SURGERY
of the distal femur, CORA in order to perform a correc-
tive osteotomy. It stands for the anatomic lateral distal
femoral angle. The technique for measurement can be
found in most surgical texts.
However in the 20% of cases we see major complica-
tions it can be a nightmare to repair. Major complications
require a corrective surgery with additional cost to the
owner and morbidity to the animal. These complications
can be symptomatic return of the patella luxation, tibial
crest fracture, infection or tibia fracture. Implant migra-
tion is often seen and even though it requires another
surgical procedure to remove it will often not affect the
outcome once clinical union has occurred.
The 60% of dogs that develop a recurrent patella lux-
ation at 4-6 weeks post TCT often are asymptomatic.
Most of these will not require corrective surgery unless
symptomatic as previously stated.
The underlying question is what harm is this recurrent
patella luxation doing to the articular cartilage down the
line?
Figure 4A
The big challenge and hope of this lecture is that the
surgeon will no longer apply 1 surgical technique to all
patients with patella luxations. Instead then we should be
assessing the underlying anatomical deformities of the
patient and plan the surgery from there. The author sus-
pects the high failure rate for TCT, up to 50%, is caused
by this technique being used in all patients presenting
with medial patella luxation without thought to the un-
derlying anatomical deformities leading to or exacerbat-
ing the patella luxation.
Hopefully with further studies on the initial cause of pa-
tella luxation in young dogs and the long term outcomes
of CDFO we can develop a treatment modality that gives
us an excellent outcome in surgically correcting patella
luxations.
It is recommended, given the extra cost to the client, that
patients which are radiographically selected for a CDFO
should have a computed tomography scan performed
of the femur and the R-aLDFA should be measured on
the CT images. This gives the most accurate measure-
ment of the femoral deformity in all planes. This allows
the surgeon accurate planning for the surgery and gives
the best possible outcome.
Figure 4B
The reality of patella luxation surgery is that we don’t
understand the cause of the disease in these patients
hence the conflicting literature on how to fix it. Current
evidence, be it only a few small studies, is pointing to-
wards a lower complication rate with CDFO than TCT.
This needs to be further evaluated to help us provide the
best options for our patients. The reality is that the TCT
with associated soft tissue procedures is an excellent
surgical procedure in 80% of cases.
Issue 03 | JUNE 2017 | 15