The epicondylar axis of the elbow is a surface anatomical approximation of the true flexion-extension (F-E) axis used in the application of an external fixator/elbow arthroplasty. We hypothesise that the epicondylar axis coincides with the true F-E axis in terms of both angular displacement and position (ie. offset). This suggests that it can serve as a good landmark in total dynamic external fixator application and elbow arthroplasty. Three-dimensional elbow models were obtained through manual segmentation and reconstruction from 142±40 slices of CT scans per elbow in 15 cadeveric specimens. Epicondylar axis was defined to be the axis through the 2 epicondyles manually identified on the elbow models. F-E axis was defined to be the normal of a circle fitted on 20 points identified on the trochlear groove. The long axis of the elbow was identified through a line fit through the center of the distal humerus on several slices along the elbow CT. Angle between the long axis and epicondylar axis was measured. Angular deviation of the epicondylar axis and the F-E axis was calculated in reference to the long axis. All axes were projected onto the orthogonal planes on the elbow CTs and all measurements were repeated. Angular differences in the axial, saggital and coronal planes are described in internal/external rotation, flexion/extension and valgus/varus respectively. Offset in the axial and coronal planes are described in the following directions respectively: proximal/distal and anterior/posterior respectively. Comparisons between angles were performed using student's t-test.Introduction
Methods
Based upon genetic analysis, decorin is an exciting pharmacologic agent of potential anti-fibrogenic effect on arthrofibrosis in our animal model. While the pathophysiology of arthrofibrosis is not fully understood, some anti-fibrotic molecules such as decorin could potentially be used for the prevention or treatment of joint stiffness. The goal of this study was to determine whether intra-articular administration of decorin influences the expression of genes involved in the fibrotic cascade ultimately leading to less contracture in an animal model.Summary
Introduction
This 3-dimensional CT study on cadaveric proximal ulna provides further insight into the size and geometry of the proximal ulna intramedullary cavity with potential applications to design and sizing of proximal ulna components. Total elbow arthroplasty (TEA) is an established treatment for varying pathologies of the elbow with very good functional outcomes. Optimal fit of ulna components in TEA is predicated on a detailed appreciation of the 3-dimensional anatomy of the proximal ulna intra-medullary cavity, but literature remains scarce. Three-dimensional (3D) models of the proximal ulna have been constructed using computed tomography (CT) programs, accurately defining the angular relations with the cross-sectional extra-medullary dimensions. However, current CT-based thresholding techniques lack accuracy in differentiating cortical from cancellous bone in the metaphyseal region, and thus cannot properly define the intra-medullary region of uncored proximal ulnae. We investigate the geometric dimensions of the proximal ulna intra-medullary cavity using CT studies of cored cadaveric ulnae.Summary Statement
Introduction
