3D Slicer open-source software plug-in for vector-based angle calculation of canine hind limb alignment in computed...

Area of Science:

• Veterinary Orthopedics
• Medical Imaging Analysis
• Biomechanical Engineering

Background:

• Accurate assessment of canine angular limb deformities is crucial for successful orthopedic surgery.
• Computed tomography (CT) is widely used but its 2D measurements can have projection errors.
• Existing 3D techniques still rely on 2D image planes for angular measurements.

Purpose of the Study:

• To develop a true three-dimensional (3D) open-source technique for measuring canine hind limb alignment using CT scans.
• To provide an accessible and accurate tool for veterinary surgeons.

Main Methods:

• Developed an open-source 3D Slicer plug-in utilizing vector calculations in 3D space.
• Calculated angles including femoral torsion, varus, femorotibial rotation, tibial torsion, varus, and tibiotalar rotation.
• Compared measurements from 113 canine CT scans against a validated technique (VoXim®).

Main Results:

• Measurements were successfully obtained in all 113 CT scans.
• The maximum difference between the new technique and the validated method was 1.4° for tibial torsion.
• Bland-Altman analysis showed no significant differences, with mean variations under 0.07°.

Conclusions:

• The 3D Slicer extension provides sufficiently accurate angular measurements for clinical veterinary orthopedic and surgical purposes.
• This free, open-source software aims to improve the 3D measurement of canine hind limb deformities.
• The tool enhances diagnostic capabilities for complex angular limb deformities in dogs.