Advances in the Canine Cranial Cruciate Ligament, 2nd edition

Arthroscopic Follow-Up after Surgical Stabilization of the Stifle 285

CaCL

*** CrCL

Figure 33.13 The caudal cruciate ligament (CaCL) has
substantial tearing (∗∗∗) in this patient with an incompetent
cranial cruciate ligament (CrCL) tear treated with
a tibial plateau leveling osteotomy. This is an uncommon
finding at follow-up arthroscopic examination.

may be latent and require careful palpation
with a probe to identify. Meniscal tears that
occur subsequent to treatment of CR are termed
postlimimary tears. Follow-up arthroscopy has

CrCL

Figure 33.14 Appearance of an incompetent partial
cranial cruciate ligament (CrCL) 2 years after tibial
plateau leveling osteotomy (TPLO) surgery. Instability of
the stifle was present due to stretching of the CrCL before
TPLO. The ligament continues to have mild laxity, but
inflammation has subsided and no further damage to the
ligament is seen after TPLO. The TPLO procedure appears
to have protected the CrCL from progressive damage.

provided valuable information towards the

understanding of the impact of progressive

cruciate ligament fiber rupture and its treat-

ment on the menisci over time. MR at the time

of stabilization of the CrCL-deficient stifle has

been recommended to prevent further injury

to the caudal pole of the medial meniscus after

TPLO. Conversely, MR may result in joint

instability and impairment of load transmis-

sion, which may accelerate the progression of

osteoarthritis (Pozziet al. 2008). Meniscectomy,

which has similar mechanical results as MR on

the stifle, leads to osteoarthritis in both humans

and animals. Kimet al. (2009) suggested that

the risk of postliminary meniscal injury is

smaller after TPLO due to the neutralization of

cranial tibial thrust, and thus the need for MR

is controversial. In addition, Lutheret al. (2009)

reported that MR alone in CrCL-intact stifles

was associated with articular cartilage loss

and further meniscal pathology. These studies

would tend to suggest that MR is contraindi-

cated at the time of surgical stabilization of a

CR stifle. These findings, however, are based

onin vitroorex vivostudies or in dogs that

had intact CrCL. Aman & Beale (2009) used

follow-up arthroscopy to assess clinical patients

with CR. This study compared CrCL-deficient

stifles of dogs having undergone TPLO with

MR to dogs having undergone TPLO with no

MR. Follow-up arthroscopy was used to assess

the stifles at long-term follow-up. The findings

of this study suggested that there may not be

a significant difference in the progression of

osteoarthritis between dogs receiving TPLO

with MR and dogs receiving TPLO without

MR. The group found a risk of postliminary

meniscal injury with or without MR, but severe

meniscal injury was much more likely without

MR. A higher incidence of bucket-handle tears

was seen in dogs not receiving a MR. Small

radial tears were the predominant type of tear

seen if MR was performed. Meniscal tears were

more common in the dogs having MR at the

meniscotibial ligament as compared to a mid-

body incision. MR at the meniscotibial ligament

or mid-body appeared to remain functional

in all dogs having the procedure performed.

The meniscotibial ligament did not appear to

reattach. The mid-body MR incisions appeared

to heal with great variation (Figure 33.17). Some

of the mid-body MR incisions healed with a