Biomechanical Evaluation of Plate Versus Lag Screw Only Fixation of Distal Fibula Fractures.

Traditional fixation of unstable Orthopaedic Trauma Association type B/C ankle fractures consists of a lag screw and a lateral or posterolateral neutralization plate. Several studies have demonstrated the clinical success of lag screw only fixation; however, to date no biomechanical comparison of the different constructs has been performed. The purpose of the present study was to evaluate the biomechanical strength of these different constructs.

Effects of posterior distraction forces on anterior column intradiscal pressure in the dual growing rod technique.

Background: Little evidence is available addressing biomechanical properties of posterior distraction forces and their effects on anterior spinal column in the growing rod technique. The question is often asked if posterior distraction forces may be kyphogenic. The goal of this study is to determine whether posterior distraction forces transmitted anteriorly through different foundation constructs (i.

Biomechanical Testing of Unstable Slipped Capital Femoral Epiphysis Screw Fixation: Worth the Risk of a Second Screw?

Background: In a prior biomechanical study, 2-screw fixation of anatomically reduced slipped capital femoral epiphysis (SCFE) demonstrated marginally greater stability than single-screw fixation. However, the authors judged the benefits of a second screw to be minimal compared with the additional complication risk. A similar evaluation of fixation stability in unstable moderately displaced SCFE is performed.

Negative pressure therapy for closed spine incisions: a pilot study.

Unlabelled: Negative pressure therapy (NPT), used on open wounds or postoperative infections, has not been evaluated on closed spinal incisions. This was analyzed after 3 days and 5 days of NPT application using biomechanics and histology in a porcine model.

Methods: In 8 mature miniature pigs, 2 end-to-end midline spine incisions were closed in a standard fashion.

Comparison of 3-dimensional spinal reconstruction accuracy: biplanar radiographs with EOS versus computed tomography.

Study Design: Experimental study for systematic evaluation of 3-dimensional (3D) reconstructions from low-dose digital stereoradiography.

Objective: To assess the accuracy of EOS (EOS Imaging, Paris, France) 3-dimensional (3D) reconstructions compared with 3D computed tomography (CT) and the effect spine positioning within the EOS unit has on reconstruction accuracy.

Summary Of Background Data: Scoliosis is a 3D deformity, but 3D morphological analyses are still rare.

Biomechanical comparison of kyphoplasty versus a titanium mesh implant with cement for stabilization of vertebral compression fractures.

Study Design: In vitro biomechanical investigation.

Objective: To evaluate differences in biomechanical stability of vertebral compression fractures repaired using balloon kyphoplasty versus a titanium mesh implant.

Summary Of Background Data: Vertebral compression fractures may be stabilized using an expandable balloon followed by cement injection.

Reconstruction plates for stabilization of mid-shaft clavicle fractures: differences between nonlocked and locked plates in two different positions.

Reconstruction plates permit contouring to the irregular anatomic shape of the clavicle. This study evaluated the biomechanical stability of locking and nonlocking clavicle reconstruction plates for treating midshaft, transverse fractures, comparing anterior-inferior to superior plate position. Twenty-four synthetic clavicles with mid-shaft fractures were repaired with either a locking or nonlocking clavicle reconstruction plate in either the anterior-inferior or superior plate position (n = 6/group).

Unilateral and bilateral sacropelvic fixation result in similar construct biomechanics.

Study Design: In vitro biomechanical investigation of lumbosacropelvic spinal instrumentation.

Objective: Determine whether unilateral iliac fixation, with or without an L6 to S1 interbody graft, provides equivalent biomechanical stability compared with bilateral iliac fixation.

Summary Of Background Data: Recent clinical evidence has shown improved clinical outcomes of unilateral iliac fixation compared with bilateral instrumentation that contradicts biomechanical data supporting bilateral instrumentation, although no specific investigation has compared unilateral versus bilateral instrumentation.

Differences in biomechanical stability of femur fracture fixation when using titanium nails of increasing diameter.

Purpose: The purpose of this study was to compare the biomechanical stability generated when utilizing increasing sizes of titanium (Ti) flexible nails for fixation of simulated comminuted femur fractures.

Methods: Five synthetic adolescent-sized femur models were reamed to create a 9-mm canal. A 2-cm section was removed in the mid-diaphysis to simulate comminution.

A biomechanical and radiographic analysis of standard and intracortical suture anchors for arthroscopic rotator cuff repair.

Purpose: To compare the fixation strength and radiographic motion of an anchor designed for intracortical (IC) fixation (FT Anchor, Arthrex, Naples, FL) with that of standard anchors used for rotator cuff repair.

Type Of Study: In vitro human cadaveric biomechanical study.

Methods: Four types of metallic suture anchors (8 per group) were randomly inserted into human cadaveric humeri using an IC anchor and 3 types of standard anchors.

Increasing the insertion depth of suture anchors for rotator cuff repair does not improve biomechanical stability.

The purpose of this study was to evaluate whether deeper-than-recommended insertion of a suture anchor within the rotator cuff footprint of human cadaveric humeri affects fixation characteristics. Metallic 5-mm screw-in anchors loaded with a single No. 2 suture were placed in the infraspinatus footprint of 8 human cadaveric humeri at standard and deep depths.

A comparison of the fixation stability of multiple screw constructs for two types of pelvic osteotomies.

Periacetabular osteotomies are performed to improve femoral head coverage in a variety of clinical conditions. The stability of the osteotomy fragment between Ganz's periacetabular osteotomy was compared with that of Tonnis's triple innominate osteotomy under simulated weight-bearing conditions with a variety of screw constructs using three-dimensional analysis of fragment displacement and angular rotation. Generally, small amounts of displacement (<2 mm) and angular rotation (<3 degrees) were encountered for each fixation technique.

Freedom of acetabular fragment rotation following three surgical techniques for correction of congenital deformities of the hip.

Femoral head coverage achieved with an acetabular osteotomy for hip dysplasia is achieved by acetabular rotation that can be restricted by osteotomy orientation and soft tissue attachments to the acetabular fragment. Procedures that allow excess rotation or motion in an undesirable direction (especially external rotation) may have undesirable consequences. Rotational aspects of these procedures have not been well described and are not well appreciated radiographically.

Biomechanical comparison of stainless steel and titanium nails for fixation of simulated femoral fractures.

Flexible intramedullary nails are commonly used to treat femoral fractures in children. This study evaluated the biomechanical differences between stainless steel and titanium nails when securing transverse and comminuted fractures in a synthetic femur model. Retrograde flexible stainless steel and titanium nails placed in a divergent "C" pattern were mechanically tested, and axial rotation and compression stiffness were analyzed with a two-way ANOVA.