Defining A Safe Entry Point for a Sacral Screw in Lateral Plating in Feline Ilial Fractures

Introduction: Ilial fractures are common in cats. Lateral plating is the most commonly used technique for repair; however, it is associated with a high rate of screw loosening due to the limited bone purchase. A sacral screw has been suggested to increase bone purchase. However, defining the exact position for a screw engaging the sacral body can be challenging. The purpose of this study was to define a safe entry point for a sacral body screw in lateral plating of feline ilial fractures.

Materials and Methods: Six cadaveric feline hemipelves were used to define a safe entry point. An orientation pin and a parallel aiming guide were used to drive a second pin from the cut medial surface of the sacral body towards the lateral ilial surface. The ilial acetabular length (IAL) and ischial ilial height (IIH) were measured. Proportions of the position of the hole to the IIH and the IAL were calculated. This resulted in the initial definition of the safe entry point: IAL/2.5 and IIH/2. Consecutively 10 hemipelves were allocated randomly to the different groups: (1) surgical resident and (2) expert surgeon. Both performed the measurements and defined the safe entry point according to IAL/2.5 and IIH/2. Position of the hole in the sacral body was assessed. A Bland Altman analysis was performed for measurements.

Results: All holes were located in the central sacral body position in both groups. The Bland Altman analysis showed excellent results comparing the two observers.

Discussion/Conclusion: Using the proportion IAL/2.5 and IIH/2 allows safe and consistent sacral body screw placement

Acknowledgement: None.