Publications by authors named "Etienne J O'Brien"
An 8-year-old gelding was evaluated for intermittent dorsal displacement of the soft palate (DDSP) at exercise. Standing laterolateral radiographs demonstrated an abnormal crossed appearance of the stylohyoid bones. Computed tomography (CT) confirmed abnormal positioning of the left stylohyoid bone and articulations with both the left thyrohyoid and ceratohyoid bones.
View Article and Find Full Text PDFBackground: The ovine stifle joint is an ideal preclinical model to study knee joint biomechanics. Knowledge of the ovine ligamentous and meniscal loading during normal gait is currently limited.
Methods: The in vivo kinematics of the ovine stifle joint (N=4) were measured during "normal" gait using a highly accurate instrumented spatial linkage (ISL, 0.
Heterotopic mineralization may result in tendon weakness, but effects on other biomechanical responses have not been reported. We used a needle injury, which accelerates spontaneous mineralization of murine Achilles tendons, to test two hypotheses: that injured tendons would demonstrate altered biomechanical responses; and that unilateral injury would accelerate mineralization bilaterally. Mice underwent left hind (LH) injury (I; n = 11) and were euthanized after 20 weeks along with non-injured controls (C; n = 9).
View Article and Find Full Text PDFHeterotopic tendon mineralization (ossification or calcification), which may be a feature of tendinopathy or which may develop following surgical trauma (repair or graft harvest), has not received much attention. The purpose of this article is to review the prevalence, mechanisms and consequences of heterotopic tendon mineralization and to identify the gaps in our current understanding. We focus on endochondral heterotopic ossification and draw on knowledge of the mechanisms of this process in other tissues and conditions.
View Article and Find Full Text PDFWe tested the hypothesis that immediate reattachment of the native anterior cruciate ligament (ACL) can prevent kinematic changes and the development of osteoarthritis (OA). Five sheep underwent anatomic unilateral ACL reconstruction (ACL-R). Animals from a previous study served as sham (n = 7) or non-operated (n = 17) controls.
View Article and Find Full Text PDFArticle Synopsis
- The human ACL consists of two distinct bundles, the anteromedial (AM) and posterolateral (PL) bundles, which may have different functions and structural characteristics.
- Tendons are commonly used for surgical reconstruction of ACL injuries, but some patients experience complications like re-rupture and osteoarthritis, highlighting the need to understand ACL structure for better replacement options.
- A study comparing the ACL bundles of mature and immature sheep found that while the two bundles mature at different rates, they do not exhibit significant differences in mature animals; thus, they can be treated as parts of a single functional structure for replacement purposes.
Article Synopsis
- The study investigates how combined ACL/MCL injuries affect the development of osteoarthritis (OA) in sheep, noting that not all animals show the same level of disability or OA progression.
- The research involved three groups of sheep (normal, ACL/MCL transected, and sham) and assessed their joint conditions and movements over a 20-week period post-surgery.
- Findings indicate that ACL/MCL deficient sheep displayed significant movement abnormalities and joint damage, with a correlation between medial-lateral translation changes and the severity of OA, suggesting that individual variations in biomechanical stability influence OA risk.