Acromioclavicular Joint Stabilization: A Biomechanical Study of Bidirectional Stability and Strength.

Background: It is important to restore horizontal and vertical stability to the acromioclavicular (AC) joint when treating dislocations of this joint. Most surgical stabilization techniques of the AC joint have primarily addressed the coracoclavicular ligament complex; however, these techniques may not satisfactorily restore horizontal stability to the AC joint.

Purpose: To evaluate the strength and bidirectional stability of 3 AC joint stabilizing techniques in a cadaveric model.

An intramedullary Echidna pin for fixation of comminuted clavicle fractures: a biomechanical study.

Background: Intramedullary fixation of comminuted mid-shaft clavicle fractures has traditionally been employed with satisfactory clinical outcomes; however, pins with smooth surfaces may protrude from the bone and are prone to migration, while some threaded pins are difficult to remove post-operatively. The aim of this proof-of-concept study was to develop and evaluate the biomechanical strength of a novel intramedullary Echidna pin device designed to maintain fracture reduction, resist migration and facilitate ease of post-operative removal.

Methods: Thirty human clavicle specimens were harvested and fractured in a comminuted mid-shaft butterfly configuration.

Fractal analysis of eye movements during reading.

We present a new method for the analysis of reading eye movements based on the methods of nonlinear dynamics. In this preliminary study, the eye movements of normal and abnormal readers were analyzed for evidence of chaotic, nonlinear dynamical behavior. Both power spectral density analysis and fractal dimension determination showed evidence of nonlinearity as manifest in chaotic behavior.