The Anterolateral Capsule of the Knee Behaves Like a Sheet of Fibrous Tissue

2016 ◽  
Vol 45 (4) ◽  
pp. 849-855 ◽  
Author(s):  
Daniel Guenther ◽  
Amir A. Rahnemai-Azar ◽  
Kevin M. Bell ◽  
Sebastián Irarrázaval ◽  
Freddie H. Fu ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Fibrous Tissue ◽  
Lateral Collateral Ligament ◽  
Longitudinal Axis ◽  
The Other ◽  
Surrounding Tissue ◽  
Anterior Tibial ◽  
Anterolateral Capsule ◽  
Acl Deficient ◽  
Deficient Knee

Background: The function of the anterolateral capsule of the knee has not been clearly defined. However, the contribution of this region of the capsule to knee stability in comparison with other anterolateral structures can be determined by the relative force that each structure carries during loading of the knee. Purpose/Hypothesis: The purpose of this study was to determine the forces in the anterolateral structures of the intact and anterior cruciate ligament (ACL)–deficient knee in response to an anterior tibial load and internal tibial torque. It was hypothesized that the anterolateral capsule would not function like a traditional ligament (ie, transmitting forces only along its longitudinal axis). Study Design: Controlled laboratory study. Methods: Loads (134-N anterior tibial load and 7-N·m internal tibial torque) were applied continuously during flexion to 7 fresh-frozen cadaveric knees in the intact and ACL-deficient state using a robotic testing system. The lateral collateral ligament (LCL) and the anterolateral capsule were separated from the surrounding tissue and from each other. This was done by performing 3 vertical incisions: lateral to the LCL, medial to the LCL, and lateral to the Gerdy tubercle. Attachments of the LCL and anterolateral capsule were detached from the underlying tissue (ie, meniscus), leaving the insertions and origins intact. The force distribution in the anterolateral capsule, ACL, and LCL was then determined at 30°, 60°, and 90° of knee flexion using the principle of superposition. Results: In the intact knee, the force in the ACL in response to an anterior tibial load was greater than that in the other structures ( P < .001). However, in response to an internal tibial torque, no significant differences were found between the ACL, LCL, and forces transmitted between each region of the anterolateral capsule after capsule separation. The anterolateral capsule experienced smaller forces (~50% less) compared with the other structures ( P = .048). For the ACL-deficient knee in response to an anterior tibial load, the force transmitted between each region of the anterolateral capsule was 434% greater than was the force in the anterolateral capsule ( P < .001) and 54% greater than the force in the LCL ( P = .036) at 30° of flexion. In response to an internal tibial torque at 30°, 60°, or 90° of knee flexion, no significant differences were found between the force transmitted between each region of the anterolateral capsule and the LCL. The force in the anterolateral capsule was significantly smaller than that in the other structures at all knee flexion angles for both loading conditions ( P = .004 for anterior tibial load and P = .04 for internal tibial torque). Conclusion: The anterolateral capsule carries negligible forces in the longitudinal direction, and the forces transmitted between regions of the capsule were similar to the forces carried by the other structures at the knee, suggesting that it does not function as a traditional ligament. Thus, the anterolateral capsule should be considered a sheet of tissue. Clinical Relevance: Surgical repair techniques for the anterolateral capsule should restore the ability of the tissue to transmit forces between adjacent regions of the capsule rather than along its longitudinal axis.

Medial and lateral meniscus have a different role in kinematics of the ACL-deficient knee: a systematic review

2019 ◽  
Vol 4 (5) ◽  
pp. 233-241
Author(s):  
Alberto Grassi ◽  
Giacomo Dal Fabbro ◽  
Stefano Di Paolo ◽  
Federico Stefanelli ◽  
Luca Macchiarola ◽  
...  
Keyword(s):  
Systematic Review ◽  
Medial Meniscus ◽  
Lateral Meniscus ◽  
Meniscus Tear ◽  
Pivot Shift Test ◽  
Anterior Tibial ◽  
Kinematic Evaluation ◽  
Tibial Translation ◽  
Acl Deficient ◽  
Deficient Knee

ImportanceMeniscal tears are frequently associated with anterior cruciate ligament (ACL) injury and the correct management of this kind of lesion during ACL-reconstruction procedure is critical for the restoration of knee kinematics. Although the importance of meniscus in knee biomechanics is generally accepted, the influence of medial and lateral meniscus in stability of ACL-deficient knee is still unclear.ObjectiveThe aim of this study was to review literature, which analysed effects in cadaveric specimens of meniscal tear and meniscectomy of medial and lateral meniscus on laxity in the ACL-deficient knee.Evidence reviewAuthors performed a systematic search for cadaveric studies analysing the effect of medial and lateral meniscus tears or resection on kinematics of ACL-deficient knee. Extracted data included year of publications, number of human cadaver knee specimens, description of apparatus testing and instrumented kinematic evaluation, testing protocol and results.FindingsAuthors identified 18 studies that met inclusion and exclusion criteria of current review. The major finding of the review was that the works included reported a difference role of medial and lateral meniscus in restraining ACL-deficient knee laxity. Medial meniscus tear or resection resulted in a significant increase of anterior tibial displacement. Lateral meniscus lesions or meniscectomy on the other hand significantly increased rotation and translation under a coupled valgus stress and internal-rotation torque/pivot shift test.ConclusionsMedial and lateral meniscus have a different role in stabilising the ACL-deficient knee: while the medial meniscus functions as a critical secondary stabilisers of anterior tibial translation under an anterior/posterior load, lateral meniscus appears to be a more important restraint of rotational and dynamic laxity.Level of evidenceLevel IV, systematic review of level I–IV studies.

There Are No Kinematic Differences Between Inframeniscal and Suprameniscal Anterolateral Ligament Injury in the Anterior Cruciate Ligament–Deficient Knee

2018 ◽  
Vol 46 (14) ◽  
pp. 3391-3399 ◽  
Author(s):  
Timothy A. Burkhart ◽  
Manoj Matthew ◽  
W. Scott McGuffin ◽  
Alexandra Blokker ◽  
David Holdsworth ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Internal Rotation ◽  
Knee Flexion ◽  
Pivot Shift ◽  
Cruciate Ligament ◽  
Lateral Meniscus ◽  
Anterolateral Ligament ◽  
Anterior Cruciate ◽  
Acl Deficient ◽  
Deficient Knee

Background: Previous research demonstrated that the attachment of the anterolateral ligament (ALL) to the lateral meniscus is stiffer and stronger in its tibial attachment than its femoral attachment. How this relates to anterolateral knee stability and lateral meniscal function is unknown. Hypothesis/Purpose: The hypothesis was that the ALL acts as a peripheral anchor to the lateral meniscus, aiding in anterolateral rotatory stability, and that the inframeniscal fibers of the ALL will provide greater anterolateral rotatory stability because of their greater tensile properties. The purpose was therefore to compare the difference in kinematics of the anterior cruciate ligament (ACL)–deficient knee between the infra- and suprameniscal ALL-sectioned states. Study Design: Controlled laboratory study. Methods: Eight paired fresh-frozen cadaveric knees were tested in a 5–degree of freedom loading jig under the following loading conditions: 5-N·m internal rotation at 15° incremental angles of flexion and combined 5-N·m internal rotation moment, 10-N·m valgus moment, and 88-N anterior translation force representing a pivot shift test at 0°, 15°, and 30° of flexion. The knees were tested under intact, ACL-deficient, and ACL-/ALL-deficient conditions, with the pairs of knees being randomized to either supra- or inframeniscal ALL sectioning. Resultant joint kinematics and tibiofemoral translations were measured and compared with a 2-way mixed repeated measures analysis of variance. Results: Internal rotation increased by 3° after sectioning of the ACL at 0° of knee flexion ( P = .035). At 45° of knee flexion, internal rotation increased significantly by 2° between the ACL-deficient and the ACL-/ALL-deficient conditions ( P = .049). Secondary kinematics of valgus and anterior translation were observed in response to the 5-N·m load after ACL and ALL sectioning. Analysis of the pivot shift showed increases in tibiofemoral translation after sectioning of the ACL, with further translations after sectioning of the ALL. No differences were observed between supra- and inframeniscal ALL sectioning under any of the loading conditions. Conclusion: An injury to the ALL, coexisting with ACL deficiency, results in only minor increases in knee joint patholaxity. No differences in pivot-shift kinematics or tibiofemoral rotations were observed between the supra- and inframeniscal sectioning of the ALL in the ACL-deficient knee Clinical Relevance: Tears of the midbody and/or posterior root attachment of the lateral meniscus are often observed at the time of ACL reconstruction. Increased anterolateral rotatory laxity has been observed in both lateral meniscus– and ALL-deficient states in combination with an ACL injury. While no significant functional relationship was found between the ALL and lateral meniscus, ALL sectioning did result in increased knee joint patholaxity, as demonstrated by composite tibiofemoral rotations.

Biomechanical Assessment of a Distally Fixed Lateral Extra-articular Augmentation Procedure in the Treatment of Anterolateral Rotational Laxity of the Knee

2019 ◽  
Vol 47 (9) ◽  
pp. 2102-2109 ◽  
Author(s):  
Brian M. Devitt ◽  
Breck R. Lord ◽  
Andy Williams ◽  
Andrew A. Amis ◽  
Julian A. Feller
Keyword(s):  
Repeated Measures ◽  
Knee Flexion ◽  
Knee Kinematics ◽  
Lateral Collateral Ligament ◽  
Iliotibial Band ◽  
Rotational Laxity ◽  
Intact State ◽  
Anterolateral Capsule ◽  
Injured Knee ◽  
Augmentation Procedure

Background: Most lateral extra-articular tenodesis (LET) procedures rely on passing a strip of the iliotibial band (ITB) under the fibular (lateral) collateral ligament and fixing it proximally to the femur. The Ellison procedure is a distally fixed lateral extra-articular augmentation procedure with no proximal fixation of the ITB. It has the potential advantages of maintaining a dynamic element of control of knee rotation and avoiding the possibility of overconstraint. Hypothesis: The modified Ellison procedure would restore native knee kinematics after sectioning of the anterolateral capsule, and closure of the ITB defect would decrease rotational laxity of the knee. Study Design: Controlled laboratory study. Methods: Twelve fresh-frozen cadaveric knees were tested in a 6 degrees of freedom robotic system through 0° to 90° of knee flexion to assess anteroposterior, internal rotation (IR), and external rotation laxities. A simulated pivot shift (SPS) was performed at 0°, 15°, 30°, and 45° of flexion. Kinematic testing was performed in the intact knee and anterolateral capsule–injured knee and after the modified Ellison procedure, with and without closure of the ITB defect. A novel pulley system was used to load the ITB at 30 N for all testing states. Statistical analysis used repeated measures analyses of variance and paired t tests with Bonferroni adjustments. Results: Sectioning of the anterolateral capsule increased anterior drawer and IR during isolated displacement and with the SPS (mean increase, 2° of IR; P < .05). The modified Ellison procedure reduced both isolated and coupled IR as compared with the sectioned state ( P < .05). During isolated testing, IR was reduced close to that of the intact state with the modified Ellison procedure, except at 30° of knee flexion, when it was slightly overconstrained. During the SPS, IR with the closed modified Ellison was less than that in the intact state at 15° and 30° of flexion. No significant differences in knee kinematics were seen between the ITB defect open and closed. Conclusion: A distally fixed lateral augmentation procedure can closely restore knee laxities to native values in an anterolateral capsule–sectioned knee. Although the modified Ellison did result in overconstraint to isolated IR and coupled IR during SPS, this occurred only in the early range of knee flexion. Closure of the ITB defect had no effect on knee kinematics. Clinical Relevance: A distally fixed lateral extra-articular augmentation procedure provides an alternative to a proximally fixed LET and can reduce anterolateral laxity in the anterolateral capsule–injured knee and restore kinematics close to the intact state.

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

Anterolateral Knee Extra-articular Stabilizers: A Robotic Sectioning Study of the Anterolateral Ligament and Distal Iliotibial Band Kaplan Fibers

2018 ◽  
Vol 46 (6) ◽  
pp. 1352-1361 ◽  
Author(s):  
Andrew G. Geeslin ◽  
Jorge Chahla ◽  
Gilbert Moatshe ◽  
Kyle J. Muckenhirn ◽  
Bradley M. Kruckeberg ◽  
...  
Keyword(s):  
Internal Rotation ◽  
Pivot Shift ◽  
Iliotibial Band ◽  
Anterior Tibial Translation ◽  
Tibial Internal Rotation ◽  
Anterior Tibial ◽  
Robotic Testing ◽  
Tibial Translation ◽  
Acl Deficient ◽  
Deficient Knee

Background: The individual kinematic roles of the anterolateral ligament (ALL) and the distal iliotibial band Kaplan fibers in the setting of anterior cruciate ligament (ACL) deficiency require further clarification. This will improve understanding of their potential contribution to residual anterolateral rotational laxity after ACL reconstruction and may influence selection of an anterolateral extra-articular reconstruction technique, which is currently a matter of debate. Hypothesis/Purpose: To compare the role of the ALL and the Kaplan fibers in stabilizing the knee against tibial internal rotation, anterior tibial translation, and the pivot shift in ACL-deficient knees. We hypothesized that the Kaplan fibers would provide greater tibial internal rotation restraint than the ALL in ACL-deficient knees and that both structures would provide restraint against internal rotation during a simulated pivot-shift test. Study Design: Controlled laboratory study. Methods: Ten paired fresh-frozen cadaveric knees (n = 20) were used to investigate the effect of sectioning the ALL and the Kaplan fibers in ACL-deficient knees with a 6 degrees of freedom robotic testing system. After ACL sectioning, sectioning was randomly performed for the ALL and the Kaplan fibers. An established robotic testing protocol was utilized to assess knee kinematics when the specimens were subjected to a 5-N·m internal rotation torque (0°-90° at 15° increments), a simulated pivot shift with 10-N·m valgus and 5-N·m internal rotation torque (15° and 30°), and an 88-N anterior tibial load (30° and 90°). Results: Sectioning of the ACL led to significantly increased tibial internal rotation (from 0° to 90°) and anterior tibial translation (30° and 90°) as compared with the intact state. Significantly increased internal rotation occurred with further sectioning of the ALL (15°-90°) and Kaplan fibers (15°, 60°-90°). At higher flexion angles (60°-90°), sectioning the Kaplan fibers led to significantly greater internal rotation when compared with ALL sectioning. On simulated pivot-shift testing, ALL sectioning led to significantly increased internal rotation and anterior translation at 15° and 30°; sectioning of the Kaplan fibers led to significantly increased tibial internal rotation at 15° and 30° and anterior translation at 15°. No significant difference was found when anterior tibial translation was compared between the ACL/ALL- and ACL/Kaplan fiber–deficient states on simulated pivot-shift testing or isolated anterior tibial load. Conclusion: The ALL and Kaplan fibers restrain internal rotation in the ACL-deficient knee. Sectioning the Kaplan fibers led to greater tibial internal rotation at higher flexion angles (60°-90°) as compared with ALL sectioning. Additionally, the ALL and Kaplan fibers contribute to restraint of the pivot shift and anterior tibial translation in the ACL-deficient knee. Clinical Relevance: This study reports that the ALL and distal iliotibial band Kaplan fibers restrain anterior tibial translation, internal rotation, and pivot shift in the ACL-deficient knee. Furthermore, sectioning the Kaplan fibers led to significantly greater tibial internal rotation when compared with ALL sectioning at high flexion angles. These results demonstrate increased rotational knee laxity with combined ACL and anterolateral extra-articular knee injuries and may allow surgeons to optimize the care of patients with this injury pattern.

scholarly journals The influence of posterior medial meniscocapsular lesions on tibiofemoral joint laxity with ACL deficiency and reconstruction

2017 ◽  
Vol 5 (5_suppl5) ◽  
pp. 2325967117S0017
Author(s):  
Andy Williams ◽  
Jo Stephen ◽  
Camilla Halewood ◽  
Christoph Kittl ◽  
Andrew Amis ◽  
...  
Keyword(s):  
Acl Reconstruction ◽  
Knee Kinematics ◽  
Optical Tracking ◽  
Tibial Rotation ◽  
Anterior Translation ◽  
Ramp Lesion ◽  
Anterior Tibial ◽  
The Impact ◽  
Acl Deficient ◽  
Deficient Knee

Introduction: Injury to the posterior medial meniscocapsular junction (the ‘ramp’ lesion) occurs at the time of anterior cruciate ligament (ACL) rupture (10-24% of cases); however there is a lack of objective evidence investigating how this affects knee kinematics. It is often missed when viewed arthroscopically from the front of the medial compartment as it can only be seen with the arthroscope in the posteromedial recess. Objectives: To investigate the biomechanical impact of the ‘ramp lesion’ on the ACL deficient and ACL reconstructed knee and the impact of suture repair of the lesion on the same knee states. Methods: Nine fresh frozen cadaveric knees were mounted in a 6 degrees of freedom rig where knee kinematics were recorded at 10° intervals from 0°-100° using an optical tracking system. Measurements were recorded using the following loading conditions: 90 N anterior and posterior tibial forces, 5 Nm internal and external tibial rotation torques, and a combined 90 N anterior tibial force and 5 Nm external tibial rotation torque. Manual Rolimeter readings of anterior translation were taken at 30° and 90°. The knees were tested in the following order: (1) intact, (2) ACL deficient, (3) ACL deficient + posterior meniscocapsule sectioned, (4) ACL deficient + posterior meniscocapsule repaired, (5) ACL patellar tendon reconstruction with posterior meniscocapsule repair and (6) ACL reconstructed + capsular lesion re-created. Statistical analysis was undertaken using repeated-measures ANOVA and post-hoc paired t-tests with Bonferonni correction. Results: Tibial anterior translation and external rotational laxities were both significantly increased compared to the ACL deficient knee following posterior meniscocapsular sectioning ( P < 0.05). These were both restored following ACL reconstruction and meniscocapsular lesion repair ( P > 0.05). Significant changes in anterior tibial translation between the different knee states were identified with the Rolimeter, indicating these changes are clinically detectable ( P < 0.05). Conclusion: Anterior and external rotational laxities were significantly increased after mimicking the ‘ramp lesion’ by sectioning of the posteromedial meniscocapsular junction in an ACL-deficient knee. These were not restored after ACL reconstruction alone but were restored with ACL reconstruction combined with posterior meniscocapsular repair. Tibial anterior translation changes were clinically detectable by use of the Rolimeter. This study suggests that unrepaired posteromedial meniscocapsular lesions will allow abnormal meniscal and tibiofemoral laxity to persist postoperatively, predisposing the knee to meniscal and articular damage but also adding avoidable extra strain on an ACL graft, which may yield.

scholarly journals Effect of meniscal root tear on pivot shift test after anterior cruciate ligament-deficient

2020 ◽  
Vol 8 (9_suppl7) ◽  
pp. 2325967120S0052
Author(s):  
Ming Zhou
Keyword(s):  
Pivot Shift ◽  
Cruciate Ligament ◽  
Lateral Meniscus ◽  
Pivot Shift Test ◽  
High Grade ◽  
Posterior Root ◽  
Meniscal Root Tear ◽  
Tibial Translation ◽  
Acl Deficient ◽  
Deficient Knee

Introduction: A review of the literature demonstrates that injury of the lateral meniscus, anterolateral capsule, and iliotibial(IT ) band or small lateral tibial plateau aggravate the instability of knee and contributes to a high-grade pivot shift in the ACL-deficient knee. Hypotheses: The hypothesis was that disruption of posterior root of the lateral meniscus will further destabilize the ACL-deficient knee and simulated a high-grade pivot shift but posterior root of medial meniscal not. Methods: 6 fresh-frozen cadaveric knees was performed the next test in a custom activity simulator.1.Determine the effect of PRLMT on the stability of ACL-deficient knee.In the pivot shift test, ITB force (50, 75, 100, 125, 150, and 175 N), internal rotation moments (1, 2, and 3 N.m),and valgus moments (5 and 7 N.m). tibial translation of front drawer test were performed by applying a 90-N anterior

scholarly journals Seat pitch and comfort of a staggered seat configuration

Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S151-S159
Author(s):  
Zhihui Liu ◽  
T. Rotte ◽  
S. Anjani ◽  
P. Vink
Keyword(s):  
Longitudinal Axis ◽  
The Other ◽  
Sitting Position ◽  
Lateral Direction ◽  
Top View ◽  
Design Freedom ◽  
Cabin Interior ◽  
Physical Dimensions

BACKGROUND: Staggered seats are a solution for the Flying-V aircraft, where the cabin’s longitudinal axis has a 26 degrees angle with respect to the direction of flight, to compensate for an otherwise oblique sitting position. However, little is known on acceptable pitches in this staggered configuration. OBJECTIVE: The goal of this research is to evaluate the comfort of different pitches for seats that are staggered relative to the cabin’s longitudinal axis. METHODS: Two rows of staggered seats are positioned at three different pitches (27, 29 and 31 inches). 53 participants were seated in each setup. For each, a questionnaire was completed including questions on comfort and discomfort, top view photos were taken to analyse postures and physical dimensions were recorded to define passengers’ space. RESULTS: Comfort as well as discomfort were significantly different for the three setups. The comfort at 27 inches was seen as unacceptably low. The 29 and 31-inch configurations showed to result in acceptable levels of comfort, comparable to higher-end seating layouts. There were very little complaints about space in lateral direction (elbow and seat width), showing the advantage of having your won armrest and shoulder space in the staggered configuration. Interesting was that at larger pitches more complaints were found for the seat characteristics, probably in the shorter pitch the other discomfort was overruling this. CONCLUSION: The 26-degree staggered configuration offers improvements in shoulder- and elbow-space. The results for the 29- and 31-inch are expected to allow enough design freedom for further exploration of such a configuration for the Flying-V cabin interior.

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