scholarly journals Slope reduction osteotomy decreases ACL graft forces and reduces anterior tibial translation under axial load - a biomechanical study

2019 ◽  
Vol 7 (6_suppl4) ◽  
pp. 2325967119S0021
Author(s):  
Florian B. Imhoff ◽  
Julian Mehl ◽  
Elifho Obopilwe ◽  
Andreas Imhoff ◽  
Knut Beitzel
Keyword(s):  
Axial Load ◽  
Wedge Osteotomy ◽  
Anterior Tibial Translation ◽  
Anterior Drawer ◽  
Acl Graft ◽  
Closing Wedge Osteotomy ◽  
Closing Wedge ◽  
Anterior Tibial ◽  
Tibial Translation ◽  
Acl Deficient

Aims and Objectives: To perform an anterior closing wedge osteotomy by 10° for slope reduction and investigate the effect of axial load and anterior drawer on forces on ACL graft, strain and femoro-tibial kinematics in a native, ACL-deficient and reconstructed knee. Materials and Methods: Ten cadaveric knees with an increased native slope were selected for this study based on CT meas-urements. An anterior closing-wedge osteotomy was performed by 10° and fixed with an external fixator. Tibial axial load (200 N, 400 N) was applied, while the tibial side was mounted on a free mov-ing X-Y-table with open rotation in 30° of knee flexion. Additionally, an anterior drawer (134 N) was performed with and without axial load (200 N). Specimens underwent native testing, cut ACL, and reconstructed ACL with a standardized quadruple semi-t/gracilis-allograft. Each condition was ran-domly tested with native slope and reduced slope. Change of forces on ACL-graft (attached load-cell) and strain on native ACL (via DVRT) were recorded. Throughout testing, 3D motion tracking captured anterior tibial translation (ATT) and rotation versus the fixed femur. Results: Preoperative, specimens showed an averaged lateral and medial slope of (average ±SD) 10° ± 1.4°, and age 48.2 ± 5.8years. Slope reduction significantly decreased forces on ACL graft by 17% (p=0.001) at 200 N and by 33% (p=0.0001) at 400 N of axial load. Furthermore, ATT was significantly decreased after slope reduc-tion in native (p=0.01), cut (p=0.005), and ACL-graft (p=0.01) status. Strain in native ACL de-creased by 9.7 ± 0.13% (p<0.0001) after slope reduction without any load. However, anterior drawer without axial load maintained significantly higher anterior tibial translation (native-pre 4.12 ± 0.65 mm vs. native-post 5.82 ± 1.51 mm, cut-ACL-pre 9.35 ± 1.57 mm vs cut-ACL-post 12.0 ± 3.53 mm, ACL-recon-pre 4.60 ± 0.97 mm vs. ACL-recon-post 5.73 ± 1.45 mm) and significantly higher forces on ACL graft (p=0.0006) after osteotomy. When axial load was combined with anterior drawer no significant change on ATT after osteotomy was observed. Rotational analysis did show a significant effect in the ACL cut condition due to slope correction. Overall, native and reconstruct-ed ACL showed the same tibial kinematics throughout testing. Conclusion: In general, osteotomy lowered ACL graft force and ACL strain when the joint was axially loaded. Anterior tibial translation was reduced even in an ACL deficient knee. When anterior drawer was performed without axial load, ATT was higher after slope reduction in every condition.

Slope-reducing tibial osteotomy decreases ACL-graft forces and anterior tibial translation under axial load

2019 ◽  
Vol 27 (10) ◽  
pp. 3381-3389 ◽  
Author(s):  
Florian B. Imhoff ◽  
Julian Mehl ◽  
Brendan J. Comer ◽  
Elifho Obopilwe ◽  
Mark P. Cote ◽  
...  
Keyword(s):  
Axial Load ◽  
Anterior Tibial Translation ◽  
Tibial Osteotomy ◽  
Acl Graft ◽  
Anterior Tibial ◽  
Tibial Translation

Effect of Meniscocapsular and Meniscotibial Lesions in ACL-Deficient and ACL-Reconstructed Knees: A Biomechanical Study

2018 ◽  
Vol 46 (10) ◽  
pp. 2422-2431 ◽  
Author(s):  
Nicholas N. DePhillipo ◽  
Gilbert Moatshe ◽  
Alex Brady ◽  
Jorge Chahla ◽  
Zachary S. Aman ◽  
...  
Keyword(s):  
Internal Rotation ◽  
Medial Meniscus ◽  
Pivot Shift ◽  
External Rotation ◽  
Posterior Horn ◽  
Pivot Shift Test ◽  
Anterior Tibial Translation ◽  
Anterior Tibial ◽  
Tibial Translation ◽  
Acl Deficient

Background: Ramp lesions were initially defined as a tear of the peripheral attachment of the posterior horn of the medial meniscus at the meniscocapsular junction. The separate biomechanical roles of the meniscocapsular and meniscotibial attachments of the posterior medial meniscus have not been fully delineated. Purpose: To evaluate the biomechanical effects of meniscocapsular and meniscotibial lesions of the posterior medial meniscus in anterior cruciate ligament (ACL)–deficient and ACL-reconstructed knees and the effect of repair of ramp lesions. Study Design: Controlled laboratory study. Methods: Twelve matched pairs of human cadaveric knees were evaluated with a 6 degrees of freedom robotic system. All knees were subjected to an 88-N anterior tibial load, internal and external rotation torques of 5 N·m, and a simulated pivot-shift test of 10-N valgus force coupled with 5-N·m internal rotation. The paired knees were randomized to the cutting of either the meniscocapsular or the meniscotibial attachments after ACL reconstruction (ACLR). Eight comparisons of interest were chosen before data analysis was conducted. Data from the intact state were compared with data from the subsequent states. The following states were tested: intact (n = 24), ACL deficient (n = 24), ACL deficient with a meniscocapsular lesion (n = 12), ACL deficient with a meniscotibial lesion (n = 12), ACL deficient with both meniscocapsular and meniscotibial lesions (n = 24), ACLR with both meniscocapsular and meniscotibial lesions (n = 16), and ACLR with repair of both meniscocapsular and meniscotibial lesions (n = 16). All states were compared with the previous states. For the repair and reconstruction states, only the specimens that underwent repair were compared with their intact and sectioned states, thus excluding the specimens that did not undergo repair. Results: Cutting the meniscocapsular and meniscotibial attachments of the posterior horn of the medial meniscus significantly increased anterior tibial translation in ACL-deficient knees at 30° ( P ≤ .020) and 90° ( P < .005). Cutting both the meniscocapsular and meniscotibial attachments increased tibial internal (all P > .004) and external (all P < .001) rotation at all flexion angles in ACL-reconstructed knees. Reconstruction of the ACL in the presence of meniscocapsular and meniscotibial tears restored anterior tibial translation ( P > .053) but did not restore internal rotation ( P < .002), external rotation ( P < .002), and the pivot shift ( P < .05). To restore the pivot shift, an ACLR and a concurrent repair of the meniscocapsular and meniscotibial lesions were both necessary. Repairing the meniscocapsular and meniscotibial lesions after ACLR did not restore internal rotation and external rotation at angles >30°. Conclusion: Meniscocapsular and meniscotibial lesions of the posterior horn of the medial meniscus increased knee anterior tibial translation, internal and external rotation, and the pivot shift in ACL-deficient knees. The pivot shift was not restored with an isolated ACLR but was restored when performed concomitantly with a meniscocapsular and meniscotibial repair. However, the effect of this change was minimal; although statistical significance was found, the overall clinical significance remains unclear. The ramp lesion repair used in this study failed to restore internal rotation and external rotation at higher knee flexion angles. Further studies should examine improved meniscus repair techniques for root tears combined with ACLRs. Clinical Relevance: Meniscal ramp lesions should be repaired at the time of ACLR to avoid continued knee instability (anterior tibial translation) and to eliminate the pivot-shift phenomenon.

Anterior Cruciate Ligament Graft Conditioning Required to Prevent an Abnormal Lachman and Pivot Shift After ACL Reconstruction: A Robotic Study of 3 ACL Graft Constructs

2019 ◽  
Vol 47 (6) ◽  
pp. 1376-1384 ◽  
Author(s):  
Frank R. Noyes ◽  
Lauren E. Huser ◽  
Brad Ashman ◽  
Michael Palmer
Keyword(s):  
Patellar Tendon ◽  
Pivot Shift ◽  
Cruciate Ligament ◽  
Anterior Tibial Translation ◽  
Acl Graft ◽  
Flexion Extension ◽  
Anterior Tibial ◽  
Tibial Translation ◽  
Bone Patellar Tendon ◽  
Anterior Posterior

Background: Anterior cruciate ligament (ACL) graft conditioning protocols to decrease postoperative increases in anterior tibial translation and pivot-shift instability have not been established. Purpose: To determine what ACL graft conditioning protocols should be performed at surgery to decrease postoperative graft elongation after ACL reconstruction. Study Design: Controlled laboratory study. Methods: A 6 degrees of freedom robotic simulator evaluated 3 ACL graft constructs in 7 cadaver knees for a total of 19 graft specimens. Knees were tested before and after ACL sectioning and after ACL graft conditioning protocols before reconstruction. The ACL grafts consisted of a 6-strand semitendinosus-gracilis TightRope, bone–patellar tendon–bone TightRope, and bone–patellar tendon–bone with interference screws. Two graft conditioning protocols were used: (1) graft board tensioning (20 minutes, 80 N) and (2) cyclic conditioning (5°-120° of flexion, 90-N anterior tibial load) after graft reconstruction to determine the number of cycles needed to obtain a steady state with no graft elongation. After conditioning, the grafts were cycled a second time under anterior-posterior loading (100 N, 25° of flexion) and under pivot-shift loading (100 N anterior, 5-N·m internal rotation, 7 N·m valgus) to verify that the ACL flexion-extension conditioning protocol was effective. Results: Graft board tensioning did not produce a steady-state graft. Major increases in anterior tibial translation occurred in the flexion-extension graft-loading protocol at 25° of flexion (mean ± SD: semitendinosus-gracilis TightRope, 3.4 ± 1.1 mm; bone–patellar tendon–bone TightRope, 3.2 ± 1.0 mm; bone–patellar tendon–bone with interference screws, 2.4 ± 1.5 mm). The second method of graft conditioning (40 cycles, 5°-120° of flexion, 90-N anterior load) produced a stable conditioned state for all grafts, as the anterior translations of the anterior-posterior and pivot-shift cycles were statistically equivalent ( P < .05, 1-20 cycles). Conclusion: ACL graft board conditioning protocols are not effective, leading to deleterious ACL graft elongations after reconstruction. A secondary ACL graft conditioning protocol of 40 flexion-extension cycles under 90-N graft loading was required for a well-conditioned graft, preventing further elongation and restoring normal anterior-posterior and pivot-shift translations. Clinical Relevance: There is a combined need for graft board tensioning and robust cyclic ACL graft loading before final graft fixation to restore knee stability.

Lateral Extra-articular Tenodesis Reduces Anterior Cruciate Ligament Graft Force and Anterior Tibial Translation in Response to Applied Pivoting and Anterior Drawer Loads

2020 ◽  
Vol 48 (13) ◽  
pp. 3183-3193
Author(s):  
Niv Marom ◽  
Hervé Ouanezar ◽  
Hamidreza Jahandar ◽  
Zaid A. Zayyad ◽  
Thomas Fraychineaud ◽  
...  
Keyword(s):  
Cruciate Ligament ◽  
Lateral Compartment ◽  
Anterior Tibial Translation ◽  
Anterior Drawer ◽  
Lachman Test ◽  
Acl Graft ◽  
Anterior Drawer Test ◽  
Anterior Laxity ◽  
Tibial Translation ◽  
Intact Knee

Background: The biomechanical effect of lateral extra-articular tenodesis (LET) performed in conjunction with anterior cruciate ligament (ACL) reconstruction (ACLR) on load sharing between the ACL graft and the LET and on knee kinematics is not clear. Purpose/Hypothesis: The purpose was to quantify the effect of LET on (1) forces carried by both the ACL graft and the LET and (2) tibiofemoral kinematics in response to simulated pivot shift and anterior laxity tests. We hypothesized that LET would decrease forces carried by the ACL graft and anterior tibial translation (ATT) in response to simulated pivoting maneuvers and during simulated tests of anterior laxity. Study Design: Controlled laboratory study. Methods: Seven cadaveric knees (mean age, 39 ± 12 years [range, 28-54 years]; 4 male) were mounted to a robotic manipulator. The robot simulated clinical pivoting maneuvers and tests of anterior laxity: namely, the Lachman and anterior drawer tests. Each knee was assessed in the following states: ACL intact, ACL sectioned, ACL reconstructed (using a bone–patellar tendon–bone autograft), and after performing LET (the modified Lemaire technique after sectioning of the anterolateral ligament and Kaplan fibers). Resultant forces carried by the ACL graft and LET at the peak applied loads were determined via superposition. ATT was determined in response to the applied loads. Results: With the applied pivoting loads, performing LET decreased ACL graft force up to 80% (44 ± 12 N; P < .001) and decreased ATT of the lateral compartment compared with that of the intact knee up to 7.6 ± 2.9 mm ( P < .001). The LET carried up to 91% of the force generated in the ACL graft during isolated ACLR (without LET). For simulated tests of anterior laxity, performing LET decreased ACL graft force by 70% (40 ± 20 N; P = .001) for the anterior drawer test with no significant difference detected for the Lachman test. No differences in ATT were deteced between ACLR with LET and the intact knee on both the Lachman and the anterior drawer tests ( P = .409). LET reduced ATT compared with isolated ACLR on the simulated anterior drawer test by 2.4 ± 1.8 mm ( P = .032) but not on the simulated Lachman test. Conclusion: In a cadaveric model, LET in combination with ACLR transferred loads from the ACL graft to the LET and reduced ATT with applied pivoting loads and during the simulated anterior drawer test. The effect of LET on ACL graft force and ATT was less pronounced on the simulated Lachman test. Clinical Relevance: LET in addition to ACLR may be a suitable option to offload the ACL graft and to reduce ATT in the lateral compartment to magnitudes less than that of the intact knee with clinical pivoting maneuvers. In contrast, LET did not offload the ACL graft or add to the anterior restraint provided by the ACL graft during the Lachman test.

Effect of Femoral Antetorsion on Tibiofemoral Translation and Rotation in the Anterior Cruciate Ligament Deficient Knee

2018 ◽  
Vol 32 (10) ◽  
pp. 960-965
Author(s):  
Mohamed Omar ◽  
Yousif Al Saiegh ◽  
Emmanouil Liodakis ◽  
Timo Stuebig ◽  
Daniel Guenther ◽  
...  
Keyword(s):  
Distal Femur ◽  
Pivot Shift ◽  
Cruciate Ligament ◽  
Anterior Tibial Translation ◽  
Tibial Rotation ◽  
Femoral Antetorsion ◽  
Anterior Drawer ◽  
Tibial Translation ◽  
Acl Deficient ◽  
Deficient Knee

AbstractWe aimed to investigate how increased or decreased femoral antetorsion would affect the biomechanics of the knee in an anterior cruciate ligament (ACL)-deficient cadaveric model. We hypothesized that external or internal rotation of the distal femur, achieved through a femoral osteotomy, would affect the magnitude of tibiofemoral translation and rotation. Navigated measurements of tibiofemoral translation and rotation during the anterior drawer, Lachman, and pivot shift tests were performed on six whole-body cadaveric specimens in each of the following four conditions: native, ACL-deficient knee, ACL-deficient knee and 20-degree internal distal femur rotation, and ACL-deficient knee and 20-degree external distal femur rotation. Increased femoral antetorsion significantly reduced anterior tibial translation in the ACL-deficient knee during the anterior drawer, Lachman, and pivot shift tests (p < 0.05). Conversely, decreasing femoral antetorsion resulted in an increase in anterior tibial translation in the anterior drawer (nonsignificant), Lachman (p < 0.05), and pivot shift (p < 0.05) tests. Internally rotating the distal femur significantly reduced the magnitude of tibial rotation during the pivot shift test in the ACL-deficient knee (p < 0.05), whereas external rotation of the distal femur significantly increased tibial rotation (p < 0.05). The magnitude of femoral antetorsion affects tibiofemoral translation in an ACL-deficient cadaveric mode. Internally rotating the distal femur 20 degrees reduced the magnitude of tibial translation and rotation similar to that of the native knee, whereas externally rotating the distal femur aggravated translational and rotational instability.

scholarly journals Lateral Extra-Articular Tenodesis Reduces ACL Graft Force Under Multiplanar Torques Simulationg Pivot Shit

2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0035
Author(s):  
Niv Marom ◽  
Herve Ouanezar ◽  
hamidreza jahandar ◽  
Zaid Zayyad ◽  
Thomas Fraychineaud ◽  
...  
Keyword(s):  
Pivot Shift ◽  
Knee Kinematics ◽  
Lateral Compartment ◽  
Anterior Tibial Translation ◽  
Acl Graft ◽  
Anterior Tibial ◽  
Text Figure ◽  
Force Reduction ◽  
Tibial Translation ◽  
Intact Knee

Objectives: Utilization of lateral extra-articular tenodesis (LET) in conjunction with anterior cruciate ligament reconstruction (ACLR) has increased in recent years, however, the biomechanical impact of LET, when performed with contemporary techniques, on both load sharing between the ACL graft and the LET and on knee kinematics is not completely clear. The purpose of this study was to quantify the effect of LET performed with ACLR, in the presence of a compromised anterolateral tissues, on (1) forces carried by the ACL graft and the LET and (2) knee kinematics, during simulated pivot shift. Methods: manipulator equipped with a six-axis force-torque sensor. The robot applied multiplanar torques simulating two types of pivot shift (PS) subluxing the lateral compartment at 15° and 30° of knee flexion. The following loading combinations were applied: (PS1) 8 Nm of valgus and 4 Nm of internal rotation torques; (PS2) 100 N compression force, 8 Nm valgus torque, 2 Nm internal rotation torque, and 30 N anterior force. Anteroposterior (AP) translation in the lateral compartment of the knee was recorded in the following states: ACL intact, sectioned, reconstructed and, finally, after sectioning the anterolateral ligament (ALL) and kaplan fibers and performing a LET. ACLR was performed utilizing a bone-patellar tendon-bone autograft, via medial parapatellar arthrotomy. LET was performed using a modified lemaire technique with a metal staple femoral fixation at 60° of flexion in neutral rotation. Resultant forces carried by the ACL graft and LET at the peak applied load in all tested conditions were determined utilizing the principle of superposition and serial sectioning. Results: Under both simulated pivot shift types and at both flexion angles the ACL force decreased with the addition of a LET, with the least force reduction of 39% for PS2 at 15° (p=0.01) and the most force reduction of 80% for PS1 at 30° (p<0.001). While decreasing ACL force, the LET carried at least 43% of the force carried by the ACL graft when tested without LET for PS2 at 15° and 91% of the force carried by the ACL graft at most, for PS1 at 30° (Table 1). For both combinations of multiplananr torques and at both flexion angles, the anterior tibial translation in the lateral compartment decreased for the ACLR+LET knee compared to the intact knee (5.3mm and 7.6mm decrease, for PS1 15° and 30° respectively, p<0.001; 4.4mm p=0.005 and 7.6mm p<0.001, for PS2 15° and 30°, respectively). (Figure 2). Conclusion: During a simulated pivot shift, LET shields the ACL graft from loading. This effect was greatest at 30° of flexion with an 80% drop in ACL graft force. While some shielding of load from the ACL graft can be beneficial, a more significant reduction in the load of the ACL graft may potentially be detrimental to the graft remodeling, maturation and function. The optimal load sharing pattern for improved clinical outcomes is not well understood and merit further investigation. In addition, LET also decreases anterior tibial translation in the lateral compartment to less than that of the intact knee, which represents overconstraint of the lateral compartment. These findings may support the purported “protective” effect of LET on the ACL graft and its important role in stabilizing the lateral compartment in the setting of combined ACL and anterolateral structures deficiency. The influence of overconstraint of the lateral compartment with LET warrants further biomechanical and clinical evaluation. [Table: see text][Figure: see text][Figure: see text]

Greater medial tibial slope is associated with increased anterior tibial translation in females with an ACL-deficient knee

2019 ◽  
Vol 28 (6) ◽  
pp. 1901-1908 ◽  
Author(s):  
Antoine Schneider ◽  
Claudia Arias ◽  
Chris Bankhead ◽  
Romain Gaillard ◽  
Sebastien Lustig ◽  
...  
Keyword(s):  
Tibial Slope ◽  
Anterior Tibial Translation ◽  
Anterior Tibial ◽  
Tibial Translation ◽  
Medial Tibial Slope ◽  
Acl Deficient ◽  
Deficient Knee
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