Posterolateral Knee Ligament Reconstruction Using the Arciero Technique Provides Greater Rotational Stability Than the Modified Larson Technique: A Biomechanical Study.

Background: It is still unknown if the double-femoral tunnel technique (Arciero [ARC]) provides better stability as compared with the single-femoral tunnel technique (modified Larson [LAR]) in posterolateral corner reconstruction. The ideal angle of fixation of the popliteofibular strand in ARC is also unknown.

Hypotheses: The ARC provides greater external rotation (ER) stability than the LAR (hypothesis 1); there is no difference in varus rotation (VR) stability between LAR and ARC (hypothesis 2); and femoral fixation of the popliteofibular strand at 60° during the ARC leads to greater ER stability than fixation at 30° or 90° of knee flexion (hypothesis 3).

Overconstraint Associated With a Modified Lemaire Lateral Extra-Articular Tenodesis Is Decreased by Using an Anterior Femoral Insertion Point in a Cadaveric Model.

Purpose: To investigate tibiofemoral knee kinematics when shifting the femoral insertion point of the modified Lemaire lateral extra-articular tenodesis (LET) anterior to the lateral epicondyle.

Methods: Six fresh-frozen human knee joints were tested on a test bench in the following states: (1) native, (2) anterolateral insufficient, (3) original Lemaire (oLET; insertion point: 4 mm posterior and 8 mm proximal to the epicondyle), (4) anterior Lemaire (aLET; insertion point: 5 mm anterior and 5 mm proximal to the epicondyle). Internal tibial rotation was statically investigated under an internal tibial torque of 5 Nm in 0°, 30°, 60°, and 90° of flexion.

Modified Lemaire Tenodesis Forces in Cadaveric Specimens Are Not Affected by Random Small-Scale Variations in the Femoral Insertion Point During Active Knee Joint Flexion-Extension.

Purpose: To directly measure lateral extra-articular tenodesis (LET) forces supporting anterior cruciate ligament reconstruction (ACLR) during dynamic flexion-extension cycles induced by simulated active muscle forces, to investigate the influence of random surgical variation in the femoral LET insertion point around the target insertion position, and to determine potential changes to the extension behavior of the knee joint in a cadaveric model.

Methods: After iatrogenic anterior cruciate ligament deficiency and simulated anterolateral rotatory instability, 7 fresh-frozen cadaveric knee joints were treated with isolated ACLR followed by combined ACLR-LET. The specimens were tested on a knee joint test bench during active dynamic flexion-extension with simulated muscle forces.

Pedicle screw augmentation in posterior constructs of the thoracolumbar spine: How many pedicle screws should be augmented?

Backgrounds: To evaluate the effects of different pedicle screw augmentation strategies on screw loosening and adjacent segment collapse at the proximal end of long-segment instrumentation.

Methods: Eighteen osteoporotic (9 male, 9 female donors; mean age: 74.7 ± 10.

Actuator and Contact Force Modeling of an Active Soft Brace for Scoliosis.

Scoliosis is an abnormality of the spinal curvature that severely affects the musculoskeletal, respiratory, and nervous systems. Conventionally, it is treated using rigid spinal braces. These braces are static, rigid, and passive in nature, and they (largely) limit the mobility of the spine, resulting in other spinal complexities.