Bone plating to stabilize atlantoaxial subluxation in four dogs

Abstract

Four dogs with atlantoaxial subluxation were treated surgically via a ventral approach and the application of an ASIF mini H plate and 2·0 mm screws to the vertebral bodies. Three dogs recovered and are well but one dog died of a cardiac arrest postoperatively.

Atlantoaxial subluxation

“…After failure of either a dorsal or ventral surgery, rescue is probably best attempted using either multiple implants and bone cement or dorsal cross-pinning (Thomas et al, 1991;Jeffery, 1996;Schulz et al, 1997;Sanders et al, 2000;(9.32-9.34; 9.43). Mini plates are another alternative but there is little margin for error when placing the screws in C2 (Stead et al, 1993).…”

Biomechanical evaluation of three ventral fixation methods for canine atlantoaxial instability: a cadaveric study

“…In the ventral approach, after reduction of the subluxated AAJ, the odontoid can be removed under visual inspection, if necessary. Stabilization of the AAJ is performed using a transarticular fixation (TAF) method that employs bone screws or positively threaded profile pins (PPP), using a supportive fixation method that employs bone screws, PPP and polymethylmethacrylate (PMMA), or employs PPP and PMMA, and using a plate fixation method, with the final goal being bony fusion of the AAJ [1, 2, 7, 9, 16, 17, 21,22,23,24,25,26, 28,29,30,31, 35]. Stabilization from the ventral aspect is an established surgical procedure, which is a widely used surgical method.…”

CT scan based determination of optimal bone corridor for atlantoaxial ventral screw fixation in miniature breed dogs

“…Atlantoaxial stabilization can be achieved using either dorsal or ventral approaches and a variety of techniques for each approach have been described …”

“…5,7,14 Atlantoaxial stabilization can be achieved using either dorsal or ventral approaches and a variety of techniques for each approach have been described. [11][12][13][15][16][17][18]20 A ventral approach to the atlantoaxial joint is preferred because it provides access to the articular surfaces, and therefore facilitates curettage of the articular surface to promote arthrodesis and also facilitates removal of the dens, if indicated. 3,7,19 However, in ventral fixation and fusion, the implants are located on the compression side of the spine, which makes them more susceptible to stress and failure.…”