Advances in Dynamization of Plate Fixation to Promote Natural Bone Healing.

The controlled dynamization of fractures can promote natural fracture healing by callus formation, while overly rigid fixation can suppress healing. The advent of locked plating technology enabled new strategies for the controlled dynamization of fractures, such as far cortical locking (FCL) screws or active plates with elastically suspended screw holes. However, these strategies did not allow for the use of non-locking screws, which are typically used to reduce bone fragments to the plate.

Effect of helmet design on impact performance of industrial safety helmets.

Background: Comparative studies of different helmet designs are essential to determine differences in helmet performance. The present study comparatively evaluated the impact performance of hardhat helmets, climbing-style safety helmets, and helmets with novel rotation-damping technologies to determine if advanced designs deliver improved protection.

Methods: Six helmet designs from three categories of safety helmets were tested: two traditional hardhat helmets (HH Type I, HH Type II), two climbing-style helmets (CS Web, CS Foam), and two helmets with dedicated rotation-damping technologies (MIPS, CEL).

Impact Performance Comparison of Advanced Bicycle Helmets with Dedicated Rotation-Damping Systems.

Bicycle helmets effectively mitigate skull fractures, but there is increasing concern on their effectiveness in mitigating traumatic brain injury (TBI) caused by rotational head acceleration. Bicycle falls typically involve oblique impacts that induce rotational head acceleration. Recently, bicycle helmet with dedicated rotation-damping systems have been introduced to mitigate rotational head acceleration.

Evaluation of a novel bicycle helmet concept in oblique impact testing.

Background: A novel bicycle helmet concept has been developed to mitigate rotational head acceleration, which is a predominant mechanism of traumatic brain injury (TBI). This WAVECEL concept employs a collapsible cellular structure that is recessed within the helmet to provide a rotational suspension. This cellular concept differs from other bicycle helmet technologies for mitigation of rotational head acceleration, such as the commercially available Multi-Directional Impact Protection System (MIPS) technology which employs a slip liner to permit sliding between the helmet and the head during impact.

Dynamic Fixation of Humeral Shaft Fractures Using Active Locking Plates: A Prospective Observational Study.

Background: Rigid locked plating constructs can suppress fracture healing by inhibiting interfragmentary motion required to stimulate natural bone healing by callus formation. Dynamic fixation with active locking plates reduces construct stiffness, enables controlled interfragmentary motion, and has been shown to induce faster and stronger bone healing in vivo compared to rigid locking plates. This prospective observational study represents the first clinical use of active locking plates.

Comparison of 4 Methods for Dynamization of Locking Plates: Differences in the Amount and Type of Fracture Motion.

Background: Decreasing the stiffness of locked plating constructs can promote natural fracture healing by controlled dynamization of the fracture. This biomechanical study compared the effect of 4 different stiffness reduction methods on interfragmentary motion by measuring axial motion and shear motion at the fracture site.

Methods: Distal femur locking plates were applied to bridge a metadiaphyseal fracture in femur surrogates.

Dynamic Stabilization of Simple Fractures With Active Plates Delivers Stronger Healing Than Conventional Compression Plating.

Objectives: Active plates dynamize a fracture by elastic suspension of screw holes within the plate. We hypothesized that dynamic stabilization with active plates delivers stronger healing relative to standard compression plating.

Methods: Twelve sheep were randomized to receive either a standard compression plate (CP) or an active plate (ACTIVE) for stabilization of an anatomically reduced tibial osteotomy.

Dynamic Stabilization with Active Locking Plates Delivers Faster, Stronger, and More Symmetric Fracture-Healing.

Background: Axial dynamization of fractures can promote healing, and overly stiff fixation can suppress healing. A novel technology, termed active plating, provides controlled axial dynamization by the elastic suspension of locking holes within the plate. This prospective, controlled animal study evaluated the effect of active plates on fracture-healing in an established ovine osteotomy model.

Dynamic locking plates provide symmetric axial dynamization to stimulate fracture healing.

Axial dynamization of an osteosynthesis construct can promote fracture healing. This biomechanical study evaluated a novel dynamic locking plate that derives symmetric axial dynamization by elastic suspension of locking holes within the plate. Standard locked and dynamic plating constructs were tested in a diaphyseal bridge-plating model of the femoral diaphysis to determine the amount and symmetry of interfragmentary motion under axial loading, and to assess construct stiffness under axial loading, torsion, and bending.

Elastically suspending the screw holes of a locked osteosynthesis plate can dampen impact loads.

Impact damping by elastic fixation is a principal engineering strategy to increase the durability of load-bearing structures exposed to prolonged dynamic loading. This biomechanical study evaluated axial impact damping provided by a novel dynamic locking plate. In this design, locking screw holes are elastically suspended within a silicone envelope inside the locking plate.

Dynamic fixation of distal femur fractures using far cortical locking screws: a prospective observational study.

Objectives: Document fixation and healing of distal femur fractures stabilized by plate osteosynthesis using far cortical locking (FCL) screws.

Design: Prospective and observational.

Setting: Two level 1 and 1 level 2 trauma centers.

Healing results of periprosthetic distal femur fractures treated with far cortical locking technology: a preliminary retrospective study.

Introduction: Periprosthetic distal femur fractures are severe injuries occurring in the often osteoporotic bone of the elderly. Far cortical locking (FCL) screws, which have been shown to promote increased callus formation in animal models, have recently become available for clinical use. The purpose of this study is to report preliminary healing and complication rates of periprosthetic distal femur fractures treated with FCL constructs.

Angular Impact Mitigation system for bicycle helmets to reduce head acceleration and risk of traumatic brain injury.

Angular acceleration of the head is a known cause of traumatic brain injury (TBI), but contemporary bicycle helmets lack dedicated mechanisms to mitigate angular acceleration. A novel Angular Impact Mitigation (AIM) system for bicycle helmets has been developed that employs an elastically suspended aluminum honeycomb liner to absorb linear acceleration in normal impacts as well as angular acceleration in oblique impacts. This study tested bicycle helmets with and without AIM technology to comparatively assess impact mitigation.

Surgical stabilization of flail chest injuries with MatrixRIB implants: a prospective observational study.

Background: Surgical stabilization of flail chest injury with generic osteosynthesis implants remains challenging. A novel implant system comprising anatomic rib plates and intramedullary splints may improve surgical stabilization of flail chest injuries. This observational study evaluated our early clinical experience with this novel implant system to document if it can simplify the surgical procedure while providing reliable stabilization.

Far cortical locking enables flexible fixation with periarticular locking plates.

The high stiffness of periarticular locked plating constructs can suppress callus formation and fracture healing. Replacing standard locking screws with far cortical locking (FCL) screws can decrease construct stiffness and can improve fracture healing in diaphyseal plating constructs. However, FCL function has not been tested in conjunction with periarticular plating constructs in which FCL screws are confined to the diaphyseal segment.

Biplanar fixation of a locking plate in the diaphysis improves construct strength.

Background: Elevation of a locking plate over the bone surface not only supports biological fixation, but also decreases the torsional strength of the fixation construct. Biplanar fixation by means of a staggered screw hole arrangement may combat this decreased torsional strength caused by plate elevation. This biomechanical study evaluated the effect of biplanar fixation on the torsional strength of locking plate fixation in the femoral diaphysis.

Basosquamous carcinoma involving the anterior skull base: a neglected tumor treated using intraoperative navigation as a guide to achieve safe resection margins.

Basosquamous carcinoma (BSC) or metatypical carcinoma is a rare and controversial form of basal cell carcinoma (BCC) that was first described by MacCormac in 1910. Numerous theories have been described in the literature regarding its origin but it is generally accepted as a variant of BCC that differentiates into squamous cell carcinoma (SCC). At present, it has an unsatisfactorily established phenotype but is considered to behave more like an SCC than a BCC.

A novel bioreactor for the dynamic stimulation and mechanical evaluation of multiple tissue-engineered constructs.

Systematic advancements in the field of musculoskeletal tissue engineering require clear communication about the mechanical environments that promote functional tissue growth. To support the rapid discovery of effective mechanostimulation protocols, this study developed and validated a mechanoactive transduction and evaluation bioreactor (MATE). The MATE provides independent and consistent mechanical loading of six specimens with minimal hardware.

Effects of hybrid plating with locked and nonlocked screws on the strength of locked plating constructs in the osteoporotic diaphysis.

Background: Hybrid plating (HP) may improve fixation strength of locked plating (LP) constructs by combining the use of locked and nonlocked screws within a bone segment. This biomechanical study evaluated whether a hybrid bridge plating construct provides greater fixation strength than an all-locked construct in the osteoporotic diaphysis.

Methods: LP and HP constructs were applied to a validated surrogate of the osteoporotic femoral diaphysis in a bridge plating configuration.

Far cortical locking can improve healing of fractures stabilized with locking plates.

Background: Locked bridge plating relies on secondary bone healing, which requires interfragmentary motion for callus formation. This study evaluated healing of fractures stabilized with a locked plating construct and a far cortical locking construct, which is a modified locked plating approach that promotes interfragmentary motion. The study tested whether far cortical locking constructs can improve fracture-healing compared with standard locked plating constructs.

Locked plating of distal femur fractures leads to inconsistent and asymmetric callus formation.

Objectives: Locked plating constructs may be too stiff to reliably promote secondary bone healing. This study used a novel imaging technique to quantify periosteal callus formation of distal femur fractures stabilized with locking plates. It investigated the effects of cortex-to-plate distance, bridging span, and implant material on periosteal callus formation.

Less-invasive stabilization of rib fractures by intramedullary fixation: a biomechanical evaluation.

Background: This study evaluated intramedullary fixation of rib fractures with Kirschner wires and novel ribs splints. We hypothesized that rib splints can provide equivalent fixation strength while avoiding complications associated with Kirschner wires, namely wire migration and cutout.

Methods: The durability, strength, and failure modes of rib fracture fixation with Kirschner wires and rib splints were evaluated in 22 paired human ribs.

Anatomically contoured plates for fixation of rib fractures.

Background: : Intraoperative contouring of long bridging plates for stabilization of flail chest injuries is difficult and time consuming. This study implemented for the first time biometric parameters to derive anatomically contoured rib plates. These plates were tested on a range of cadaveric ribs to quantify plate fit and to extract a best-fit plating configuration.

A computational technique to measure fracture callus in radiographs.

Callus formation occurs in the presence of secondary bone healing and has relevance to the fracture's mechanical environment. An objective image processing algorithm was developed to standardize the quantitative measurement of periosteal callus area in plain radiographs of long bone fractures. Algorithm accuracy and sensitivity were evaluated using surrogate models.