Femoral Tunnel Research Articles

The Triple Varus Knee: A Case Presentation

Background: Knee instability due to posterior cruciate ligament (PCL) and posterolateral corner (PLC) deficiency is a devastating condition that negatively affects patient quality of life. This video presents the surgical management of a triple varus knee, including combined high tibial osteotomy (HTO), revision PCL and PLC reconstruction, and meniscus root repair. Indications: Combined HTO and revision PCL and PLC reconstruction is indicated for patients with previously failed PCL and PLC reconstruction in the setting of varus malalignment. Technique Description: The procedure begins with a medial opening-wedge biplanar HTO, which is fixed with a patient-specific locking plate. The PCL femoral tunnel is drilled via a low anterolateral portal, and the tibial insertion is debrided via a posteromedial portal. The medial meniscus is carefully freed from the posterior capsule, and 2 luggage tag sutures are placed through the posterior root. The PCL tibial tunnel and meniscus root tunnels are drilled via their respective guides. The meniscal sutures are passed through the tunnel but not fixed. An Achilles bone-block allograft is passed through the PCL tibial tunnel and fixed with suspensory fixation and an interference screw on the femoral side, while the tibial side is left free. A peroneal nerve neurolysis is performed. A fibular tunnel is drilled, and a semitendinosus allograft is whip-stitched on both sides and passed through the tunnel. A Beath pin is inserted into the femur, and the tunnel is over drilled. Both limbs of the graft are passed deep to the iliotibial band and into the tunnel. The tibial side of the PCL is fixed with an interference screw at 90° of knee flexion. The PLC grafts are fixed with an interference screw at 30° of knee flexion with slight valgus. The medial meniscus root sutures are tied over a button, with 60° of knee flexion. Screws from osteotomy fixation are replaced as needed. Results: Although outcomes following the combined procedure are lacking, good to excellent clinical outcomes have been reported in isolation following each procedure. Conclusion: A combination of HTO and revision PCL and PLC reconstruction should be considered for patients with persistent instability and/or pain in the setting of triple varus knee. 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.

Physeal-Sparing, All-Inside Anterior Cruciate Ligament Reconstruction Using Quadrupled Semitendinosus Autograft and Suture Tape Augmentation for Skeletally Immature Patients

The anterior cruciate ligament (ACL) is the primary soft-tissue structure for anterior stabilization of the knee and is one of the most frequently injured structures. The incidence of ACL injuries in children and adolescents ranges from 92 to 151 per 100,000 person-years. The choice of surgical treatment for this population group is controversial, with a widespread concern that adult reconstruction techniques may damage the epiphyseal plate, compromise growth, or cause deformity. In this article, we describe a physeal-sparing, all-inside ACL reconstruction technique for skeletally immature patients. This technique is supported by retrograde drilling of the femoral tunnel and retrograde drilling of the tibial tunnel, both of which are able to avoid the epiphyseal growth line. Fixation of the quadrupled semitendinosus autograft and suture tape augmentation are achieved by soft-tissue buttons on the femur and tibia. The surgical details of this reproducible reconstruction technique are elaborated.

App-Based Analysis of Fluoroscopic Images According to Bernard-Hertel Method for the Determination of Femoral Tunnel Positioning in Anterior Cruciate Ligament Reconstruction

The accurate positioning of the femoral tunnel is crucial for the success of anterior cruciate ligament reconstruction. Malpositioning of the tunnel is believed to be one of the most important reasons for graft failure. While use of anatomic landmarks and industry-supplied aiming devices aid the surgeon in placing the drill pin in the correct position, fluoroscopic imaging is an additional tool used intraoperatively to verify pin placement. While interpretation of fluoroscopic imaging is frequently based on eyeball measurement, a more accurate analysis of a lateral image uses the quadrant method by Bernard-Hertel. This method has been primarily used for scientific research due to its complexity and has not been integrated into clinical routine yet. We present a digital app-based approach to easily quantify the femoral pin position based on the quadrant method. This approach is mobile and easy to use. Quantification of pin position of femoral bone tunnel on a lateral fluoroscopic image may be used for quality control and teaching purposes or may provide the surgeon with additional information during ACL reconstruction.

Surgical Approach to Acute Osteochondral Fracture With Patellar Instability in Skeletally Immature Patients

Background: Patellar instability is a common condition that affects many young, active patients and can lead to long-term disability. This video aims to provide insights in the treatment of acute osteochondral fractures in skeletally immature patients after acute patellar dislocation. Indications: Patients who present with acute patellar dislocation and evidence of osteochondral fracture or osteochondral fracture with a loose body are potential candidates for medial patellofemoral ligament reconstruction (MPFLR) with osteochondral fragment fixation. Technique Description: In case 1, arthroscopy revealed a medial patellar facet defect. A medial patellar incision was made with dissection down to the vastus medialis oblique fascia and medial retinaculum. Before continuing to capsulotomy, the dissection for the MPFLR is completed by dissecting down to create a plane between layers 2 and 3. Capsulotomy is then performed with retrieval of the loose body, preparation of the patellar defect, and fixation of the osteochondral fragment. The MPFLR is then performed. An allograft is fixed to the patella with 2 pushlock anchors, and to a distally directed femoral tunnel using a 7-mm pitchfork SwiveLock tenodesis anchor, with care to avoid the medial femoral physis. The capsulotomy is then closed underneath the graft, with layer 2 closed above it. In case 2, a large osteochondral fracture of the lateral femoral condyle with loose cartilage flaps was arthroscopically identified. An anterior incision was made and a lateral lengthening was completed to perform a laterally based arthrotomy to expose the defect on the lateral femoral condyle. The defect site was prepared and the loose body was secured and fixated into the donor site lesion using bioabsorbable screws. The MPFLR was completed as in case 1, and the wound was closed in standard fashion. Results: Acute patellar dislocation with osteochondral fracture has been shown to lower both subjective and functional patient outcome measures. A recent study suggests that in large osteochondral fractures after patella dislocation, internal fixation improves mid- and long-term outcomes when compared with debridement alone. Conclusion: The MPFLR with concurrent osteochondral fracture fixation in patients with open physes is a reliable option for improving patellar stability and protecting articular cartilage from further injury. 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.

Posterior Cruciate Ligament Reconstruction With Quadriceps Tendon Autograft and Concomitant Meniscal Ramp Repair

Background: Quadriceps autograft, though well established for anterior cruciate ligament reconstruction, is underutilized in posterior cruciate ligament (PCL) reconstruction largely due to slow adoption. All-inside meniscal ramp repair and quadriceps tendon autograft PCL reconstruction have been described in isolation, but not concomitantly in a video journal. Indications: PCL reconstruction is indicated in grade 3 isolated tears with instability that have not improved with nonoperative management and in instances with associated injuries such as meniscal ramp tears, as observed in this 18-year-old division I football player. Graft selection is dependent upon surgeon and patient preference, with quadriceps autograft delivering a viable option with desirable long-term outcomes. Technique Description: A partial-thickness quadriceps tendon autograft was harvested, the remnant PCL stump was debrided, and a reamer was used to drill the all-inside tibial tunnel for traction suture passage. An accessory low anterolateral portal was utilized to drill the femoral tunnel for passage of the femoral traction stitch. Traction sutures were withdrawn, and the graft was passed into the tibia, docked into the femur, fixated with an interference screw, and tensioned over the tibial button. A medial meniscal ramp tear was also identified and repaired in all-inside fashion with a 90° SutureLasso, polydioxanone suture (PDS), and suturetape via standard arthroscopic knot tying. Following the procedure, the patient began a PCL reconstruction rehabilitation protocol with a PCL rebound brace. Due to the meniscal ramp repair, toe touch weightbearing with the knee in extension during ambulation was completed for 6 weeks. Physical therapy (PT) focused on early quadriceps and patellar mobilization as well as active-assisted range of motion exercises. Results: At 6 months postoperation, the patient continued to progress in PT without major concerns. A full recovery and return to sport are expected approximately 9 to 12 months after surgery, as is consistent with the standard protocol. Discussion/Conclusion: This study describes the treatment of chronic PCL with concomitant meniscal ramp tear in a division I athlete. Further adoption of PCL reconstruction utilizing quadriceps autograft, even in the context of concomitant ligamentous or meniscal reconstruction, such as medial meniscal ramp repair, will aid in the widespread treatment of PCL injuries. 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.

Progress in research on and classification of surgical methods of arthroscopic reconstruction of the ACL and ALL using a shared tendon graft through the femoral tunnel.

Anterior cruciate ligament (ACL) tear is a common clinical injury, and ACL reconstruction has reached a very mature stage. However, with the accumulation of cases, scholars have found that isolated ACL reconstruction may not completely solve the problem of knee rotational stability. With the increase in our understanding of knee joint structure, ACL combined with anterolateral ligament (ALL) reconstruction has become accepted by most scholars, and this operation has also achieved good clinical results. At present, there is no unified surgical method for ACL combined with ALL reconstruction. There are differences in bone tunnel location, reconstruction methods, and graft selection. Compared with the independent reconstruction of the ACL and ALL during the operation, shared tendon graft reconstruction of the ACL and ALL has the advantages of preserving tendon and avoiding tunnel convergence. So far, there is no relevant literature summarizing the reconstruction of the ACL and ALL with a shared tendon graft. This paper reviews the anatomic study of the ALL, the study of isometric points, surgical indications, and surgical methods and their classification for shared tendon graft reconstruction of the ACL and ALL.

Outcomes of RigidFix Cross Pin Fixation in Femoral and Tibial Tunnel for Anterior Cruciate Ligament Reconstruction.

There is no clear consensus so far on which fixation method is most favorable for the tibial tunnel in anterior cruciate ligament reconstruction (ACLR). The purpose of this paper is to investigate the outcome of RigidFix cross pins fixation in the tibial tunnel and to explore the advantages of RigidFix applied both in the femoral and tibial tunnel with hamstring tendon graft in anterior cruciate ligament reconstruction. This retrospective study included 53 patients (male/female, 45/8) who underwent anterior cruciate ligament reconstruction using autologous hamstring tendons between January 2013 and December 2017 at our institute. The participants in group A (n = 36) received anterior cruciate ligament reconstruction with RigidFix cross pins fixation in both femoral and tibial tunnels, while those in group B (n = 17) with RigidFix cross pins fixation in the femoral tunnel and Interference screw fixation in the tibial tunnel. The visual analogue scale (VAS) score, International Knee Documentation Committee subjective knee form 2000 (IKDC2000) score, Lysholm knee scoring scale, Tegner activity score and the side-to-side difference were compared at 2 and 5 years postoperatively. The graft diameter, number of strands in graft and the average diameter of each strand were also compared between the two groups. The categorical parameters were analyzed by chi-square test and the continuous variables conforming to a normal distribution were analyzed by Student's t-test. At 2 years postoperation, the VAS score (1.61 ± 0.55), side-to-side difference (1.50 ± 0.58) in group A were significantly lower than that in group B, and the IKDC2000 score (88.81 ± 3.88), Tegner activity score (6.14 ± 0.60) in group A were significantly higher than that in group B. At 5 years postoperation, the VAS score (1.64 ± 0.68), side-to-side difference (1.73 ± 0.63) in group A were significantly lower than that in group B, and the IKDC2000 score (89.09 ± 3.85), Tegner activity score (6.58 ± 0.94) in group A were slso significantly higher than that in group B. There was statistical difference in the change of the side-to-side difference between the two groups (group A vs. B, 0.22 ± 0.08 vs. 0.34 ± 0.11, p < 0.001). There were also statistical differences in the graft diameter (group A vs. B, 7.83 ± 0.74 vs. 7.41 ± 0.51, p = 0,038), number of strands in graft (5.67 ± 0.72 vs. 4.00 ± 0.00, p < 0.001) and the average diameter of each strand (1.41 ± 0.22 vs. 1.85 ± 0.13, p < 0.001) between the two groups. RigidFix cross pins fixation in the tibial tunnel for anterior cruciate ligament reconstruction can achieve better 5-year results when compared with the interference screw, and the hamstring tendon can be folded into a thicker graft when RigidFix cross pins were applied in both femoral and tibial tunnels.

Anatomic femoral tunnel position in medial patellofemoral ligament reconstruction: anterior versus posterior

BackgroundThis study aimed to compare the clinical and radiological outcomes of medial patellofemoral ligament reconstruction (MPFLR) between anatomic femoral tunnel positions at anterior and posterior footprints.MethodsFifty-seven patients who underwent MPFLR for patellofemoral instability with anterior or posterior femoral tunnels between 2014 and 2021 with at least 2 years of follow-up were retrospectively analyzed. Based on postoperative images, the femoral tunnel positions anterior to the line connecting the adductor tubercle and medial epicondyle were assigned to the anterior group, group A, and those posterior to the line to the posterior group, group P. Thirty-two patients were included in group A (mean age, 22.4 ± 8.8 years), and another 25 patients were included in group P (mean age, 21.1 ± 6.1 years). The International Knee Documentation Committee (IKDC) subjective score, Lysholm score, Tegner activity score, Kujala score, and complications were evaluated. Radiologically, the Caton–Deschamps index (CDI), patellar tilt angle, and patellofemoral osteoarthritis (PFOA) using the Kellgren–Lawrence (KL) scale were evaluated. The patellofemoral cartilage status according to the International Cartilage Repair Society (ICRS) grade, bone contusion, femoral tunnel enlargement, and MPFL graft signal intensity were also evaluated.ResultsAll clinical scores significantly improved in both groups (p < 0.01). No differences were noted between the two groups in terms of their preoperative demographic data, postoperative clinical scores (IKDC, Lysholm, Tegner, and Kujala), complications, or radiological findings (CDI, patellar tilt angle, PFOA, bone contusion, femoral tunnel enlargement, and graft signal intensity). The ICRS grade for the medial facet of the patella progressed in group A (30%, p = 0.02) but not in group P (18%, p = n.s.). Additionally, no significant differences were observed in the other compartments of the patellofemoral joint.ConclusionsThe clinical outcomes were significantly improved in both groups; however, MPFLR with anterior femoral tunnel position had worse cartilage status on the medial facet of the patella than the posterior femoral tunnel position.Level of evidenceLevel III.

Modification of Outside-In Technique In Preparing Femoral Tunnel During Anterior Cruciate Ligament Reconstruction—“PL-Portal Outside-In Technique”

We propose modifying the outside-in technique by adopting a posterolateral (PL) portal as the working portal to introduce the anterior cruciate ligament reconstruction (ACLR) aiming guide while keeping the anteromedial portal as the viewing portal, the “PL-portal outside-in technique.” This modification facilitates the preparation of an anatomical femoral tunnel, even when preserving a “big” ACL remnant or in small joint scenarios, such as pediatric ACLR. There is a minimal learning curve in adopting this technique because a standard 30° arthroscope is used, and the viewing portal is anterior.

Simultaneous Tunnel Grafting and Anterior Cruciate Ligament Reconstructions Revision Using Double Suspensory Fixation: A Single-Stage Solution

The anterior cruciate ligament (ACL) is often vulnerable to sports-related injuries, leading to numerous ACL reconstructions (ACLRs) annually in the United States. Although largely successful, these procedures face the risk of recurrent instability due to graft failure. ACLR failures are typically attributed to technical errors and patient-related factors, with improper positioning of the tibial and femoral tunnels as the most common technical mistake. Current 2-stage revision techniques involve primary bone grafting followed by secondary tendon graft placement, resulting in increased costs and extended rehabilitation times. This article proposes a single-stage revision strategy involving simultaneous tunnel grafting and ACLR revision. The method employs double suspensory fixation by adjustable loop buttons, thereby eliminating the dependence on metaphyseal bone stock for stable graft fixation. This new procedure may offer a more efficient and cost-effective approach, reducing the need for a second surgery and potentially allowing patients to return to normal activities more quickly.

Radiographic Landmark Measurements for the Femoral Footprint of the Medial Patellofemoral Complex May Be Affected by Visible Femoral Shaft Length on Lateral Knee Radiographs

To assess the effect of visible femoral shaft length on the accuracy of radiographic landmarks of the medial patellofemoral complex (MPFC). In 9 cadaveric knees, the MPFC footprint was exposed on the medial femur, and its proximal and distal boundaries were marked. Lateral fluoroscopic images of the knee were assessed in 1-cm length increments, beginning 1 cm proximal to the medial condyle and continuing proximally to 8 cm. The MPFC midpoint was described on each image relative to the posterior cortical line of the femur and a line perpendicular to this line through the proximal margin of the medial condyle. In addition, the MPFC midpoint was assessed relative to a line from the proximal posterior cortex to the midpoint of Blumensaat line. Using the posterior cortical line as a reference, the MPFC radiographic landmark moved anteriorly with decreasing visible femoral shaft on radiographs, particularly at 4 cm and less. However, no proximal-distal change was noted. Linear regression analysis demonstrated a relationship between visible femoral shaft and MPFC position on radiographs (R= 0.461, R2= 0.212, B= -0.636, P < .001). For every centimeter decrease in the visible femoral shaft, the radiographic MPFC footprint moved anteriorly by 0.636 mm. Receiver operating characteristic curve analysis revealed that a minimum of 4 cm of femoral shaft on lateral radiographs is required for accurate MPFC footprint localization (area under the curve= 0.80; sensitivity= 76.7%; specificity= 69.0%; P < .001). In contrast, no anterior-posterior change was seen when referencing a line from the proximal posterior cortex to the midpoint of Blumensaat line. When using the posterior cortical line to identify the midpoint of the MPFC, at least 4 cm of femoral shaft should be visible for accurate assessment. If less than 4 cm of shaft is visible, a line through the midpoint of Blumensaat line and the proximal posterior cortex can be used as an alternative method to estimate the position of the femoral footprint. As fluoroscopy is frequently used intraoperatively for MPFC reconstruction, our findings may serve as a guide when assessing femoral tunnel placement on fluoroscopy.

Hybrid Press-fit and Adjustable Button Femoral Fixation of Anterior Cruciate Ligament Semitendinosus and Bone-patellar Tendon-bone Autografts—A Technical Note

Introduction: Many fixation methods are available for anterior cruciate ligament (ACL) grafts. Adjustable buttons (ABs) are characterized by their high fixation strength but have the disadvantage of potential stretching of their linking suture material. Press-fit bone plugs provide fixation at the joint line and enhance biological graft healing. Using both is thought to result in a higher fixation strength, enhancing graft biology and transferring the fixation point to the joint line. Materials and Methods: It is the aim of this technical note to describe a certain technique of ACL graft hybrid fixation for hamstrings or bone-tendon-bone grafts, using AB combined with bone grafting of the femoral and tibial tunnels with press-fit bone plugs or bone chips. Discussion: ABs are commonly used fixation devices for ACL grafts. AB also allows the surgeon to tighten the ACL graft in full or near full extension. The ultimate load to failure of AB has the potential disadvantage of rendering the ACL graft progressively slack. AB augmented with press-fitting bone plugs enhances biological potentials, adds to fixation strength, and transfers the fixation level of the graft from the outer femoral cortex to the joint line. Conclusion: Hybrid AB and bone plug fixation of ACL autografts, whether hamstrings or bone-tendon bone, optimizes ACL graft fixation by gaining advantages and omitting the disadvantages of both techniques.

Effect of anteromedial portal location on femoral tunnel inclination, length, and location in hamstring autograft-based single-bundle anterior cruciate ligament reconstruction: a prospective study

BackgroundPortal positioning in arthroscopic anterior cruciate ligament reconstruction is critical in facilitating the drilling of the femoral tunnel. However, the traditional approach has limitations. A modified inferior anteromedial portal was developed. Therefore, this study aims to compare the modified and conventional far anteromedial portals for femoral tunnel drilling, assessing factors such as tunnel length, inclination, iatrogenic chondral injury risk, and blowout.Material and methodsPatients scheduled for hamstring autograft-based anatomical single-bundle arthroscopic anterior cruciate ligament reconstruction were divided into two groups: modified and far anteromedial groups. Primary outcomes include differences in femoral tunnel length intraoperatively, tunnel inclination on anteroposterior radiographs, and exit location on lateral radiographs. Secondary outcomes encompass tunnel-related complications and reconstruction failures. To identify potential risk factors for shorter tunnel lengths and posterior exits, regression analysis was conducted.ResultsTunnel parameters of 234 patients were analyzed. In the modified portal group, femoral tunnel length and inclination were significantly higher, with tunnels exhibiting a more anterior exit position (p < 0.05). A higher body mass index exerted a negative influence on tunnel length and inclination. However, obese patients in the modified portal group had longer tunnels, increased inclination, and a lower risk of posterior exit. Only a few tunnel-related complications were observed in the far anteromedial group.ConclusionThe modified portal allowed better control of tunnel length and inclination, ensuring a nonposterior femoral tunnel exit, making it beneficial for obese patients.

PEEK Interference Screws Show Significant Tunnel Enlargement After ACL Reconstruction and is Comparable to Adjustable-Length Loop Cortical Button Fixation

BackgroundIt is unclear whether the use of polyetheretherketone (PEEK) interference screws for anterior cruciate ligament (ACL) reconstruction leads to postoperative tunnel enlargement. Femoral tunnel enlargement was further compared with adjustable-length loop cortical fixation.MethodsEighteen patients with ACL reconstruction using hamstring grafts were retrospectively divided into two groups. Eleven patients were treated with the ACL reconstruction technique using a PEEK interference screw for femoral graft fixation. Seven patients received adjustable-length loop cortical buttons for femoral fixation. Tibial ACL graft fixation was performed using PEEK interference screws. Tunnel volume changes were assessed using computed tomography (CT) scans performed after surgery (100%) and after 1 year. The maximal tunnel diameter was measured.ResultsThe group with femoral screw fixation showed a mean tunnel volume change of 108.15 ± 13.7% on the tibial side and 124.07 ± 25.38% on the femoral side. The group with femoral button fixation showed a tunnel volume change of 111.12 ± 12.72% on the tibial side and 130.96 ± 21.71% on the femoral side. The differences in femoral tunnel volume changes were not significant (P = 0.562). Femoral tunnels with PEEK screw fixation showed significantly larger diameter after 12 months in comparison with button fixation (13.02 ± 1.43 mm vs. 10.46 ± 1.29 mm, P < 0.001).ConclusionsPEEK interference screws were associated with significant tibial and femoral tunnel enlargement. Femoral tunnel enlargement was comparable between PEEK interference screws and button fixation. Final femoral tunnel diameter was significantly larger with PEEK screw fixation in comparison to button fixation.

The apex of the deep cartilage is a stable landmark to position the femoral tunnel during remnant-preserving anterior cruciate ligament reconstruction.

The aim of this retrospective cohort study was to investigate whether the apex of the deep cartilage (ADC) could help surgeons position the femoral tunnel accurately in remnant-preserving anterior cruciate ligament (ACL) reconstruction (ACLR). In the current retrospective cohort study, a total of 134 patients who underwent ACLR between 2016 and 2020 were included. The femoral tunnel position was located using ADC as the landmark. The patients were divided into two groups: the remnant-preserving group (RP group, n = 68) underwent remnant-preserving ACLR, and the nonremnant group (NRP group, n = 66) underwent traditional ACLR with remnant removal. Postoperatively, the femoral tunnel position was evaluated on 3D-CT. The length from the ADC to the shallow cartilage margin (L) and to the centre of the femoral tunnel (l) and the length from the centre of the femoral tunnel to a low cartilage ratio in the direction from high to low (H) were measured. The l/L values of the RP and NRP groups were both 0.4 ± 0.1 after rounding (n.s.), and the H values were 9.3 ± 1.6mm and 9.3 ± 1.7mm, respectively (n.s.). There was no significant difference in l/L or H between the two groups. The estimation plot also showed high consistency of H and l/L of the two groups. The inter- and intraobserver reliability of I, L, l/L, and H were almost perfect. The apex of the deep cartilage is a good landmark for positioning the femoral tunnel in remnant-preserving ACL reconstruction. Level III.

Race and Gender Differences in Anterior Cruciate Ligament Femoral Footprint Location and Orientation: A 3D-MRI Study.

The femoral tunnel position is crucial to anatomic single-bundle anterior cruciate ligament (ACL) reconstruction, but the ideal femoral footprint position are mostly based on small-sized cadaveric studies and elderly patients with a single ethnic background. This study aimed to identify potential race- or gender-specific differences in the ACL femoral footprint location and ACL orientation, determine the correlation between the ACL orientation and the femoral footprint location. Magnetic resonance images (MRIs) of 90 Caucasian participants and 90 matched Chinese subjects were used for reconstruction of three-dimensional (3D) femur and tibial models. ACL footprints were sketched by several experienced orthopedic surgeons on the MRI photographs. The anatomical coordinate system was applied to reflect the ACL footprint location and orientation of scanned samples. The femoral ACL footprint locations were represented by their distance from the origin in the anteroposterior (A/P) and distal-proximal (D/P) directions. The orientation of the ACL was described with the sagittal, coronal and transverse deviation angles. The ACL orientation and femoral footprint position were compared by the two-sided t-test. Multiple regression analysis was used to study the correlation between the orientation and femoral footprint position. The average femur footprint A/P position was -6.6 ± 1.6 mm in the Chinese group and -5.1 ± 2.3 mm in the Caucasian group, (p < 0.001). The average femur footprint D/P position was -2.8 ± 2.4 mm in Chinese and - 3.9 ± 2.0 mm in Caucasians, (p = 0.001). The Chinese group had a mean difference of a 1.5 mm (6.1%) more posterior and 1.1 mm (5.3%) more proximal in the position from the flexion-extension axis (FEA). And the males have a sagittal plane elevation about 4-5° higher than females in both racial groups. Furthermore, for every 1% (0.40 mm) increase in A/P and D/P values, the sagittal angle decreased by about 0.12° and 0.24°, respectively; the coronal angle decreased by about 0.10° and 0.30°, respectively. For every 1% (0.40 mm) increase in D/P value, the transverse angle increased by about 0.14°. The significant race- and gender-specific differences in the femoral footprint and orientation of the ACL should be taken in consideration during anatomic single-bundle ACL reconstruction. Furthermore, the quantitative relationship between the ACL orientation and the footprint location might provide some reference for surgeons to develop a surgical strategy in ACL single-bundle reconstruction and revision.

Reconstruction of Superficial Medial Collateral Ligament: Modified Danish Technique with Dual Adjustable Loop Suspensory Fixation

Injury to the superficial medial collateral ligament (MCL) is treated conservatively for low-grade injury and with surgery for high-grade injury, especially in association with cruciate ligament injury. Acute injuries are treated with MCL repair, and chronic injury requires reconstruction. Anatomic MCL reconstruction can be done using free allograft or autograft and fixed using screws or suspensory fixation. We describe here an anatomic technique that is a modification of a Danish technique in which we reroute the semitendinosus, keeping its tibial attachment intact. The semitendinosus is rerouted anatomically in the tibial tunnel, and a graft is then passed anatomically in the femoral tunnel. The graft is fixed in both tunnels with adjustable loop suspensory fixation, which gives the unique advantage of controlled tensioning of the graft for MCL reconstruction. In this technique further re-tensioning is possible if the knee is unstable in valgus stress, even after final fixation.

Reconstruction of the Posterior Cruciate Ligament and Medial Collateral Ligament With a Single Combined Femoral Tunnel

Background: Lesions of the medial collateral ligament (MCL) are the most common knee ligament injuries and, when they occur in isolation, they often progress with satisfactory outcomes using conservative treatment. However, MCL lesions associated with anterior cruciate ligament or posterior cruciate ligament (PCL) injuries in knee dislocations should be reconstructed to prevent failure of the central pivot. In knees with combined injuries involving the PCL and the MCL, the confluence of tunnels in the medial femoral condyle can be a potential problem during reconstruction surgery. Indications: The indication of this technique is the combined injury of the PCL and the MCL. Technique Description: The technique consists in the reconstruction of the PCL and the MCL with an Achilles tendon allograft. The bone plug of the graft is fixed on the tibial bed with the inlay technique. The graft passes through a single femoral tunnel drilled in the medial femoral condyle, with entrance point on the footprint of the PCL on the inner wall of the condyle and exit on the origin of the native MCL, near to the medial epicondyle. The graft is fixed in the femoral tunnel with an interference screw and continues to the isometric point of the anatomic insertion of the MCL in the tibia, where an interference screw is used to fix it. Results: Results from our group using this technique have shown good clinical outcomes, with complications and failure rates similar to other series in the literature. Discussion/Conclusion: This technique is an excellent option for surgeons, when an Achilles tendon allograft is available, to avoid confluence of tunnels in the medial femoral condyle. It presents good results and acceptable complication rates, compatible with the severity of this lesion. 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.

Posterior Proximal Cartilage of the Lateral Femoral Condyle as a Reference for Positioning the Femoral Tunnel in ACL Reconstruction

Background: Due to the similarity among specimens in the height of the anterior cruciate ligament (ACL) on the distal proximal axis in relation to the proximal posterior cartilage of the lateral femoral condyle (point C), it is known this point can be used as an arthroscopic intraoperative parameter to define the position of the femoral tunnel in ACL reconstruction. Indications: For ACL reconstruction, point C can be used as an arthroscopic intraoperative parameter to define the position of the femoral tunnel on the distal proximal and anteroposterior axes. Technique Description: For access to the joint, standard arthroscopic ports, both anterolateral (AL) and anteromedial (AM), are used. By directing the camera toward the posterior region of the lateral femoral condyle through the AM port, it is possible to visualize the end of the posterior and proximal articular cartilage, the so-called C point. In this case, we sought to position the center of the femoral tunnel in the center of the AM band of the ACL. Holding the camera through the AM portal and visualizing point C, a millimeter-scale femoral guide is introduced through the AL portal toward the posterior femoral cartilage (point C) and positioned over it, creating a line between point C and the lateral distal femoral cartilage. The distance between point C and the distal femoral cartilage is measured. At this time, an accessory AM portal 1.5 cm from the AM port is constructed. Through it, with the aid of an ice pick or radiofrequency tip, a marking is made in the deep to shallow axis at 35% of this distance. Then, approximately 2 mm above the imaginary line formed by the union of point C and the lateral distal femoral cartilage, the center of the femoral tunnel is marked. Results: Point C is an anatomical landmark that is easy to view and is present in all knees; thus, it can be used as a reference during surgery for positioning the femoral tunnel. Discussion/Conclusion: Point C can be used as an arthroscopic intraoperative parameter to define the position of the femoral tunnel in ACL 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.

Effect of Age and Femoral Tunnel Drilling Technique on the Prevalence of Intra-articular Pathology at Both Primary and Revision ACL Reconstruction

Background: Studies have shown that meniscal and chondral lesions are more common at the time of revision anterior cruciate ligament reconstruction (ACLR) compared with primary surgery; however, few have evaluated the same patients through both primary and revision surgery. Purpose: To describe the prevalence of meniscal and chondral lesions at the time of primary and subsequent revision ACLR and to determine the effect of age and femoral tunnel drilling technique on the development of intra-articular pathology over time. Study Design: Case series; Level of evidence, 4. Methods: All patients who had primary and subsequent revision ACLR in the same knee between 1997 and 2022 were identified from a prospectively collated database. The grading of chondral surfaces in each compartment, the presence of any meniscal tears, and treatment performed were recorded. Patients were grouped according to age and femoral tunnel drilling technique to allow subgroup analysis. Results: Overall, 262 patients were included. Median age at primary surgery was 20.2 years. Lateral meniscal tears were more prevalent than medial tears at both primary (34.7% vs 28.2%; P = .11) and revision surgery (44.3% vs 40.8%; P = .43). Chondral lesions were most frequently found on the patella (8.8%) and the medial femoral condyle (MFC; 8.0%) at primary surgery. Between surgeries, new lesions developed most commonly on the MFC (13.0%) and the lateral femoral condyle (LFC; 11.1%). It was significantly more common for lateral meniscal tears treated with repair or left in situ at primary surgery to be healed at the time of revision surgery than medial tears ( P = .01). Significantly more patients who had transtibial drilling of the femoral tunnel had a new meniscal tear at revision surgery ( P = .001). Age did not have a significant influence on the prevalence of meniscal pathology. Conclusion: The prevalence of intra-articular pathology increased between primary and revision ACLR. Lateral meniscal tears were more prevalent than medial tears at both surgeries. At revision surgery, new chondral lesions were more commonly found on the MFC than the LFC. The higher incidence of new meniscal tears observed in the transtibial group may reflect the more vertical graft orientation with this technique and its inferior ability to control rotation.