Total Knee Replacement in the Dog 365monobloc tibial component was the original
design concept used in human knee replace-
ment and still has validity for use. The fixation
surface of the femoral component is covered
with sintered Co-Cr beads, allowing for cement-
less or cemented fixation. The UHMWPE tib-
ial component is designed for polymethyl-
methacrylate (PMMA) bone cement fixation.
Case selection: indications and
contraindications for surgery
The primary indication for canine TKR is
osteoarthritis (OA), most commonly secondary
to cruciate ligament rupture. The majority of
dogs present with a history of at least one pre-
vious surgical procedure. The conversion of a
failed extracapsular repair is relatively straight-
forward and can be performed as a one-stage
procedure. Conversion from a tibial plateau lev-
eling osteotomy (TPLO) is best performed as
a two-stage procedure with plate and screw
removal as stage one at least 6 weeks before
TKR (Figure 44.2). Since infection is an absolute
contraindication for total joint replacement, it is
recommended that synovial fluid analysis and
tissue culture be performed on any joint that is
suspect of infection or has had previous surgery.
OA secondary to other conditions can also
be managed with TKR. Eskelinenet al. (2012)
performed TKR to manage stifle OA associated
with a healed supracondylar femoral fracture.
Burtonet al. (2014) reported the management
of a non-union unicondylar multifragmentary
proximal tibial fracture and secondary OA with
a combination of TKR combined with fracture
internal fixation using a lag screw and an anti-
rotational Kirschner wire.
Surgical technique
Details of the surgical technique can be found
in the literature (Allenet al. 2009; Liska & Doyle
2009). TKR can be performed through either a
medial or lateral stifle arthrotomy. The patella
is luxated to improve exposure of the distal
femur and proximal tibia. The infrapatellar
fat pad, cruciate ligaments and menisci are
removed. Custom-designed instruments and
cutting blocks are used to guide the tibial
(A)(B)Figure 44.2 Conversion from (A) tibial plateau leveling
osteotomy (TPLO) to (B) total knee replacement (TKR) in
the dog. This is performed as a two-step procedure, with
removal of the TPLO implants followed 6–8 weeks later
by implantation of the TKR. Images courtesy of Dr Noel
Fitzpatrick.ostectomy (Figure 44.3A) and the four femoral
ostectomies (Figure 44.3B,C).
The ostectomized bone surfaces are prepared
to accommodate the keel of the tibial implant
and the post of the femoral implant. The can-
cellous bone surfaces are cleaned of debris with
pulsatile lavage and suction. Before prosthesis
fixation, trial components are used to confirm
correct implant size and position. The trials also
facilitate evaluation of joint stability and col-
lateral ligament tension. The tibial component