Fig 1.
Measurement of articular process joint height and vertebral body height to create APJ height ratio.
Fig 2.
Measurement of articular process joint area and vertebral body height to create APJ area ratio.
Table 1.
Clinical and initial imaging findings on operated horses before surgery.
Fig 3.
Operated sites in 22 horses undergoing surgical cervical stabilization.
Grayed box = operative site, white box = non-operative site.
Fig 4.
Mean observer DCCR (%) and DDR (%) at C2-3 in neutral (n = 22) and flexed (n = 18) neck positions.
Horizontal line reflects the median.
Fig 5.
Mean observer DCCR (%) and DDR (%) at C3-4 in neutral and flexed neck positions in horses that were not operated (n = 18) versus were operated (n = 4) at this site.
Horizontal line reflects the median.
Fig 6.
Mean observer DCCR (%) and DDR (%) at C4-5 in neutral, flexed and extended neck positions in horses that were not operated (n = 10) versus operated (n = 12) at this site.
Horizontal line reflects the median.
Fig 7.
Mean observer DCCR (%) and DDR (%) at C5-6 in neutral, flexed and extended neck positions in horses that were not operated (n = 16) versus operated (n = 6) at this site.
Horizontal line reflects the median.
Table 2.
Mean myelographic measures at C6-7 articulation by operative group.
Fig 8.
Mean observer DCCR (%) and DDR (%) at C6-7 in neutral, flexed and extended neck positions in horses that were not operated (n = 13) versus operated (n = 9) at this site.
Horizontal line reflects the median.
Table 3.
Correlations of DCCR and DDR by position and intervertebral junction.
Table 4.
Surgical complications and long-term post-operative findings in 22 horses undergoing cervical interbody fusion.
Fig 9.
A-C: Post-operative lateral cervical radiograph acquired 7 years after cervical stabilization procedure at C3-4 and C4-5 (Horse #19).
A. Mild ventral migration of the C3-4 cylindrical metal implant recorded soon after initial placement has remained stable over time. No implant breakage is identified. B. The C3-4 articular process joint is smaller and diffusely reduced in opacity, relative to the C4-5 and C5-6 articular process joints. C. Linear dystrophic mineralization of the dorsal cervical soft tissues.
Fig 10.
Pair plot demonstrating change in APJ joint height ratio at 13 operated articulations in nine horses imaged 4.4 ± 2.2 years postoperatively.
Fig 11.
Pair plot demonstrating change in APJ joint area ratio at 13 operated articulations in nine horses imaged 4.4 ± 2.2 years postoperatively.
Fig 12.
A-C: Postoperative transverse plane computed tomography images at the level of the cervical articular process joints obtained 3.4 years after cervical interbody fusion at C5-6 (Horse #41).
A. Hounsfield measurements of the C4-5 articular process joints (cranial to the surgical site). B. Hounsfield measurements of the C5-6 articular process joints (at the surgical site). C. Hounsfield measurements of the C6-7 articular process joints (caudal to the surgical site). In images A and C, the articular processes have thick cortical and subchondral bone with well-defined, trabecular bone. In image B, the operated site, the articular processes have poorly defined bony trabecular pattern and diffusely reduced mineral attenuation and thickness of the subchondral and cortical bone.