Summary
Objectives: Femoral osteotomies are frequently completed to correct malalignment associated with
patellar luxation. The objectives of this study were to compare the use of: 1) two
different types of jig; and 2) different types of osteotomy in the realignment of
canine femoral bone models which possessed various iterations of angular deformity.
Methods: Models of canine femora possessing distal varus, external torsion and a combination
of varus and torsion underwent correction utilizing two alignment jigs (Slocum jig
and Deformity Reduction Device) and either a closing wedge ostectomy (CWO) or an opening
wedge osteotomy (OWO). Post-correctional alignment was evaluated by radiographic assessment
and compared between groups.
Results: The use of the Slocum jig resulted in frontal plane overcorrection when used with
CWO in models of femoral varus, and when used with OWO in models of femoral varus
and external torsion when compared to other techniques. The Deformity Reduction Device
tended to realign the frontal plane closer to the post-correction target value in
all angulation types. The use of both jigs resulted in undercorrection in the transverse
plane in models with varus and torsion.
Clinical significance: Jig selection and osteotomy type may lead to different post-correctional alignment
results when performing distal femoral osteotomies. Whereas OWO allows accurate correction
when used with either jig to address frontal plane deformities, the Deformity Reduction
Device can be utilized with both CWO and OWO to correct torsion-angulation femoral
deformities to optimize frontal plane alignment.
Keywords
Patella luxation - alignment jig - corrective osteotomy - femoral deformities
