Page 101 - Clinical Manual of Small Animal Endosurgery

Operative Arthroscopy 89

Arthroscopically assisted surgery of the cranial cruciate ligament and
meniscal surgery

In dogs with cranial cruciate ligament insufficiency, currently the goals
of surgery are:

• removal of the degenerate cranial cruciate ligament,
• inspection of the menisci and treatment of meniscal tears,
• restoration of stifle stability to prevent or minimise tibial subluxation
during load-bearing.
Debate continues regarding the role of surgical excision of the degenerate
cranial cruciate ligament in restoring stifle comfort and relieving pain in
dogs affected with cranial cruciate ligament disease. Some authors claim
that tibial plateau-levelling osteotomy (TPLO) surgery is protective of
the diseased cranial cruciate ligament, arresting its progressive degenera-
tion and breakdown. These authors advocate leaving a degenerate cranial
cruciate ligament in situ, recommending solely debridement of the com-
pletely ruptured component of the ligament, preserving the intact portion
of ligament. The proposed protective effect of TPLO on cranial cruciate
ligament breakdown is based on reports of ‘second-look’ arthroscopy
performed following TPLO. To date there are no histological studies that
support the theory that degeneration of the cranial cruciate ligament is
arrested by TPLO. In contrast, clinical evidence indicates that in many
cases of cranial cruciate ligament disease failure to remove en masse
the incompletely ruptured diseased cranial cruciate ligament results in
ongoing lameness, hence the author currently recommends routine exci-
sion of diseased cranial cruciate ligament in its entirety in all cases.
Removal of the diseased ligament appears to be more important when
the ligament is only partially ruptured compared to when the ligament
is already completely incompetent and broken down. Presumably, the
process of ongoing rupture is associated with inflammation and pain and
it would appear that this pain diminishes following severance or follow-
ing final and complete naturally occurring rupture of the ligament. Deb-
ridement of the cranial cruciate ligament is most readily achieved using
a motorised shaver.
Clinically relevant injury to the medial meniscus occurs predominantly
in association with rupture of the cranial cruciate ligament. Meniscal
lesions (medial and lateral meniscus) also occur in association with
osteochondrosis lesions of the femoral condyle and as a consequence of
traumatic injury to the stifle joint. Arthroscopic treatment of meniscal
lesions is technically challenging and the surgeon should be prepared to
convert the arthroscopic procedure to a limited arthrotomy in the event
that the arthroscopic investigation/surgery proves unsatisfactory.
Following a systematic examination of the proximal compartment of
the stifle joint, the cranial cruciate ligament is inspected visually and