Trantibial anterior cruciate ligament double bundle reconstruction technique: two tibial bundle in one tibial tunnel

ACL double-bundle reconstruction with one tibial tunnel provides equal stability compared to two tibial tunnels

PURPOSE

The purpose of this study was to investigate whether an anterior cruciate ligament (ACL) double-bundle reconstruction with one tibial tunnel displays the same in vitro stability as a conventional double-bundle reconstruction with two tibial tunnels when using the same tensioning protocol.

METHODS

In 11 fresh-frozen cadaveric knees, ACL double-bundle reconstruction with one and two tibial tunnels was performed. The two grafts were tightened using 80 N in different flexion angles (anteromedial-bundle at 60° and posterolateral-bundle at 15°). Anterior tibial translation (134 N) and translation with combined rotatory and valgus loads (10 Nm valgus stress and 4 Nm internal tibial torque) were determined at 0°, 30°, 60° and 90° flexion. Measurements were taken in intact ACL, resected ACL, three-tunnel reconstruction and four-tunnel reconstruction. Additionally, the tension on the grafts was determined. Student's t test was performed for statistical analysis of the related samples. Significance was set at p < 0.017 according to Bonferroni correction.

RESULTS

The two reconstructive techniques displayed no significant differences in comparison with the intact ACL in anterior tibial translation at 0°, 60° and 90° of flexion. The same results were obtained for the anterior tibial translation with a combined rotatory load at 60° and 90°. When directly comparing both reconstructive techniques, there were no significant differences for the anterior tibial translation and combined rotatory load at all flexion angles. The measured tension on grafts displayed similar load sharing between both bundles. Except at full extension, both grafts displayed a significantly different tension increase under anterior tibial translation for both techniques (p = 0.0086).

CONCLUSIONS

Tightening both bundles in ACL double-bundle reconstruction with one or two tibial tunnels in different flexion angles achieved comparable restoration of stability, although there was different load sharing on the bundles. With regard to individualized ACL reconstruction, the double-bundle technique with one tibial tunnel offers a possibility to address small tibial insertion sites without compromising the advantages of a double-bundle procedure.

Outcomes and second-look arthroscopic evaluation after double-bundle anterior cruciate ligament reconstruction with use of a single tibial tunnel

BACKGROUND

The correlation between graft appearance and clinical outcome after double-bundle anterior cruciate ligament (ACL) reconstruction is a major concern. In this study, the graft appearance was assessed with use of second-look arthroscopy and was correlated with the clinical outcome. Overall clinical outcomes after double-bundle ACL reconstruction with use of a single tibial tunnel were analyzed.

METHODS

Thirty-seven knees that underwent second-look arthroscopy after double-bundle ACL reconstruction and sixty-two knees that underwent double-bundle ACL reconstruction without subsequent second-look arthroscopy were included in this retrospective study. The ninety-nine patients enrolled were followed for thirty-five months (range, twenty-four to fifty-eight months), and the mean duration from ACL reconstruction to second-look arthroscopy was twenty-five months (range, twelve to thirty-six months). Graft thickness, apparent graft tension, and synovial coverage were graded during second-look arthroscopy. Correlations were sought between graft appearance and Lysholm knee scores, International Knee Documentation Committee (IKDC) grades, anterior laxity, and pivot-shift test results.

RESULTS

Postoperatively, ninety-four (94.9%) of the ninety-nine knees had an IKDC rating of B or higher, mean anterior laxity was 1.29 mm (range, 0 to 6 mm), and ninety-two knees (92.9%) had a negative pivot-shift result. With regard to graft thickness and tension, anteromedial bundles were graded as A in twenty-eight (75.7%) of the thirty-seven second-look knees and as B in nine knees (24.3%). Posterolateral bundles were graded as A in twenty-five knees (67.6%), B in six knees (16.2%), and C in six knees (16.2%). With regard to synovial coverage, anteromedial bundles were graded as C in only two knees (5.4%) and posterolateral bundles were graded as C in six knees (16.2%). No correlation was found between graft appearance and clinical outcome.

CONCLUSIONS

In the present study, we observed that clinical outcomes were as satisfactory with a single tibial tunnel as with two tibial tunnels. However, more tears and poorer synovial coverage were observed for posterolateral than for anteromedial bundles during second-look arthroscopy. No significant correlation was found between graft appearance and clinical outcome.

An implant-free double-bundle reconstruction of the anterior cruciate ligament: operative technique and influence on tibiofemoral kinematics

BACKGROUND

Reconstruction of the anterior cruciate ligament is a standard surgical procedure in sports traumatology. The widespread replacement method using hamstring tendons has an important shortcoming namely delayed or missing bony healing in contrast to patellar tendon grafts where implant-free fixation is established by using the adjacent bone blocks. The purpose of this study was to describe a new implant-free surgical procedure using hamstring tendon grafts and to analyse the influence on tibiofemoral kinematics in vitro.

METHODS

Nine human knee specimens with arthroscopically transected anterior cruciate ligaments were mounted on a dynamic knee simulator and weight-bearing muscle-loaded knee flexions were simulated while a robotic universal force sensor system was used to provide external tibial loads. Three different loading conditions were simulated including partial body weight only, an additional 50 N anterior tibial force or an additional Five Nm of internal rotational torque. After reconstruction of the anterior cruciate ligament using a tibial bone block hybrid technique these three trials were repeated. The kinematics was measured with an ultrasonic measuring system and different loading and ligament conditions were examined. Graft tunnel placement was verified by computed tomography.

FINDINGS

Our fixation method achieved stability to anterior tibial drawer force whereas internal tibial rotation did not change before and after the reconstruction. Computed tomography confirmed anatomical graft and tunnel placement.

INTERPRETATION

The presented operative procedure is technically feasible and leads to reproducible results concerning knee joint kinematics and graft placement.

"Anatomic" anterior cruciate ligament reconstruction: a systematic review of surgical techniques and reporting of surgical data

PURPOSE

The aim of this systematic review was to evaluate studies published on anatomic double-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

A systematic electronic search was performed by use of the Medline and Embase databases. Studies that were published from January 1995 to April 2009 were included. The selection criteria were studies that reported on a surgical technique for "anatomic double-bundle ACL reconstruction" on skeletally mature living human subjects and were written in English. Data collected and analyzed included a variety of surgical data. Tables were created to provide an overview of surgical techniques for anatomic ACL reconstruction.

RESULTS

Seventy-four studies were included in this review. Some surgical factors were adequately reported in the majority of the articles: visualizing the native ACL insertion sites, placing the tunnels in the footprint, graft type, and fixation method. However; ACL insertion site measurement, femoral intercondylar notch measurement, individualization of surgery, and intraoperative/postoperative imaging were poorly reported. The most variety was seen in knee flexion angle during femoral tunnel drilling and tensioning pattern of the grafts.

CONCLUSIONS

For most surgical data, there was a gross under-reporting of specific operative technique data. We believe that the details of an "anatomic" operative technique are crucial for the valid interpretations of the outcomes. Thus we encourage authors to report their surgical technique in a specific and standardized fashion.

Placement of femoral tunnel between the AM and PL bundles using a transtibial technique in single-bundle ACL reconstruction

Two different approaches for drilling the femoral tunnel are commonly used in single-bundle anterior cruciate ligament (ACL) reconstruction: creating the femoral tunnel through the tibial tunnel or drilling the tunnel through a low anteromedial arthroscopy portal. When using a transtibial drilling technique, the location of the femoral tunnel is restricted by the angulation of the tibial tunnel in the coronal plane and may lead to a high placement of the femoral tunnel in the intercondylar notch. However, some authors refer that the femoral tunnel can be positioned correctly in the center of the femoral ACL footprint by means of a transtibial technique if the tibial tunnel forms an angle between 60 degrees and 65 degrees to the medial joint line of the tibia in the coronal plane. The purpose of this study was to evaluate prospectively with CT scans whether a femoral tunnel drilled through a tibial tunnel at an angle of 60 degrees-65 degrees in the coronal plane is created between the AM and PL bundles in the lateral femoral condyle. Our results showed that the median difference of the distance between the center of the femoral tunnel and the center of the AM and PL bundles along the Blumensaat's line was 6 and 5%, respectively. In the height of the femoral condyle, the median difference of the distance between the center of the femoral tunnel and the center of the AM and PL bundles was 0 and 31%, respectively. In conclusion, when drilling the femoral tunnel via a transtibial technique with the tibial tunnel angled 60 degrees-65 degrees in the coronal plane, the center of the femoral tunnel is created in the AM bundle footprint in the height of the femoral condyle.