Accuracy and safety of pin placement during lateral versus dorsal stabilization of lumbar spinal fracture-luxation in dogs.

OBJECTIVE: To determine the accuracy and safety of pin placement for lateral vertebral stabilization to the reference dorsal stabilization.

STUDY DESIGN: A randomized noninferiority trial.

SAMPLE POPULATION: Twenty Greyhound cadaveric lumbar spines (L1-L6).

METHODS: One hundred and fifty-nine lumbar vertebral pins placed in 80 vertebrae were assessed; these pins were distributed approximately equally between the dorsal and lateral approaches, and between 2 surgeons. Pin angle accuracy, bone purchase distance, and distances from pin to the spinal canal and the aorta were measured for each pin.

RESULTS: The lateral approach was superior for pin angle accuracy and bone purchase. The mean angle of deviation was 15.3° with the dorsal approach and 7.0° with the lateral approach. The mean bone purchase was 16.7 mm with the dorsal approach and 22.2 mm with the lateral approach. Pins were placed at a mean of 2.3 mm from the spinal canal with the dorsal approach and 1.7 mm with the lateral approach. Pins were placed at a mean of 3.8 mm from the aorta with the dorsal approach and 8.0 mm with the lateral approach. The percentage of pins breaching the spinal canal was 14% with the dorsal approach and 19% with the lateral approach. Fourteen percent of pins placed via the dorsal approach breached the aorta, whereas no pins placed via the lateral approach breached the aorta.

CONCLUSION: Relative to the dorsal approach, the lateral approach improves angle accuracy, bone purchase, and distance between pins, and the aorta and is noninferior with regards to the distance between pins and the spinal canal.