266 Surgical Treatment
Femoral torsion and angulation are routinely
abnormal in dogs with CR and PL. Bow-legged
dogs have varus angulation of the distal portion
of the femur combined with internal torsion
(genu varum) (Read & Robbins 1982). Knock-
kneed dogs have valgus angulation of the distal
portion of the femur combined with external
torsion (genu valgum) (Kalffet al. 2014). Cor-
rect patellar tracking requires realignment of
the trochlear groove. Minor trochlear groove
malalignment can be corrected by angling the
trochlear block or wedge, while major trochlear
groove malalignment is best managed with a
corrective ostectomy of the distal portion of
the femur (Swiderski & Palmer 2007), poten-
tially combined with trochlear block or wedge
recession.
Stabilization of the CrCL-deficient stifle and
the correction of deformities of proximal por-
tion of the tibia require a combination of
surgical procedures. If necessary, the quadri-
ceps mechanism is realigned through trans-
position of the tibial tuberosity. In dogs with
medial PL, lateralization of the tuberosity is
often performed; conversely, in dogs with lat-
eral luxation, the tuberosity is moved medi-
ally. The tuberosity is also displaced distally
in patients with patella alta. Distal transpo-
sition can be achieved with tibial tuberosity
osteotomy, angling the osteotomy and then
repositioning the tuberosity and securing it
using Kirschner wires or a tibial tuberosity
advancement (TTA) plate. If tibial anatomy is
within normal limits but rotational laxity of the
stifle joint is present, the tibial position can be
controlled using a fabellar-to-tibial crest suture,
which will also provide extracapsular stabiliza-
tion of cranial tibial translation when CR is
present (see also Chapter 25).
TPLO can also be used to manage dogs with
combined CR and PL, particularly medial PL
in large dogs (Figure 31.5) (Fitzpatricket al.
2010; Langenbach & Marcellin-Little 2010). A
medial skin incision, followed by a lateral
arthrotomy of the stifle joint, is performed to
allow for trochleoplasty or corrective closing
wedge femoral ostectomy, and inspection of
intra-articular structures including the CrCL(A) (B) (C) (D)Figure 31.5 Mediolateral radiographs of the tibiae of a 3-year-old Bulldog with bilateral rupture of the cranial cruciate
ligament combined with medial patellar luxation. Tibial plateau leveling osteotomy (TPLO) has been performed on the
right (A and B) and left (C and D) legs. A ‘right-sided’ TPLO plate has been used to stabilize the tibial plateau of the left
leg (D) and synthetic bone graft is visible at the surgical site.