Page 57 - Clinical Manual of Small Animal Endosurgery

Diagnostic Arthroscopy 45

remove the debris and haemorrhage created during operative surgery.
For the soft-tissue shaver, suction draws tissue into the shaver tip ena-
bling efficient debridement of soft tissue. Each burr/shaver tip comprises
two pieces: a rotating blade and an outer cannula. Numerous different
styles of arthroscopic shaver and burr tips are available although rela-
tively few are applicable for small animal arthroscopy. A protected or
semi-protected burr tip is preferable for use in small joints to prevent
iatrogenic damage to tissue juxtaposed to surgical lesions. Power shaver/
burr blades are sold as ‘single use’, but multiple use of each blade is
possible in small animal arthroscopy because in a typical procedure the
blade does relatively little work and hence it remains sharp for several
procedures. Careful cleaning and re-sterilisation are required for safe
reuse of the blades.

Electrocautery
Arthroscopic electrocautery or radiofrequency units include a control
box and a connecting cable, with a handpiece or tip, of which there are
several designs. Electrocautery/radiofrequency generates heat by creating
molecular friction in tissues, which is useful for cauterising vessels and
for ablating tissue, like proliferated synovium, diseased cranial cruciate
ligament, damaged menisci and the fat pad of the stifle joint. Monopolar
electrocautery directs electrical current from the instrument tip to the
tissue surface, through the patient’s body to the earth plate, while bipolar
units create an arc of electrical energy that travels through the tissues
and fluid at the instrument tip and back to the anode of the instrument
tip. As a consequence, the zone of heated tissue is more controlled.
The heat generated by arthroscopic electrocautery is potentially damag-
ing to articular cartilage and care must be taken to avoid excessive
heating of cartilage peripheral to the surgical lesion within the articular
environment.

Arthroscopic tower
A wheeled trolley or tower is required to keep the camera control unit,
monitor, light source, pressure pump, recording device, electrocautery
unit and any additional equipment together and conveniently mobile to
allow movement of the gear around the operating room. Arthroscopy
towers are of sturdy construction so that they can comfortably withstand
the weight of the various items of equipment (Fig. 2.16).

Equipment care
Arthroscopic equipment should be cleaned with a suitable mild detergent
immediately following each arthroscopic procedure. Surgical instruments