Tibial Tunnel Position Research Articles

Femoral and tibial tunnel positioning on graft isometry in anterior cruciate ligament reconstruction: a cadaveric study.

To assess distance changes between the femoral and tibial attachment points of 3 different anterior cruciate ligament (ACL) tunnel entry positions throughout the range of knee motion in cadaveric knees. The ACLs of 11 fresh-frozen cadaveric knees (from 6 men and 5 women) were removed using radiofrequency. Three tibial tunnel placements were made using a cannulated awl, and three 2.4-mm pilot tunnels were drilled on the lateral femoral condyle. One end of an inelastic suture was inserted from each of the 3 femoral holes and fixed on the femoral cortex using a suture button in turn, whereas the other end of the suture was passed through the cannulated awl and fixed on each of the 3 tibial placements in turn, with constant tension. Distance changes of the suture throughout the range of knee movement (0º, 90º, and 135º of knee flexion) were measured for each combination of tibial and femoral positions. The distance was minimum when the knee was in full extension (p < 0.0001). Most of the distance changes occurred during initial flexion (0º-90º). The most isometric position (mean ± standard deviation [SD] distance change, 2.78 ± 0.93 mm; p < 0.0001) was noted when the suture was at the anteromedial bundle placement in the femur and anterior in the tibia. The least isometric position (mean ± SD distance change, 10.37 ± 2.08 mm; p < 0.0001) was noted when the suture was at the mid-bundle position in the femur and at the posterolateral bundle insertion in the tibia. The anatomic position resulted in a mean ± SD distance change of 7.63 ± 2.01 mm (p < 0.0001). The femoral position had a greater influence on distance change than the tibial position. None of the ACL graft positions was isometric. Anatomic ACL positioning resulted in comparable anisometry to the native ACL. The minimum distance for all graft positions was noted in full extension, in which position the graft should be fixed during anatomic ACL reconstruction.

The predictive effect of anatomic femoral and tibial graft tunnel placement in posterior cruciate ligament reconstruction on functional and radiological outcome.

Biomechanical reports have advocated anatomic graft tunnel placement for reconstruction of the posterior cruciate ligament (PCL) to restore knee joint stability and facilitate optimal functional outcome. However, in vivo investigations that correlate tunnel position to functional results are lacking so far. This study evaluates the anatomic accuracy of femoral and tibial tunnel apertures on postoperative computed tomography (CT) scans and compares these findings to subjective and objective clinical outcome parameters. After single-bundle PCL reconstruction, 29 patients were stratified into several subgroups according to the anatomic accuracy of femoral and tibial tunnel apertures measured on postoperative CT scans. A threshold value for the centres of the tunnel apertures was determined using a measurement grid system as a radiographic reference. To evaluate the functional and radiological results, visual analogue scale, International Knee Documentation Committee (IKDC), Tegner, Lysholm, Knee Injury and Osteoarthritis Outcome Score and osteoarthritis scores were obtained. Comparison between functional outcome and tunnel position yielded a statistically significant difference for subjective IKDC score and angle segment α and for objective stability and tunnel position P3 but no statistically significant difference with respect to intercondylar depth, intercondylar height and tibial tunnel position P2. No correlation was found between anatomic tunnel position and present or progressive osteoarthritis on follow-up. Of the patients, 72 % classified their result as excellent and good and 90 % would repeat surgical treatment. Despite a small sample size and subject to the threshold values we used, our data indicate a potentially minor effect of anatomic tunnel placement on midterm functional outcome following PCL reconstruction.

Skeletal imaging following reconstruction of the posterior cruciate ligament: in vivo comparison of fluoroscopy, radiography, and computed tomography.

Intra- and postoperative validation of anatomic footprint replication in posterior cruciate ligament (PCL) reconstruction can be conducted using fluoroscopy, radiography, or computed tomography (CT) scans. However, effectiveness and exposure to radiation of these imaging modalities are unknown. The objective of this study was to evaluate the comparative effectiveness of fluoroscopy, radiography, and CT in detecting femoral and tibial tunnel positions following an all-inside reconstruction of the PCL ligament in vivo. The study design was a retrospective case series. Intraoperative fluoroscopic images, postoperative radiographs, and CT scans were obtained in 50 consecutive patients following single-bundle PCL reconstruction. The centers of the tibial and femoral tunnel apertures were identified and correlated to measurement grid systems. The results of fluoroscopic, radiographic, and CT measurements were compared to each other and accumulated radiation dosages were calculated. Comparing the imaging groups, no statistically significant difference could be detected for the reference of the femoral tunnel to the intercondylar depth and height, for the reference of the tibial tunnel to the mediolateral diameter of the tibial plateau and for the superoinferior distance of the tibial tunnel entry to the tibial plateau and to the former physis line. Effective doses resulting from fluoroscopic, radiographic, and CT exposure averaged 2.9mSv, standard deviation (±SD) 4.1mSv, to 1.3 ± 0.8mSv and to 3.6 ± 1.0mSv, respectively. Fluoroscopy, radiography, and CT yield approximately equal effectiveness in detecting parameters used for quality validation intra- and postoperatively. An accumulating exposure to radiation must be considered.

Factors Influencing Graft Impingement on the Wall of the Intercondylar Notch After Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction

Background: Anatomic placement of the bone tunnel reportedly reduces impingement of the graft with the intercondylar roof, but as a trade-off, the risk of impingement with the lateral wall of the intercondylar notch would increase instead in anatomic double-bundle anterior cruciate ligament (ACL) reconstruction. Purpose: The 2 grafts for the anteromedial bundle (AMB) and posterolateral bundle (PLB) were separately analyzed for the frequency of and risk factors for graft impingement on the wall of the intercondylar notch. Study Design: Case control study; Level of evidence, 3. Methods: A total of 51 patients (53 knees) who underwent primary anatomic double-bundle ACL reconstruction were enrolled. Based on the graft orientation plane reconstructed with 3-dimensional imaging software, graft-wall impingement was defined as overlap between the lateral wall of the notch and the line connecting each center of the intra-articular apertures of the femoral and tibial bone tunnels. The rate of wall impingement was assessed for each bundle. Parameters for bone tunnel positioning in the femur and tibia, notch width index, and knee joint rotation angle were compared between patients with and without wall impingement. The most important risk factors for wall impingement were assessed by logistic regression analysis. Results: Wall impingement for the AMB was observed in 22 knees (42%), whereas no patients exhibited wall impingement for the PLB. Regarding femoral bone tunnel positioning according to the quadrant method, the AMB bone tunnel was placed significantly higher in impingement-positive patients than in impingement-negative patients (P = .03). Regarding tibial tunnel positioning, the tunnel was placed significantly more anteriorly (P = .02) and laterally (P = .02) in the impingement-positive group than in the impingement-negative group. Bone tunnels positioned 48% to 50% from the medial border of the tibia demonstrated a 100% incidence of wall impingement. Based on logistic regression analysis, lateral deviation of the AMB tibial bone tunnel was significantly associated with wall impingement (odds ratio, 1.403; P = .048). Conclusion: The tibial bone tunnel position in the coronal orientation was most likely associated with wall impingement. Considering that tibial bone tunnels are generally created with the knee in 90° of flexion and move laterally as the knee extends because of screw-home movement, the AMB bone tunnel for the tibia should be positioned as medially as possible within its footprint to minimize the risk of wall impingement after anatomic double-bundle ACL reconstruction.

Tibial Tunnel Placement Accuracy During Anterior Cruciate Ligament Reconstruction: Independent Femoral Versus Transtibial Femoral Tunnel Drilling Techniques

This study aimed to compare the accuracy of tibial tunnel placement using independent femoral (IF) versus transtibial (TT) techniques. Ten matched pairs of cadaveric knees were randomized so that one knee in the pair underwent arthroscopic TT drilling of the femoral tunnel and the other underwent IF drilling through an accessory medial portal. For both techniques, an attempt was made to place the femoral and tibial tunnels as close to the center of the respective anterior cruciate ligament (ACL) footprints as possible. Preoperative and postoperative computed tomography using a technique optimized for ligament evaluation allowed comparison of the anatomic ACL tibial footprint to the tibial tunnel aperture. The percentage of tunnel aperture contained within the native footprint, as well as the distance from the center of the tunnel aperture to the center of the footprint, was measured. Additionally, graft obliquity relative to the tibial plateau was evaluated in the sagittal plane. The percentage of tibial tunnel aperture contained within the native footprint averaged 71.6% ± 17.2% versus 52.1% ± 23.4% (P = .04) in the IF and TT groups, respectively. The distance from the center of the footprint to the center of the tibial tunnel aperture was 3.50 ± 1.6 mm and 4.40 ± 1.7 mm (P = .27) in the IF and TT groups, respectively. TT drilling placed 6 of 10 tunnels posterior to the center of the footprint versus 3 of 10 tunnels in IF drilling. The graft obliquity angles were 54.8° in TT specimens and 47.5° in IF specimens (P = .09). This study adds to the literature suggesting that TT drilling with an 8-mm reamer has deleterious effects on tibial tunnel aperture and position. IF drilling, which does not involve repeated reaming of the tibial tunnel, is associated with the placement of a higher percentage of the tunnel aperture within the native tibial footprint. There was not a significant difference between the IF and TT techniques in their ability to place the center of the tibial aperture near the center of the footprint or in graft obliquity. ACL reconstruction has continued to evolve in an attempt to restore the functional anatomy and biomechanical behavior of the knee. Tibial tunnel characteristics-such as location, aperture topography, and tunnel obliquity-are important factors to consider in ACL reconstruction. This study compares tibial tunnels after IF and TT techniques.

Effect of Notchplasty in Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction

Background: The effects of notchplasty on the clinical outcome after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction remain unclear. Hypothesis: Anatomic ACL reconstruction with notchplasty would result in less risk of loss of extension and would provide adequate space for better graft healing, leading to better knee stability compared with anatomic ACL reconstruction without notchplasty. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 137 patients who underwent anatomic double-bundle ACL reconstruction were included. Seventy-three patients without notchplasty were classified as the control group, and 64 patients with 2-mm notchplasty were classified as the notchplasty group. The following evaluation methods were used: loss of extension, patient’s subjective feeling of limited extension and pain at passive full extension, muscle strength, manual laxity tests, KT-1000 arthrometer measurement, patellofemoral joint findings, Tegner score, Lysholm score, subjective scores, and time to return to sports. Tearing of the reconstructed ACL and additional synovectomy were recorded. Both tibial and femoral tunnel positions were measured using 2-view radiographs: a Rosenberg and a lateral view. Results: Loss of extension was larger in the notchplasty group compared with controls (at 6 months: 0.8° vs 1.4°, P = .012; at 2 years: 0.4° vs 0.9°, P = .0053). The number of patients with a feeling of limited extension was also larger in the notchplasty group (at 6 months: 13 patients graded 1+ [somewhat limited] and 2 patients graded 2+ [very limited] vs 18 graded 1+ and 6 graded 2+, P = .015; at 2 years: 2 graded 1+ and 0 graded 2+ vs 4 graded 1+ and 5 graded 2+, P = .011). Six patients in the notchplasty group required additional synovectomy because of the prolonged loss of extension, whereas no patient in the control group required additional synovectomy. There were no differences between groups regarding muscle strength, patellofemoral findings, Lysholm score, Tegner score, subjective scores, or time to return to sports. The KT-1000 arthrometer measurement was better in the notchplasty group (1.2 vs 0.4 mm, P = .0017). However, 6 patients in the notchplasty group showed an overconstrained knee (KT-1000 measurement ≤–2 mm), compared with only 1 patient in the control group. There were no differences between groups in the other manual laxity tests or the tunnel positions. Conclusion: In anatomic double-bundle ACL reconstruction, anterior stability was improved and there were no harmful effects on patellofemoral joint findings by 2-mm notchplasty; however, notchplasty likely caused overconstrained knee, leading to a need for additional synovectomy in some patients. In contrast, anatomic double-bundle ACL reconstruction without notchplasty did not increase the incidence of loss of extension or of graft failure.

Anatomic Single Bundle Anterior Cruciate Ligament Reconstruction by Low Accessory Anteromedial Portal Technique: An In Vivo 3D CT Study.

PurposeProper femoral tunnel position is important for anatomical reconstruction of the anterior cruciate ligament (ACL). The purpose of this study was to evaluate the positions of femoral and tibial tunnels created using an accessory anteromedial portal technique in single bundle ACL reconstruction.Materials and MethodsThe femoral tunnel was targeted at the mid-portion of the ACL bundles. We evaluated postoperative computed tomography scans of 32 patients treated by ACL reconstruction using a free-hand low accessory anteromedial portal technique. On the tibial side, the tunnel position was evaluated using Tsukada's method. On the femoral side, the position was evaluated using 1) the quadrant method, 2) Mochizuki's method, 3) Mochizuki's method, and 4) Takahashi's method. Tunnel obliquity was also evaluated.ResultsThe mean tibial tunnel position was located at 44.6%±2.5% anterior from the anterior margin and 48.0%±3.0% in medial from the medial margin. The mean femoral tunnel position was located at the center between the anteromedial and posterolateral bundles: Quadrant method, 26.7%±2.7%/30.0%±2.9%; Watanabe's method, 37.7%±2.5%/26.6%±2.2%; Mochizuki's method, 38.7%±2.7%; Takahashi's method, 21.8%±2.2%. The mean femoral tunnel obliquity was 57.7°±6.2° in the sagittal plane and 49.9°±5.6° in the coronal plane.ConclusionsIn anatomic single bundle ACL reconstruction, the low anteromedial portal technique can restore accurate position of the native footprint. Accurate femoral tunnel position facilitates recovery of stability and decreases graft failure rate.

Variability of tunnel positioning in fluoroscopic-assisted ACL reconstruction.

Intraoperative fluoroscopy has been proposed as a feasible method to improve the accuracy of anatomical tunnel positioning. However, it has so far not been determined, whether this technique reduces the variability of tunnel positioning in a clinical set-up. Therefore, the purpose of this study was to determine the variability of tunnel positions applying intraoperative fluoroscopy. Femoral and tibial tunnel positions of 112 fluoroscopic ACL reconstruction cases were determined according to validated radiological measurement methods. Mean positions, standard deviations and ranges were calculated to determine the variability of the tunnel positions. Subgroup variability analysis was performed to analyse cases in which tunnel positions were corrected. Applying intraoperative fluoroscopy, the variability of tunnel positions was found to be 3% at the femur (range 15.4%) and 2.3% at the tibia (9.7%). In 34 cases (30.0%), non-satisfactory tunnel positions were identified and could be corrected achieving more accurate positions regarding to radiological parameters (14× femur, 16× tibia, 4× femur and tibia). The results of the presented study indicate that intraoperative fluoroscopy allows to identify non-accurate tunnel positions regarding to radiological criteria. The determined low variability indicates that fluoroscopic-based ACL reconstruction can be recommended as a feasible, easy and effective adjunct that enables surgeons to create more consistent and reliable tunnel positions in ACL reconstruction. IV.

Bony Landmarks of the Anterior Cruciate Ligament Tibial Footprint

Background: Although the importance of tibial tunnel position for achieving stability after anterior cruciate ligament (ACL) reconstruction was recently recognized, there are fewer detailed reports of the anatomy of the tibial topographic footprint compared with the femoral side. Hypothesis: The ACL tibial footprint has a relationship to bony prominences and surrounding bony landmarks. Study Design: Descriptive laboratory study. Methods: This study consisted of 2 anatomic procedures for the identification of bony prominences that correspond to the ACL tibial footprint and 3 surrounding landmarks: the anterior ridge, lateral groove, and intertubercular fossa. In the first procedure, after computed tomography (CT) was performed on 12 paired, embalmed cadaveric knees, 12 knees were visually observed, while their contralateral knees were histologically observed. Comparisons were made between macroscopic and microscopic findings and 3-dimensional (3D) CT images of these bony landmarks. In the second procedure, the shape of the bony prominence and incidence of their bony landmarks were evaluated from the preoperative CT data of 60 knee joints. Results: In the first procedure, we were able to confirm a bony prominence and all 3 surrounding landmarks by CT in all cases. Visual evaluation confirmed a small bony eminence at the anterior boundary of the ACL. The lateral groove was not confirmed macroscopically. The ACL was not attached to the lateral intercondylar tubercle, ACL tibial ridge, and intertubercular space at the posterior boundary. Histological evaluation confirmed that the anterior ridge and lateral groove were positioned at the anterior and lateral boundaries, respectively. There was no ligament tissue on the intercondylar space corresponding to the intercondylar fossa. In the second investigation, the bony prominence showed 2 morphological patterns: an oval type (58.3%) and a triangular type (41.6%). The 3 bony landmarks, including the anterior ridge, lateral groove, and intertubercular fossa, existed in 96.6%, 100.0%, and 96.6% of the cases, respectively. Conclusion: There is a bony prominence corresponding to the ACL footprint and bony landmarks on the anterior, posterior, and lateral boundaries. Clinical Relevance: The study results may help create an accurate and reproducible tunnel, which is essential for successful ACL reconstruction surgery.

Anatomic Single-Bundle ACL Reconstruction Is Possible with Use of the Modified Transtibial Technique

Anatomic anterior cruciate ligament (ACL) reconstruction is essential to the restoration of normal knee kinematics and to achieving successful results after ACL surgery. The purpose of this study was to evaluate whether anatomic single-bundle ACL reconstruction can be performed with use of the modified transtibial technique such that the tunnel characteristics are not substantially different from those of the anteromedial transportal technique, with comparable clinical results. One hundred and four patients underwent single-bundle ACL reconstruction performed with use of either the modified transtibial technique or the anteromedial transportal technique. Each group included fifty-two patients retrospectively matched on the basis of age, sex, and body mass index. All patients had postoperative computed tomography (CT) and a minimum duration of follow-up of twenty-four-months. CT parameters, including tunnel position, tunnel length and shape, and graft obliquity, were evaluated. Clinical assessments were based on manual laxity tests, arthrometric analysis, and clinical scores recorded preoperatively and at the time of follow-up. The femoral tunnel was placed at a slightly inferior and anterior position with use of the modified transtibial technique compared with the anteromedial transportal technique, but the difference was not significant (superior-inferior mean [and standard deviation], 35.7% ± 3.1% versus 33.9% ± 4.1%, p > 0.05, and anterior-posterior mean, 31.6 ± 6.8% versus 35.1 ± 6.9%, p > 0.05, as assessed with use of the quadrant method). The femoral tunnel length was significantly longer (p < 0.05) and the tibial tunnel length was significantly shorter (p < 0.05) with use of the modified transtibial technique compared with the anteromedial transportal technique (mean femoral tunnel length, 40.5 ± 4.2 mm versus 34.4 ± 2.6 mm and mean tibial tunnel length, 32.3 ± 3.1 mm versus 35.5 ± 2.7 mm); however, tunnel length was sufficient to allow for adequate fixation. There were no significant differences between the two groups in terms of tibial tunnel position, graft obliquity, tibial tunnel widening, and clinical results. Tunnel characteristics including anatomic position, graft obliquity, and tunnel widening after single-bundle ACL reconstruction performed with use of the modified transtibial technique were not significantly different from those of the anteromedial transportal technique, and clinical results were comparable.

In VivoThree-Dimensional Imaging Analysis of Femoral and Tibial Tunnel Locations in Single and Double Bundle Anterior Cruciate Ligament Reconstructions

BackgroundAnatomic footprint restoration of anterior cruciate ligament (ACL) is recommended during reconstruction surgery. The purpose of this study was to compare and analyze the femoral and tibial tunnel positions of transtibial single bundle (SB) and transportal double bundle (DB) ACL reconstruction using three-dimensional computed tomography (3D-CT).MethodsIn this study, 26 patients who underwent transtibial SB ACL reconstruction and 27 patients with transportal DB ACL reconstruction using hamstring autograft. 3D-CTs were taken within 1 week after the operation. The obtained digital images were then imported into the commercial package Geomagic Studio v10.0. The femoral tunnel positions were evaluated using the quadrant method. The mean, standard deviation, standard error, minimum, maximum, and 95% confidence interval values were determined for each measurement.ResultsThe femoral tunnel for the SB technique was located 35.07% ± 5.33% in depth and 16.62% ± 4.99% in height. The anteromedial (AM) and posterolateral (PL) tunnel of DB technique was located 30.48% ± 5.02% in depth, 17.12% ± 5.84% in height and 34.76% ± 5.87% in depth, 45.55% ± 6.88% in height, respectively. The tibial tunnel with the SB technique was located 45.43% ± 4.81% from the anterior margin and 47.62% ± 2.51% from the medial tibial articular margin. The AM and PL tunnel of the DB technique was located 33.76% ± 7.83% from the anterior margin, 45.56% ± 2.71% from the medial tibial articular margin and 53.19% ± 3.74% from the anterior margin, 46.00% ± 2.48% from the medial tibial articular margin, respectively. The tibial tunnel position with the transtibial SB technique was located between the AM and PL tunnel positions formed with the transportal DB technique.ConclusionsUsing the 3D-CT measuring method, the location of the tibia tunnel was between the AM and PL footprints, but the center of the femoral tunnel was at more shallow position from the AM bundle footprint when ACL reconstruction was performed by the transtibial SB technique.

Anterior cruciate ligament reconstruction: Can optimal graft placement be achieved with a free-hand drilled transtibial technique?

Objective: Anterior cruciate ligament (ACL) injuries are common among athletes and active individuals participating in sports. ACL reconstruction using the single-bundle technique can be performed through transtibial or anteromedial portals. The transtibial technique carries the theoretical risk of vertical placement of the femoral tunnel in the intercondylar notch. The aim of this study is to assess the efficacy of a free-hand drilled-transtibial technique in achieving optimal graft positioning. Materials and Methods: We analyzed a retrospective series of post-operative knee radiographs in 52 consecutive patients who underwent a single-bundle ACL reconstruction by a single surgeon using this transtibial method, from June 2009 to January 2010. Tunnel positioning was radiographically assessed by an independent single observer, who was not involved in the management of patients. The graft inclination angle, the coronal and the sagittal femoral and tibial tunnel placements were evaluated. Results: Post-operative radiographs of 40 patients (40 knees) were retrospectively evaluated for femoral and tibial tunnel positioning. In the coronal plane, the mean graft inclination angle was 21°, the femoral tunnel was positioned at a mean of 43% lateral to the lateral femoral condyle and the tibial tunnel at a mean of 46% lateral to the medial border of the medial tibial plateau. In the sagittal plane, the femoral tunnel was placed at 84% posteriorly across Blumensaat's line and the tibial tunnel at a mean of 43% along the length of the tibial plateau. The results were consistent with optimal tunnel positioning according to anatomic and clinical studies. Conclusion: The transtibial technique described in this series can achieve optimal tunnel positioning for single-bundle ACL reconstruction.

Influence of tibial rotation on tibial tunnel position measurements using lateral fluoroscopy in anterior cruciate ligament reconstruction

The purpose of the current study was to evaluate the influence of internal and external knee rotation on tibial tunnel position measurements in anterior cruciate ligament reconstruction using the Amis and Jakob line. Anatomic double bundle ACL reconstruction was performed in seven cadaveric knees. Afterwards, the knees were CT scanned, and 3D CT models were established. Utilizing these models, strict lateral and radiographs with the knees in 5°, 10°, and 20° of internal as well as external rotation were established. Using these radiographs, the positions of the anteromedial (AM) and posterolateral (PL) tibial tunnels were measured using the Amis and Jacob line. The tunnel positions of the strict lateral were compared to the rotated radiographs. To assess the inter- and intraobserver reliability, two independent observers measured the tunnel positions, and one observer measured twice. Significant differences for the AM tunnel position were observed if more than 10° of external or 20° of internal rotation were applied. For the PL tunnel position, no significant differences were found between the strict lateral and the rotated radiographs. Inter- and intraobserver reliability was good. The accuracy of the Amis and Jakob line is dependent on the degree of knee rotation and the position of the measured tunnel. Therefore, when using the Amis and Jakob line to determine the tibial tunnel position during surgery, attention should be paid to rotational alignment of lateral radiographs. However, the maximum rotation tested in the present study (20°) showed only a difference in tunnel position of 3.3 % compared to optimal rotational alignment. Thus, in most cases, the effects of minor malrotation on tunnel position measurement should be of minimal clinical significance.

BIOLOGIC REACTIONS AT ACL GRAFT INSERTION SITES MEASURED BY 99MTC-HDP-SPECT/CT TRACER UPTAKE

IntroductionNot much is known about biologic reactions at ACL graft insertion sites. SPECT/CT is a hybrid imaging modality, which combines a 3D single photon emission computed tomography and a conventional...

Tunnel Positions in Transportal Versus Transtibial Anterior Cruciate Ligament Reconstruction: A Case-Control Magnetic Resonance Imaging Study

The purpose of this study was to examine the difference in the position of bone tunnels prepared by the transportal technique versus the transtibial technique in anterior cruciate ligament (ACL) reconstruction. A consecutive series of 42 patients receiving single-bundle ACL reconstructions were recruited between July 1, 2007, and December 31, 2008. The preparations of the femoral tunnel were performed by the transtibial technique in the first 21 cases and by the transportal technique in the subsequent 21 cases. Magnetic resonance imaging examination was performed in 39 patients (93%) 1 year after the index operation (20 transtibial and 19 transportal). Optimal tunnel position was defined as a lateralized femoral tunnel at a position of less than 11 o'clock for a right knee or more than 1 o'clock for a left knee, an adequate posteriorized femoral tunnel in the fourth quadrant of the modified Bernard line, and a tibial tunnel located in the second quadrant of the modified Amis line. The average clock position was 10:18 in the transportal group and 10:54 in the transtibial group (P < .001). Five outliers were found in the transtibial group but none in the transportal group. Concerning the femoral tunnel position on the sagittal-cut magnetic resonance imaging scan, the average position along the modified Bernard line was 74% in the transportal group and 69% in the transtibial group (P = .029). Concerning the tibial tunnel position, the average tibial tunnel positions along the modified Amis line were 47% and 52%, respectively (P = .019). The adoption of the transportal technique in single-bundle ACL reconstruction produced improved positions in both the femoral and tibial tunnels when compared with the transtibial technique. Level III, case-control study.

Characterization of Cruciate Ligament Impingement: The Influence of Femoral or Tibial Tunnel Positioning at Different Degrees of Knee Flexion

We aimed to analyze how different positions of the tibial and femoral tunnels when used for anterior cruciate ligament (ACL) reconstruction affect relations with the posterior cruciate ligament (PCL) at different degrees of knee flexion. Information gained from this study may be helpful in determining optimal placement of the graft in ACL reconstructive surgery. We divided 10 cadaveric knees into 2 groups of 5 and had either their femoral or tibial ACL insertion detached. For each specimen, 16 different positions were reproduced during ACL reconstruction based on a combination of 4 different tunnels in the tibia for group A (anterior-medial, anterior-lateral, posterior-medial, and posterior-lateral) and 4 in the femur for group B (anterior-proximal, anterior-distal, posterior-proximal, and posterior-distal) with 4° of knee flexion for each (0°, 45°, 90°, and 135°). We performed a magnetic resonance imaging (MRI) study for each configuration and analyzed the cruciate ligament positioning. We identified 3 different situations: no contact between cruciate ligaments, contact without deformity, and contact with deformity. In group A, the degree of flexion (P = .003) and ligament insertion positioned in the posterior quadrants (P < .05) were statistically significant for the presence of ACL impingement. Ligament contact with deformity was identified in 18 (22.5%) configurations, mostly when the knee was flexed 45° and 90° and the ACL was in the posterior quadrants. For group B, "contact with deformity" was identified in 23 MR images, mostly (12 cases) with the graft position being in the anterior-distal configuration, but it was not significant for the occurrence of cruciate impingement. Impingement with ligament deformity is greater when the graft is fixed at the posterior quadrants of the tibial footprint, regardless of the degree of knee flexion. Although quite common, the ligament position in the femoral footprint was not a primary cause of ACL impingement with deformity. This study helps identify positions of the tibial or femoral tunnels during ACL reconstruction to avoid impingement between cruciate ligaments.

Radiographic Findings in Revision Anterior Cruciate Ligament Reconstructions from the MARS Cohort

The Multicenter ACL (anterior cruciate ligament) Revision Study (MARS) group was developed to investigate revision ACL reconstruction outcomes. An important part of this is obtaining and reviewing radiographic studies. The goal for this radiographic analysis is to establish radiographic findings for a large revision ACL cohort to allow comparison with future studies. The study was designed as a cohort study. Various established radiographic parameters were measured by three readers. These included sagittal and coronal femoral and tibial tunnel position, joint space narrowing, and leg alignment. Inter- and intraobserver comparisons were performed. Femoral sagittal position demonstrated 42% were more than 40% anterior to the posterior cortex. On the sagittal tibia tunnel position, 49% demonstrated some impingement on full-extension lateral radiographs. Limb alignment averaged 43% medial to the medial edge of the tibial plateau. On the Rosenberg view (45-degree flexion view), the minimum joint space in the medial compartment averaged 106% of the opposite knee, but it ranged down to a minimum of 4.6%. Lateral compartment narrowing at its minimum on the Rosenberg view averaged 91.2% of the opposite knee, but it ranged down to a minimum of 0.0%. On the coronal view, verticality as measured by the angle from the center of the tibial tunnel aperture to the center of the femoral tunnel aperture measured 15.8 degree ± 6.9% from vertical. This study represents the radiographic findings in the largest revision ACL reconstruction series ever assembled. Findings were generally consistent with those previously demonstrated in the literature.

Three-Dimensional Reconstruction Computed Tomography Evaluation of Tunnel Location during Single-Bundle Anterior Cruciate Ligament Reconstruction: A Comparison of Transtibial and 2-Incision Tibial Tunnel-Independent Techniques

BackgroundAnatomic tunnel positioning is important in anterior cruciate ligament (ACL) reconstructive surgery. Recent studies have suggested the limitations of a traditional transtibial technique to place the ACL graft within the anatomic tunnel position of the ACL on the femur. The purpose of this study is to determine if the 2-incision tibial tunnel-independent technique can place femoral tunnel to native ACL center when compared with the transtibial technique, as the placement with the tibial tunnel-independent technique is unconstrained by tibial tunnel.MethodsIn sixty-nine patients, single-bundle ACL reconstruction with preservation of remnant bundle using hamstring tendon autograft was performed. Femoral tunnel locations were measured with quadrant methods on the medial to lateral view of the lateral femoral condyle. Tibial tunnel locations were measured in the anatomical coordinates axis on the top view of the proximal tibia. These measurements were compared with reference data on anatomical tunnel position.ResultsWith the quadrant method, the femoral tunnel centers of the transtibial technique and tibial tunnel-independent technique were located. The mean (± standard deviation) was 36.49% ± 7.65% and 24.71% ± 4.90%, respectively, from the over-the-top, along the notch roof (parallel to the Blumensaat line); and at 7.71% ± 7.25% and 27.08% ± 7.05%, from the notch roof (perpendicular to the Blumensaat line). The tibial tunnel centers of the transtibial technique and tibial tunnel-independent technique were located at 39.83% ± 8.20% and 36.32% ± 8.10%, respectively, of the anterior to posterior tibial plateau depth; and at 49.13% ± 4.02% and 47.75% ± 4.04%, of the medial to lateral tibial plateau width. There was no statistical difference between the two techniques in tibial tunnel position. The tibial tunnel-independent technique used in this study placed femoral tunnel closer to the anatomical ACL anteromedial bundle center. In contrast, the transtibial technique placed the femoral tunnel more shallow and higher from the anatomical position, resulting in more vertical grafts.ConclusionsAfter single-bundle ACL reconstruction, three-dimensional computed tomography showed that the tibial tunnel-independent technique allows for the placement of the graft closer to the anatomical femoral tunnel position when compared with the traditional transtibial technique.

Evaluating the accuracy of a navigation system and fluoroscopic imaging for tibial tunnel positioning during reconstruction of the anterior cruciate ligament

Evaluating the accuracy of a navigation system and fluoroscopic imaging for tibial tunnel positioning during reconstruction of the anterior cruciate ligament

The effect of anterior cruciate ligament graft orientation on rotational knee kinematics

To determine whether coronal graft orientation and tunnel placement for single-bundle anterior cruciate ligament (ACL) reconstruction is associated with tibial rotation excursion during functional activities. Eighty-four patients who had undergone ACL reconstruction over a ten-year time span had tibial rotation measured during level walking, using a three-dimensional motion analysis system. Fifty-two patients also had measures taken during the more dynamic task of single-limb landing. During the 10-year period, the position of the graft was deliberately changed from a vertical to more horizontal orientation in the coronal plane. Post-operative radiographs were analysed for the coronal graft orientation and femoral and tibial tunnel positions. Radiographic measurements of graft orientation and tunnel position were then correlated with the amount of tibial rotational excursion recorded during the walking and landing tasks. For the single-limb landing task, a significant positive correlation was observed between the coronal graft angle and rotational excursion (R=0.35, R (2) =0.12, p=0.01). This indicated greater rotational excursion was associated with vertical graft orientation, but only explained 12% of the variance. No correlations were found between coronal graft angle and tibial rotation during level walking. These findings support the notion that ACL graft orientation may play a role in rotational kinematics of the ACL-reconstructed knee, particularly during higher impact activities. IV.