256 Surgical Treatment
rotation (Figure 30.2B), and this can be deter-
mined by identifying the safe rotation distance
in the appropriate saw blade size (radius) row
in the TPLO chart; the sTPA is the preop-
erative TPA that corresponds to this rotation
distance.
If the required rotation chord length (the rota-
tion needed to achieve a TPA of 5◦) is signifi-
cantly greater than the safe rotation cord length
(Figure 30.2C), a TPLO combined with a clos-
ing cranial wedge ostectomy (TPLO/CCWO)
should be considered (Talaatet al. 2006). The
angle of the CCWO is the difference between
the preoperative TPA and the sTPA. By uti-
lizing the TPLO/CCWO procedure, the mag-
nitude of both the TPLO and CCWO can be
adjusted to correct the TPA and proximal tib-
ial deformity as needed, based on individ-
ual patient anatomy. In a retrospective study
evaluating treatment options for eTPA, out-
come, based on owner assessment, was superior
with ‘full-rotation TPLO’ (correction of the TPA
to less than 14◦) compared to ‘under-rotated
TPLO’ (leveling to> 14 ◦) (Duerret al. 2008), and
supplemental fixation with additional implants
was associated with a lower complication rate
(Duerret al. 2008). Additionally, this procedure
can be simultaneously combined with a medial
or lateral closing wedge ostectomy to address
moderate to severe proximal tibial varus or val-
gus, and/or moderate to severe tibial torsion
(Figure 30.3) (Wehet al. 2011).(A)(B)(C)(D)(E)Figure 30.3 Diagrammatic representation of a proximal tibial valgus deformity treated by tibial plateau leveling
osteotomy (TPLO) and a coplanar medial wedge ostectomy. The apex of the medial closing wedge is coincident with the
exit of the TPLO radial osteotomy at the caudolateral tibial cortex. Tibial torsion can be corrected at the level of the
medial closing wedge (arrows) without loss of apposition at the radial osteotomy. The inset depicts various closing wedge
configurations: (A) Coplanar cranial closing wedge. (B) Coplanar lateral closing wedge. (C) Coplanar medial closing
wedge. (D) Biplanar medial and cranial closing wedge. (E) Biplanar lateral and cranial closing wedge. Source: Wehet al.
- Reproduced with permission from John Wiley & Sons, Inc.