Success and Failure after Stifle Stabilization Surgery 321024681012141618VI (% bw)Time after Surgery (weeks)0 6 26TPLO + Scope
(n = 4)
Scope (n = 4)Figure 39.1 Graph showing vertical impulse
(VI; % body weight) of dogs before
arthroscopic surgery and at 2 and 6 months
after surgery. In a group of dogs with cruciate
ligament rupture and a medial meniscal tear,
dogs treated with only arthroscopic
debridement of the ruptured cranial cruciate
ligament and medial meniscus were
compared with dogs that received
arthroscopic debridement together with tibial
plateau leveling osteotomy (TPLO).
to reduce the risk of a medial meniscal tear after
surgery. One fact that surgeons should consider
is that release of the medial meniscal rapidly
causes OA and lameness within 12 weeks, even
in a stable stifle (Lutheret al. 2009). In research
hounds, evidence of cartilage loss can be seen
grossly using India ink staining and via MRI T2
mapping. In addition, it should be accepted that
medial meniscal tears occur more commonly in
an unstable stifle as opposed to a stable stifle;
thus, if the stabilization procedure performed
requires a release of the medial meniscus than
it should be questioned as to how effective
it is at stabilizing the cruciate-deficient stifle
joint. Empirically, meniscal pathology and
OA are the greatest limits to outcome after
surgery for CR. This suggestion is supported
by a small study that evaluated dogs with
chronic lameness (>3 months) from surgical
treatment for CR, minimal instability, and a
medial meniscal tear (Conzemius 2007). In
this study, outcome was measured objectively
using GRFs in dogs that had either arthroscopic
debridement of the CrCL and medial meniscus
or arthroscopic debridement and TPLO stabi-
lization; no differences were found between
groups (Figure 39.1).
For decades, veterinary surgeons have
debated which surgical procedure provides
the best outcome after treatment of CR. One
component of this is to establish that the pro-
cedure in question adequately stabilizes the
stifle. This is based on the assumption that the
degree of instability is related to the degree
of lameness. The term ‘assumption’ is used
because the evidence provided to date does not
state that instability is good, but does suggest
that it may not be all that bad. In one study
(Hillet al. 1999), dogs which had undergone
surgery more than 1 year previously were
allocated to groups based on owner interview,
as having either a satisfactory or unsatisfactory
outcome. Surprisingly, dogs in the satisfactory
outcome group had almost twice the amount of
instability and less than half the stifle pain on
physical examination.Conclusions
Advances in understanding of how to inter-
pret success and define outcome measures will
lead to continued improvement in clinical treat-
ments. Whilst it appears that surgical manage-
ment can improve lameness in most dogs with
CR, the unfortunate fact is that as yet no sur-
gical procedure has been developed, whether
it includes stabilization or not, that eliminates
lameness.References
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