Summary
Objective: To compare the biomechanical properties of bone and implant constructs when used
for the centre of rotation and angulation (CORA) based levelling osteotomy, with and
without implantation of a trans-osteotomy headless compression screw tested under
three-point flexural and torsional forces; thereby determining the contribution of
a trans-osteotomy headless compression screw with regards to stability of the construct.
Methods: Experimental biomechanical study utilizing 12 pairs of cadaveric canine tibias. Using
the CORA based levelling osteotomy (CBLO) procedure, the osteotomy was stabilized
with either a standard non-locking CBLO bone plate augmented with a headless compression
screw (HCS) or a CBLO bone plate alone. Tibial constructs were mechanically tested
in three-point craniocaudal flexural testing or in torsion.
Results: In three-point flexural testing, the difference between the two constructs was not
significant. In torsion, the difference in the angle of failure between constructs
with a HCS (48.46°) and constructs without a HCS (81.65°) was significant (p = 0.036).
Maximum torque achieved by constructs with a HCS (21.7 Nm) was greater than those
without (18.7 Nm) (p = 0.056). Stiffness differences between both groups in torsion
and bending were not significant. Use of a HCS did increase the stability of the CBLO
construct in torsional testing, but not in flexural testing.
Keywords
Biomechanics - cranial cruciate ligament injury - centre of rotation and angulation
- levelling osteotomy
