Tibial Insertion Of Anterior Cruciate Ligament Research Articles

Bony and soft tissue landmarks of the ACL tibial insertion site: an anatomical study

To identify and describe reliable landmarks for tibial tunnel placement in anatomical ACL reconstruction. Eight non-paired cadaveric knees were used. After dissection, the tibial plateaus, menisci and ACL insertions were grossly observed to identify anatomical landmarks and relate them to the ACL insertion site. The specimens were scanned with a laser scanner, and 3-Dimensional images were obtained. Measurements of the ACL tibial insertion were taken. The center of the ACL and its bundles was measured regarding the distance from the medial tibial eminence and intermeniscal ligament. The medial tibial eminence demonstrated a constant relationship with the ACL tibial insertion site center and its bundles, as well as the intermeniscal ligament. The anterior root of the lateral meniscus had a variable relationship with the ACL tibial insertion. The length of the ACL tibial insertion was 18.1±2.8mm and the width was 10.7±1.9mm. The width of the AM bundle was 11.1±2.1mm and the PL 7.9±2.0mm. The ACL center was 9.1±1.5mm posterior to the intermeniscal ligament and 5.7±1.1mm anterior to a projected line from the apex of the medial tibial eminence. The center of the AM bundle was at 4.6±0.7mm posterior to the intermeniscal ligament. The center of the PL bundle was 1.4±0.7mm anterior to the medial tibial eminence. The medial tibial eminence and the intermeniscal ligament may be used as landmarks to guide the correct tunnel placement in an anatomical ACL reconstruction.

Anterior Cruciate Ligament Reconstruction Using Remnant Preservation and a Femoral Tensioning Technique: Clinical and Magnetic Resonance Imaging Results

The purpose of this study was to investigate the clinical and magnetic resonance imaging (MRI) results of anterior cruciate ligament (ACL) reconstruction with autogenous hamstring tendon by use of remnant preservation and a femoral tensioning technique. A total of 53 patients who had ACL reconstruction by use of remnant ACL stump preservation and a femoral tensioning technique were evaluated. Clinical evaluation at a minimum of 2 years after surgery included range of motion, Lachman test, pivot-shift test, KT-2000 arthrometer testing (MEDmetric, San Diego, CA), and clinical scores. Plain radiographs were evaluated for tunnel enlargement. MRI was obtained for evaluation of graft continuity, cyclops-like mass lesion, and positioning of the tibial tunnel. Second-look arthroscopy was performed in 33 patients. The clinical scores improved postoperatively. There were statistically significant differences between preoperative and postoperative Lachman tests, pivot-shift tests, and KT-2000 arthrometer measurements. Postoperative MRI was available in 48 patients, and it showed intact graft in 45 patients, 2 partial tears, and 1 complete loss of graft. There were cyclops-like mass lesions in 12 patients, but none showed an extension limitation or pain at extension. The position of the tibial tunnel on the sagittal and coronal view was similar to the position of the normal ACL tibial insertion. The measured tibial tunnel widening on the radiographs at final follow-up was 2.2 ± 1.5 mm. Reconstruction of the ACL by use of preservation and femoral tensioning of the remnant tissue showed good clinical results without increased concerns regarding incorrect tunnel formation. Postoperative MRI showed an increased incidence of cyclops-like mass lesions, but no clinical significance was observed. Level IV, case series.

Size Variability of the Human Anterior Cruciate Ligament Insertion Sites

Background: Current trends in anterior cruciate ligament reconstruction (ACLR) have been toward anatomical reconstruction that restores the normal size and location of the anterior cruciate ligament insertions and its 2 bundles, the posterolateral (PL) and anteromedial (AM) bundles. This has resulted in a more individualized approach to ACLR. Several studies have shown that the size of the anterior cruciate ligament insertion sites is variable; however, these studies are limited by use of relatively small sample sizes and cadaveric specimens. Purpose: This study was undertaken to evaluate the in vivo size variability of the anterior cruciate ligament insertion sites and its AM and PL bundles during arthroscopy in a large series of patients and to correlate these findings with individuals’ physical characteristics (height, weight, and body mass index). Study Design: Cross-sectional study; Level of evidence, 3. Methods: In 137 patients undergoing ACLR during the first 6 months after injury, the femoral and tibial anterior cruciate ligament insertion sites and the 2 bundles were identified, marked with electrocautery, and measured with an arthroscopic ruler. Additionally, physical characteristics of the patients, including self-reported height, weight, and body mass index, were recorded. Results: The tibial anterior cruciate ligament insertion site had a mean length of 17.0 ± 2.0 mm. The tibial AM bundle length was 9.1 ± 1.2 mm and the width was 9.2 ± 1.1 mm. The tibial PL bundle insertion site length averaged 7.4± 1.0 mm and the width averaged 7.0 ± 1.0 mm. The femoral insertion sites had a mean length of 16.5 ± 2.0 mm. The length of the femoral AM bundle insertion site averaged 9.2 ± 1.2 mm and the width averaged 8.9 ± 0.9 mm. The femoral PL bundle insertion site length averaged 7.1 ± 1.1 mm and the width averaged 6.9 ± 1.0 mm. There were significant positive correlations between patient height and weight (P < .05) with femoral and tibial anterior cruciate ligament insertion site length, tibial PL bundle insertion site length, femoral AM bundle insertion site length, and tibial AM bundle and PL bundle insertion site areas. However, the coefficients of determination values were low (1.0% to 19.4%). Conclusion: There is a large variation in size of the anterior cruciate ligament insertion sites and the AM and PL bundles. Additionally, there are significant but weak correlations between the size of the insertions and height, weight, and body mass index of the individual patient.

A systematic review of the femoral origin and tibial insertion morphology of the ACL

Transtibial single bundle anterior cruciate ligament (ACL) reconstruction has been the gold standard for several years. This technique often fails to restore native ACL femoral origin and tibial insertion anatomy of the ACL. Recently, there is a strong trend towards a more anatomical approach in single and double bundle ACL reconstruction. Using the anatomic double bundle structure of the ACL as a principle, the entirety of both tibial insertion and femoral origin of both bundles, the posterolateral and anteromedial, may be restored. Reflected by recent publications over the past two years, there is an increasing interest in the anatomy of the ACL. In the current study, a PubMed literature search was performed looking for measurements of the ACL femoral origin and tibial insertion. These studies show a large variability in the size and the anatomy of the femoral origin and tibial ACL insertion using different methods and specimens. The diversity of reported measurements makes clinical application of these data difficult at best. Thus, it is of paramount importance to understand the individual variations in size and shape of the ACL femoral origin and tibial ACL insertion. This study is a systematic review of the morphology of the ACL femoral origin and tibial insertion as reported in the literature.

Double-Bundle Anterior Cruciate Ligament Reconstruction: The Italian Experience

In our original technique, semitendinosus/gracilis tendons are harvested without detaching their tibial insertion, and sutures are tightened at their free proximal extremities. The tibial tunnel is performed in the medial-posterior portion of the native anterior cruciate ligament tibial insertion. For the femoral tunnel, the knee is flexed at 130° and the guide pin is advanced in the 9:30 clockwise position until it passes the lateral femoral condyle cortex. The exit point in the lateral aspect of the femur has to be immediately above the end of the lateral femoral condyle. After the lateral incision, the tendons are passed over the top. The correct placement is found by palpating the posterior tubercle of the lateral femoral condyle. The stitches on the free proximal end of the tendons are tied onto the passing suture that is pulled through the joint to the over the top position. A suture loop is introduced into the joint through the anteromedial portal using a suture passer and then pulled into the femoral tunnel under the arthroscopic view. The stitches on the free end of the tendons are looped again onto the passing suture, which is pulled through the femoral tunnel, the knee joint, and the tibial tunnel to retrieve back the graft from the tibial incision. The combined gracilis and semitendinosus graft are then tensioned and fixed with a transosseous suture or a staple. This technique reproduces the kinematic effect of posterolateral and anteromedial anterior cruciate ligament bundles with a 4-stranded graft, although achieving a better anatomic and functional result.

Anatomical study of the human anterior cruciate ligament stump’s tibial insertion footprint

The aim of this study is to define the topographical relationship of the anatomical bundles of the human anterior cruciate ligament's (ACL) stump over the tibial insertion site. Between January and April 2007, a total of 36 resected tibial plateaus were retrieved from patients who underwent total knee replacements. These samples had intact cruciate ligaments with no major osteophyte around the ACL tibial insertion footprint. The anatomical bundles of the ACL were identified and mapped, based on the topographical relationship over the tibial insertion footprint. Measurements of the dimensions of the ACL tibial footprint and tibial plateau were performed. The mean width and midsagittal depth of the tibia plateau was 78.7 +/- 6.5 and 46.4 +/- 5.0 mm, respectively. The mean width and midsagittal depth of the ACL tibial footprint was 10.3 +/- 1.9 and 19.5 +/- 2.6 mm, respectively. Out of the 36 freshly dissected ACL stumps, it was not possible to distinguish separate bundles in 14 (38.9%) cases. The average distance between the centers of the two bundles was 9.3 +/- 1.8 mm. The mean AP alignment of the tibial footprint was 89.6 degrees +/- 26.4 degrees , with a very wide range of 23 degrees -158 degrees . Of the 22 specimens with separate anatomical bundles, the alignment of the tibial footprint was AM-PL in six (27.3%), sagittal (85 degrees -95 degrees ) in five (22.7), AL-PM in nine (40.9%), and lateral-medial (L-M) in two (9.1%) cases. This study provides new information about the topographical anatomy of the ACL tibial insertion footprint. Based on gross anatomy, separate anatomical bundles of the ACL can be distinguished in 61.1% [22] of the specimens. The topographical alignment of the separate bundles is varied on a very wide range.

Tibial Insertions of the Anteromedial and Posterolateral Bundles of the Anterior Cruciate Ligament: Morphometry, Arthroscopic Landmarks, and Orientation Model for Bone Tunnel Placement

For arthroscopic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction, the size of the available area for tibial bone tunnel placement is crucial. Therefore, tibial insertions of the anteromedial (AM) and posterolateral (PL) bundles in the area intercondylaris anterior (AIA) of the tibia were quantified, landmarks were characterized, and an arthroscopic orientation model was developed. The tibial insertions of the AM and PL bundles were dissected in 50 human cadaver knees. The footprints were documented on digital photographs and measured using a digital image analysis system. The average tibial ACL insertion area was 114 mm2 and varied considerably in size from 67 to 259 mm2. It was significantly smaller in female knees (P = .04) compared to male knees. The insertion area of the AM bundle was an average of 67 mm2 and that of the PL was 52 mm2. The centers of both bundles were an average of 5 mm apart near the middle of the ACL insertion. Important landmarks for arthroscopic DB bone tunnel placement were the ACL stump, respectively, its anterior and posterior borders; the rims of the articular surfaces of the medial and lateral tibial condyles, which border the AIA; and the posterior horn of the lateral meniscus. The new "tibial square model" indicates a minimum anteroposterior length of 14 to 15 mm for separate AM and PL bone tunnel placement. The prospective area for tibial bone tunnels varied from spacious to very small among the specimens, and the insertions and centers of the AM and PL bundles cannot be exactly anatomically reconstructed. For DB ACL reconstruction, an intraoperative hypothetical situation of 6 mm for the AM tunnel and 5 mm for the PL tunnel may be reasonable when considering an average length of the tibial ACL insertion area of 14 mm in women and 15 mm in men. Individual anatomic variations make it difficult to have general guidelines, but tibial landmarks and the "tibial square model" may assist in individualized bone tunnel placement. Anatomic description of morphology of tibial AM and PL insertions, landmarks, and orientation models for reproducible arthroscopic DB bone tunnel placement.

Histological changes and apoptosis of cartilage layer in human anterior cruciate ligament tibial insertion after rupture

The purpose of this study is to investigate the histological changes and apoptosis of cartilaginous layers in human anterior cruciate ligament (ACL) tibial insertion at different time periods after rupture. By using a core reamer, 35 tibial insertions of ruptured ACLs were obtained during primary ACL reconstructions (number of days after injury: 19-206 days). A histological examination was performed and a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining assay was carried out to detect apoptosis. The average thickness of the cartilage layer, the glycosaminoglycan-stained area and the number of chondrocytes per millimeter decreased with time. The percentage average of TUNEL-positive chondrocytes was 42.0 +/- 16.2. The histological degenerative changes of the cartilage layer in the ruptured ACL tibial insertion progressed with time, especially in the first 2 months. Moreover, chondrocyte apoptosis continued from 19 to 206 days after rupture. The results may help elucidate the etiology of the histological changes of the insertion, and may help in devising optimal treatment protocols for ACL injuries if apoptosis is controlled. Moreover, we consider that using a surviving ligament and minimizing a debridement of ACL remnant during ACL reconstruction may be important for ACL reconstruction to maintain cartilage layers in ACL insertions.

ACL reconstruction and the implication of its tibial attachment for stability of the joint: anthropometric and biomechanical study

The planar topography of the anterior cruciate ligament (ACL) insertion was investigated and correlated to the use of the double-bundle/double tibial tunnel ACL reconstruction technique within the ACL tibial insertion area. The anteroposterior and mediolateral length of the tibial ACL attachment and the distances of the tibial insertion area from the anterior and posterior tibial borders were measured and the stability of the joint was tested using the double-bundle/double tibial tunnel ACL reconstruction technique. The anteroposterior length, 19.54 mm in men and 17.36 mm in women, of the ACL insertion, averaged approximately 40% of the total intercondylar anteroposterior dimension of the plateau. This broad distribution of insertion fibres ensures ligament tension and hence joint stability. The reported anteroposterior broad insertion of ACL fibres to the tibia is not sufficiently reproduced by the use of one or more bundles having a common tibial tunnel for the ACL reconstruction. In our view, this might be better achieved with two different bundles, with separate tunnels, and independent tensioning in different knee angles. This technique might achieve better results in human knee stability as opposed to other reported techniques.

A positioning study of the tibial non-impingement region during the reconstruction of anterior cruciate ligament (ACL)

目的 探讨前交叉韧带(ACL)重建术中胫骨隧道无撞击重建区的定位.方法选用10具正常新鲜冷冻尸体膝关节标本,膝关节完全伸直时,标记髁间窝顶延长线和ACL胫骨附着处的交点.膝关节屈曲90°时,测量ACL胫骨附着处上标记点与ACL前缘间的距离及标记点与胫骨棘间区后缘间的距离.然后,再测量标记点前部分的前后径、后部分的前后径和内外径,并计算后部分的面积.结果由ACL胫骨附着处前缘到胫骨棘间区后缘的前后径平均为(21.40±1.17)mm.ACL胫骨附着处标记点前部分的前后径平均为(8.90±0.74)mm(占总前后径的41.59%).胫骨附着处标记点后部分的前后径平均为(12.50±0.85)mm(占总前后径的58.41%),内外径平均为(10.65±0.97)mm,面积平均为(133.80±21.01)mm2.结论ACL胫骨附着处上标记点的后部分是胫骨隧道无撞击区,位于胫骨棘间区的后缘中点与该点前12.50mm之间,在该区域行ACL重建可以避免移植物与髁间窝顶部的撞击.绝对撞击区位于ACL胫骨附着部前缘与其后8.90 mm之间,应尽量避免在此区域内定位胫骨隧道。

Anatomic anterior cruciate ligament reconstruction using the over-the-top passage of hamstring tendons

The anterior cruciate ligament (ACL) reconstruction using a double-bundle gracilis and semitendinosus technique guarantees a more anatomic reconstruction and allows the surgeon to avoid the use of hardware for graft fixation. The tendons are harvested, maintaining their tibial insertion. The tibial tunnel is located in the medioposterior part of the ACL tibial insertion. For the femoral tunnel, the guide pin is advanced from anteromedial portal to 10 o’clock position in the medial wall of the lateral condyle and passes until reach the femoral cortex. The exit point in the lateral aspect of the femur should be immediately above the end of the lateral femoral condyle . The tendons are passed over the top. The correct placement is found by palpating the posterior tubercle of the lateral femoral condyle with a finger. The stitches on the free end of the tendons are tied onto the passing suture that is pulled through the knee joint into the over-the-top position. A suture loop is introduced into the joint through the anteromedial portal using a suture passer and then pulled into the femoral tunnel. The stitches on the free end of the tendons are looped again onto the passing suture, which is pulled through the femoral tunnel, knee joint, and tibial tunnel to retrieve the graft from the tibial incision . The combined gracilis and semitendinosus tendons are then tensioned and secured with a transosseous suture knot. This technique attempts to reproduce the kinematic effect of both anteromedial and posterolateral bundle of the ACL.

The Normal Anterior Cruciate Ligament as a Model for Tensioning Strategies in Anterior Cruciate Ligament Grafts

Background There is some confusion about the relationship between the tension placed on the graft and the joint position used in the fixation of anterior cruciate ligament grafts. This is because of deficiency in accurate basic science about this important interaction in the normal and reconstructed anterior cruciate ligament. Hypothesis If the normal femoral attachment of the anterior cruciate ligament can be preserved and the tibial insertion isolated and tested, an accurate force-flexion curve of the human anterior cruciate ligament can be mapped out and used as a standard for proper graft tensioning protocols in anterior cruciate ligament reconstruction. Study Design Controlled laboratory study. Methods In 10 fresh-frozen human cadaveric knees, an isolated bone plug containing the tibial anterior cruciate ligament insertion was connected with a custom-made tensiometer. The knees were moved through the whole range of motion; the starting point chosen was an anterior cruciate ligament tension of 10 N, which was applied at 10 ° of knee flexion and resulted in a baseline curve. This curve was compared with the results recorded when the starting point was below the baseline curve, similar to, or above it. Results The anterior cruciate ligament showed low tension close to slackness in midflexion after starting with 10 N at 10 ° of flexion. Starting points below the baseline curve shifted the whole curve downward; those above the baseline curve increased the force in the anterior cruciate ligament, resulting in a tight anterior cruciate ligament in midflexion. Clinical Relevance The normal anterior cruciate ligament shows a physiological laxity in midflexion. This study gives guidelines for tensioning protocols in anterior cruciate ligament grafts to replicate the force-flexion curve characteristics of the normal anterior cruciate ligament.

A potential animal model for creating a controlled and reversible anterior cruciate ligament insufficiency

We developed and tested a device to manipulate the axial position of the tibial anterior cruciate ligament (ACL) insertion in vitro to create a potential animal model that could simulate both ACL insufficiency and ‘optimal’ ACL reconstruction. This model is based on the concept that controlled incremental proximal displacement of the tibial ACL insertion simulates ACL insufficiency. Replacing the insertion at the joint level and then adjusting its position until the forces recorded equaled those in the ACL-intact knee can simulate ‘optimal’ ACL reconstruction. Anterior tibial translation (ATT) was quantified in vitro in 24 sheep cadaver knees with the ACL intact and after the ACL was cut or detached (ACL insufficiency). In 8 knees, a bone plug including the tibial ACL insertion was detached, mounted in a specially designed device, and adjusted to reproduce ATT of the ACL-intact knee. ATT was then measured after proximal displacement of the tibial ACL insertion in calibrated 1 mm increments. The results revealed that detaching the ACL increased ATT by 132–700%. Controlled 3 mm proximal displacement of the insertion using this device increased ATT by more than 100%. Comparing the increase in ATT due to controlled displacement of the ACL insertion to that due to detaching the ACL, in only one case was the same magnitude of ACL insufficiency reproduced. Despite the variability between knees, the device was able to reproduce ATT of the ACL-intact knee and to substantially increase ATT with controlled proximal displacement of the tibial ACL insertion. Use of this device, if successful in an in vivo ACL reconstruction model, could help define any quantitative association between altered joint kinematics and degenerative changes in the joint.

Insertion-site anatomy of the human menisci: Gross, arthroscopic, and topographical anatomy as a basis for meniscal transplantation

A cadaveric study was performed to determine the insertion-site anatomy of the human menisci, their topographical relationships to adjacent intra-articular structures, and which arthroscopic portal provides for optimal visualization of each insertion site. Fifteen fresh-frozen cadaver knees were studied (ages 48 to 63 years). Ten knees underwent arthroscopy using four standard arthroscopic portals. Visualization and placement of an arthroscopic guide over each meniscal horn insertion site was attempted through the four arthroscopic portals. Guide wires were drilled to mark horn insertions followed by a gross dissection to evaluate accuracy of the guide wire gross dissection to evaluate accuracy of the guide wire placement and to isolate meniscal horn insertion sites. Insertion sites were outlined and evaluated for size and topographical relationships to other intra-articular structures. Five additional knees were dissected free of all soft tissues except the tibial insertions of the meniscal roots and anterior cruciate ligament/posterior cruciate ligament. Each tibia was mounted in a jig and a digitizing system was used to record coordinates of points along the outline of each bony meniscal horn insertion site, the ACL tibial insertion, and the articular surface of each tibial plateau. The x, y, z coordinates for each point were calculated and loaded into a computer program allowing for surface area determination and computer-generated topographical maps to assess relative position of each specific insertion site. Placement of the arthroscope in the anterolateral portal allows optimal visualization and guide wire placement for both lateral meniscal horn insertion sites. Medial meniscal anterior and posterior horn insertion sites are best visualized with the arthroscope in the anteromedial and posteromedial portals respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Construction of finite element model and stress analysis of anterior cruciate ligament tibial insertion.

Objective:The aim of the present study was to develop a more realistic finite element (FE) model of the human anterior cruciate ligament (ACL) tibial insertion and to analyze the stress distribution in the ACL internal fibers under load.Methods:The ACL tibial insertions were processed histologically. With Photoshop software, digital images taken from the histological slides were collaged, contour lines were drawn, and different gray values were filled based on the structure. The data were exported to Amira software and saved as “.hmascii” file. This document was imported into HyperMesh software. The solid mesh model generated using HyperMesh software was imported into Abaqus software. The material properties were introduced, boundary conditions were set, and load was added to carry out the FE analysis.Results:The stress distribution of the ACL internal fibers was uneven. The lowest stress could be observed in the ACL lateral fibers under tensile and shear load.Conclusion:The establishment of ACL tibial insertion FE model and mechanical analysis could reveal the stress distribution in the ACL internal fibers under load. There was greater load carrying capacity in the ACL lateral fibers which could sustain greater tensile and shear forces.

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A positional relationship between the anterior cruciate ligament (ACL) and the anterior horn of the lateral meniscus (AHLM) has not previously been a topic of interest in the literature because the AHLM is already known to be obviously adjacent to the ACL and is assumed as a lateral border. The objective of this study was to investigate the positional anatomic relationship between the ACL and AHLM by histological evaluation of sequential slices and computed tomography (CT) of the tibial insertion sites.The ACL has a specific positional relationship with the AHLM and there is an identifiable distinct bony border between them. The position of the AHLM could be an important and useful landmark for accurate tibial tunnel positioning in anatomical ACL reconstruction.Descriptive laboratory study.Twelve ACL-intact knees from embalmed cadavers were used in this study. Six knees were sectioned into four slices for histologic examination in the coronal planes parallel to the AHLM alignment. Before sectioning, these knees were subjected to three-dimensional (3-D) volume-rendering CT. Each of the four slices demonstrated the insertion area of the ACL relative to the position of the AHLM. Each histologic slice was compared with the corresponding CT image. Only histological examination in the sagittal planes was performed in the other six knees.The ACL fibres were broadly attached at the region anterior to the AHLM. However, the ACL and AHLM shared a clear border identifiable on the coronal CT images and appeared as a prominence of the bony ridge on the 3-D CT images. No dense ACL fibres were attached to the region posterior to the AHLM. Based on the histological data, the geometry of the ACL tibial insertion was L-shaped along the AHLM.The ACL and AHLM have a specific positional relationship not only in the mediolateral direction but also anteroposteriorly. The AHLM serves not only as a lateral border, but also as a useful reference in an anterioposterior direction for tunnel positioning in ACL reconstruction. Specifically, the ACL fibres were found to be broadly attached onto the bony surface in the region anterior to the AHLM and there was no firm attachment of the ACL in the region posterior to the AHLM on the tibial side, which is useful in avoiding posterior tunnel placement.