scholarly journals Kinematics of the posterolateral corner of the knee: A human cadaveric cutting study.

2017 ◽  
Vol 5 (4_suppl4) ◽  
pp. 2325967117S0013
Author(s):  
Tobias Drenck ◽  
Christoph Domnick ◽  
Mirco Herbort ◽  
Michael Raschke ◽  
Karl-Heinz Frosch

Aims and Objectives: The posterolateral corner of the knee consists of different structures, which contribute to instability when damaged after injury or within surgery. Knowing the kinematic influences may help to improve clinical diagnostics and surgical techniques. The purpose was to determine static stabilizing effects of the posterolateral corner by dissecting stepwise all fibers and ligaments (the arcuat complex, AC) connected with the popliteus tendon (PLT) and the influence on lateral stability in the lateral collateral ligament (LCL) intact-state. Materials ans Methods: Kinematics were examined in 13 fresh-frozen human cadaveric knees using a robotic/UFS testing system with an optical tracking system. The knee kinematics were determined for 134 N anterior/posterior loads, 10 Nm valgus/varus loads and 5 Nm internal/external rotational loads in 0°, 20°, 30°, 60° and 90° of knee flexion. The posterolateral corner structures were consecutively dissected: The I.) intact knee joint, II.) with dissected posterior cruciate ligament, III.) meniscofibular/-tibial fibers, IV.) popliteofibular ligament, V.) popliteotibial fascicle (last structure of static AC), VI.) PLT and VII.) LCL. Results: The external rotation angle increased significantly by 2.6° to 7.9° (P<.05) in 0° to 90° of knee flexion and posterior tibial translation increased by 2.9 mm to 5.9 mm in 20° to 90° of knee flexion (P<.05) after cutting the AC/PLT structures (with intact LCL) in contrast to the PCL deficient knee. Differences between dissected static AC and dissected PLT were only found in 60° and 90° external rotation tests (by 2.1° and 3.1°; P<.05). In the other 28 kinematic tests, no significant differences between PLT and AC were found. Cutting the AC/PLT complex did not further decrease varus, valgus or anterior tibial stability in any flexion angle in comparison to the PCL dissected state. Conclusion: The arcuat complex is an important static stabilizer for external rotatory and posterior tibial loads of the knee, even in the lateral collateral ligament intact-state. After dissecting the major parts of the arcuat complex, the static stabilizing function of the popliteus tendon is lost. The arcuat complex has no varus-stabilizing function in the LCL-intact knee. The anatomy and function of these structures for external-rotational and posterior-translational stabilization should be considered for clinical diagnostics and when performing surgery in the posterolateral corner.

Author(s):  
Paul Arauz ◽  
Yun Peng ◽  
Tiffany Castillo ◽  
Christian Klemt ◽  
Young-Min Kwon

AbstractThis is an experimental study. As current posterior-substituting (PS) total knee arthroplasties have been reported to incompletely restore intrinsic joint biomechanics of the healthy knee, the recently designed single axis radius PS knee system was introduced to increase posterior femoral translation and promote ligament isometry. As there is a paucity of data available regarding its ability to replicate healthy knee biomechanics, this study aimed to assess joint and articular contact kinematics as well as ligament isometry of the contemporary single axis radius PS knee system. Implant kinematics were measured from 11 cadaveric knees using an in vitro robotic testing system. In addition, medial collateral ligament (MCL) and lateral collateral ligament (LCL) forces were quantified under simulated functional loads during knee flexion for the contemporary PS knee system. Posterior femoral translation between the intact knee and the single axis radius PS knee system differed significantly (p < 0.05) at 60, 90, and 120 degrees of flexion. The LCL force at 60 degrees (9.06 ± 2.81 N) was significantly lower (p < 0.05) than those at 30, 90, and 120 degrees of flexion, while MCL forces did not differ significantly throughout the range of tested flexion angles. The results from this study suggest that although the contemporary single axis radius PS knee system has the potential to mimic the intact knee kinematics under muscle loading during flexion extension due to its design features, single axis radius PS knee system did not fully replicate posterior femoral translation and ligament isometry of the healthy knee during knee flexion.


2007 ◽  
Vol 35 (7) ◽  
pp. 1117-1122 ◽  
Author(s):  
Keith L. Markolf ◽  
Benjamin R. Graves ◽  
Susan M. Sigward ◽  
Steven R. Jackson ◽  
David R. McAllister

Background With grade 3 posterolateral injuries of the knee, reconstructions of the lateral collateral ligament, popliteus tendon, and popliteofibular ligament are commonly performed in conjunction with a posterior cruciate ligament reconstruction to restore knee stability. Hypothesis A lateral collateral ligament reconstruction, alone or with a popliteus tendon or popliteofibular ligament reconstruction, will produce normal varus rotation patterns and restore posterior cruciate ligament graft forces to normal levels in response to an applied varus moment. Study Design Controlled laboratory study. Methods Forces in the native posterior cruciate ligament were recorded for 15 intact knees during passive extension from 120° to 0° with an applied 5 N·m varus moment. The posterior cruciate ligament was removed and reconstructed with a single bundle inlay graft tensioned to restore intact knee laxity at 90°. Posterior cruciate ligament graft force, varus rotation, and tibial rotation were recorded before and after a grade 3 posterolateral corner injury. Testing was repeated with lateral collateral ligament, lateral collateral ligament plus popliteus tendon, and lateral collateral ligament plus popliteofibular ligament graft reconstructions; all grafts were tensioned to 30 N at 30° with the tibia locked in neutral rotation. Results All 3 posterolateral graft combinations rotated the tibia into slight valgus as the knee was taken through a passive range of motion. During the varus test, popliteus tendon and popliteofibular ligament reconstructions internally rotated the tibia from 1.5° (0° flexion) to approximately 12° (45° flexion). With an applied varus moment, mean varus rotations with a lateral collateral ligament graft were significantly less than those with the intact lateral collateral ligament beyond 0° flexion; mean decreases ranged from 0.8° (at 5° flexion) to 5.6° (at 120° flexion). Addition of a popliteus tendon or popliteofibular ligament graft further reduced varus rotation (compared with a lateral collateral ligament graft) beyond 25° of flexion; both grafts had equal effects. A lateral collateral ligament reconstruction alone restored posterior cruciate ligament graft forces to normal levels between 0° and 100° of flexion; lateral collateral ligament plus popliteus tendon and lateral collateral ligament plus popliteofibular ligament reconstructions reduced posterior cruciate ligament graft forces to below-normal levels—beyond 95° and 85° of flexion, respectively. Conclusions With a grade 3 posterolateral corner injury, popliteus tendon or popliteofibular ligament reconstructions are commonly performed to limit external tibial rotation; we found that they also limited varus rotation. With the graft tensioning protocols used in this study, all posterolateral graft combinations tested overconstrained varus rotation. Further studies with posterolateral reconstructions are required to better restore normal kinematics and provide more optimum load sharing between the PCL graft and posterolateral grafts. Clinical Relevance A lower level of posterolateral graft tension, perhaps applied at a different flexion angle, may be indicated to better restore normal varus stability. The clinical implications of overconstraining varus rotation are unknown.


2005 ◽  
Vol 33 (3) ◽  
pp. 360-369 ◽  
Author(s):  
Jon K. Sekiya ◽  
Marcus J. Haemmerle ◽  
Kathryne J. Stabile ◽  
Tracy M. Vogrin ◽  
Christopher D. Harner

Background Failure to address both components of a combined posterior cruciate ligament and posterolateral corner injury has been implicated as a reason for abnormal biomechanics and inferior clinical results. Hypothesis Combined double-bundle posterior cruciate ligament and posterolateral corner reconstruction restores the kinematics and in situ forces of the intact knee ligaments. Study Design Controlled laboratory study Methods Ten fresh-frozen human cadaveric knees were tested using a robotic testing system through sequential cutting and reconstructing of the posterior cruciate ligament and posterolateral corner. The knees were subjected to a 134-N posterior tibial load and a 5-N.m external tibial torque at multiple flexion angles. The double-bundle posterior cruciate ligament reconstruction was performed using Achilles and semitendinosus tendons. The posterolateral corner reconstruction consisted of reattaching the popliteus tendon to its femoral origin and reconstructing the popliteofibular ligament with a gracilis tendon. Results Under the posterior load, the combined reconstruction reduced posterior translation to within 1.2 - 1.5 mm of the intact knee. The in situ forces in the posterior cruciate ligament grafts were significantly less than those in the native posterior cruciate ligament at all angles except full extension. Conversely, the forces in the posterolateral corner grafts were significantly higher than those in the native structures at all angles. Under the external torque with the combined reconstruction, external rotation as well as in situ forces in the posterior cruciate ligament and posterolateral corner grafts were not different from the intact knee. Conclusions A combined posterior cruciate ligament and posterolateral corner reconstruction can restore intact knee kinematics at time zero. In situ forces in the intact posterior cruciate ligament and posterolateral corner were not reproduced by the reconstruction; however, the posterolateral corner reconstruction reduced the loads experienced by the posterior cruciate ligament grafts. Clinical Relevance By addressing both structures of this combined injury, this technique restores native kinematics under the applied loads at fixed flexion angles and demonstrates load sharing among the grafts creating a potentially protective effect against early failure of the posterior cruciate ligament grafts but with increased force in the posterolateral corner construct.


2005 ◽  
Vol 33 (12) ◽  
pp. 1838-1845 ◽  
Author(s):  
Thomas Nau ◽  
Yan Chevalier ◽  
Nicola Hagemeister ◽  
Jacques A. deGuise ◽  
Nicolas Duval

Background Various surgical techniques to treat posterolateral knee instability have been described. To date, the recommended treatment is an anatomical form of reconstruction, in which the 3 key structures of the posterolateral corner are addressed: the lateral collateral ligament, the popliteofibular ligament, and the popliteus tendon. Hypothesis Two methods of surgical reconstruction will restore posterolateral knee instability, in terms of static laxity as well as dynamic 6 degrees of freedom kinematics, to statistically significant levels compared with the intact state. Study Design Controlled laboratory study. Methods Two surgical techniques (A and B) were used to reconstruct the posterolateral structures in 10 cadaveric knees. Static tests were performed on the intact, sectioned, and reconstructed knees at 30° and 90° of flexion for anterior-posterior laxity and external rotational laxity, as well as at 0° and 30° of flexion for varus laxity; dynamic 6 degrees of freedom kinematic testing, through a path of motion from 90° of flexion to full extension, was also performed. Results For the static varus tests, external rotation and varus laxity were significantly increased after the posterolateral structures were cut. Both reconstruction techniques restored external rotation and varus laxity to levels not significantly different from the intact state. For technique B, dynamic testing did not show any significant difference for all degrees of freedom kinematics compared with the intact state. However, for technique A, a significant internal tibial rotation was observed throughout the entire path of motion from 0° to 90° of knee flexion. Conclusions Both surgical techniques for anatomical posterolateral corner reconstruction showed good results in the static laxity tests. The anatomical reconstruction of all structures, including the popliteus tendon, resulted in an abnormal internal tibial rotation during dynamic testing.


2007 ◽  
Vol 35 (9) ◽  
pp. 1521-1527 ◽  
Author(s):  
Benjamin R. Coobs ◽  
Robert F. LaPrade ◽  
Chad J. Griffith ◽  
Bradley J. Nelson

Background The fibular collateral ligament is the primary stabilizer to varus instability of the knee. Untreated fibular collateral ligament injuries can lead to residual knee instability and can increase the risk of concurrent cruciate ligament reconstruction graft failures. Anatomic reconstructions of the fibular collateral ligament have not been biomechanically validated. Purpose To describe an anatomic fibular collateral ligament reconstruction using an autogenous semitendinosus graft and to test the hypothesis that using this reconstruction technique to treat an isolated fibular collateral ligament injury will restore the knee to near normal stability. Study Design Controlled laboratory study. Methods Ten nonpaired, fresh-frozen cadaveric knees were biomechanically subjected to a 10 N·m varus moment and 5 N·m external and internal rotation torques at 0°, 15°, 30°, 60°, and 90° of knee flexion. Testing was performed with an intact and sectioned fibular collateral ligament, and also after an anatomic reconstruction of the fibular collateral ligament with an autogenous semitendinosus graft. Motion changes were assessed with a 6 degree of freedom electromagnetic motion analysis system. Results After sectioning, we found significant increases in varus rotation at 0°, 15°, 30°, 60°, and 90°, external rotation at 60° and 90°, and internal rotation at 0°, 15°, 30°, 60°, and 90° of knee flexion. After reconstruction, there were significant decreases in motion in varus rotation at 0°, 15°, 30°, 60°, and 90°, external rotation at 60° and 90°, and internal rotation at 0°, 15°, and 30° of knee flexion. In addition, we observed a full recovery of knee stability in varus rotation at 0°, 60°, and 90°, external rotation at 60° and 90°, and internal rotation at 0° and 30° of knee flexion. Conclusion An anatomic fibular collateral ligament reconstruction restores varus, external, and internal rotation to near normal stability in a knee with an isolated fibular collateral ligament injury. Clinical Significance An anatomic reconstruction of the fibular collateral ligament with an autogenous semitendinosus graft is a viable option to treat nonrepairable acute or chronic fibular collateral ligament tears in patients with varus instability.


2021 ◽  
Vol 29 (5) ◽  
pp. 249-252
Author(s):  
MARCEL FARACO SOBRADO ◽  
CAMILO PARTEZANI HELITO ◽  
LUCAS DA PONTE MELO ◽  
ANDRE MARANGONI ASPERTI ◽  
RICCARDO GOMES GOBBI ◽  
...  

ABSTRACT Objective: To analyse the distances between the femoral insertions of the popliteus tendon (PT) and the lateral collateral ligament (LCL) through dissections of cadaveric specimens in a mixed population. Methods: Fresh cadavers were dissected, and the anthropometric data of all specimens were recorded. The distances from the origin of the PT to the LCL in the femoral region and the diameter of each structure were measured using a digital calliper. Results: In total, 11 unpaired knees were dissected, eight men and three women, with an average age of 71.5 ± 15.2 years, weight of 57.2 ± 15.6 kg, and a mean height of 170.5 ± 8.2 cm. The distance from the center of the femoral footprint of the LCL to the PT was 10.0 ± 2.4 mm. The distances between the edges closest to each other and those more distant from each other were 3.1 ± 1.1 mm and 16.3 ± 2.4 mm, respectively. Conclusion: The distance between the midpoints of the PT and the LCL in our mixed population is smaller than the distances often reported in the literature. PLC reconstruction with separate tunnels for the LCL and PT may not be technically possible for individuals of any population. Level of Evidence III, Diagnostic studies.


2017 ◽  
Vol 5 (3_suppl3) ◽  
pp. 2325967117S0012
Author(s):  
Alexander R. Vap ◽  
Jason M. Schon ◽  
Gilbert Moatshe ◽  
Raphael Cruz ◽  
Alex Brady ◽  
...  

Objectives: The purpose of this study was to assess the effect of sequentially cutting the posterolateral, anterolateral, posteromedial and anteromedial structures of the knee on rotational kinematics in the setting of intact cruciate and collateral ligaments. It was hypothesized that cutting of the iliotibial band (ITB), anterolateral ligament and lateral capsule (ALL/LC), the posterior oblique ligament (POL), and the posteromedial capsule (PMC) would significantly increase internal rotation and that the anteromedial capsule (AMC), and the popliteus tendon and popliteofibular ligament (PLT/PFL) when sectioned would lead to a significant increase in external rotation of the knee. Methods: Ten pairs ( n = 20) of cadaveric knees were assigned to two sequential cutting groups (posterolateral-to-posteromedial and posteromedial-to-posterolateral). Specimen were subjected to 5 N-m of internal and external rotation torque at knee flexion angles 0° through 90° in the intact and after each cut state. Rotational changes were measured and compared to the intact and previous states following each cut. Results: Sectioning of the ITB significantly increased internal rotation at 60° and 90° by 5.4° and 6.2[[Unsupported Character - Codename ­]]°, respectively (after ALL/LC cut) and 3.5° and 3.8° (prior to ALL/LC cut) ( Figure 1 ). At 60° and 90°, section of the ALL/LC produced significant increases in internal rotation of 3.1[[Unsupported Character - Codename ­]]° and 3.5°, respectively (after ITB cut) and of 0.5° (prior to ITB cut) ( Figure 1 ). At 0°, section of the POL produced significant increases in internal rotation of 2.0° (ITB intact) and 1.8° (after ITB cut) ( Figure 1 ). Sectioning the PLT/PFL complex significantly increased external rotation at 60° and 90° by 2.7° and 2.9°, respectively (prior to sectioning medial structures) and 2.2° and 2.7[[Unsupported Character - Codename ­]]°, respectively (after sectioning medial structures) ( Figure 2 ). Sectioning the AMC produced significant increases in external rotation at 30°- 90° of flexion, however the magnitude of change was < 1° ( Figure 2 ). [Figure: see text][Figure: see text] Conclusion: Collectively the anterolateral corner structures had a primary role in internal rotational control of the knee from 60° to 90° of knee flexion. The ITB was the most significant primary stabilizer for internal rotation in ACL intact knees. The POL contributed to internal rotational control at full extension, while the PLT/PFL complex controlled external rotation of the knee at higher flexion angles (60° and 90°). Internal rotation control of the knee has been mainly attributed to the cruciate and collateral ligaments. This study delineates the primary and secondary roles of the ITB, the ALL/LC, POL and PLT/PFL to rotatory stability of the knee. As such, it provides new information about the understanding of rotational instabilities of the knee.


2012 ◽  
pp. 31-42
Author(s):  
C. J. Griffith ◽  
C. A. Wijdicks ◽  
R. F. LaPrade

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