Varying Femoral Tunnels between the Anatomical Footprint and Isometric Positions

2005 ◽  
Vol 33 (5) ◽  
pp. 712-718 ◽  
Author(s):  
Volker Musahl ◽  
Anton Plakseychuk ◽  
Andrew Vanscyoc ◽  
Tomoyuki Sasaki ◽  
Richard E. Debski ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Femoral Tunnel ◽  
Cruciate Ligament ◽  
Anterior Tibial Translation ◽  
Tunnel Position ◽  
Anterior Tibial ◽  
Anterior Cruciate ◽  
Tibial Translation ◽  
Tunnel Positions ◽  
Intact Knee

Background Knee kinematics and in situ forces resulting from anterior cruciate ligament reconstructions with 2 femoral tunnel positions were evaluated. Hypothesis A graft placed inside the anatomical footprint of the anterior cruciate ligament will restore knee function better than a graft placed at a position for best graft isometry. Study Design Controlled laboratory study. Methods Ten cadaveric knees were tested in response to a 134-N anterior load and a combined 10-N·m valgus and 5-N·m internal rotation load. A robotic universal force-moment sensor testing system was used to apply loads, and resulting kinematics were recorded. An active surgical robot system was used for positioning tunnels in 2 locations in the femoral notch: inside the anatomical footprint of the anterior cruciate ligament and a position for best graft isometry. The same quadrupled hamstring tendon graft was used for both tunnel positions. The 2 loading conditions were applied. Results At 30° of knee flexion, anterior tibial translation in response to the anterior load for the intact knee was 9.8 ± 3.1 mm. Both femoral tunnel positions resulted in significantly higher anterior tibial translation (position 1: 13.8 ± 4.6 mm; position 2: 16.6 ± 3.7 mm; P <. 05). There was a significant difference between the 2 tunnel positions. At the same flexion angle, the anterior tibial translation in response to the combined load for the intact knee was 7.7 ± 4.0 mm. Both femoral tunnel positions resulted in significantly higher anterior tibial translation (position 1: 10.4 ± 5.5 mm; position 2: 12.0 ± 5.2 mm; P <. 05), with a significant difference between the tunnel positions. Conclusion Neither femoral tunnel position restores normal kinematics of the intact knee. A femoral tunnel position inside the anatomical footprint of the anterior cruciate ligament results in knee kinematics closer to the intact knee than does a tunnel position located for best graft isometry. Clinical Relevance Anatomical femoral tunnel position is important in reproducing function of the anterior cruciate ligament.

The Position of the Tibia during Graft Fixation Affects Knee Kinematics and Graft Forces for Anterior Cruciate Ligament Reconstruction

2001 ◽  
Vol 29 (6) ◽  
pp. 771-776 ◽  
Author(s):  
Jürgen Höher ◽  
Akihiro Kanamori ◽  
Jennifer Zeminski ◽  
Freddie H. Fu ◽  
Savio L-Y. Woo
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Knee Kinematics ◽  
Anterior Tibial Translation ◽  
Posterior Tibial ◽  
Anterior Tibial ◽  
Anterior Cruciate ◽  
Tibial Translation ◽  
Intact Knee

Ten cadaveric knees (donor ages, 36 to 66 years) were tested at full extension, 15°, 30°, and 90° of flexion under a 134-N anterior tibial load. In each knee, the kinematics as well as in situ force in the graft were compared when the graft was fixed with the tibia in four different positions: full knee extension while the surgeon applied a posterior tibial load (Position 1), 30° of flexion with the tibia at the neutral position of the intact knee (Position 2), 30° of flexion with a 67-N posterior tibial load (Position 3), and 30° of flexion with a 134-N posterior tibial load (Position 4). For Positions 1 and 2, the anterior tibial translation and the in situ forces were up to 60% greater and 36% smaller, respectively, than that of the intact knee. For Position 3, knee kinematics and in situ forces were closest to those observed in the intact knee. For Position 4, anterior tibial translation was significantly decreased by up to 2 mm and the in situ force increased up to 31 N. These results suggest that the position of the tibia during graft fixation is an important consideration for the biomechanical performance of an anterior cruciate ligament-reconstructed knee.

A Novel Graft Fixation Technique for Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Grafts

2017 ◽  
Vol 12 (1) ◽  
Author(s):  
Guoan Li ◽  
Ali Hosseini ◽  
Hemanth Gadikota ◽  
Thomas Gill
Keyword(s):  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Reconstruction Technique ◽  
Tibial Rotation ◽  
Pullout Strength ◽  
Anterior Tibial ◽  
Anterior Cruciate ◽  
Tibial Translation ◽  
Intact Knee

This study evaluated the biomechanical efficacy of single-tunnel double-bundle anterior cruciate ligament (ACL) reconstruction technique. The graft construct is achieved using a novel fixation device that splits an ACL (SPACL) graft into two bundles, recreating the anteromedial (AM) and posterolateral (PL) bundles for ACL reconstruction. A pullout strength test of the SPACL was performed using a 7-mm bovine digital extensor tendon graft. The capability in restoration of knee kinematics after SPACL reconstruction was investigated using cadaveric human knees on a robotic testing system under an anterior tibial load of 134 N and a simulated quadriceps load of 400 N. The data indicated that the SPACL graft has a pullout strength of 823.7±172.3 N. Under the 134 N anterior tibial load, the anteroposterior joint laxity had increased constraint using the SPACL reconstruction but not significantly (p > 0.05) at all selected flexion angles. Under the 400 N quadriceps load, no significant differences were observed between the anterior tibial translation of intact knee and SPACL conditions at all selected flexion angles, but the SPACL graft induced a significant increase in external tibial rotation compared to the intact knee condition at all selected flexion angles with a maximal external rotation of −3.20 deg ±3.6 deg at 90 deg flexion. These data showed that the SPACL technique is equivalent or superior to existing ACL reconstruction techniques in restoration of knee laxity and kinematics. The new SPACL reconstruction technique could provide a valuable alternation to contemporary ACL reconstruction surgery by more closely recreating native ACL kinematics.

The Effectiveness of Reconstruction of the Anterior Cruciate Ligament Using the Novel Knot/Press-Fit Technique

2005 ◽  
Vol 33 (6) ◽  
pp. 856-863 ◽  
Author(s):  
Robert H.P. Kilger ◽  
Maribeth Thomas ◽  
Scott Hanford ◽  
Dimosthenis A. Alaseirlis ◽  
Hans H. Paessler ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Knee Kinematics ◽  
Hamstring Tendon ◽  
Anterior Tibial Translation ◽  
Press Fit ◽  
Anterior Tibial ◽  
Tendon Grafts ◽  
Anterior Cruciate ◽  
Tibial Translation

Background A variety of fixation devices are used for anterior cruciate ligament reconstruction with hamstring tendon grafts. These devices increase costs and can present artifacts in magnetic resonance imaging as well as complications in revision surgery. Therefore, a novel knot/press-fit technique that requires no implantable devices has been introduced. Null Hypothesis The knot/press-fit technique restores knee kinematics as well as the more commonly used EndoButton CL fixation and has similar biomechanical properties as other devices published in the literature. Study Design Controlled laboratory study. Methods Eight fresh-frozen cadaveric knees (52 ± 7 years) were tested using a robotic/universal force-moment sensor testing system. The knee kinematics of the intact, anterior cruciate ligament-deficient, EndoButton-reconstructed, and knot/pressfit-reconstructed knee in response to both a 134-N anterior tibial load and a combined rotatory load at multiple knee flexion angles was determined. Differences between the 4 knee states were evaluated with a 2-factor repeated-measures analysis of variance (P <. 05). To determine the stiffness and strength of the knot/press-fit fixation, the femur-graft-tibia complex was tested in uniaxial tension. Results In response to an anterior tibial load, the anterior tibial translation for the knot/press-fit reconstruction was found to be not significantly different from that of the intact anterior cruciate ligament as well as that of the EndoButton reconstruction (P >. 05). In response to a combined rotatory load, neither reconstruction procedure could effectively reduce the coupled anterior tibial translation to that of the intact knee, and no significant difference between the 2 reconstructions could be detected (P >. 05). The stiffness of the knot/press-fit complex was found to be 37.8 ± 9.6 N/mm, and the load at failure was 540 ± 97.7 N, which is equal to other devices published in the literature. Clinical Relevance The experiment suggests that the knot/press-fit technique may be a reliable alternative for the femoral fixation of hamstring tendon grafts.

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