34th Annual Scientific Meeting proceedings

Objectives:

To determine the femoral conformation of normal non-lame French Bulldogs (FBD) using CT, and to assess whether they are repeatable and how experience influences their measurement.

Methods:

Non lame FBD CTs were retrospectively reviewed using open-access 3D DICOM reconstruction software to measure: femoral varus angle (FVA), anatomical lateral distal femoral angle (aLDFA), anatomical lateral proximal femoral angle (aLPFA), the mechanical caudodistal femoral angle (mCdDFA), the angle of inclination of the femoral neck (AFI), and the angle of femoral torsion (FTA). Measurements were made on 3 occasions by 3 observers of varying experience using published methodology. Intra- and inter-class correlation coefficient was used to assess reliability.

Results:

35 femurs were included. Mean FVA was 6.8±2.9°, mean aLDFA was 96.7± 3.0°, mean aLPFA was 106.2± 5.6°, mean mCdDFA was 114.5±1.5°, mean AFI was 133.2±4.1°, and mean FTA was 20.4±3.5°. Intra-observer agreement was good to excellent for all measurements. Inter-observer agreement was poor for the AFI and FTA, good for the FVA, and good to excellent for all other measurements.

Conclusions:

Our results provide a useful reference range for the FBD breed to aid assessment in disease and surgical planning. Measurements were mostly reliable despite the use of open-access software. The described methods are appropriate and not influenced by experience, which is particularly important for aLDFA/FVA which is frequently used to plan patellar luxation surgery. The only caveat is femoral torsion which can also be important but was not reliable between observers.