Surgical Management of Cruciate Ligament Rupture Combined with Patella Luxation 267(A) (B)Figure 31.6 Realignment of the
tibia when performing tibial
plateau leveling osteotomy
(TPLO) combined with patella
luxation correction includes
several steps performed while the
patella is in its reduced position
and the stifle joint is held in
extension and facing cranially.
First, an assistant stabilizes the
tibial plateau in its leveled
position while the surgeon
externally rotates the distal tibia
around its long axis to eliminate
internal torsion of the tibia.
Second, the surgeon slides the
tibial plateau 3–6 mm medially,
laterally translating the tibial
tuberosity and the entire distal
fragment. Third, to address genu
varum, the distal fragment is
moved abaxially against the
tibial plateau, creating a medial
gap of 1–3 mm (A). After the
procedure is completed, a
stabilizing Kirschner wire is
inserted from the tibial crest into
the tibial plateau (B). Source:
Adapted from Langenbach &
Marcellin-Little 2010.
and medial meniscus. A cranial sartorius mus-
cle release and lateral retinacular imbrication
are then performed. A medial approach to the
proximal portion of the tibia is made and a
TPLO is performed. The appropriate osteotomy
position is measured on radiographs before
surgery (Mossmanet al. 2015). Once the tibial
plateau is freed, the jig is removed to allow rota-
tion of the plateau. An assistant stabilizes the
thigh while the surgeon carefully levels the tib-
ial plateau and realigns the proximal and dis-
tal portions of the tibia to correct tibial tor-
sion and varus (Figure 31.6). The construct is
secured with a 1.14 mm- or 1.55 mm-diameter
(0.045′′or 0.062′′) Kirschner wire, depending on
patient size, placed from the craniolateral aspect
of the tibial crest into the central tibial plateau.
A stainless steel rod is used to check for cor-
rect alignment in surgery of the tibia and femur.
The patella is checked for stability. Once align-
ment is achieved, a TPLO plate is applied. A
pre-contoured locking TPLO plate can be used,
but this may need to be adjusted using bending
irons to fit the tibia. Plate contouring leads to
a change in the orientation of locking screws.
This may lead to an inappropriate screw ori-
entation in the proximal bone fragment. Con-
sequently, it may necessary to use non locking
screws in the proximal portion of the plate to
ensure appropriate screw orientation. In some
instances, a pre-contoured TPLO plate intended
for the opposite side can be used (Figure 31.5D).
An alternative approach is to perform a stan-
dard TPLO and then correct the patella luxaton
using a frontal plane tibial tuberosity transposi-
tion (Leonardet al. 2016). The tibial crest frag-
ment is stabilized using pin and tension band
wire fixation (Leonardet al. 2016).
If a closing wedge ostectomy of the femur
is performed in the same patient, the wedge
can be morselized and used as graft in the
medial cortical defect. Alternatively, a syn-
thetic bone graft can be used to fill the medial
defect between the distomedial aspect of the
tibial plateau and the proximomedial aspect
of the tibial shaft. The Kirschner wire can be
left in place to enhance stability, or it can be
removed.