Professor - Equine Surgery University of Saskatchewan, Saskatchewan, Canada
Definitive diagnosis of equine temporomandibular joint (TMJ) disease may require advanced diagnostic imaging. Arthroscopy is a minimally invasive, diagnostic and treatment modality, yet there are few published comparisons between the available systems. The objective was to compare and contrast two arthroscopic systems for assessing the equine TMJ compartments in cadavers and standing horses. The hypothesis was that the standard 2.5mm 30° videoarthroscope system (STAN) would yield superior images and be more robust than the needle scope (NAS). The two compartments of both TMJs in 14 cadaveric equine heads were assessed using a caudally placed arthroscope portal. The NAS was used first and the results compared to the findings of examination using STAN. Three healthy horses were subsequently examined to determine the validity of the procedure in live animals in Phase II. Both systems, in combination with mandibular manipulation, allowed evaluation of the caudal aspects of both joint compartments of the TMJ in Phase I. However, the extreme margins of the joint were more commonly visualized using STAN. Live horses were successfully examined under standing sedation and local analgesia. NAS is a relatively inexpensive diagnostic tool, which can be used to evaluate the TMJ in the absence of advanced diagnostic imaging such as computed tomography or magnetic resonance imaging. However, if arthroscopic treatment is required after advanced imaging and pre-operative diagnosis, superior image quality and ease of manipulation may favor STAN. The main study limitation was that the order of system use was not randomized.
