Influence of neck position on commonly performed radiographic measurements of the cervical vertebral region in horses.

This research study investigates how various neck positions may influence measurements taken from radiographic images of a horse’s cervical vertebrae. The overall findings indicate that while some measurements were slightly impacted by neck position, many were not. This suggests that different neck positions may not significantly alter these types of readings in horses free of cervical disease.

Objective and Methodology

• The objective of the research was to evaluate how different neck positions affect radiographic measurements of the cervical vertebrae in horses.
• The study was conducted on 18 horses, which despite being examined for lameness, were free of cervical disease.
• Each horse’s cervical vertebrae from C1 to T1 were X-rayed in three different neck positions: low, neutral, and high.
• Various measurements were taken at each segment in each neck position. The measurements included the minimum sagittal diameter, the intra-vertebral sagittal diameter (intra-VSD) ratio, inter-VSD ratio, length of the articular processes joint ratio, vertebral alignment angle, and vertebral fossa angle.
• The values taken in high and low neck positions were compared against the measurements taken in the neutral position.

Results

• No statistically significant differences were noted in the minimum sagittal diameter, intra-VSD ratio, or the vertebral fossa angle when the neck was in a low or high position compared to the neutral position.
• Compared to the neutral position, the high neck position resulted in a greater vertebral alignment angle at C3-4 and inter-VSD ratio at C4-5, as well as a lower length of the articular processes joint ratio at the C2-3, C3-4, and C4-5 segments.
• In contrast, the low neck position resulted in a lower vertebral alignment angle at C4-5, although these observed differences were marginal.

Conclusions and Clinical Relevance

• The study concludes that while neck position can influence some radiographic measurements of the cervical vertebrae, many of these measurements were not, or were only marginally, affected by neck position.
• This suggests some variation in neck position while acquiring radiographs might be acceptable without greatly affecting the readings, at least in horses that are free from cervical disease.