Summary
Twenty-eight feline pelves (56 hemipelves) were examined in order to identify the
location for optimal sacroiliac screw placement in sacroiliac fracture-luxation repair.
A drill hole was started on the median plane of the hemipelvis in the centre of the
body of the first sacral segment until it penetrated the lateral cortex of the ilial
wing, thus providing optimal drill hole placement. The position of the drill hole
on the articular surface of the sacral wing and on the lateral surface of the ilial
wing was measured. The distance of the drill hole from the cranial margin of the sacral
wing was 51% of sacral wing length, just cranial to the crescent shaped hyaline cartilage.
The distance from the dorsal margin was 47% of sacral wing height. The drill bit direction
has to be adjusted to the cranio-caudal inclination (range 10° to 29°) and dorso-ventral
inclination (range 2° to 25°) of the sacral wing. A notch in the cranial edge of the
sacral wing was present, with variable position, in 34% of the specimens and is consequently
not a useful landmark for sacroiliac screw placement. The drill hole on the lateral
surface of the ilium was located in craniocaudal direction at a distance of 69% of
sacral tuber length, measured from the cranial dorsal iliac spine. The dorso-ventral
position of the drill hole was at a distance of 52% of ilial wing height measured
from the sacral tuber. The ventral gluteal line, present in 93% of the cases, is a
useful landmark to locate optimal screw hole position on the ilial wing.
Keywords
Sacroiliac joint - anatomy - feline - fracture-luxation - lag screw fixation