The Effect of Lateral Extra-articular Tenodesis in an ACL-Reconstructed Knee With Partial Medial Meniscectomy: A Biomechanical Study.

Background: Knee laxity increases with medial meniscectomy in anterior cruciate ligament (ACL)-reconstructed knees; however, the biomechanical effect of an additional lateral extra-articular tenodesis (LET) is unknown.

Purpose/hypothesis: The purpose of this study was to determine the kinematic effect of a LET in knees that underwent combined ACL reconstruction (ACL-R) and partial medial meniscus posterior horn (MMPH) meniscectomy. It was hypothesized that the addition of LET would reduce laxity in the ACL-reconstructed knee.

Augmenting ACL Repair With Suture Tape Improves Knee Laxity: A Biomechanical Study.

Background: Anterior cruciate ligament (ACL) repair is an alternative to reconstruction; however, suture tape support may be necessary to achieve adequate outcomes.

Purposes: To investigate the influence of suture tape augmentation (STA) of proximal ACL repair on knee kinematics and to evaluate the effect of the 2 flexion angles of suture tape fixation.

Study Design: Controlled laboratory study.

No Difference in Knee Kinematics Between Anterior Cruciate Ligament-First and Posterior Cruciate Ligament-First Fixation During Single-Stage Multiligament Knee Reconstruction: A Biomechanical Study.

Background: For combined reconstruction of both the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL), there is no consensus regarding which graft should be tensioned and fixed first.

Purpose: The purpose of this study was to determine which sequence of graft tensioning and fixation better restores normal knee kinematics. The hypothesis was that ACL-first fixation would more closely restore normal knee kinematics, graft force, and the tibiofemoral orientation in the neutral (resting) position compared with PCL-first fixation.

Arthroscopic centralization reduces extrusion of the medial meniscus with posterior root defect in the ACL reconstructed knee.

Purpose: The purpose of this study was to evaluate the effects of arthroscopic meniscal centralization reinforcement for a medial meniscus (MM) posterior root defect on knee kinematics and meniscal extrusion in the anterior cruciate ligament reconstructed (ACLR) knee. The hypothesis was that the medial meniscus centralization would reduce extrusion and anterior laxity in ACLR knee with a medical meniscal defect.

Methods: Fourteen fresh-frozen human cadaveric knees were tested using a six-degrees-of-freedom robotic system under the following loading conditions: (a) an 89.

Arthroscopic Centralization for Lateral Meniscal Injuries Reduces Laxity in the Anterior Cruciate Ligament-Reconstructed Knee.

Background: A lateral meniscal (LM) disorder is one factor that causes rotational laxity after anterior cruciate ligament (ACL) reconstruction (ACLR). There are different types of irreparable meniscal disorders, one of which is a massive meniscal defect.

Hypothesis/purpose: The purpose of this study was to evaluate the kinematic effects of arthroscopic centralization on an irreparable LM defect.

ACL graft with extra-cortical fixation rotates around the femoral tunnel aperture during knee flexion.

Purpose: An understanding of the behavior of a new ACL graft in the femoral tunnel during knee motion and external loading can provide information pertinent to graft healing, tunnel enlargement, and graft failure. The purpose of the study was to measure the percentage of the tunnel filled by the graft and determine the amount and location of the graft-tunnel contact with knee motion and under external knee loads.

Methods: Single bundle anatomical ACL reconstruction was performed on six cadaveric knees.

Low to moderate risk of nerve damage during peroneus longus tendon autograft harvest.

Purpose: This study aims to evaluate the proximity of the tendon stripper to both the peroneal and sural nerves during peroneus longus tendon (PLT) autograft harvesting.

Methods: Ten fresh-frozen human cadaveric lower extremities were used to harvest a full-thickness PLT autograft using a standard closed blunt-ended tendon stripper. The distance to the sural nerve from the PLT (at 0, 1, 2 and 3 cm proximal to lateral malleolus (LM), and the distance to the peroneal nerve and its branches from the end of the tendon stripper were measured by two separate observers using ImageJ software.

Effect of Percentage of Femoral Anterior Cruciate Ligament Insertion Site Reconstructed With Hamstring Tendon on Knee Kinematics and Graft Force.

Background: Previous studies have stated that closely matching the size of the anterior cruciate ligament (ACL) insertion site footprint is important for biomechanical function and clinical stability after ACL reconstruction. However, the ACL varies widely regarding the area of femoral insertion, tibial insertion, and midsubstance of ACL, and reconstructing the insertion site area with a uniform diameter graft can result in a cross-sectional area that is greater than that of the midsubstance of the native ACL. Therefore, understanding the effect of relative graft size in ACL reconstruction on knee biomechanics is important for surgical planning.

Suture tape augmentation improves laxity of MCL repair in the ACL reconstructed knee.

Purpose: Medial collateral ligament (MCL) injury is very common and surgical repair is sometimes necessary. Especially in the setting of simultaneous anterior cruciate ligament reconstruction (ACLR) as the ACL is the secondary restraint against valgus stress. The goal of this study was to evaluate knee biomechanics after suture repair of the MCL augmented with suture tape, as compared to MCL repair alone, in the setting of concomitant ACL reconstruction (ACLR).

Peroneus longus tendon autograft has functional outcomes comparable to hamstring tendon autograft for anterior cruciate ligament reconstruction: a systematic review and meta-analysis.

Purpose: This review aimed to assess whether peroneus longus tendon (PLT) autograft would have comparable functional outcomes and graft survival rates when compared to hamstring tendon (HT) autograft for anterior cruciate ligament (ACL) reconstruction.

Methods: PubMed, Web of Science, Cochrane Library, Ovid (MEDICINE), and EMBASE databases were queried for original articles from clinical studies including the keywords: ACL reconstruction and PLT autograft. Studies comparing PLT autograft versus HT autograft were included in this analysis and the following data were extracted from studies meeting the inclusion criteria: graft diameter, functional outcomes (Tegner activity scale, Lysholm score, and International Knee Documentation Committee (IKDC) subjective score), knee laxity (Lachman test), and complications (donor site pain or paresthesia, graft failure).

Partial meniscectomy does not affect the biomechanics of anterior cruciate ligament reconstructed knee with a lateral posterior meniscal root tear.

Purpose: The purpose of this study was to determine the effects of a lateral meniscus posterior root tear, partial meniscectomy, and total meniscectomy on knee biomechanics in the setting of anterior cruciate ligament (ACL) reconstruction.

Methods: Thirteen fresh-frozen cadaver knees were tested with a robotic testing system under an 89.0-N anterior tibial load at full extension (FE), 15°, 30°, 60° and 90° of knee flexion and a simulated pivot-shift loading (7.

Single-bundle MCL reconstruction with anatomic single-bundle ACL reconstruction does not restore knee kinematics.

Purpose: The purpose of this study was to evaluate and compare knee kinematics and kinetics following either single bundle, modified triangular or double-bundle reconstruction of the superficial medial collateral ligament (sMCL) with single bundle anatomic ACL reconstruction.

Methods: Using a cadaveric model (n = 10), the knee kinematics and kinetics following three MCL reconstructions (single-bundle (SB), double-bundle (DB), modified triangular) with single bundle anatomic ACL reconstruction were compared with the intact and deficient knee state. The knees were tested under (1) an 89-N anterior tibial load, (2) 5 N-m internal and external rotational tibial torques, and (3) a 7 N-m valgus torque.

Notchplasty alters knee biomechanics after anatomic ACL reconstruction.

Purpose: The aims of this study were (1) to study the biomechanics of single-bundle anatomic ACL reconstructed knees with and without notchplasty using a robotic testing system and (2) to determine if there would be a difference between performing a small or large notchplasty.

Methods: Fifteen fresh-frozen specimens were used in this study. The ACL reconstruction (ACL-R) was performed using an anatomic single-bundle technique with the 8 mm soft tissue graft fixed at 30° with suspensory fixation on the femoral side and a screw and washer on the tibial side.

The femoral posterior fan-like extension of the ACL insertion increases the failure load.

Purpose: To examine the role of the posterior fan-like extension of the ACL's femoral footprint on the ACL failure load.

Methods: Sixteen (n = 16) fresh frozen, mature porcine knees were used in this study and randomized into two groups (n = 8): intact femoral ACL insertion (ACL intact group) and cut posterior fan-like extension of the ACL (ACL cut group). In the ACL cut group, flexing the knees to 90°, created a folded border between the posterior fan-like extension and the midsubstance insertion of the femoral ACL footprint and the posterior fan-like extension was dissected and both areas were measured.

Arthroscopic centralization restores residual knee laxity in ACL-reconstructed knee with a lateral meniscus defect.

Purpose: The aim of this study was to evaluate the effects of knee biomechanics with an irreparable lateral meniscus defect using the centralization capsular meniscus support procedure in the setting of the ACL-reconstructed knee in a porcine model. The hypothesis is the arthroscopic centralization will decrease the laxity and rotation of the ACL-reconstructed knee.

Methods: Twelve fresh-frozen porcine knees were tested using a robotic testing system under the following loading conditions: (a) an 89.

Coronal tibial anteromedial tunnel location has minimal effect on knee biomechanics.

Purpose: Studies have found anatomic variation in the coronal position of the insertion site of anteromedial (AM) bundle of the anterior cruciate ligament (ACL) on the tibia, which can lead to questions about tunnel placement during ACL reconstruction. The purpose of this study was to determine how mediolateral placement of the tibial AM graft tunnel in double-bundle ACL reconstructions affects knee biomechanics.

Methods: Two different types of double-bundle ACL reconstructions were performed.

Anatomic and non-anatomic anterior cruciate ligament posterolateral bundle augmentation affects graft function.

Purpose: The purpose of this study is to compare knee laxity and graft function (tissue force) between anatomic and non-anatomic posterolateral (PL) bundle augmentation.

Methods: Twelve (n = 12) fresh-frozen mature, unpaired porcine knees were tested using a robotic testing system. Four knee states were compared: (a) intact anterior cruciate ligament (ACL), (b) deficient PL and intermediate bundles, (c) anatomic PL augmentation, and (d) non-anatomic PL augmentation.

Anterior cruciate ligament graft fixation first in anterior and posterior cruciate ligament reconstruction best restores knee kinematics.

Purpose: To evaluate the effect of different graft fixation sequences in one-stage anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction on (1) knee biomechanics and (2) tibiofemoral alignment.

Methods: Twelve porcine knees were used in this study. Five fixation sequences were performed (angle indicating knee flexion): (a) PCL at 30° and ACL at 30°, (b) PCL at 90° and ACL at 30°, (c) ACL at 30° and PCL at 30°, (d) ACL at 30° and PCL at 90°, and (e) ACL and PCL simultaneous fixation at 30°.

Medial collateral ligament reconstruction is necessary to restore anterior stability with anterior cruciate and medial collateral ligament injury.

Purpose: The purpose of this study was to compare knee kinematics and graft forces in anterior cruciate ligament (ACL) reconstruction combined with one of two superficial medial collateral ligament (sMCL) reconstruction techniques (parallel or triangular vector sMCL reconstruction).

Methods: Twenty porcine knees were divided into two groups (n = 20), parallel or triangular vector sMCL reconstruction, with both groups having anatomic single-bundle ACL reconstruction. The knees were tested under (1) an 89-N anterior tibial load, (2) 4 Nm internal and external rotational tibial torques, and (3) a 7 Nm valgus torque.

Anatomic and Histological Investigation of the Anterolateral Capsular Complex in the Fetal Knee.

Background: There is currently disagreement with regard to the presence of a distinct ligament in the anterolateral capsular complex of the knee and its role in the pivot-shift mechanism and rotatory laxity of the knee.

Purpose: To investigate the anatomic and histological properties of the anterolateral capsular complex of the fetal knee to determine whether there exists a distinct ligamentous structure running from the lateral femoral epicondyle inserting into the anterolateral tibia.

Study Design: Descriptive laboratory study.

The effect of anterior cruciate ligament graft rotation on knee biomechanics.

Purpose: The purpose of this study was to evaluate the effects on knee biomechanics of rotating the distal end of the bone-patellar tendon graft 90° in anatomic single-bundle (SB) anterior cruciate ligament (ACL) reconstruction with a porcine model.

Methods: Twenty (n = 20) porcine knees were evaluated using a robotic testing system. Two groups and three knee states were compared: (1) intact ACL, (2) deficient ACL and (3) anatomic SB ACL reconstruction with (a) non-rotated graft or (b) rotated graft (anatomic external fibre rotation).