Page 104 - Clinical Manual of Small Animal Endosurgery

92 Clinical Manual of Small Animal Endosurgery

cranially using a probe, and the mid substance of the fragment is firmly
grasped with a grasper and maintained in mild traction by the assistant.
Meniscal surgery is best performed using a radiofrequency surgery wand
(Fig. 3.14b). Radiofrequency surgery produces heating of the articular
environment and its injurious effect on articular cartilage should be
minimised by maintaining high flow rates of irrigation fluid in the effort
to prevent excessive intra-articular temperatures.
A fine-tipped tissue-ablation wand is inserted through the medial
portal, proximal to the grasper and, while maintaining gentle traction
on the grasper, the cranial and axial edges of the torn portion are ablated,
progressing towards the normal peripheral meniscal tissue until the
cranial extent of the torn portion becomes free. Inspection of the caudal
attachment of the torn portion is facilitated by continued traction on the
grasping forceps. Insertion of the ablation tip either proximal or some-
times distal to the grasping forceps enables severance of the caudal
attachment. Ablation is directed towards the uninjured peripheral menis-
cal tissue with the intention of preserving maximal peripheral tissue by
ablating with care. Once ablation is complete the wand is removed and
the meniscal lesion is removed in the jaws of the grasper. Removal of the
torn portion greatly improves the view of the remaining peripheral
meniscal tissue and this is closely inspected visually; its functional integ-
rity is determined using the probe. The cut edge of the meniscus is evalu-
ated and additional ablation is performed, as necessary, to create a
smooth axial contour to the remaining peripheral meniscus. The periph-
eral meniscus is probed carefully and the axial edge is gently tractioned
with grasping forceps to check for additional longitudinal or horizontal
tears and when such tears are identified they are treated by grasping,
ablation and retrieval of the axial portion of damaged meniscus.
Following meniscal surgery the remaining peripheral meniscal tissue
should be firm, the axial edge should have a smooth contour and gentle
traction and probing of the meniscal tissue should confirm its functional
integrity. Once medial meniscal surgery is complete the lateral meniscus
is inspected. The arthroscope is tilted medially and the light post is
rotated so that it remains directed axially, as mentioned previously. The
inspection of the lateral meniscus commences at the caudal aspect of the
joint and the caudal meniscofemoral ligament of the lateral meniscus is
identified. Progressive medial tilting of the scope with controlled with-
drawal enables a visual sweep over the lateral meniscus, progressing
towards the cranial pole. Tiny radial tears are reported to occur, pre-
dominantly in the cranial horn and these are of unlikely clinical signifi-
cance. Small longitudinal tears are also occasionally reported and because
these may be of some clinical significance, when seen, they should be
removed by ablation. Following meniscal surgery, the joint is irrigated
copiously to remove surgical debris. Prior to the completion of surgery,
if no additional regional local anaesthesia has been performed, an intra-
articular injection of ropivacaine and morphine (see above) may be given
to augment the postoperative analgesia protocol routinely employed.