Fig. 2

Ventrodorsal radiography with extended hips reveals an asymmetric lumbosacral transitional vertebra (LTV). The lumbosacral transitional vertebra (LTV) segment exhibits a sacral-like transverse process with a broad contact area on the left. The rotation of the LTV segment is evident on both the vertical and longitudinal axes, leaning towards the left. This is observed through the spinous process (yellow arrow), cranial articular facets (red arrows), and cranial and caudal endplates compared to the last normal lumbar vertebra (blue arrows). The pelvis demonstrates longitudinal axis rotation, noticeable in the wider left iliac wing and the asymmetric appearance of the obturator foramen. Additionally, a counterclockwise vertical rotation of the pelvis and sacrum is observed and a caudal displacement of the sacroiliac joint (green arrow). This displacement shortens the distance from the sacroiliac joint to the hip joint on the right side. Moreover, inadequate coverage of the left acetabulum leads to subluxation of the left hip joint. Axial malpositioning of a normal dog during the radiographic examination results in apparent rotation of the pelvis and the caudal lumbar spine in the same direction. However, if the direction or degree of the rotation, or both together, between the pelvis and lumbar spine are different, an inherent malposition should be considered [8]. The black lines demonstrate the measurement of the sacroiliac joint length. (The radiograph is for illustration purposes and not from the NKK database)