Defining a safe corridor for trans-iliac pin placement in cats.

Area of Science:

• Veterinary surgery
• Orthopedic surgery
• Comparative anatomy

Background:

• Trans-iliac pin placement is crucial for pelvic fracture repair in cats.
• Fluoroscopy is typically used to ensure safe pin placement, but its absence poses challenges.
• Identifying a predictable safe corridor is essential for non-fluoroscopic surgical techniques.

Purpose of the Study:

• To determine if a predictable safe corridor exists for trans-iliac pin placement in cats without using fluoroscopy.
• To evaluate different starting points for pin insertion to maximize safety.
• To assess the feasibility of non-fluoroscopic trans-iliac pinning in feline patients.

Main Methods:

• Pelvic radiographs of 21 cats were analyzed to define potential pin corridors.
• Two starting points (midpoint and dorsal) were evaluated for pin insertion.
• Calculations assessed the safe angular range and pin exit location, with repeatability tested in six cats.

Main Results:

• A risk of vertebral foramina penetration was noted with 1.6 and 2.0 mm pins using the mid-iliac wing start point.
• A dorsal start point reduced the available placement area but significantly decreased the risk of entering hazardous zones for pins up to 2.0 mm.
• Safe corridors were identified for cats weighing between 2.0 and 5.5 kg.

Conclusions:

• A theoretical safe corridor for trans-iliac pin placement is available in cats weighing 2.0–5.5 kg.
• Using a mid-iliac wing start point, a 1.2 mm pin is safest.
• A dorsal start point allows for up to a 2.0 mm pin if aligned correctly with the sacrum.