Coupled rotation patterns in cervical spine axial rotation can change when the head is kept level.

The biomechanical literature describes axial rotation occurring coupled with lateral bending and flexion in the cervical spine. Since the head is kept level during some activities of daily living, we set out to investigate the changes in total and segmental motion that occur when a level gaze constraint is applied to cadaveric cervical spine specimens during axial rotation. 1.

Comparison of the biomechanical stability of transverse and oblique screw trajectories in retrograde intramedullary nailing of supracondylar femur fractures.

Background: The goal was to determine the effect of addition of oblique trajectory distal interlock screws to a retrograde intramedullary femoral nail on implant stability (stiffness), cycles to failure and mode of failure. The hypothesis was that addition of oblique screws would increase implant stability and number of loading cycles to failure.

Methods: Eight matched pairs were tested; one femur implanted with a femoral nail with only transverse distal interlock screws and the other with transverse and oblique interlock screws.

Kinematics of a cervical disc prosthesis implanted above or below one- and two-level fusions.

Background: The theoretical advantages of hybrid constructs over multi-level fusion have been illustrated in clinical and biomechanical studies. However, there is no biomechanical data on hybrid constructs using load control analyses. There is also no clear data on whether there is a biomechanical difference if the arthroplasty is below or above a 1- or 2-level fusion.

Osteoinductivity and biomechanical assessment of a 3D printed demineralized bone matrix-ceramic composite in a rat spine fusion model.

We recently developed a recombinant growth factor-free bone regenerative scaffold composed of stoichiometric hydroxyapatite (HA) ceramic particles and human demineralized bone matrix (DBM) particles (HA-DBM). Here, we performed the first pre-clinical comparative evaluation of HA-DBM relative to the industry standard and established positive control, recombinant human bone morphogenetic protein-2 (rhBMP-2), using a rat posterolateral spinal fusion model (PLF). Female Sprague-Dawley rats underwent bilateral L4-L5 PLF with implantation of the HA-DBM scaffold or rhBMP-2.

Loading of the lumbar spine during transition from standing to sitting: effect of fusion versus motion preservation at L4-L5 and L5-S1.

Background Context: Transition from standing to sitting significantly decreases lumbar lordosis with the greatest lordosis-loss occurring at L4-S1. Fusing L4-S1 eliminates motion and thus the proximal mobile segments maybe recruited during transition from standing to sitting to compensate for the loss of L4-S1 mobility. This may subject proximal segments to supra-physiologic flexion loading.

Effectiveness of cervical zero profile integrated cage with and without supplemental posterior Interfacet stabilization.

Background: Conditions requiring cervical decompression and stabilization are commonly treated using anterior cervical discectomy and fusion using an anterior cage-plate construct. Anterior zero profile integrated cages are an alternative to a cage-plate construct, but literature suggests they may result in less motion reduction. Interfacet cages may improve integrated cage stability.

Neutral cervical sagittal vertical axis and cervical lordosis vary with T1 tilt.

Objective: The authors conducted a study to determine whether a change in T1 tilt results in a compensatory change in the cervical sagittal vertical axis (SVA) in a cadaveric spine model.

Methods: Six fresh-frozen cadavers (occiput [C0]-T1) were cleaned of soft tissue and mounted on a customized test apparatus. A 5-kg mass was applied to simulate head weight.

Kinematic assessment of an elastic-core cervical disc prosthesis in one and two-level constructs.

Introduction: Anterior cervical discectomy and fusion has been associated with the development of adjacent segment degeneration (ASD), with clinical incidence of approximately 3% per year. Cervical total disc arthroplasty (TDA) has been proposed as an alternative to prevent ASD.

Hypotheses: TDA in optimal placement using an elastic-core cervical disc (RHINE, K2M Inc.

Motion response of a polycrystalline diamond adaptive axis of rotation cervical total disc arthroplasty.

Background: Cervical fusion is associated with adjacent segment degeneration. Cervical disc arthroplasty is considered an alternative to reduce risk of adjacent segment disease. Kinematics after arthroplasty should closely replicate healthy in vivo kinematics to reduce adjacent segment stresses.

First Record of in Kentucky.

were collected for the 1st time in Madison County, KY, during a survey of adult female mosquitoes in the summer of 2016. A total of 15 females were captured from 4 survey sites during the months of July and August. Twelve of the specimens collected were captured in BG-1 Sentinel™ Traps baited with carbon dioxide, octenol, and BG-human skin extract lure®, while the other 3 specimens were captured with the Centers for Disease Control and Prevention Miniature Light Traps baited with carbon dioxide and octenol.

Cuttine edge: T cells from aged mice are resistant to depletion early during virus infection.

Aging is associated with decreased expansion of T cells upon stimulation. In young mice, infection induces a transient T cell depletion followed by the development of an Ag-specific T cell response that controls the infection. We found that T cells were depleted early after infection with E55 + murine leukemia retrovirus in young, but not aged, mice.

Decreased IL-2, IFN-gamma, and IL-10 production by aged mice during the acute phase of E55+ retrovirus infection.

We previously reported that aged mice demonstrated a 12-week delay in virus clearance compared to young mice after infection with E55+ murine leukemia retrovirus (E55+MuLV). The current study demonstrates that both the levels of IL-2, IFN-gamma, and IL-10 and the number of cells producing IL-2 and IFN-gamma were lower at 2 and 4 weeks postinfection (p.i.