediatric ACL reconstruction preoperative planning, graft harvesting and tunnel drilling.

Tunnel Convergence Rate in Combined Anteromedial Portal Anterior Cruciate Ligament and Anterolateral Structure Reconstructions Is Influenced by Anterior Cruciate Ligament Knee Flexion Angle, Tunnel Position, and Direction

The goal of the present study was to evaluate a potential tunnel convergence in combined anterior cruciate ligament (ACL) reconstruction using the anteromedial portal technique and lateral extra-articular tenodesis (LET). Ten fresh frozen femora were dissected and a K-wires were inserted into the middle of the ACL stump, according to an ACL reconstruction at 110° and 140° knee flexion. ACL reconstruction at 120° and 130° was simulated. Seven K-wires with different femoral insertion sites and angulations were drilled into the lateral femoral condyle relative to the lateral epicondyle (E3: 8 mm proximal and 4 mm posterior; E1: 5 mm proximal and 5 mm anterior and E2: over-the-top position). Tunnel conflict rate was evaluated using a measuring arm and a metrology software. Drilling the femoral ACL tunnel in low knee flexion (110°-120°) significantly (P < .001) reduced the tunnel conflict rate compared to the ACL drilled in high knee flexion (130°-140°). Changing the insertion point from proximal and posterior (E3) to proximal and anterior (E1) showed a reduced tunnel conflict rate from 40 ± 21.2% to 15 ± 26% and no tunnel conflict for an ACL drilled at 110°-130° knee flexion. A possible tunnel conflict in simultaneous ACL reconstruction using the AMP technique and LET was dependent on ACL knee flexion angle, LET insertion site, and angulation. This posed the dilemma that no generally applicable LET configuration could be recommended to avoid a tunnel conflict. However, it appears that an insertion point located proximal and anterior to the lateral epicondyle results in less tunnel conflicts than an insertion point located proximal and posterior. An insertion point located proximal and anterior to the lateral epicondyle with a 30° proximal and 30° anterior angulation could reliably avoid a tunnel conflict when the ACL was drilled between 110 and 130° using a low anteromedial portal.